4 This directory contains Device Tree overlays. Device Tree makes it possible
5 to support many hardware configurations with a single kernel and without the
6 need to explicitly load or blacklist kernel modules. Note that this isn't a
7 "pure" Device Tree configuration (c.f. MACH_BCM2835) - some on-board devices
8 are still configured by the board support code, but the intention is to
9 eventually reach that goal.
11 On Raspberry Pi, Device Tree usage is controlled from /boot/config.txt. By
12 default, the Raspberry Pi kernel boots with device tree enabled. You can
13 completely disable DT usage (for now) by adding:
17 to your config.txt, which should cause your Pi to revert to the old way of
18 doing things after a reboot.
20 In /boot you will find a .dtb for each base platform. This describes the
21 hardware that is part of the Raspberry Pi board. The loader (start.elf and its
22 siblings) selects the .dtb file appropriate for the platform by name, and reads
23 it into memory. At this point, all of the optional interfaces (i2c, i2s, spi)
24 are disabled, but they can be enabled using Device Tree parameters:
26 dtparam=i2c=on,i2s=on,spi=on
28 However, this shouldn't be necessary in many use cases because loading an
29 overlay that requires one of those interfaces will cause it to be enabled
30 automatically, and it is advisable to only enable interfaces if they are
33 Configuring additional, optional hardware is done using Device Tree overlays
36 GPIO numbering uses the hardware pin numbering scheme (aka BCM scheme) and
37 not the physical pin numbers.
42 The Advanced Options section of the raspi-config utility can enable and disable
43 Device Tree use, as well as toggling the I2C and SPI interfaces. Note that it
44 is possible to both enable an interface and blacklist the driver, if for some
45 reason you should want to defer the loading.
50 As well as describing the hardware, Device Tree also gives enough information
51 to allow suitable driver modules to be located and loaded, with the corollary
52 that unneeded modules are not loaded. As a result it should be possible to
53 remove lines from /etc/modules, and /etc/modprobe.d/raspi-blacklist.conf can
54 have its contents deleted (or commented out).
59 Overlays are loaded using the "dtoverlay" config.txt setting. As an example,
60 consider I2C Real Time Clock drivers. In the pre-DT world these would be loaded
61 by writing a magic string comprising a device identifier and an I2C address to
62 a special file in /sys/class/i2c-adapter, having first loaded the driver for
63 the I2C interface and the RTC device - something like this:
67 echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
69 With DT enabled, this becomes a line in config.txt:
71 dtoverlay=i2c-rtc,ds1307
73 This causes the file /boot/overlays/i2c-rtc.dtbo to be loaded and a "node"
74 describing the DS1307 I2C device to be added to the Device Tree for the Pi. By
75 default it usees address 0x68, but this can be modified with an additional DT
78 dtoverlay=i2c-rtc,ds1307,addr=0x68
80 Parameters usually have default values, although certain parameters are
81 mandatory. See the list of overlays below for a description of the parameters
84 Making new Overlays based on existing Overlays
85 ==============================================
87 Recent overlays have been designed in a more general way, so that they can be
88 adapted to hardware by changing their parameters. When you have additional
89 hardware with more than one device of a kind, you end up using the same overlay
90 multiple times with other parameters, e.g.
92 # 2 CAN FD interfaces on spi but with different pins
93 dtoverlay=mcp251xfd,spi0-0,interrupt=25
94 dtoverlay=mcp251xfd,spi0-1,interrupt=24
96 # a realtime clock on i2c
97 dtoverlay=i2c-rtc,pcf85063
99 While this approach does work, it requires knowledge about the hardware design.
100 It is more feasible to simplify things for the end user by providing a single
101 overlay as it is done the traditional way.
103 A new overlay can be generated by using ovmerge utility.
104 https://github.com/raspberrypi/utils/blob/master/ovmerge/ovmerge
106 To generate an overlay for the above configuration we pass the configuration
107 to ovmerge and add the -c flag.
109 ovmerge -c mcp251xfd-overlay.dts,spi0-0,interrupt=25 \
110 mcp251xfd-overlay.dts,spi0-1,interrupt=24 \
111 i2c-rtc-overlay.dts,pcf85063 \
112 >> merged-overlay.dts
114 The -c option writes the command above as a comment into the overlay as
115 a marker that this overlay is generated and how it was generated.
116 After compiling the overlay it can be loaded in a single line.
120 It does the same as the original configuration but without parameters.
122 The Overlay and Parameter Reference
123 ===================================
125 N.B. When editing this file, please preserve the indentation levels to make it
126 simple to parse programmatically. NO HARD TABS.
130 Info: Configures the base Raspberry Pi hardware
131 Load: <loaded automatically>
133 ant1 Select antenna 1 (default). CM4 only.
135 ant2 Select antenna 2. CM4 only.
137 noant Disable both antennas. CM4 only.
139 audio Set to "on" to enable the onboard ALSA audio
140 interface (default "off")
142 axiperf Set to "on" to enable the AXI bus performance
144 See /sys/kernel/debug/raspberrypi_axi_monitor
147 bdaddr Set an alternative Bluetooth address (BDADDR).
148 The value should be a 6-byte hexadecimal value,
149 with or without colon separators, written least-
150 significant-byte first. For example,
151 bdaddr=06:05:04:03:02:01
152 will set the BDADDR to 01:02:03:04:05:06.
154 cam0_reg Enables CAM 0 regulator.
155 Only required on CM1 & 3.
157 cam0_reg_gpio Set GPIO for CAM 0 regulator.
158 Default 31 on CM1, 3, and 4S.
159 Default of GPIO expander 5 on CM4, but override
160 switches to normal GPIO.
162 cam1_reg Enables CAM 1 regulator.
163 Only required on CM1 & 3.
165 cam1_reg_gpio Set GPIO for CAM 1 regulator.
166 Default 3 on CM1, 3, and 4S.
167 Default of GPIO expander 5 on CM4, but override
168 switches to normal GPIO.
170 eee Enable Energy Efficient Ethernet support for
171 compatible devices (default "on"). See also
172 "tx_lpi_timer". Pi3B+ only.
174 eth_downshift_after Set the number of auto-negotiation failures
175 after which the 1000Mbps modes are disabled.
176 Legal values are 2, 3, 4, 5 and 0, where
177 0 means never downshift (default 2). Pi3B+ only.
179 eth_led0 Set mode of LED0 - amber on Pi3B+ (default "1"),
180 green on Pi4 (default "0").
181 The legal values are:
185 0=link/activity 1=link1000/activity
186 2=link100/activity 3=link10/activity
187 4=link100/1000/activity 5=link10/1000/activity
188 6=link10/100/activity 14=off 15=on
192 0=Speed/Activity 1=Speed
193 2=Flash activity 3=FDX
198 eth_led1 Set mode of LED1 - green on Pi3B+ (default "6"),
199 amber on Pi4 (default "8"). See eth_led0 for
202 eth_max_speed Set the maximum speed a link is allowed
203 to negotiate. Legal values are 10, 100 and
204 1000 (default 1000). Pi3B+ only.
206 hdmi Set to "off" to disable the HDMI interface
209 i2c_arm Set to "on" to enable the ARM's i2c interface
212 i2c_vc Set to "on" to enable the i2c interface
213 usually reserved for the VideoCore processor
216 i2c An alias for i2c_arm
218 i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
221 i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
224 i2c_baudrate An alias for i2c_arm_baudrate
226 i2s Set to "on" to enable the i2s interface
229 i2s_dma4 Use to enable 40-bit DMA on the i2s interface
230 (the assigned value doesn't matter)
233 krnbt Set to "off" to disable autoprobing of Bluetooth
234 driver without need of hciattach/btattach
237 krnbt_baudrate Set the baudrate of the PL011 UART when used
240 pcie Set to "off" to disable the PCIe interface
242 (2711 only, but not applicable on CM4S)
243 N.B. USB-A ports on 4B are subsequently disabled
245 spi Set to "on" to enable the spi interfaces
248 spi_dma4 Use to enable 40-bit DMA on spi interfaces
249 (the assigned value doesn't matter)
252 random Set to "on" to enable the hardware random
253 number generator (default "on")
255 sd Set to "off" to disable the SD card (or eMMC on
256 non-lite SKU of CM4).
259 sd_overclock Clock (in MHz) to use when the MMC framework
262 sd_poll_once Looks for a card once after booting. Useful
263 for network booting scenarios to avoid the
264 overhead of continuous polling. N.B. Using
265 this option restricts the system to using a
266 single card per boot (or none at all).
269 sd_force_pio Disable DMA support for SD driver (default off)
271 sd_pio_limit Number of blocks above which to use DMA for
274 sd_debug Enable debug output from SD driver (default off)
276 sdio_overclock Clock (in MHz) to use when the MMC framework
277 requests 50MHz for the SDIO/WLAN interface.
279 tx_lpi_timer Set the delay in microseconds between going idle
280 and entering the low power state (default 600).
281 Requires EEE to be enabled - see "eee".
283 uart0 Set to "off" to disable uart0 (default "on")
285 uart1 Set to "on" or "off" to enable or disable uart1
288 watchdog Set to "on" to enable the hardware watchdog
291 act_led_trigger Choose which activity the LED tracks.
292 Use "heartbeat" for a nice load indicator.
295 act_led_activelow Set to "on" to invert the sense of the LED
297 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
300 act_led_gpio Set which GPIO to use for the activity LED
301 (in case you want to connect it to an external
303 (default "16" on a non-Plus board, "47" on a
305 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
311 As for act_led_*, but using the PWR LED.
312 Not available on Model A/B boards.
314 N.B. It is recommended to only enable those interfaces that are needed.
315 Leaving all interfaces enabled can lead to unwanted behaviour (i2c_vc
316 interfering with Pi Camera, I2S and SPI hogging GPIO pins, etc.)
317 Note also that i2c, i2c_arm and i2c_vc are aliases for the physical
318 interfaces i2c0 and i2c1. Use of the numeric variants is still possible
319 but deprecated because the ARM/VC assignments differ between board
320 revisions. The same board-specific mapping applies to i2c_baudrate,
321 and the other i2c baudrate parameters.
325 Info: Pi 3B, 3B+, 3A+ and 4B use a GPIO expander to drive the LEDs which can
326 only be accessed from the VPU. There is a special driver for this with a
327 separate DT node, which has the unfortunate consequence of breaking the
328 act_led_gpio and act_led_activelow dtparams.
329 This overlay changes the GPIO controller back to the standard one and
330 restores the dtparams.
331 Load: dtoverlay=act-led,<param>=<val>
332 Params: activelow Set to "on" to invert the sense of the LED
335 gpio Set which GPIO to use for the activity LED
336 (in case you want to connect it to an external
341 Name: adafruit-st7735r
342 Info: Overlay for the SPI-connected Adafruit 1.8" 160x128 or 128x128 displays,
343 based on the ST7735R chip.
344 This overlay uses the newer DRM/KMS "Tiny" driver.
345 Load: dtoverlay=adafruit-st7735r,<param>=<val>
346 Params: 128x128 Select the 128x128 driver (default 160x128)
347 rotate Display rotation {0,90,180,270} (default 90)
348 speed SPI bus speed in Hz (default 4000000)
349 dc_pin GPIO pin for D/C (default 24)
350 reset_pin GPIO pin for RESET (default 25)
351 led_pin GPIO used to control backlight (default 18)
355 Info: Overlay for the SPI-connected Adafruit 1.8" display (based on the
356 ST7735R chip). It includes support for the "green tab" version.
357 This overlay uses the older fbtft driver.
358 Load: dtoverlay=adafruit18,<param>=<val>
359 Params: green Use the adafruit18_green variant.
360 rotate Display rotation {0,90,180,270}
361 speed SPI bus speed in Hz (default 4000000)
362 fps Display frame rate in Hz
363 bgr Enable BGR mode (default off)
364 debug Debug output level {0-7}
365 dc_pin GPIO pin for D/C (default 24)
366 reset_pin GPIO pin for RESET (default 25)
367 led_pin GPIO used to control backlight (default 18)
371 Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
373 Load: dtoverlay=adau1977-adc
377 Name: adau7002-simple
378 Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter.
379 Load: dtoverlay=adau7002-simple,<param>=<val>
380 Params: card-name Override the default, "adau7002", card name.
384 Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
385 Load: dtoverlay=ads1015,<param>=<val>
386 Params: addr I2C bus address of device. Set based on how the
387 addr pin is wired. (default=0x48 assumes addr
389 cha_enable Enable virtual channel a. (default=true)
390 cha_cfg Set the configuration for virtual channel a.
391 (default=4 configures this channel for the
392 voltage at A0 with respect to GND)
393 cha_datarate Set the datarate (samples/sec) for this channel.
394 (default=4 sets 1600 sps)
395 cha_gain Set the gain of the Programmable Gain
396 Amplifier for this channel. (default=2 sets the
397 full scale of the channel to 2.048 Volts)
399 Channel (ch) parameters can be set for each enabled channel.
400 A maximum of 4 channels can be enabled (letters a thru d).
401 For more information refer to the device datasheet at:
402 http://www.ti.com/lit/ds/symlink/ads1015.pdf
406 Info: Texas Instruments ADS1115 ADC
407 Load: dtoverlay=ads1115,<param>[=<val>]
408 Params: addr I2C bus address of device. Set based on how the
409 addr pin is wired. (default=0x48 assumes addr
411 cha_enable Enable virtual channel a.
412 cha_cfg Set the configuration for virtual channel a.
413 (default=4 configures this channel for the
414 voltage at A0 with respect to GND)
415 cha_datarate Set the datarate (samples/sec) for this channel.
416 (default=7 sets 860 sps)
417 cha_gain Set the gain of the Programmable Gain
418 Amplifier for this channel. (Default 1 sets the
419 full scale of the channel to 4.096 Volts)
421 Channel parameters can be set for each enabled channel.
422 A maximum of 4 channels can be enabled (letters a thru d).
423 For more information refer to the device datasheet at:
424 http://www.ti.com/lit/ds/symlink/ads1115.pdf
428 Info: ADS7846 Touch controller
429 Load: dtoverlay=ads7846,<param>=<val>
430 Params: cs SPI bus Chip Select (default 1)
431 speed SPI bus speed (default 2MHz, max 3.25MHz)
432 penirq GPIO used for PENIRQ. REQUIRED
433 penirq_pull Set GPIO pull (default 0=none, 2=pullup)
434 swapxy Swap x and y axis
435 xmin Minimum value on the X axis (default 0)
436 ymin Minimum value on the Y axis (default 0)
437 xmax Maximum value on the X axis (default 4095)
438 ymax Maximum value on the Y axis (default 4095)
439 pmin Minimum reported pressure value (default 0)
440 pmax Maximum reported pressure value (default 65535)
441 xohms Touchpanel sensitivity (X-plate resistance)
444 penirq is required and usually xohms (60-100) has to be set as well.
445 Apart from that, pmax (255) and swapxy are also common.
446 The rest of the calibration can be done with xinput-calibrator.
447 See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
448 Device Tree binding document:
449 www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
453 Info: Analog Devices ADV7282M analogue video to CSI2 bridge.
454 Uses Unicam1, which is the standard camera connector on most Pi
456 Load: dtoverlay=adv7282m,<param>=<val>
457 Params: addr Overrides the I2C address (default 0x21)
458 media-controller Configure use of Media Controller API for
459 configuring the sensor (default off)
463 Info: Analog Devices ADV728[0|1|2]-M analogue video to CSI2 bridges.
464 This is a wrapper for adv7282m, and defaults to ADV7282M.
465 Load: dtoverlay=adv728x-m,<param>=<val>
466 Params: addr Overrides the I2C address (default 0x21)
467 adv7280m Select ADV7280-M.
468 adv7281m Select ADV7281-M.
469 adv7281ma Select ADV7281-MA.
470 media-controller Configure use of Media Controller API for
471 configuring the sensor (default off)
474 Name: akkordion-iqdacplus
475 Info: Configures the Digital Dreamtime Akkordion Music Player (based on the
476 OEM IQAudIO DAC+ or DAC Zero module).
477 Load: dtoverlay=akkordion-iqdacplus,<param>=<val>
478 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
479 Digital volume control. Enable with
480 dtoverlay=akkordion-iqdacplus,24db_digital_gain
481 (The default behaviour is that the Digital
482 volume control is limited to a maximum of
483 0dB. ie. it can attenuate but not provide
484 gain. For most users, this will be desired
485 as it will prevent clipping. By appending
486 the 24db_digital_gain parameter, the Digital
487 volume control will allow up to 24dB of
488 gain. If this parameter is enabled, it is the
489 responsibility of the user to ensure that
490 the Digital volume control is set to a value
491 that does not result in clipping/distortion!)
494 Name: allo-boss-dac-pcm512x-audio
495 Info: Configures the Allo Boss DAC audio cards.
496 Load: dtoverlay=allo-boss-dac-pcm512x-audio,<param>
497 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
498 Digital volume control. Enable with
499 "dtoverlay=allo-boss-dac-pcm512x-audio,
501 (The default behaviour is that the Digital
502 volume control is limited to a maximum of
503 0dB. ie. it can attenuate but not provide
504 gain. For most users, this will be desired
505 as it will prevent clipping. By appending
506 the 24db_digital_gain parameter, the Digital
507 volume control will allow up to 24dB of
508 gain. If this parameter is enabled, it is the
509 responsibility of the user to ensure that
510 the Digital volume control is set to a value
511 that does not result in clipping/distortion!)
512 slave Force Boss DAC into slave mode, using Pi a
513 master for bit clock and frame clock. Enable
514 with "dtoverlay=allo-boss-dac-pcm512x-audio,
518 Name: allo-boss2-dac-audio
519 Info: Configures the Allo Boss2 DAC audio card
520 Load: dtoverlay=allo-boss2-dac-audio
525 Info: Configures the Allo Digione audio card
526 Load: dtoverlay=allo-digione
530 Name: allo-katana-dac-audio
531 Info: Configures the Allo Katana DAC audio card
532 Load: dtoverlay=allo-katana-dac-audio
536 Name: allo-piano-dac-pcm512x-audio
537 Info: Configures the Allo Piano DAC (2.0/2.1) audio cards.
538 (NB. This initial support is for 2.0 channel audio ONLY! ie. stereo.
539 The subwoofer outputs on the Piano 2.1 are not currently supported!)
540 Load: dtoverlay=allo-piano-dac-pcm512x-audio,<param>
541 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
542 Digital volume control.
543 (The default behaviour is that the Digital
544 volume control is limited to a maximum of
545 0dB. ie. it can attenuate but not provide
546 gain. For most users, this will be desired
547 as it will prevent clipping. By appending
548 the 24db_digital_gain parameter, the Digital
549 volume control will allow up to 24dB of
550 gain. If this parameter is enabled, it is the
551 responsibility of the user to ensure that
552 the Digital volume control is set to a value
553 that does not result in clipping/distortion!)
556 Name: allo-piano-dac-plus-pcm512x-audio
557 Info: Configures the Allo Piano DAC (2.1) audio cards.
558 Load: dtoverlay=allo-piano-dac-plus-pcm512x-audio,<param>
559 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
560 Digital volume control.
561 (The default behaviour is that the Digital
562 volume control is limited to a maximum of
563 0dB. ie. it can attenuate but not provide
564 gain. For most users, this will be desired
565 as it will prevent clipping. By appending
566 the 24db_digital_gain parameter, the Digital
567 volume control will allow up to 24dB of
568 gain. If this parameter is enabled, it is the
569 responsibility of the user to ensure that
570 the Digital volume control is set to a value
571 that does not result in clipping/distortion!)
572 glb_mclk This option is only with Kali board. If enabled,
573 MCLK for Kali is used and PLL is disabled for
574 better voice quality. (default Off)
578 Info: Universal device tree overlay for SPI devices
580 Just specify the SPI address and device name ("compatible" property).
581 This overlay lacks any device-specific parameter support!
583 For devices on spi1 or spi2, the interfaces should be enabled
584 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
587 1. SPI NOR flash on spi0.1, maximum SPI clock frequency 45MHz:
588 dtoverlay=anyspi:spi0-1,dev="jedec,spi-nor",speed=45000000
589 2. MCP3204 ADC on spi1.2, maximum SPI clock frequency 500kHz:
590 dtoverlay=anyspi:spi1-2,dev="microchip,mcp3204"
591 Load: dtoverlay=anyspi,<param>=<val>
592 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
594 dev Set device name to search compatible module
596 speed Set SPI clock frequency in Hz
597 (integer, optional, default 500000)
601 Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and
603 Load: dtoverlay=apds9960,<param>=<val>
604 Params: gpiopin GPIO used for INT (default 4)
605 noints Disable the interrupt GPIO line.
609 Info: Configures the Orchard Audio ApplePi-DAC audio card
610 Load: dtoverlay=applepi-dac
615 Info: Arducam 64MP camera module.
616 Uses Unicam 1, which is the standard camera connector on most Pi
618 Load: dtoverlay=arducam-64mp,<param>=<val>
619 Params: rotation Mounting rotation of the camera sensor (0 or
621 orientation Sensor orientation (0 = front, 1 = rear,
622 2 = external, default external)
623 media-controller Configure use of Media Controller API for
624 configuring the sensor (default on)
625 cam0 Adopt the default configuration for CAM0 on a
626 Compute Module (CSI0, i2c_vc, and cam0_reg).
627 vcm Select lens driver state. Default is enabled,
628 but vcm=off will disable.
631 Name: arducam-pivariety
632 Info: Arducam Pivariety camera module.
633 Uses Unicam 1, which is the standard camera connector on most Pi
635 Load: dtoverlay=arducam-pivariety,<param>=<val>
636 Params: rotation Mounting rotation of the camera sensor (0 or
638 orientation Sensor orientation (0 = front, 1 = rear,
639 2 = external, default external)
640 media-controller Configure use of Media Controller API for
641 configuring the sensor (default on)
642 cam0 Adopt the default configuration for CAM0 on a
643 Compute Module (CSI0, i2c_vc, and cam0_reg).
647 Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
649 Load: dtoverlay=at86rf233,<param>=<val>
650 Params: interrupt GPIO used for INT (default 23)
651 reset GPIO used for Reset (default 24)
652 sleep GPIO used for Sleep (default 25)
653 speed SPI bus speed in Hz (default 3000000)
654 trim Fine tuning of the internal capacitance
655 arrays (0=+0pF, 15=+4.5pF, default 15)
658 Name: audioinjector-addons
659 Info: Configures the audioinjector.net audio add on soundcards
660 Load: dtoverlay=audioinjector-addons,<param>=<val>
661 Params: non-stop-clocks Keeps the clocks running even when the stream
662 is paused or stopped (default off)
665 Name: audioinjector-bare-i2s
666 Info: Configures the audioinjector.net audio bare i2s soundcard
667 Load: dtoverlay=audioinjector-bare-i2s
671 Name: audioinjector-isolated-soundcard
672 Info: Configures the audioinjector.net isolated soundcard
673 Load: dtoverlay=audioinjector-isolated-soundcard
677 Name: audioinjector-ultra
678 Info: Configures the audioinjector.net ultra soundcard
679 Load: dtoverlay=audioinjector-ultra
683 Name: audioinjector-wm8731-audio
684 Info: Configures the audioinjector.net audio add on soundcard
685 Load: dtoverlay=audioinjector-wm8731-audio
690 Info: Configures the audiosense-pi add on soundcard
691 For more information refer to
692 https://gitlab.com/kakar0t/audiosense-pi
693 Load: dtoverlay=audiosense-pi
698 Info: Switches PWM sound output to GPIOs on the 40-pin header
699 Load: dtoverlay=audremap,<param>=<val>
700 Params: swap_lr Reverse the channel allocation, which will also
701 swap the audio jack outputs (default off)
702 enable_jack Don't switch off the audio jack output. Does
703 nothing on BCM2711 (default off)
704 pins_12_13 Select GPIOs 12 & 13 (default)
705 pins_18_19 Select GPIOs 18 & 19
706 pins_40_41 Select GPIOs 40 & 41 (not available on CM4, used
708 pins_40_45 Select GPIOs 40 & 45 (don't use on BCM2711 - the
709 pins are on different controllers)
713 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
714 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
715 Load: dtoverlay=balena-fin
719 Name: bmp085_i2c-sensor
720 Info: This overlay is now deprecated - see i2c-sensor
724 Name: camera-mux-2port
725 Info: Configures a 2 port camera multiplexer
726 Note that currently ALL IMX290 modules share a common clock, therefore
727 all modules will need to have the same clock frequency.
728 Load: dtoverlay=camera-mux-2port,<param>=<val>
729 Params: cam0-arducam-64mp Select Arducam64MP for camera on port 0
730 cam0-imx219 Select IMX219 for camera on port 0
731 cam0-imx258 Select IMX258 for camera on port 0
732 cam0-imx290 Select IMX290 for camera on port 0
733 cam0-imx477 Select IMX477 for camera on port 0
734 cam0-imx519 Select IMX519 for camera on port 0
735 cam0-imx708 Select IMX708 for camera on port 0
736 cam0-ov2311 Select OV2311 for camera on port 0
737 cam0-ov5647 Select OV5647 for camera on port 0
738 cam0-ov7251 Select OV7251 for camera on port 0
739 cam0-ov9281 Select OV9281 for camera on port 0
740 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
741 cam1-arducam-64mp Select Arducam64MP for camera on port 1
742 cam1-imx219 Select IMX219 for camera on port 1
743 cam1-imx258 Select IMX258 for camera on port 1
744 cam1-imx290 Select IMX290 for camera on port 1
745 cam1-imx477 Select IMX477 for camera on port 1
746 cam1-imx519 Select IMX519 for camera on port 1
747 cam1-imx708 Select IMX708 for camera on port 1
748 cam1-ov2311 Select OV2311 for camera on port 1
749 cam1-ov5647 Select OV5647 for camera on port 1
750 cam1-ov7251 Select OV7251 for camera on port 1
751 cam1-ov9281 Select OV9281 for camera on port 1
752 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
755 Name: camera-mux-4port
756 Info: Configures a 4 port camera multiplexer
757 Note that currently ALL IMX290 modules share a common clock, therefore
758 all modules will need to have the same clock frequency.
759 Load: dtoverlay=camera-mux-4port,<param>=<val>
760 Params: cam0-arducam-64mp Select Arducam64MP for camera on port 0
761 cam0-imx219 Select IMX219 for camera on port 0
762 cam0-imx258 Select IMX258 for camera on port 0
763 cam0-imx290 Select IMX290 for camera on port 0
764 cam0-imx477 Select IMX477 for camera on port 0
765 cam0-imx519 Select IMX519 for camera on port 0
766 cam0-imx708 Select IMX708 for camera on port 0
767 cam0-ov2311 Select OV2311 for camera on port 0
768 cam0-ov5647 Select OV5647 for camera on port 0
769 cam0-ov7251 Select OV7251 for camera on port 0
770 cam0-ov9281 Select OV9281 for camera on port 0
771 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
772 cam1-arducam-64mp Select Arducam64MP for camera on port 1
773 cam1-imx219 Select IMX219 for camera on port 1
774 cam1-imx258 Select IMX258 for camera on port 1
775 cam1-imx290 Select IMX290 for camera on port 1
776 cam1-imx477 Select IMX477 for camera on port 1
777 cam1-imx519 Select IMX519 for camera on port 1
778 cam1-imx708 Select IMX708 for camera on port 1
779 cam1-ov2311 Select OV2311 for camera on port 1
780 cam1-ov5647 Select OV5647 for camera on port 1
781 cam1-ov7251 Select OV7251 for camera on port 1
782 cam1-ov9281 Select OV9281 for camera on port 1
783 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
784 cam2-arducam-64mp Select Arducam64MP for camera on port 2
785 cam2-imx219 Select IMX219 for camera on port 2
786 cam2-imx258 Select IMX258 for camera on port 2
787 cam2-imx290 Select IMX290 for camera on port 2
788 cam2-imx477 Select IMX477 for camera on port 2
789 cam2-imx519 Select IMX519 for camera on port 2
790 cam2-imx708 Select IMX708 for camera on port 2
791 cam2-ov2311 Select OV2311 for camera on port 2
792 cam2-ov5647 Select OV5647 for camera on port 2
793 cam2-ov7251 Select OV7251 for camera on port 2
794 cam2-ov9281 Select OV9281 for camera on port 2
795 cam2-imx290-clk-freq Set clock frequency for an IMX290 on port 2
796 cam3-arducam-64mp Select Arducam64MP for camera on port 3
797 cam3-imx219 Select IMX219 for camera on port 3
798 cam3-imx258 Select IMX258 for camera on port 3
799 cam3-imx290 Select IMX290 for camera on port 3
800 cam3-imx477 Select IMX477 for camera on port 3
801 cam3-imx519 Select IMX519 for camera on port 3
802 cam3-imx708 Select IMX708 for camera on port 3
803 cam3-ov2311 Select OV2311 for camera on port 3
804 cam3-ov5647 Select OV5647 for camera on port 3
805 cam3-ov7251 Select OV7251 for camera on port 3
806 cam3-ov9281 Select OV9281 for camera on port 3
807 cam3-imx290-clk-freq Set clock frequency for an IMX290 on port 3
811 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
812 Load: dtoverlay=cap1106,<param>=<val>
813 Params: int_pin GPIO pin for interrupt signal (default 23)
817 Info: Configures Chip Dip audio cards.
818 Load: dtoverlay=chipdip-dac
823 Info: Configures the Cirrus Logic Audio Card
824 Load: dtoverlay=cirrus-wm5102
829 Info: Largely for Compute Modules 1&3 where the original instructions for
830 adding a camera used GPIOs 0&1 for CAM1 and 28&29 for CAM0, whilst all
831 other platforms use 28&29 (or 44&45) for CAM1.
832 The default assignment through using this overlay is for
833 i2c0 to use 28&29, and i2c10 (aka i2c_csi_dsi) to use 28&29, but the
834 overrides allow this to be changed.
835 Load: dtoverlay=cm-swap-i2c0,<param>=<val>
836 Params: i2c0-gpio0 Use GPIOs 0&1 for i2c0
837 i2c0-gpio28 Use GPIOs 28&29 for i2c0 (default)
838 i2c0-gpio44 Use GPIOs 44&45 for i2c0
839 i2c10-gpio0 Use GPIOs 0&1 for i2c0 (default)
840 i2c10-gpio28 Use GPIOs 28&29 for i2c0
841 i2c10-gpio44 Use GPIOs 44&45 for i2c0
845 Info: Set custom CMA sizes, only use if you know what you are doing, might
846 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
847 Load: dtoverlay=cma,<param>=<val>
848 Params: cma-512 CMA is 512MB (needs 1GB)
849 cma-448 CMA is 448MB (needs 1GB)
850 cma-384 CMA is 384MB (needs 1GB)
851 cma-320 CMA is 320MB (needs 1GB)
852 cma-256 CMA is 256MB (needs 1GB)
853 cma-192 CMA is 192MB (needs 1GB)
857 cma-size CMA size in bytes, 4MB aligned
858 cma-default Use upstream's default value
861 Name: crystalfontz-cfa050_pi_m
862 Info: Configures the Crystalfontz CFA050-PI-M series of Raspberry Pi CM4
863 based modules using the CFA7201280A0_050Tx 7" TFT LCD displays,
864 with or without capacitive touch screen.
865 Requires use of vc4-kms-v3d.
866 Load: dtoverlay=crystalfontz-cfa050_pi_m,<param>=<val>
867 Params: captouch Enable capacitive touch display
871 Info: 8" TFT LCD display and touch panel used by cutiepi.io
872 Load: dtoverlay=cutiepi-panel
877 Info: Configures the dacberry400 add on soundcard
878 Load: dtoverlay=dacberry400
883 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
884 Also sometimes found with the part number(s) AM230x.
885 Load: dtoverlay=dht11,<param>=<val>
886 Params: gpiopin GPIO connected to the sensor's DATA output.
891 Info: Configures the Dion Audio KIWI STREAMER
892 Load: dtoverlay=dionaudio-kiwi
897 Info: Configures the Dion Audio LOCO DAC-AMP
898 Load: dtoverlay=dionaudio-loco
902 Name: dionaudio-loco-v2
903 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
904 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
905 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
906 Digital volume control. Enable with
907 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
908 (The default behaviour is that the Digital
909 volume control is limited to a maximum of
910 0dB. ie. it can attenuate but not provide
911 gain. For most users, this will be desired
912 as it will prevent clipping. By appending
913 the 24dB_digital_gain parameter, the Digital
914 volume control will allow up to 24dB of
915 gain. If this parameter is enabled, it is the
916 responsibility of the user to ensure that
917 the Digital volume control is set to a value
918 that does not result in clipping/distortion!)
922 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
923 UART0/ttyAMA0 over GPIOs 14 & 15.
924 N.B. To disable the systemd service that initialises the modem so it
925 doesn't use the UART, use 'sudo systemctl disable hciuart'.
926 Load: dtoverlay=disable-bt
931 Info: Disable EMMC2 controller on BCM2711.
932 The allows the onboard EMMC storage on Compute Module 4 to be disabled
933 e.g. if a fault has occurred.
934 Load: dtoverlay=disable-emmc2
939 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
940 Load: dtoverlay=disable-wifi
945 Info: Overlay for a generic 18-bit DPI display
946 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
947 2-3 seconds after the kernel has started.
948 Load: dtoverlay=dpi18
953 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
954 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
955 the output 3-3 seconds after the kernel has started.
956 Load: dtoverlay=dpi18cpadhi
961 Info: Overlay for a generic 24-bit DPI display
962 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
963 2-3 seconds after the kernel has started.
964 Load: dtoverlay=dpi24
969 Info: Configures the NW Digital Radio DRAWS Hat
971 The board includes an ADC to measure various board values and also
972 provides two analog user inputs on the expansion header. The ADC
973 can be configured for various sample rates and gain values to adjust
974 the input range. Tables describing the two parameters follow.
991 4 = 1600sps (default)
995 Load: dtoverlay=draws,<param>=<val>
996 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
997 input voltage sensor (default 1)
999 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
1002 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
1003 5V rail voltage sensor (default 1)
1005 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
1008 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
1009 AIN2 input (default 2)
1011 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
1013 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
1014 AIN3 input (default 2)
1016 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
1018 alsaname Name of the ALSA audio device (default "draws")
1022 Info: Selects the dwc_otg USB controller driver which has fiq support. This
1023 is the default on all except the Pi Zero which defaults to dwc2.
1024 Load: dtoverlay=dwc-otg
1029 Info: Selects the dwc2 USB controller driver
1030 Load: dtoverlay=dwc2,<param>=<val>
1031 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
1033 g-rx-fifo-size Size of rx fifo size in gadget mode
1035 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
1039 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
1043 Info: Overlay for the EDT FT5406 touchscreen.
1044 This works with the Raspberry Pi 7" touchscreen when not being polled
1046 By default the overlay uses the i2c_csi_dsi I2C interface, but this
1048 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
1049 config.txt to stop the firmware polling the touchscreen.
1050 Load: dtoverlay=edt-ft5406,<param>=<val>
1051 Params: sizex Touchscreen size x (default 800)
1052 sizey Touchscreen size y (default 480)
1053 invx Touchscreen inverted x axis
1054 invy Touchscreen inverted y axis
1055 swapxy Touchscreen swapped x y axis
1056 i2c0 Choose the I2C0 bus on GPIOs 0&1
1057 i2c1 Choose the I2C1 bus on GPIOs 2&3
1058 i2c3 Choose the I2C3 bus (configure with the i2c3
1059 overlay - BCM2711 only)
1060 i2c4 Choose the I2C4 bus (configure with the i2c4
1061 overlay - BCM2711 only)
1062 i2c5 Choose the I2C5 bus (configure with the i2c5
1063 overlay - BCM2711 only)
1064 i2c6 Choose the I2C6 bus (configure with the i2c6
1065 overlay - BCM2711 only)
1066 addr Sets the address for the touch controller. Note
1067 that the device must be configured to use the
1072 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
1073 Load: dtoverlay=enc28j60,<param>=<val>
1074 Params: int_pin GPIO used for INT (default 25)
1076 speed SPI bus speed (default 12000000)
1080 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
1081 Load: dtoverlay=enc28j60-spi2,<param>=<val>
1082 Params: int_pin GPIO used for INT (default 39)
1084 speed SPI bus speed (default 12000000)
1088 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
1089 GPIO 4 (pin 7 on GPIO header) for interrupt.
1090 Load: dtoverlay=exc3000,<param>=<val>
1091 Params: interrupt GPIO used for interrupt (default 4)
1092 sizex Touchscreen size x (default 4096)
1093 sizey Touchscreen size y (default 4096)
1094 invx Touchscreen inverted x axis
1095 invy Touchscreen inverted y axis
1096 swapxy Touchscreen swapped x y axis
1100 Info: Overlay for SPI-connected displays using the fbtft drivers.
1102 This overlay seeks to replace the functionality provided by fbtft_device
1103 which is now gone from the kernel.
1105 Most displays from fbtft_device have been ported over.
1107 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1109 It is also possible to specify the controller (this will use the default
1110 init sequence in the driver).
1112 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1114 For devices on spi1 or spi2, the interfaces should be enabled
1115 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
1117 The following features of fbtft_device have not been ported over:
1118 - parallel bus is not supported
1119 - the init property which overrides the controller initialization
1120 sequence is not supported as a parameter due to memory limitations in
1121 the bootloader responsible for applying the overlay.
1123 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
1126 Load: dtoverlay=fbtft,<param>=<val>
1128 spi<n>-<m> Configure device at spi<n>, cs<m>
1130 speed SPI bus speed in Hz (default 32000000)
1131 cpha Shifted clock phase (CPHA) mode
1132 cpol Inverse clock polarity (CPOL) mode
1134 adafruit18 Adafruit 1.8
1135 adafruit22 Adafruit 2.2 (old)
1136 adafruit22a Adafruit 2.2
1137 adafruit28 Adafruit 2.8
1138 adafruit13m Adafruit 1.3 OLED
1139 admatec_c-berry28 C-Berry28
1141 er_tftm050_2 ER-TFTM070-2
1142 er_tftm070_5 ER-TFTM070-5
1144 ew24ha0_9bit EW24HA0 in 9-bit mode
1145 freetronicsoled128 Freetronics OLED128
1148 itdb28_spi ITDB02-2.8 with SPI interface circuit
1149 mi0283qt-2 Watterott MI0283QT-2
1150 mi0283qt-9a Watterott MI0283QT-9A
1151 nokia3310 Nokia 3310
1152 nokia3310a Nokia 3310a
1153 nokia5110 Nokia 5110
1155 pitft Adafruit PiTFT 2.8
1157 rpi-display Watterott rpi-display
1158 sainsmart18 Sainsmart 1.8
1159 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
1160 tinylcd35 TinyLCD 3.5
1161 tm022hdh26 Tianma TM022HDH26
1162 tontec35_9481 Tontect 3.5 with ILI9481 controller
1163 tontec35_9486 Tontect 3.5 with ILI9486 controller
1164 waveshare32b Waveshare 3.2
1165 waveshare22 Waveshare 2.2
1167 bd663474 BD663474 display controller
1168 hx8340bn HX8340BN display controller
1169 hx8347d HX8347D display controller
1170 hx8353d HX8353D display controller
1171 hx8357d HX8357D display controller
1172 ili9163 ILI9163 display controller
1173 ili9320 ILI9320 display controller
1174 ili9325 ILI9325 display controller
1175 ili9340 ILI9340 display controller
1176 ili9341 ILI9341 display controller
1177 ili9481 ILI9481 display controller
1178 ili9486 ILI9486 display controller
1179 pcd8544 PCD8544 display controller
1180 ra8875 RA8875 display controller
1181 s6d02a1 S6D02A1 display controller
1182 s6d1121 S6D1121 display controller
1183 seps525 SEPS525 display controller
1184 sh1106 SH1106 display controller
1185 ssd1289 SSD1289 display controller
1186 ssd1305 SSD1305 display controller
1187 ssd1306 SSD1306 display controller
1188 ssd1325 SSD1325 display controller
1189 ssd1331 SSD1331 display controller
1190 ssd1351 SSD1351 display controller
1191 st7735r ST7735R display controller
1192 st7789v ST7789V display controller
1193 tls8204 TLS8204 display controller
1194 uc1611 UC1611 display controller
1195 uc1701 UC1701 display controller
1196 upd161704 UPD161704 display controller
1198 width Display width in pixels
1199 height Display height in pixels
1200 regwidth Display controller register width (default is
1202 buswidth Display bus interface width (default 8)
1203 debug Debug output level {0-7}
1204 rotate Display rotation {0, 90, 180, 270} (counter
1205 clockwise). Not supported by all drivers.
1206 bgr Enable BGR mode (default off). Use if Red and
1207 Blue are swapped. Not supported by all drivers.
1208 fps Frames per second (default 30). In effect this
1209 states how long the driver will wait after video
1210 memory has been changed until display update
1211 transfer is started.
1212 txbuflen Length of the FBTFT transmit buffer
1214 startbyte Sets the Start byte used by fb_ili9320,
1215 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1216 gamma String representation of Gamma Curve(s). Driver
1217 specific. Not supported by all drivers.
1218 reset_pin GPIO pin for RESET
1219 dc_pin GPIO pin for D/C
1220 led_pin GPIO pin for LED backlight
1224 Info: Configures the Fe-Pi Audio Sound Card
1225 Load: dtoverlay=fe-pi-audio
1230 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1231 nicely with a "traffic-light" display of red, amber and green LEDs on
1232 GPIOs 7, 8 and 25 respectively.
1233 Load: dtoverlay=fsm-demo,<param>=<val>
1234 Params: fsm_debug Enable debug logging (default off)
1238 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on
1239 SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical
1240 GPIO header pins 22, 13 and 12 respectively) in addition to the
1241 SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19,
1242 23 and 24 respectively).
1243 Load: dtoverlay=gc9a01,<param>=<val>
1244 Params: speed Display SPI bus speed
1246 rotate Display rotation {0,90,180,270}
1248 width Width of the display
1250 height Height of the display
1252 fps Delay between frame updates
1254 debug Debug output level {0-7}
1258 Info: An overlay for the Ghost amplifier.
1259 Load: dtoverlay=ghost-amp,<param>=<val>
1260 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1265 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1266 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1267 Load: dtoverlay=goodix,<param>=<val>
1268 Params: interrupt GPIO used for interrupt (default 4)
1269 reset GPIO used for reset (default 17)
1272 Name: googlevoicehat-soundcard
1273 Info: Configures the Google voiceHAT soundcard
1274 Load: dtoverlay=googlevoicehat-soundcard
1279 Info: This is a generic overlay for detecting charger with GPIO.
1280 Load: dtoverlay=gpio-charger,<param>=<val>
1281 Params: gpio GPIO pin to trigger on (default 4)
1282 active_low When this is 1 (active low), a falling
1283 edge generates a charging event and a
1284 rising edge generates a discharging event.
1285 When this is 0 (active high), this is
1286 reversed. The default is 0 (active high)
1287 gpio_pull Desired pull-up/down state (off, down, up)
1289 type Set a charger type for the pin. (Default: mains)
1293 Info: Configure a GPIO pin to control a cooling fan.
1294 Load: dtoverlay=gpio-fan,<param>=<val>
1295 Params: gpiopin GPIO used to control the fan (default 12)
1296 temp Temperature at which the fan switches on, in
1297 millicelcius (default 55000)
1298 hyst Temperature delta (in millicelcius) below
1299 temp at which the fan will drop to minrpm
1304 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1305 an output, driven low or high as indicated by the presence or absence
1306 of the active_low parameter. Note that a hogged GPIO is not available
1307 to other drivers or for gpioset/gpioget.
1308 Load: dtoverlay=gpio-hog,<param>=<val>
1309 Params: gpio GPIO pin to hog (default 26)
1310 active_low If set, the hog drives the GPIO low (defaults
1311 to off - the GPIO is driven high)
1315 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1316 based gpio_ir_recv driver maps received keys directly to a
1317 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1318 not required! The key mapping and other decoding parameters can be
1319 configured by "ir-keytable" tool.
1320 Load: dtoverlay=gpio-ir,<param>=<val>
1321 Params: gpio_pin Input pin number. Default is 18.
1323 gpio_pull Desired pull-up/down state (off, down, up)
1326 invert "1" = invert the input (active-low signalling).
1327 "0" = non-inverted input (active-high
1328 signalling). Default is "1".
1330 rc-map-name Default rc keymap (can also be changed by
1331 ir-keytable), defaults to "rc-rc6-mce"
1335 Info: Use GPIO pin as bit-banged infrared transmitter output.
1336 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1337 a PWM so it can be used together with onboard analog audio.
1338 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1339 Params: gpio_pin Output GPIO (default 18)
1341 invert "1" = invert the output (make it active-low).
1342 Default is "0" (active-high).
1346 Info: This is a generic overlay for activating GPIO keypresses using
1347 the gpio-keys library and this dtoverlay. Multiple keys can be
1348 set up using multiple calls to the overlay for configuring
1349 additional buttons or joysticks. You can see available keycodes
1350 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1351 linux/input-event-codes.h#L64
1352 Load: dtoverlay=gpio-key,<param>=<val>
1353 Params: gpio GPIO pin to trigger on (default 3)
1354 active_low When this is 1 (active low), a falling
1355 edge generates a key down event and a
1356 rising edge generates a key up event.
1357 When this is 0 (active high), this is
1358 reversed. The default is 1 (active low)
1359 gpio_pull Desired pull-up/down state (off, down, up)
1360 Default is "up". Note that the default pin
1361 (GPIO3) has an external pullup
1362 label Set a label for the key
1363 keycode Set the key code for the button
1368 Info: This is a generic overlay for activating LEDs (or any other component)
1369 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1370 overlay. While there are many existing methods to activate LEDs on the
1371 RPi, this method offers some advantages:
1372 1) Does not require any userspace programs.
1373 2) LEDs can be connected to the kernel's led-trigger framework,
1374 and drive the LED based on triggers such as cpu load, heartbeat,
1375 kernel panic, key input, timers and others.
1376 3) LED can be tied to the input state of another GPIO pin.
1377 4) The LED is setup early during the kernel boot process (useful
1378 for cpu/heartbeat/panic triggers).
1380 Typical electrical connection is:
1381 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1382 The GPIO pin number can be changed with the 'gpio=' parameter.
1384 To control an LED from userspace, write a 0 or 1 value:
1385 echo 1 > /sys/class/leds/myled1/brightness
1386 The 'myled1' name can be changed with the 'label=' parameter.
1388 To connect the LED to a kernel trigger from userspace:
1389 echo cpu > /sys/class/leds/myled1/trigger
1390 echo heartbeat > /sys/class/leds/myled1/trigger
1391 echo none > /sys/class/leds/myled1/trigger
1392 To connect the LED to GPIO.26 pin (physical pin 37):
1393 echo gpio > /sys/class/leds/myled1/trigger
1394 echo 26 > /sys/class/leds/myled1/gpio
1396 cat /sys/class/leds/myled1/trigger
1398 More information about the Linux kernel LED/Trigger system:
1399 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1400 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1401 Load: dtoverlay=gpio-led,<param>=<val>
1402 Params: gpio GPIO pin connected to the LED (default 19)
1403 label The label for this LED. It will appear under
1404 /sys/class/leds/<label> . Default 'myled1'.
1405 trigger Set the led-trigger to connect to this LED.
1406 default 'none' (LED is user-controlled).
1407 Some possible triggers:
1408 cpu - CPU load (all CPUs)
1409 cpu0 - CPU load of first CPU.
1410 mmc - disk activity (all disks)
1411 panic - turn on on kernel panic
1412 heartbeat - indicate system health
1413 gpio - connect to a GPIO input pin (note:
1414 currently the GPIO PIN can not be set
1415 using overlay parameters, must be
1416 done in userspace, see examples above.
1417 active_low Set to 1 to turn invert the LED control
1418 (writing 0 to /sys/class/leds/XXX/brightness
1419 will turn on the GPIO/LED). Default '0'.
1422 Name: gpio-no-bank0-irq
1423 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1424 which can be useful for UIO drivers.
1425 N.B. Using this overlay will trigger a kernel WARN during booting, but
1426 this can safely be ignored - the system should work as expected.
1427 Load: dtoverlay=gpio-no-bank0-irq
1432 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1433 for user-space GPIO edge detection systems.
1434 Load: dtoverlay=gpio-no-irq
1439 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1440 overlay interferes with the normal power-down sequence, preventing the
1441 kernel from resetting the SoC (a necessary step in a normal power-off
1442 or reboot). This also disables the ability to trigger a boot by driving
1445 The GPIO starts in an inactive state. At poweroff time it is driven
1446 active for 100ms, then inactive for 100ms, then active again. It is
1447 safe to remove the power at any point after the initial activation of
1450 Users of this overlay are required to provide an external mechanism to
1451 switch off the power supply when signalled - failure to do so results
1452 in a kernel BUG, increased power consumption and undefined behaviour.
1453 Load: dtoverlay=gpio-poweroff,<param>=<val>
1454 Params: gpiopin GPIO for signalling (default 26)
1456 active_low Set if the power control device requires a
1457 high->low transition to trigger a power-down.
1458 Note that this will require the support of a
1459 custom dt-blob.bin to prevent a power-down
1460 during the boot process, and that a reboot
1461 will also cause the pin to go low.
1462 input Set if the gpio pin should be configured as
1464 export Set to export the configured pin to sysfs
1465 active_delay_ms Initial GPIO active period (default 100)
1466 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1467 timeout_ms Specify (in ms) how long the kernel waits for
1468 power-down before issuing a WARN (default 3000).
1472 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1473 is configured as an input key that generates KEY_POWER events.
1475 This event is handled by systemd-logind by initiating a
1476 shutdown. Systemd versions older than 225 need an udev rule
1477 enable listening to the input device:
1479 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1480 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1481 ATTRS{keys}=="116", TAG+="power-switch"
1483 Alternatively this event can be handled also on systems without
1484 systemd, just by traditional SysV init daemon. KEY_POWER event
1485 (keycode 116) needs to be mapped to KeyboardSignal on console
1486 and then kb::kbrequest inittab action which is triggered by
1487 KeyboardSignal from console can be configured to issue system
1488 shutdown. Steps for this configuration are:
1490 Add following lines to the /etc/console-setup/remap.inc file:
1492 # Key Power as special keypress
1493 keycode 116 = KeyboardSignal
1495 Then add following lines to /etc/inittab file:
1497 # Action on special keypress (Key Power)
1498 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1500 And finally reload configuration by calling following commands:
1502 # dpkg-reconfigure console-setup
1503 # service console-setup reload
1506 This overlay only handles shutdown. After shutdown, the system
1507 can be powered up again by driving GPIO3 low. The default
1508 configuration uses GPIO3 with a pullup, so if you connect a
1509 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1510 you get a shutdown and power-up button. Please note that
1511 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1512 Load: dtoverlay=gpio-shutdown,<param>=<val>
1513 Params: gpio_pin GPIO pin to trigger on (default 3)
1514 For Raspberry Pi 1 Model B rev 1 set this
1515 explicitly to value 1, e.g.:
1517 dtoverlay=gpio-shutdown,gpio_pin=1
1519 active_low When this is 1 (active low), a falling
1520 edge generates a key down event and a
1521 rising edge generates a key up event.
1522 When this is 0 (active high), this is
1523 reversed. The default is 1 (active low).
1525 gpio_pull Desired pull-up/down state (off, down, up)
1528 Note that the default pin (GPIO3) has an
1529 external pullup. Same applies for GPIO1
1530 on Raspberry Pi 1 Model B rev 1.
1532 debounce Specify the debounce interval in milliseconds
1537 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1538 data, 2 gpio pins for enable and register select and 1 optional pin
1539 for enabling/disabling the backlight display.
1540 Load: dtoverlay=hd44780-lcd,<param>=<val>
1541 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1543 pin_d5 GPIO pin for data pin D5 (default 13)
1545 pin_d6 GPIO pin for data pin D6 (default 19)
1547 pin_d7 GPIO pin for data pin D7 (default 26)
1549 pin_en GPIO pin for "Enable" (default 21)
1551 pin_rs GPIO pin for "Register Select" (default 20)
1553 pin_bl Optional pin for enabling/disabling the
1554 display backlight. (default disabled)
1556 display_height Height of the display in characters
1558 display_width Width of the display in characters
1561 Name: hdmi-backlight-hwhack-gpio
1562 Info: Devicetree overlay for GPIO based backlight on/off capability.
1563 Use this if you have one of those HDMI displays whose backlight cannot
1564 be controlled via DPMS over HDMI and plan to do a little soldering to
1565 use an RPi gpio pin for on/off switching. See:
1566 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1567 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1568 Params: gpio_pin GPIO pin used (default 17)
1569 active_low Set this to 1 if the display backlight is
1570 switched on when the wire goes low.
1571 Leave the default (value 0) if the backlight
1572 expects a high to switch it on.
1576 Info: Configures the HifiBerry Amp and Amp+ audio cards
1577 Load: dtoverlay=hifiberry-amp
1581 Name: hifiberry-amp100
1582 Info: Configures the HifiBerry AMP100 audio card
1583 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1584 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1585 Digital volume control. Enable with
1586 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1587 (The default behaviour is that the Digital
1588 volume control is limited to a maximum of
1589 0dB. ie. it can attenuate but not provide
1590 gain. For most users, this will be desired
1591 as it will prevent clipping. By appending
1592 the 24dB_digital_gain parameter, the Digital
1593 volume control will allow up to 24dB of
1594 gain. If this parameter is enabled, it is the
1595 responsibility of the user to ensure that
1596 the Digital volume control is set to a value
1597 that does not result in clipping/distortion!)
1598 slave Force DAC+ Pro into slave mode, using Pi as
1599 master for bit clock and frame clock.
1600 leds_off If set to 'true' the onboard indicator LEDs
1601 are switched off at all times.
1602 auto_mute If set to 'true' the amplifier is automatically
1603 muted when the DAC is not playing.
1604 mute_ext_ctl The amplifier's HW mute control is enabled
1605 in ALSA mixer and set to <val>.
1606 Will be overwritten by ALSA user settings.
1609 Name: hifiberry-amp3
1610 Info: Configures the HifiBerry Amp3 audio card
1611 Load: dtoverlay=hifiberry-amp3
1616 Info: Configures the HifiBerry DAC audio cards
1617 Load: dtoverlay=hifiberry-dac
1621 Name: hifiberry-dacplus
1622 Info: Configures the HifiBerry DAC+ audio card
1623 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1624 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1625 Digital volume control. Enable with
1626 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1627 (The default behaviour is that the Digital
1628 volume control is limited to a maximum of
1629 0dB. ie. it can attenuate but not provide
1630 gain. For most users, this will be desired
1631 as it will prevent clipping. By appending
1632 the 24dB_digital_gain parameter, the Digital
1633 volume control will allow up to 24dB of
1634 gain. If this parameter is enabled, it is the
1635 responsibility of the user to ensure that
1636 the Digital volume control is set to a value
1637 that does not result in clipping/distortion!)
1638 slave Force DAC+ Pro into slave mode, using Pi as
1639 master for bit clock and frame clock.
1640 leds_off If set to 'true' the onboard indicator LEDs
1641 are switched off at all times.
1644 Name: hifiberry-dacplusadc
1645 Info: Configures the HifiBerry DAC+ADC audio card
1646 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1647 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1648 Digital volume control. Enable with
1649 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1650 (The default behaviour is that the Digital
1651 volume control is limited to a maximum of
1652 0dB. ie. it can attenuate but not provide
1653 gain. For most users, this will be desired
1654 as it will prevent clipping. By appending
1655 the 24dB_digital_gain parameter, the Digital
1656 volume control will allow up to 24dB of
1657 gain. If this parameter is enabled, it is the
1658 responsibility of the user to ensure that
1659 the Digital volume control is set to a value
1660 that does not result in clipping/distortion!)
1661 slave Force DAC+ Pro into slave mode, using Pi as
1662 master for bit clock and frame clock.
1663 leds_off If set to 'true' the onboard indicator LEDs
1664 are switched off at all times.
1667 Name: hifiberry-dacplusadcpro
1668 Info: Configures the HifiBerry DAC+ADC PRO audio card
1669 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1670 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1671 Digital volume control. Enable with
1672 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1673 (The default behaviour is that the Digital
1674 volume control is limited to a maximum of
1675 0dB. ie. it can attenuate but not provide
1676 gain. For most users, this will be desired
1677 as it will prevent clipping. By appending
1678 the 24dB_digital_gain parameter, the Digital
1679 volume control will allow up to 24dB of
1680 gain. If this parameter is enabled, it is the
1681 responsibility of the user to ensure that
1682 the Digital volume control is set to a value
1683 that does not result in clipping/distortion!)
1684 slave Force DAC+ADC Pro into slave mode, using Pi as
1685 master for bit clock and frame clock.
1686 leds_off If set to 'true' the onboard indicator LEDs
1687 are switched off at all times.
1690 Name: hifiberry-dacplusdsp
1691 Info: Configures the HifiBerry DAC+DSP audio card
1692 Load: dtoverlay=hifiberry-dacplusdsp
1696 Name: hifiberry-dacplushd
1697 Info: Configures the HifiBerry DAC+ HD audio card
1698 Load: dtoverlay=hifiberry-dacplushd
1702 Name: hifiberry-digi
1703 Info: Configures the HifiBerry Digi and Digi+ audio card
1704 Load: dtoverlay=hifiberry-digi
1708 Name: hifiberry-digi-pro
1709 Info: Configures the HifiBerry Digi+ Pro and Digi2 Pro audio card
1710 Load: dtoverlay=hifiberry-digi-pro
1715 Info: Enables "High Peripheral" mode
1716 Load: dtoverlay=highperi
1721 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1722 Default values match Texy's display shield
1723 Load: dtoverlay=hy28a,<param>=<val>
1724 Params: speed Display SPI bus speed
1726 rotate Display rotation {0,90,180,270}
1728 fps Delay between frame updates
1730 debug Debug output level {0-7}
1732 xohms Touchpanel sensitivity (X-plate resistance)
1734 resetgpio GPIO used to reset controller
1736 ledgpio GPIO used to control backlight
1740 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1741 Default values match Texy's display shield
1742 Load: dtoverlay=hy28b,<param>=<val>
1743 Params: speed Display SPI bus speed
1745 rotate Display rotation {0,90,180,270}
1747 fps Delay between frame updates
1749 debug Debug output level {0-7}
1751 xohms Touchpanel sensitivity (X-plate resistance)
1753 resetgpio GPIO used to reset controller
1755 ledgpio GPIO used to control backlight
1759 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1760 Default values match Texy's display shield
1761 Load: dtoverlay=hy28b-2017,<param>=<val>
1762 Params: speed Display SPI bus speed
1764 rotate Display rotation {0,90,180,270}
1766 fps Delay between frame updates
1768 debug Debug output level {0-7}
1770 xohms Touchpanel sensitivity (X-plate resistance)
1772 resetgpio GPIO used to reset controller
1774 ledgpio GPIO used to control backlight
1778 Info: Configures the Audiophonics I-SABRE Q2M DAC
1779 Load: dtoverlay=i-sabre-q2m
1784 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1785 Load: dtoverlay=i2c-bcm2708
1790 Info: Adds support for a number of I2C fan controllers
1791 Load: dtoverlay=i2c-fan,<param>=<val>
1792 Params: addr Sets the address for the fan controller. Note
1793 that the device must be configured to use the
1796 i2c0 Choose the I2C0 bus on GPIOs 0&1
1798 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1800 i2c3 Choose the I2C3 bus (configure with the i2c3
1801 overlay - BCM2711 only)
1803 i2c4 Choose the I2C4 bus (configure with the i2c4
1804 overlay - BCM2711 only)
1806 i2c5 Choose the I2C5 bus (configure with the i2c5
1807 overlay - BCM2711 only)
1809 i2c6 Choose the I2C6 bus (configure with the i2c6
1810 overlay - BCM2711 only)
1812 minpwm PWM setting for the fan when the SoC is below
1813 mintemp (range 0-255. default 0)
1814 maxpwm PWM setting for the fan when the SoC is above
1815 maxtemp (range 0-255. default 255)
1816 midtemp Temperature (in millicelcius) at which the fan
1817 begins to speed up (default 50000)
1819 midtemp_hyst Temperature delta (in millicelcius) below
1820 mintemp at which the fan will drop to minrpm
1823 maxtemp Temperature (in millicelcius) at which the fan
1824 will be held at maxrpm (default 70000)
1826 maxtemp_hyst Temperature delta (in millicelcius) below
1827 maxtemp at which the fan begins to slow down
1830 emc2301 Select the Microchip EMC230x controller family
1831 - EMC2301, EMC2302, EMC2303, EMC2305.
1835 Info: Adds support for software i2c controller on gpio pins
1836 Load: dtoverlay=i2c-gpio,<param>=<val>
1837 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1839 i2c_gpio_scl GPIO used for I2C clock (default "24")
1841 i2c_gpio_delay_us Clock delay in microseconds
1842 (default "2" = ~100kHz)
1844 bus Set to a unique, non-zero value if wanting
1845 multiple i2c-gpio busses. If set, will be used
1846 as the preferred bus number (/dev/i2c-<n>). If
1847 not set, the default value is 0, but the bus
1848 number will be dynamically assigned - probably
1853 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1854 Load: dtoverlay=i2c-mux,<param>=<val>
1855 Params: pca9542 Select the NXP PCA9542 device
1857 pca9545 Select the NXP PCA9545 device
1859 pca9548 Select the NXP PCA9548 device
1861 addr Change I2C address of the device (default 0x70)
1863 i2c0 Choose the I2C0 bus on GPIOs 0&1
1865 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1867 i2c3 Choose the I2C3 bus (configure with the i2c3
1868 overlay - BCM2711 only)
1870 i2c4 Choose the I2C3 bus (configure with the i2c3
1871 overlay - BCM2711 only)
1873 i2c5 Choose the I2C5 bus (configure with the i2c4
1874 overlay - BCM2711 only)
1876 i2c6 Choose the I2C6 bus (configure with the i2c6
1877 overlay - BCM2711 only)
1880 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1883 Name: i2c-pwm-pca9685a
1884 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1885 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1886 Params: addr I2C address of PCA9685A (default 0x40)
1887 i2c0 Choose the I2C0 bus on GPIOs 0&1
1888 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1889 i2c3 Choose the I2C3 bus (configure with the i2c3
1890 overlay - BCM2711 only)
1891 i2c4 Choose the I2C3 bus (configure with the i2c3
1892 overlay - BCM2711 only)
1893 i2c5 Choose the I2C5 bus (configure with the i2c4
1894 overlay - BCM2711 only)
1895 i2c6 Choose the I2C6 bus (configure with the i2c6
1896 overlay - BCM2711 only)
1900 Info: Adds support for a number of I2C Real Time Clock devices
1901 Load: dtoverlay=i2c-rtc,<param>=<val>
1902 Params: abx80x Select one of the ABx80x family:
1903 AB0801, AB0803, AB0804, AB0805,
1904 AB1801, AB1803, AB1804, AB1805
1906 bq32000 Select the TI BQ32000 device
1908 ds1307 Select the DS1307 device
1910 ds1339 Select the DS1339 device
1912 ds1340 Select the DS1340 device
1914 ds3231 Select the DS3231 device
1916 m41t62 Select the M41T62 device
1918 mcp7940x Select the MCP7940x device
1920 mcp7941x Select the MCP7941x device
1922 pcf2127 Select the PCF2127 device
1924 pcf2129 Select the PCF2129 device
1926 pcf85063 Select the PCF85063 device
1928 pcf85063a Select the PCF85063A device
1930 pcf8523 Select the PCF8523 device
1932 pcf85363 Select the PCF85363 device
1934 pcf8563 Select the PCF8563 device
1936 rv1805 Select the Micro Crystal RV1805 device
1938 rv3028 Select the Micro Crystal RV3028 device
1940 rv3032 Select the Micro Crystal RV3032 device
1942 rv8803 Select the Micro Crystal RV8803 device
1944 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1946 s35390a Select the ABLIC S35390A device
1948 i2c0 Choose the I2C0 bus on GPIOs 0&1
1950 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1952 i2c3 Choose the I2C3 bus (configure with the i2c3
1953 overlay - BCM2711 only)
1955 i2c4 Choose the I2C3 bus (configure with the i2c3
1956 overlay - BCM2711 only)
1958 i2c5 Choose the I2C5 bus (configure with the i2c4
1959 overlay - BCM2711 only)
1961 i2c6 Choose the I2C6 bus (configure with the i2c6
1962 overlay - BCM2711 only)
1964 addr Sets the address for the RTC. Note that the
1965 device must be configured to use the specified
1968 trickle-diode-disable Do not use the internal trickle charger diode
1971 trickle-diode-type Diode type for trickle charge - "standard" or
1972 "schottky" (ABx80x and RV1805 only)
1974 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1975 ABx80x, BQ32000, RV1805, RV3028, RV3032)
1977 trickle-voltage-mv Charge pump voltage for trickle charge (RV3032)
1979 wakeup-source Specify that the RTC can be used as a wakeup
1982 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1983 off or 1 for Vdd < VBackup (RV3028, RV3032)
1987 Info: Adds support for a number of I2C Real Time Clock devices
1988 using the software i2c controller
1989 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1990 Params: abx80x Select one of the ABx80x family:
1991 AB0801, AB0803, AB0804, AB0805,
1992 AB1801, AB1803, AB1804, AB1805
1994 bq32000 Select the TI BQ32000 device
1996 ds1307 Select the DS1307 device
1998 ds1339 Select the DS1339 device
2000 ds1340 Select the DS1340 device
2002 ds3231 Select the DS3231 device
2004 m41t62 Select the M41T62 device
2006 mcp7940x Select the MCP7940x device
2008 mcp7941x Select the MCP7941x device
2010 pcf2127 Select the PCF2127 device
2012 pcf2129 Select the PCF2129 device
2014 pcf85063 Select the PCF85063 device
2016 pcf85063a Select the PCF85063A device
2018 pcf8523 Select the PCF8523 device
2020 pcf85363 Select the PCF85363 device
2022 pcf8563 Select the PCF8563 device
2024 rv1805 Select the Micro Crystal RV1805 device
2026 rv3028 Select the Micro Crystal RV3028 device
2028 rv3032 Select the Micro Crystal RV3032 device
2030 rv8803 Select the Micro Crystal RV8803 device
2032 sd3078 Select the ZXW Shenzhen whwave SD3078 device
2034 s35390a Select the ABLIC S35390A device
2036 addr Sets the address for the RTC. Note that the
2037 device must be configured to use the specified
2040 trickle-diode-disable Do not use the internal trickle charger diode
2043 trickle-diode-type Diode type for trickle charge - "standard" or
2044 "schottky" (ABx80x and RV1805 only)
2046 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
2047 ABx80x, BQ32000, RV1805, RV3028, RV3032)
2049 trickle-voltage-mv Charge pump voltage for trickle charge (RV3032)
2051 wakeup-source Specify that the RTC can be used as a wakeup
2054 backup-switchover-mode Backup power supply switch mode. Must be 0 for
2055 off or 1 for Vdd < VBackup (RV3028, RV3032)
2057 i2c_gpio_sda GPIO used for I2C data (default "23")
2059 i2c_gpio_scl GPIO used for I2C clock (default "24")
2061 i2c_gpio_delay_us Clock delay in microseconds
2062 (default "2" = ~100kHz)
2066 Info: Adds support for a number of I2C barometric pressure, temperature,
2067 light level and chemical sensors on i2c_arm
2068 Load: dtoverlay=i2c-sensor,<param>=<val>
2069 Params: addr Set the address for the BH1750, BME280, BME680,
2070 BMP280, BMP380, CCS811, DS1621, HDC100X, JC42,
2071 LM75, MCP980x, MPU6050, MPU9250, MS5637, MS5803,
2072 MS5805, MS5837, MS8607, SHT3x or TMP102
2074 aht10 Select the Aosong AHT10 temperature and humidity
2077 bh1750 Select the Rohm BH1750 ambient light sensor
2078 Valid addresses 0x23 or 0x5c, default 0x23
2080 bme280 Select the Bosch Sensortronic BME280
2081 Valid addresses 0x76-0x77, default 0x76
2083 bme680 Select the Bosch Sensortronic BME680
2084 Valid addresses 0x76-0x77, default 0x76
2086 bmp085 Select the Bosch Sensortronic BMP085
2088 bmp180 Select the Bosch Sensortronic BMP180
2090 bmp280 Select the Bosch Sensortronic BMP280
2091 Valid addresses 0x76-0x77, default 0x76
2093 bmp380 Select the Bosch Sensortronic BMP380
2094 Valid addresses 0x76-0x77, default 0x76
2096 bno055 Select the Bosch Sensortronic BNO055 IMU
2097 Valid address 0x28-0x29, default 0x29
2099 ccs811 Select the AMS CCS811 digital gas sensor
2100 Valid addresses 0x5a-0x5b, default 0x5b
2102 ds1621 Select the Dallas Semiconductors DS1621 temp
2103 sensor. Valid addresses 0x48-0x4f, default 0x48
2105 hdc100x Select the Texas Instruments HDC100x temp sensor
2106 Valid addresses 0x40-0x43, default 0x40
2108 htu21 Select the HTU21 temperature and humidity sensor
2110 int_pin Set the GPIO to use for interrupts (max30102,
2111 mpu6050 and mpu9250 only)
2113 jc42 Select any of the many JEDEC JC42.4-compliant
2114 temperature sensors, including:
2115 ADT7408, AT30TS00, CAT34TS02, CAT6095,
2116 MAX6604, MCP9804, MCP9805, MCP9808,
2117 MCP98242, MCP98243, MCP98244, MCP9843,
2118 SE97, SE98, STTS424(E), STTS2002, STTS3000,
2119 TSE2002, TSE2004, TS3000, and TS3001.
2120 The default address is 0x18.
2122 lm75 Select the Maxim LM75 temperature sensor
2123 Valid addresses 0x48-0x4f, default 0x4f
2125 lm75addr Deprecated - use addr parameter instead
2127 max17040 Select the Maxim Integrated MAX17040 battery
2130 max30102 Select the Maxim Integrated MAX30102 heart-rate
2131 and blood-oxygen sensor
2133 mcp980x Select the Maxim MCP980x range of temperature
2134 sensors (i.e. MCP9800, MCP9801, MCP9802 and
2135 MCP9803). N.B. For MCP9804, MCP9805 and MCP9808,
2136 use the "jc42" option.
2137 Valid addresses are 0x18-0x1f (default 0x18)
2139 mpu6050 Select the InvenSense MPU6050 IMU. Valid
2140 valid addresses are 0x68 and 0x69 (default 0x68)
2142 mpu9250 Select the InvenSense MPU9250 IMU. Valid
2143 valid addresses are 0x68 and 0x69 (default 0x68)
2145 ms5637 Select the Measurement Specialities MS5637
2146 pressure and temperature sensor.
2148 ms5803 Select the Measurement Specialities MS5803
2149 pressure and temperature sensor.
2151 ms5805 Select the Measurement Specialities MS5805
2152 pressure and temperature sensor.
2154 ms5837 Select the Measurement Specialities MS5837
2155 pressure and temperature sensor.
2157 ms8607 Select the Measurement Specialities MS8607
2158 pressure and temperature sensor.
2160 no_timeout Disable the SMBUS timeout. N.B. Only supported
2161 by some jc42 devices - using with an
2162 incompatible device can stop it from being
2165 reset_pin GPIO to be used to reset the device (bno055
2166 only, disabled by default)
2168 sht3x Select the Sensirion SHT3x temperature and
2169 humidity sensors. Valid addresses 0x44-0x45,
2172 sht4x Select the Sensirion SHT4x temperature and
2173 humidity sensors. Valid addresses 0x44-0x45,
2176 si7020 Select the Silicon Labs Si7013/20/21 humidity/
2179 sps30 Select the Sensirion SPS30 particulate matter
2180 sensor. Fixed address 0x69.
2182 sgp30 Select the Sensirion SGP30 VOC sensor.
2185 tmp102 Select the Texas Instruments TMP102 temp sensor
2186 Valid addresses 0x48-0x4b, default 0x48
2188 tsl4531 Select the AMS TSL4531 digital ambient light
2191 veml6070 Select the Vishay VEML6070 ultraviolet light
2194 i2c0 Choose the I2C0 bus on GPIOs 0&1
2196 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
2198 i2c3 Choose the I2C3 bus (configure with the i2c3
2199 overlay - BCM2711 only)
2201 i2c4 Choose the I2C3 bus (configure with the i2c3
2202 overlay - BCM2711 only)
2204 i2c5 Choose the I2C5 bus (configure with the i2c4
2205 overlay - BCM2711 only)
2207 i2c6 Choose the I2C6 bus (configure with the i2c6
2208 overlay - BCM2711 only)
2212 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
2213 platforms - platforms other then Compute Modules can only use this
2214 to disable transaction combining.
2215 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
2216 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
2217 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
2218 camera and display connectors. This overlay disables that mux and
2219 configures /dev/i2c0 to point at whichever set of pins is requested.
2220 dtparam=i2c_vc=on will try and enable the mux, so combining the two
2221 will cause conflicts.
2222 Load: dtoverlay=i2c0,<param>=<val>
2223 Params: pins_0_1 Use pins 0 and 1 (default)
2224 pins_28_29 Use pins 28 and 29
2225 pins_44_45 Use pins 44 and 45
2226 pins_46_47 Use pins 46 and 47
2227 combine Allow transactions to be combined (default
2232 Info: Deprecated, legacy version of i2c0.
2237 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
2238 platforms - platforms other then Compute Modules can only use this
2239 to disable transaction combining.
2240 Load: dtoverlay=i2c1,<param>=<val>
2241 Params: pins_2_3 Use pins 2 and 3 (default)
2242 pins_44_45 Use pins 44 and 45
2243 combine Allow transactions to be combined (default
2248 Info: Deprecated, legacy version of i2c1.
2253 Info: Enable the i2c3 bus. BCM2711 only.
2254 Load: dtoverlay=i2c3,<param>
2255 Params: pins_2_3 Use GPIOs 2 and 3
2256 pins_4_5 Use GPIOs 4 and 5 (default)
2257 baudrate Set the baudrate for the interface (default
2262 Info: Enable the i2c4 bus. BCM2711 only.
2263 Load: dtoverlay=i2c4,<param>
2264 Params: pins_6_7 Use GPIOs 6 and 7
2265 pins_8_9 Use GPIOs 8 and 9 (default)
2266 baudrate Set the baudrate for the interface (default
2271 Info: Enable the i2c5 bus. BCM2711 only.
2272 Load: dtoverlay=i2c5,<param>
2273 Params: pins_10_11 Use GPIOs 10 and 11
2274 pins_12_13 Use GPIOs 12 and 13 (default)
2275 baudrate Set the baudrate for the interface (default
2280 Info: Enable the i2c6 bus. BCM2711 only.
2281 Load: dtoverlay=i2c6,<param>
2282 Params: pins_0_1 Use GPIOs 0 and 1
2283 pins_22_23 Use GPIOs 22 and 23 (default)
2284 baudrate Set the baudrate for the interface (default
2289 Info: Configures any passive I2S DAC soundcard.
2290 Load: dtoverlay=i2s-dac
2295 Info: move I2S function block to GPIO 28 to 31
2296 Load: dtoverlay=i2s-gpio28-31
2301 Info: Enables I2C connected Ilitek 251x multiple touch controller using
2302 GPIO 4 (pin 7 on GPIO header) for interrupt.
2303 Load: dtoverlay=ilitek251x,<param>=<val>
2304 Params: interrupt GPIO used for interrupt (default 4)
2305 sizex Touchscreen size x, horizontal resolution of
2306 touchscreen (in pixels)
2307 sizey Touchscreen size y, vertical resolution of
2308 touchscreen (in pixels)
2312 Info: Sony IMX219 camera module.
2313 Uses Unicam 1, which is the standard camera connector on most Pi
2315 Load: dtoverlay=imx219,<param>=<val>
2316 Params: rotation Mounting rotation of the camera sensor (0 or
2318 orientation Sensor orientation (0 = front, 1 = rear,
2319 2 = external, default external)
2320 media-controller Configure use of Media Controller API for
2321 configuring the sensor (default on)
2322 cam0 Adopt the default configuration for CAM0 on a
2323 Compute Module (CSI0, i2c_vc, and cam0_reg).
2324 vcm Configure a VCM focus drive on the sensor.
2328 Info: Sony IMX258 camera module.
2329 Uses Unicam 1, which is the standard camera connector on most Pi
2331 Load: dtoverlay=imx258,<param>=<val>
2332 Params: rotation Mounting rotation of the camera sensor (0 or
2334 orientation Sensor orientation (0 = front, 1 = rear,
2335 2 = external, default external)
2336 media-controller Configure use of Media Controller API for
2337 configuring the sensor (default on)
2338 cam0 Adopt the default configuration for CAM0 on a
2339 Compute Module (CSI0, i2c_vc, and cam0_reg).
2340 vcm Configure a VCM focus drive on the sensor.
2341 4lane Enable 4 CSI2 lanes. This requires a Compute
2342 Module (1, 3, or 4).
2346 Info: Sony IMX290 camera module.
2347 Uses Unicam 1, which is the standard camera connector on most Pi
2349 Load: dtoverlay=imx290,<param>
2350 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2351 Module (1, 3, or 4).
2352 clock-frequency Sets the clock frequency to match that used on
2354 Modules from Vision Components use 37.125MHz
2355 (the default), whilst those from Innomaker use
2357 mono Denote that the module is a mono sensor.
2358 orientation Sensor orientation (0 = front, 1 = rear,
2359 2 = external, default external)
2360 rotation Mounting rotation of the camera sensor (0 or
2362 media-controller Configure use of Media Controller API for
2363 configuring the sensor (default on)
2364 cam0 Adopt the default configuration for CAM0 on a
2365 Compute Module (CSI0, i2c_vc, and cam0_reg).
2369 Info: Sony IMX296 camera module.
2370 Uses Unicam 1, which is the standard camera connector on most Pi
2372 Load: dtoverlay=imx296,<param>=<val>
2373 Params: rotation Mounting rotation of the camera sensor (0 or
2375 orientation Sensor orientation (0 = front, 1 = rear,
2376 2 = external, default external)
2377 media-controller Configure use of Media Controller API for
2378 configuring the sensor (default on)
2379 cam0 Adopt the default configuration for CAM0 on a
2380 Compute Module (CSI0, i2c_vc, and cam0_reg).
2381 clock-frequency Sets the clock frequency to match that used on
2382 the board, which should be one of 54000000
2383 (the default), 37125000 or 74250000.
2387 Info: Sony IMX327 camera module.
2388 Uses Unicam 1, which is the standard camera connector on most Pi
2390 Load: dtoverlay=imx327,<param>
2391 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2392 Module (1, 3, or 4).
2393 clock-frequency Sets the clock frequency to match that used on
2395 Modules from Vision Components use 37.125MHz
2396 (the default), whilst those from Innomaker use
2398 mono Denote that the module is a mono sensor.
2399 orientation Sensor orientation (0 = front, 1 = rear,
2400 2 = external, default external)
2401 rotation Mounting rotation of the camera sensor (0 or
2403 media-controller Configure use of Media Controller API for
2404 configuring the sensor (default on)
2405 cam0 Adopt the default configuration for CAM0 on a
2406 Compute Module (CSI0, i2c_vc, and cam0_reg).
2410 Info: Sony IMX378 camera module.
2411 Uses Unicam 1, which is the standard camera connector on most Pi
2413 Load: dtoverlay=imx378,<param>=<val>
2414 Params: rotation Mounting rotation of the camera sensor (0 or
2416 orientation Sensor orientation (0 = front, 1 = rear,
2417 2 = external, default external)
2418 media-controller Configure use of Media Controller API for
2419 configuring the sensor (default on)
2420 cam0 Adopt the default configuration for CAM0 on a
2421 Compute Module (CSI0, i2c_vc, and cam0_reg).
2425 Info: Sony IMX462 camera module.
2426 Uses Unicam 1, which is the standard camera connector on most Pi
2428 Load: dtoverlay=imx462,<param>
2429 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2430 Module (1, 3, or 4).
2431 clock-frequency Sets the clock frequency to match that used on
2433 Modules from Vision Components use 37.125MHz
2434 (the default), whilst those from Innomaker use
2436 mono Denote that the module is a mono sensor.
2437 orientation Sensor orientation (0 = front, 1 = rear,
2438 2 = external, default external)
2439 rotation Mounting rotation of the camera sensor (0 or
2441 media-controller Configure use of Media Controller API for
2442 configuring the sensor (default on)
2443 cam0 Adopt the default configuration for CAM0 on a
2444 Compute Module (CSI0, i2c_vc, and cam0_reg).
2448 Info: Sony IMX477 camera module.
2449 Uses Unicam 1, which is the standard camera connector on most Pi
2451 Load: dtoverlay=imx477,<param>=<val>
2452 Params: rotation Mounting rotation of the camera sensor (0 or
2454 orientation Sensor orientation (0 = front, 1 = rear,
2455 2 = external, default external)
2456 media-controller Configure use of Media Controller API for
2457 configuring the sensor (default on)
2458 cam0 Adopt the default configuration for CAM0 on a
2459 Compute Module (CSI0, i2c_vc, and cam0_reg).
2463 Info: Sony IMX519 camera module.
2464 Uses Unicam 1, which is the standard camera connector on most Pi
2466 Load: dtoverlay=imx519,<param>=<val>
2467 Params: rotation Mounting rotation of the camera sensor (0 or
2469 orientation Sensor orientation (0 = front, 1 = rear,
2470 2 = external, default external)
2471 media-controller Configure use of Media Controller API for
2472 configuring the sensor (default on)
2473 cam0 Adopt the default configuration for CAM0 on a
2474 Compute Module (CSI0, i2c_vc, and cam0_reg).
2475 vcm Select lens driver state. Default is enabled,
2476 but vcm=off will disable.
2480 Info: Sony IMX708 camera module.
2481 Uses Unicam 1, which is the standard camera connector on most Pi
2483 Load: dtoverlay=imx708,<param>=<val>
2484 Params: rotation Mounting rotation of the camera sensor (0 or
2486 orientation Sensor orientation (0 = front, 1 = rear,
2487 2 = external, default external)
2488 vcm Select lens driver state. Default is enabled,
2489 but vcm=off will disable.
2490 media-controller Configure use of Media Controller API for
2491 configuring the sensor (default on)
2492 cam0 Adopt the default configuration for CAM0 on a
2493 Compute Module (CSI0, i2c_vc, and cam0_reg).
2494 link-frequency Allowable link frequency values to use in Hz:
2495 450000000 (default), 447000000, 453000000.
2499 Info: Configures the IQaudio Codec audio card
2500 Load: dtoverlay=iqaudio-codec
2505 Info: Configures the IQaudio DAC audio card
2506 Load: dtoverlay=iqaudio-dac,<param>
2507 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2508 Digital volume control. Enable with
2509 "dtoverlay=iqaudio-dac,24db_digital_gain"
2510 (The default behaviour is that the Digital
2511 volume control is limited to a maximum of
2512 0dB. ie. it can attenuate but not provide
2513 gain. For most users, this will be desired
2514 as it will prevent clipping. By appending
2515 the 24db_digital_gain parameter, the Digital
2516 volume control will allow up to 24dB of
2517 gain. If this parameter is enabled, it is the
2518 responsibility of the user to ensure that
2519 the Digital volume control is set to a value
2520 that does not result in clipping/distortion!)
2523 Name: iqaudio-dacplus
2524 Info: Configures the IQaudio DAC+ audio card
2525 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2526 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2527 Digital volume control. Enable with
2528 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2529 (The default behaviour is that the Digital
2530 volume control is limited to a maximum of
2531 0dB. ie. it can attenuate but not provide
2532 gain. For most users, this will be desired
2533 as it will prevent clipping. By appending
2534 the 24db_digital_gain parameter, the Digital
2535 volume control will allow up to 24dB of
2536 gain. If this parameter is enabled, it is the
2537 responsibility of the user to ensure that
2538 the Digital volume control is set to a value
2539 that does not result in clipping/distortion!)
2540 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2541 starting/stopping audio playback.
2542 unmute_amp If specified, unmute the IQaudIO amp once when
2543 the DAC driver module loads.
2546 Name: iqaudio-digi-wm8804-audio
2547 Info: Configures the IQAudIO Digi WM8804 audio card
2548 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2549 Params: card_name Override the default, "IQAudIODigi", card name.
2550 dai_name Override the default, "IQAudIO Digi", dai name.
2551 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2556 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2557 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2558 Load: dtoverlay=iqs550,<param>=<val>
2559 Params: interrupt GPIO used for interrupt (default 4)
2560 reset GPIO used for reset (optional)
2561 sizex Touchscreen size x (default 800)
2562 sizey Touchscreen size y (default 480)
2563 invx Touchscreen inverted x axis
2564 invy Touchscreen inverted y axis
2565 swapxy Touchscreen swapped x y axis
2569 Info: Infineon irs1125 TOF camera module.
2570 Uses Unicam 1, which is the standard camera connector on most Pi
2572 Load: dtoverlay=irs1125,<param>=<val>
2573 Params: media-controller Configure use of Media Controller API for
2574 configuring the sensor (default off)
2575 cam0 Adopt the default configuration for CAM0 on a
2576 Compute Module (CSI0, i2c_vc, and cam0_reg).
2580 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2581 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2582 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2583 Params: spi<n>-<m> Enable flash device on SPI<n>, CS#<m>
2584 fastr Add fast read capability to the flash device
2585 speed Maximum SPI frequency (Hz)
2586 flash-spi<n>-<m> Same as spi<n>-<m> (deprecated)
2587 flash-fastr-spi<n>-<m> Same as spi<n>->m>,fastr (deprecated)
2591 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2593 Load: dtoverlay=justboom-both,<param>=<val>
2594 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2595 Digital volume control. Enable with
2596 "dtoverlay=justboom-dac,24db_digital_gain"
2597 (The default behaviour is that the Digital
2598 volume control is limited to a maximum of
2599 0dB. ie. it can attenuate but not provide
2600 gain. For most users, this will be desired
2601 as it will prevent clipping. By appending
2602 the 24dB_digital_gain parameter, the Digital
2603 volume control will allow up to 24dB of
2604 gain. If this parameter is enabled, it is the
2605 responsibility of the user to ensure that
2606 the Digital volume control is set to a value
2607 that does not result in clipping/distortion!)
2611 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2613 Load: dtoverlay=justboom-dac,<param>=<val>
2614 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2615 Digital volume control. Enable with
2616 "dtoverlay=justboom-dac,24db_digital_gain"
2617 (The default behaviour is that the Digital
2618 volume control is limited to a maximum of
2619 0dB. ie. it can attenuate but not provide
2620 gain. For most users, this will be desired
2621 as it will prevent clipping. By appending
2622 the 24dB_digital_gain parameter, the Digital
2623 volume control will allow up to 24dB of
2624 gain. If this parameter is enabled, it is the
2625 responsibility of the user to ensure that
2626 the Digital volume control is set to a value
2627 that does not result in clipping/distortion!)
2631 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2632 Load: dtoverlay=justboom-digi
2637 Info: This overlay has been deprecated and removed - see gpio-ir
2642 Info: Adds support for the ltc294x family of battery gauges
2643 Load: dtoverlay=ltc294x,<param>=<val>
2644 Params: ltc2941 Select the ltc2941 device
2646 ltc2942 Select the ltc2942 device
2648 ltc2943 Select the ltc2943 device
2650 ltc2944 Select the ltc2944 device
2652 resistor-sense The sense resistor value in milli-ohms.
2653 Can be a 32-bit negative value when the battery
2654 has been connected to the wrong end of the
2657 prescaler-exponent Range and accuracy of the gauge. The value is
2658 programmed into the chip only if it differs
2659 from the current setting.
2661 - Default value is 128
2662 - the exponent is in the range 0-7 (default 7)
2663 See the datasheet for more information.
2667 Info: Configures the Maxim MAX98357A I2S DAC
2668 Load: dtoverlay=max98357a,<param>=<val>
2669 Params: no-sdmode Driver does not manage the state of the DAC's
2670 SD_MODE pin (i.e. chip is always on).
2671 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2672 of the DAC (default GPIO4 if parameter omitted).
2676 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2678 For devices on spi1 or spi2, the interfaces should be enabled
2679 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2680 The overlay expects to disable the relevant spidev node, so also using
2681 e.g. cs0_spidev=off is unnecessary.
2684 MAX31855 on /dev/spidev0.0
2685 dtoverlay=maxtherm,spi0-0,max31855
2686 MAX31856 using a type J thermocouple on /dev/spidev2.1
2688 dtoverlay=maxtherm,spi2-1,max31856,type_j
2690 Load: dtoverlay=maxtherm,<param>=<val>
2691 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2693 max6675 Enable support for the MAX6675 (default)
2694 max31855 Enable support for the MAX31855
2695 max31855e Enable support for the MAX31855E
2696 max31855j Enable support for the MAX31855J
2697 max31855k Enable support for the MAX31855K
2698 max31855n Enable support for the MAX31855N
2699 max31855r Enable support for the MAX31855R
2700 max31855s Enable support for the MAX31855S
2701 max31855t Enable support for the MAX31855T
2702 max31856 Enable support for the MAX31856 (with type K)
2703 type_b Select a type B sensor for max31856
2704 type_e Select a type E sensor for max31856
2705 type_j Select a type J sensor for max31856
2706 type_k Select a type K sensor for max31856
2707 type_n Select a type N sensor for max31856
2708 type_r Select a type R sensor for max31856
2709 type_s Select a type S sensor for max31856
2710 type_t Select a type T sensor for max31856
2714 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2715 Load: dtoverlay=mbed-dac
2720 Info: Configures the MCP23017 I2C GPIO expander
2721 Load: dtoverlay=mcp23017,<param>=<val>
2722 Params: gpiopin Gpio pin connected to the INTA output of the
2723 MCP23017 (default: 4)
2725 addr I2C address of the MCP23017 (default: 0x20)
2727 mcp23008 Configure an MCP23008 instead.
2728 noints Disable the interrupt GPIO line.
2732 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2733 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2734 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2735 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2736 device must be the only one present on that SPI bus/CS#.
2737 Load: dtoverlay=mcp23s17,<param>=<val>
2738 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2739 devices present on SPI<n>, CS#<m>
2741 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2742 devices present on SPI<n>, CS#<m>
2744 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2745 MCP23S08 device on SPI<n>, CS#<m>, specifies
2746 the GPIO pin to which INT output of MCP23S08
2749 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2750 single MCP23S17 device on SPI<n>, CS#<m>,
2751 specifies the GPIO pin to which either INTA
2752 or INTB output of MCP23S17 is connected.
2756 Info: Configures the MCP2515 CAN controller on spi0/1/2
2757 For devices on spi1 or spi2, the interfaces should be enabled
2758 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2759 Load: dtoverlay=mcp2515,<param>=<val>
2760 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2763 oscillator Clock frequency for the CAN controller (Hz)
2765 speed Maximum SPI frequence (Hz)
2767 interrupt GPIO for interrupt signal
2771 Info: Configures the MCP2515 CAN controller on spi0.0
2772 Load: dtoverlay=mcp2515-can0,<param>=<val>
2773 Params: oscillator Clock frequency for the CAN controller (Hz)
2775 spimaxfrequency Maximum SPI frequence (Hz)
2777 interrupt GPIO for interrupt signal
2781 Info: Configures the MCP2515 CAN controller on spi0.1
2782 Load: dtoverlay=mcp2515-can1,<param>=<val>
2783 Params: oscillator Clock frequency for the CAN controller (Hz)
2785 spimaxfrequency Maximum SPI frequence (Hz)
2787 interrupt GPIO for interrupt signal
2791 Info: Configures the MCP251XFD CAN controller family
2792 For devices on spi1 or spi2, the interfaces should be enabled
2793 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2794 Load: dtoverlay=mcp251xfd,<param>=<val>
2795 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2798 oscillator Clock frequency for the CAN controller (Hz)
2800 speed Maximum SPI frequence (Hz)
2802 interrupt GPIO for interrupt signal
2804 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2806 xceiver_enable GPIO for CAN transceiver enable (optional)
2808 xceiver_active_high specifiy if CAN transceiver enable pin is
2809 active high (optional, default: active low)
2813 Info: Configures MCP3008 A/D converters
2814 For devices on spi1 or spi2, the interfaces should be enabled
2815 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2816 Load: dtoverlay=mcp3008,<param>[=<val>]
2817 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2818 spi<n>-<m>-speed integer, set the spi bus speed for this device
2822 Info: Configures MCP3202 A/D converters
2823 For devices on spi1 or spi2, the interfaces should be enabled
2824 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2825 Load: dtoverlay=mcp3202,<param>[=<val>]
2826 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2827 spi<n>-<m>-speed integer, set the spi bus speed for this device
2831 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2832 Load: dtoverlay=mcp342x,<param>=<val>
2833 Params: addr I2C bus address of device, for devices with
2834 addresses that are configurable, e.g. by
2835 hardware links (default=0x68)
2836 mcp3421 The device is an MCP3421
2837 mcp3422 The device is an MCP3422
2838 mcp3423 The device is an MCP3423
2839 mcp3424 The device is an MCP3424
2840 mcp3425 The device is an MCP3425
2841 mcp3426 The device is an MCP3426
2842 mcp3427 The device is an MCP3427
2843 mcp3428 The device is an MCP3428
2847 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2848 Load: dtoverlay=media-center,<param>=<val>
2849 Params: speed Display SPI bus speed
2850 rotate Display rotation {0,90,180,270}
2851 fps Delay between frame updates
2852 xohms Touchpanel sensitivity (X-plate resistance)
2853 swapxy Swap x and y axis
2854 backlight Change backlight GPIO pin {e.g. 12, 18}
2855 debug "on" = enable additional debug messages
2860 Info: Configures the merus-amp audio card
2861 Load: dtoverlay=merus-amp
2866 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2867 31.25kbaud, the frequency required for MIDI
2868 Load: dtoverlay=midi-uart0
2873 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2874 31.25kbaud, the frequency required for MIDI
2875 Load: dtoverlay=midi-uart1
2880 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2881 31.25kbaud, the frequency required for MIDI
2882 Load: dtoverlay=midi-uart2
2887 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2888 31.25kbaud, the frequency required for MIDI
2889 Load: dtoverlay=midi-uart3
2894 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2895 31.25kbaud, the frequency required for MIDI
2896 Load: dtoverlay=midi-uart4
2901 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2902 31.25kbaud, the frequency required for MIDI
2903 Load: dtoverlay=midi-uart5
2908 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2909 Load: dtoverlay=minipitft13,<param>=<val>
2910 Params: speed SPI bus speed (default 32000000)
2911 rotate Display rotation (0, 90, 180 or 270; default 0)
2912 width Display width (default 240)
2913 height Display height (default 240)
2914 fps Delay between frame updates (default 25)
2915 debug Debug output level (0-7; default 0)
2919 Info: Switch the onboard Bluetooth function of a BT-equipped Raspberry Pi
2920 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2921 15. Note that this option uses a lower baudrate, and should only be used
2922 with low-bandwidth peripherals.
2923 Load: dtoverlay=miniuart-bt,<param>=<val>
2924 Params: krnbt Set to "off" to disable autoprobing of Bluetooth
2925 driver without need of hciattach/btattach
2929 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2930 driver. The driver will load a file /lib/firmware/panel.bin containing
2931 the initialisation commands.
2934 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2935 dtparam=width=320,height=240
2936 dtparam=reset-gpio=23,dc-gpio=24
2937 dtparam=backlight-gpio=18
2939 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2940 and init commands at 10MHz. This makes it possible to push the envelope
2941 without messing up the controller configuration due to command
2942 transmission errors.
2944 For devices on spi1 or spi2, the interfaces should be enabled
2945 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2947 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2949 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2951 compatible Set the compatible string to load a different
2952 firmware file. Both the panel compatible value
2953 used to load the firmware file and the value
2954 used to load the driver has to be set having a
2955 NUL (\0) separator between them.
2957 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2958 spi<n>-<m> Configure device at spi<n>, cs<m>
2960 speed SPI bus speed in Hz (default 32000000)
2961 cpha Shifted SPI clock phase (CPHA) mode
2962 cpol Inverse SPI clock polarity (CPOL) mode
2963 write-only Controller is not readable
2964 (ie. MISO is not wired up).
2966 width Panel width in pixels (required)
2967 height Panel height in pixels (required)
2968 width-mm Panel width in mm
2969 height-mm Panel height in mm
2970 x-offset Panel x-offset in controller RAM
2971 y-offset Panel y-offset in controller RAM
2973 clock-frequency Panel clock frequency in Hz
2974 (optional, just informational).
2976 reset-gpio GPIO pin to be used for RESET
2977 dc-gpio GPIO pin to be used for D/C
2979 backlight-gpio GPIO pin to be used for backlight control
2981 backlight-pwm PWM channel to be used for backlight control
2982 (default of none). NB Disables audio headphone
2983 output as that also uses PWM.
2984 backlight-pwm-chan Choose channel on &pwm node for backlight
2985 control (default 0).
2986 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2987 pwm-2chan for valid options (default 18).
2988 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2989 See pwm-2chan for valid options (default 2).
2990 backlight-def-brightness
2991 Set the default brightness. Normal range 1-16.
2996 Info: Overlay for i2c connected mlx90640 thermal camera
2997 Load: dtoverlay=mlx90640
3002 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
3003 Load: dtoverlay=mmc,<param>=<val>
3004 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3009 Info: This overlay has been deprecated - use "dtoverlay=i2c-sensor,mpu6050"
3010 instead. Note that "int_pin" is the new name for the "interrupt"
3016 Info: MZ61581 display by Tontec
3017 Load: dtoverlay=mz61581,<param>=<val>
3018 Params: speed Display SPI bus speed
3020 rotate Display rotation {0,90,180,270}
3022 fps Delay between frame updates
3024 txbuflen Transmit buffer length (default 32768)
3026 debug Debug output level {0-7}
3028 xohms Touchpanel sensitivity (X-plate resistance)
3032 Info: Omnivision OV2311 camera module.
3033 Uses Unicam 1, which is the standard camera connector on most Pi
3035 Load: dtoverlay=ov2311,<param>=<val>
3036 Params: rotation Mounting rotation of the camera sensor (0 or
3038 orientation Sensor orientation (0 = front, 1 = rear,
3039 2 = external, default external)
3040 media-controller Configure use of Media Controller API for
3041 configuring the sensor (default on)
3042 cam0 Adopt the default configuration for CAM0 on a
3043 Compute Module (CSI0, i2c_vc, and cam0_reg).
3047 Info: Omnivision OV5647 camera module.
3048 Uses Unicam 1, which is the standard camera connector on most Pi
3050 Load: dtoverlay=ov5647,<param>=<val>
3051 Params: rotation Mounting rotation of the camera sensor (0 or
3053 orientation Sensor orientation (0 = front, 1 = rear,
3054 2 = external, default external)
3055 media-controller Configure use of Media Controller API for
3056 configuring the sensor (default on)
3057 cam0 Adopt the default configuration for CAM0 on a
3058 Compute Module (CSI0, i2c_vc, and cam0_reg).
3059 vcm Configure a VCM focus drive on the sensor.
3063 Info: Omnivision OV7251 camera module.
3064 Uses Unicam 1, which is the standard camera connector on most Pi
3066 Load: dtoverlay=ov7251,<param>=<val>
3067 Params: rotation Mounting rotation of the camera sensor (0 or
3069 orientation Sensor orientation (0 = front, 1 = rear,
3070 2 = external, default external)
3071 media-controller Configure use of Media Controller API for
3072 configuring the sensor (default off)
3073 cam0 Adopt the default configuration for CAM0 on a
3074 Compute Module (CSI0, i2c_vc, and cam0_reg).
3078 Info: Omnivision OV9281 camera module.
3079 Uses Unicam 1, which is the standard camera connector on most Pi
3081 Load: dtoverlay=ov9281,<param>=<val>
3082 Params: rotation Mounting rotation of the camera sensor (0 or
3084 orientation Sensor orientation (0 = front, 1 = rear,
3085 2 = external, default external)
3086 media-controller Configure use of Media Controller API for
3087 configuring the sensor (default on)
3088 cam0 Adopt the default configuration for CAM0 on a
3089 Compute Module (CSI0, i2c_vc, and cam0_reg).
3093 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
3094 Load: dtoverlay=papirus,<param>=<val>
3095 Params: panel Display panel (required):
3100 speed Display SPI bus speed
3104 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
3105 Load: dtoverlay=pca953x,<param>=<val>
3106 Params: addr I2C address of expander. Default 0x20.
3107 pca6416 Select the NXP PCA6416 (16 bit)
3108 pca9505 Select the NXP PCA9505 (40 bit)
3109 pca9535 Select the NXP PCA9535 (16 bit)
3110 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
3111 pca9537 Select the NXP PCA9537 (4 bit)
3112 pca9538 Select the NXP PCA9538 (8 bit)
3113 pca9539 Select the NXP PCA9539 (16 bit)
3114 pca9554 Select the NXP PCA9554 (8 bit)
3115 pca9555 Select the NXP PCA9555 (16 bit)
3116 pca9556 Select the NXP PCA9556 (8 bit)
3117 pca9557 Select the NXP PCA9557 (8 bit)
3118 pca9574 Select the NXP PCA9574 (8 bit)
3119 pca9575 Select the NXP PCA9575 (16 bit)
3120 pca9698 Select the NXP PCA9698 (40 bit)
3121 pcal6416 Select the NXP PCAL6416 (16 bit)
3122 pcal6524 Select the NXP PCAL6524 (24 bit)
3123 pcal9555a Select the NXP PCAL9555A (16 bit)
3124 max7310 Select the Maxim MAX7310 (8 bit)
3125 max7312 Select the Maxim MAX7312 (16 bit)
3126 max7313 Select the Maxim MAX7313 (16 bit)
3127 max7315 Select the Maxim MAX7315 (8 bit)
3128 pca6107 Select the TI PCA6107 (8 bit)
3129 tca6408 Select the TI TCA6408 (8 bit)
3130 tca6416 Select the TI TCA6416 (16 bit)
3131 tca6424 Select the TI TCA6424 (24 bit)
3132 tca9539 Select the TI TCA9539 (16 bit)
3133 tca9554 Select the TI TCA9554 (8 bit)
3134 cat9554 Select the Onnn CAT9554 (8 bit)
3135 pca9654 Select the Onnn PCA9654 (8 bit)
3136 xra1202 Select the Exar XRA1202 (8 bit)
3140 Info: NXP PCF857x family of I2C GPIO expanders.
3141 Load: dtoverlay=pcf857x,<param>=<val>
3142 Params: addr I2C address of expander. Default
3143 depends on model selected.
3144 pcf8574 Select the NXP PCF8574 (8 bit)
3145 pcf8574a Select the NXP PCF8574A (8 bit)
3146 pcf8575 Select the NXP PCF8575 (16 bit)
3147 pca8574 Select the NXP PCA8574 (8 bit)
3150 Name: pcie-32bit-dma
3151 Info: Force PCIe config to support 32bit DMA addresses at the expense of
3152 having to bounce buffers.
3153 Load: dtoverlay=pcie-32bit-dma
3157 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
3160 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
3163 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
3167 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
3168 for backwards compatibility.
3172 Name: pi3-disable-bt
3173 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
3174 alias for backwards compatibility.
3178 Name: pi3-disable-wifi
3179 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
3180 an alias for backwards compatibility.
3184 Name: pi3-miniuart-bt
3185 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
3186 an alias for backwards compatibility.
3191 Info: Configures the pibell audio card.
3192 Load: dtoverlay=pibell,<param>=<val>
3193 Params: alsaname Set the name as it appears in ALSA (default
3198 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
3199 Load: dtoverlay=pifacedigital,<param>=<val>
3200 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
3201 CS0 address. PiFace Digital supports addresses
3202 0-3, which can be configured with JP1 and JP2.
3206 Info: Configures the PiFi 40W stereo amplifier
3207 Load: dtoverlay=pifi-40
3212 Info: Configures the PiFi DAC HD
3213 Load: dtoverlay=pifi-dac-hd
3218 Info: Configures the PiFi DAC Zero
3219 Load: dtoverlay=pifi-dac-zero
3224 Info: Configures the PiFi Mini stereo amplifier
3225 Load: dtoverlay=pifi-mini-210
3230 Info: Configures the PiGlow by pimoroni.com
3231 Load: dtoverlay=piglow
3236 Info: PiScreen display by OzzMaker.com
3237 Load: dtoverlay=piscreen,<param>=<val>
3238 Params: speed Display SPI bus speed
3240 rotate Display rotation {0,90,180,270}
3242 fps Delay between frame updates
3244 debug Debug output level {0-7}
3246 xohms Touchpanel sensitivity (X-plate resistance)
3248 drm Select the DRM/KMS driver instead of the FBTFT
3253 Info: PiScreen 2 with resistive TP display by OzzMaker.com
3254 Load: dtoverlay=piscreen2r,<param>=<val>
3255 Params: speed Display SPI bus speed
3257 rotate Display rotation {0,90,180,270}
3259 fps Delay between frame updates
3261 debug Debug output level {0-7}
3263 xohms Touchpanel sensitivity (X-plate resistance)
3267 Info: Configures the Blokas Labs pisound card
3268 Load: dtoverlay=pisound
3273 Info: Adafruit PiTFT 2.2" screen
3274 Load: dtoverlay=pitft22,<param>=<val>
3275 Params: speed Display SPI bus speed
3277 rotate Display rotation {0,90,180,270}
3279 fps Delay between frame updates
3281 debug Debug output level {0-7}
3284 Name: pitft28-capacitive
3285 Info: Adafruit PiTFT 2.8" capacitive touch screen
3286 Load: dtoverlay=pitft28-capacitive,<param>=<val>
3287 Params: speed Display SPI bus speed
3289 rotate Display rotation {0,90,180,270}
3291 fps Delay between frame updates
3293 debug Debug output level {0-7}
3295 touch-sizex Touchscreen size x (default 240)
3297 touch-sizey Touchscreen size y (default 320)
3299 touch-invx Touchscreen inverted x axis
3301 touch-invy Touchscreen inverted y axis
3303 touch-swapxy Touchscreen swapped x y axis
3306 Name: pitft28-resistive
3307 Info: Adafruit PiTFT 2.8" resistive touch screen
3308 Load: dtoverlay=pitft28-resistive,<param>=<val>
3309 Params: speed Display SPI bus speed
3311 rotate Display rotation {0,90,180,270}
3313 fps Delay between frame updates
3315 debug Debug output level {0-7}
3317 drm Force the use of the mi0283qt DRM driver (by
3318 default the ili9340 framebuffer driver will
3319 be used in preference if available)
3322 Name: pitft35-resistive
3323 Info: Adafruit PiTFT 3.5" resistive touch screen
3324 Load: dtoverlay=pitft35-resistive,<param>=<val>
3325 Params: speed Display SPI bus speed
3327 rotate Display rotation {0,90,180,270}
3329 fps Delay between frame updates
3331 debug Debug output level {0-7}
3333 drm Force the use of the hx8357d DRM driver (by
3334 default the fb_hx8357d framebuffer driver will
3335 be used in preference if available)
3339 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
3340 Load: dtoverlay=pps-gpio,<param>=<val>
3341 Params: gpiopin Input GPIO (default "18")
3342 assert_falling_edge When present, assert is indicated by a falling
3343 edge, rather than by a rising edge (default
3345 capture_clear Generate clear events on the trailing edge
3347 pull Desired pull-up/down state (off, down, up)
3352 Info: Configures the PROTO Audio Codec card
3353 Load: dtoverlay=proto-codec
3358 Info: Configures a single PWM channel
3359 Legal pin,function combinations for each channel:
3360 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3361 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3363 1) Pin 18 is the only one available on all platforms, and
3364 it is the one used by the I2S audio interface.
3365 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3366 2) The onboard analogue audio output uses both PWM channels.
3367 3) So be careful mixing audio and PWM.
3368 4) Currently the clock must have been enabled and configured
3370 Load: dtoverlay=pwm,<param>=<val>
3371 Params: pin Output pin (default 18) - see table
3372 func Pin function (default 2 = Alt5) - see above
3373 clock PWM clock frequency (informational)
3377 Info: Configures both PWM channels
3378 Legal pin,function combinations for each channel:
3379 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3380 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3382 1) Pin 18 is the only one available on all platforms, and
3383 it is the one used by the I2S audio interface.
3384 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3385 2) The onboard analogue audio output uses both PWM channels.
3386 3) So be careful mixing audio and PWM.
3387 4) Currently the clock must have been enabled and configured
3389 Load: dtoverlay=pwm-2chan,<param>=<val>
3390 Params: pin Output pin (default 18) - see table
3391 pin2 Output pin for other channel (default 19)
3392 func Pin function (default 2 = Alt5) - see above
3393 func2 Function for pin2 (default 2 = Alt5)
3394 clock PWM clock frequency (informational)
3398 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
3399 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
3400 of PWM0 to reduce the CPU load during transmission compared to
3401 gpio-ir-tx which uses bit-banging.
3402 Legal pin,function combinations are:
3403 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3404 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3405 Params: gpio_pin Output GPIO (default 18)
3407 func Pin function (default 2 = Alt5)
3411 Info: Configures one or two PWM channel on PWM1 (BCM2711 only)
3413 1) The onboard analogue audio output uses both PWM channels.
3414 2) So be careful mixing audio and PWM.
3415 Note that even when only one pin is enabled, both channels are available
3416 from the PWM driver, so be careful to use the correct one.
3417 Load: dtoverlay=pwm1,<param>=<val>
3418 Params: clock PWM clock frequency (informational)
3419 pins_40 Enable channel 0 (PWM1_0) on GPIO 40
3420 pins_41 Enable channel 1 (PWM1_1) on GPIO 41
3421 pins_40_41 Enable channels 0 (PWM1_0) and 1 (PW1_1) on
3422 GPIOs 40 and 41 (default)
3423 pull_up Enable pull-ups on the PWM pins (default)
3424 pull_down Enable pull-downs on the PWM pins
3425 pull_off Disable pulls on the PWM pins
3429 Info: in-tech's Evaluation Board for PLC Stamp micro
3430 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3431 Load: dtoverlay=qca7000,<param>=<val>
3432 Params: int_pin GPIO pin for interrupt signal (default 23)
3434 speed SPI bus speed (default 12 MHz)
3438 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3439 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3440 But it requires disabling of onboard Bluetooth on
3441 Pi 3B, 3B+, 3A+, 4B and Zero W.
3442 Load: dtoverlay=qca7000-uart0,<param>=<val>
3443 Params: baudrate Set the baudrate for the UART (default
3448 Info: Enable the preservation of crash logs across a reboot. With
3449 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3450 are moved to /var/lib/systemd/pstore/ on reboot.
3451 Load: dtoverlay=ramoops,<param>=<val>
3452 Params: base-addr Where to place the capture buffer (default
3454 total-size How much memory to allocate altogether (in
3455 bytes - default 64kB)
3456 record-size How much space to use for each capture, i.e.
3457 total-size / record-size = number of captures
3459 console-size Size of non-panic dmesg captures (default 0)
3463 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3464 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3465 Load: dtoverlay=ramoops-pi4,<param>=<val>
3466 Params: base-addr Where to place the capture buffer (default
3468 total-size How much memory to allocate altogether (in
3469 bytes - default 64kB)
3470 record-size How much space to use for each capture, i.e.
3471 total-size / record-size = number of captures
3473 console-size Size of non-panic dmesg captures (default 0)
3476 Name: rotary-encoder
3477 Info: Overlay for GPIO connected rotary encoder.
3478 Load: dtoverlay=rotary-encoder,<param>=<val>
3479 Params: pin_a GPIO connected to rotary encoder channel A
3481 pin_b GPIO connected to rotary encoder channel B
3483 relative_axis register a relative axis rather than an
3484 absolute one. Relative axis will only
3485 generate +1/-1 events on the input device,
3486 hence no steps need to be passed.
3487 linux_axis the input subsystem axis to map to this
3488 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3489 rollover Automatic rollover when the rotary value
3490 becomes greater than the specified steps or
3491 smaller than 0. For absolute axis only.
3492 steps-per-period Number of steps (stable states) per period.
3493 The values have the following meaning:
3494 1: Full-period mode (default)
3496 4: Quarter-period mode
3497 steps Number of steps in a full turnaround of the
3498 encoder. Only relevant for absolute axis.
3499 Defaults to 24 which is a typical value for
3501 wakeup Boolean, rotary encoder can wake up the
3503 encoding String, the method used to encode steps.
3504 Supported are "gray" (the default and more
3505 common) and "binary".
3509 Info: Raspberry Pi official display backlight driver
3510 Load: dtoverlay=rpi-backlight
3514 Name: rpi-cirrus-wm5102
3515 Info: This overlay has been renamed to cirrus-wm5102
3520 Info: Configures the Raspberry Pi Codec Zero sound card
3521 Load: dtoverlay=rpi-codeczero
3526 Info: This overlay has been renamed to i2s-dac.
3531 Info: Configures the Raspberry Pi DAC+ card
3532 Load: dtoverlay=rpi-dacplus,<param>=<val>
3533 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3534 digital volume control. Enable by adding
3535 "dtparam=24db_digital_gain" to config.txt
3536 before any "dtoverlay" lines.
3537 The default behaviour is that the digital
3538 volume control is limited to a maximum of
3539 0dB. ie. it can attenuate but not provide
3540 gain. For most users, this will be desired
3541 as it will prevent clipping. By appending
3542 the 24db_digital_gain parameter, the digital
3543 volume control will allow up to 24dB of
3544 gain. If this parameter is enabled, it is the
3545 responsibility of the user to ensure that
3546 the digital volume control is set to a value
3547 that does not result in clipping/distortion!
3551 Info: Configures the Raspberry Pi DAC Pro sound card
3552 Load: dtoverlay=rpi-dacpro,<param>=<val>
3553 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3554 digital volume control. Enable by adding
3555 "dtparam=24db_digital_gain" to config.txt
3556 before any "dtoverlay" lines.
3557 The default behaviour is that the digital
3558 volume control is limited to a maximum of
3559 0dB. ie. it can attenuate but not provide
3560 gain. For most users, this will be desired
3561 as it will prevent clipping. By appending
3562 the 24db_digital_gain parameter, the digital
3563 volume control will allow up to 24dB of
3564 gain. If this parameter is enabled, it is the
3565 responsibility of the user to ensure that
3566 the digital volume control is set to a value
3567 that does not result in clipping/distortion!
3570 Name: rpi-digiampplus
3571 Info: Configures the Raspberry Pi DigiAMP+ sound card
3572 Load: dtoverlay=rpi-digiampplus,<param>=<val>
3573 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3574 digital volume control. Enable by adding
3575 "dtparam=24db_digital_gain" to config.txt
3576 before any "dtoverlay" lines.
3577 The default behaviour is that the digital
3578 volume control is limited to a maximum of
3579 0dB. ie. it can attenuate but not provide
3580 gain. For most users, this will be desired
3581 as it will prevent clipping. By appending
3582 the 24db_digital_gain parameter, the digital
3583 volume control will allow up to 24dB of
3584 gain. If this parameter is enabled, it is the
3585 responsibility of the user to ensure that
3586 the digital volume control is set to a value
3587 that does not result in clipping/distortion!
3588 auto_mute_amp If specified, unmute/mute the DigiAMP+ when
3589 starting/stopping audio playback (default "on").
3590 unmute_amp If specified, unmute the DigiAMP+ amp once when
3591 the DAC driver module loads (default "off").
3595 Info: This overlay has been renamed to watterott-display
3600 Info: Official Raspberry Pi display touchscreen
3601 Load: dtoverlay=rpi-ft5406,<param>=<val>
3602 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3603 touchscreen-size-y Touchscreen Y resolution (default 600);
3604 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3605 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3606 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3610 Info: Raspberry Pi PoE HAT fan
3611 Load: dtoverlay=rpi-poe,<param>[=<val>]
3612 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3613 turns on (default 40000)
3614 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3615 the fan turns off (default 2000)
3616 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3617 speeds up (default 45000)
3618 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3619 the fan slows down (default 2000)
3620 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3621 speeds up (default 50000)
3622 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3623 the fan slows down (default 2000)
3624 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3625 speeds up (default 55000)
3626 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3627 the fan slows down (default 5000)
3628 i2c Control the fan via Linux I2C drivers instead of
3633 Info: Raspberry Pi PoE+ HAT fan
3634 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3635 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3636 turns on (default 40000)
3637 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3638 the fan turns off (default 2000)
3639 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3640 speeds up (default 45000)
3641 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3642 the fan slows down (default 2000)
3643 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3644 speeds up (default 50000)
3645 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3646 the fan slows down (default 2000)
3647 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3648 speeds up (default 55000)
3649 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3650 the fan slows down (default 5000)
3651 i2c Control the fan via Linux I2C drivers instead of
3656 Info: This overlay has been renamed to proto-codec.
3661 Info: Raspberry Pi Sense HAT
3662 Load: dtoverlay=rpi-sense
3667 Info: Raspberry Pi Sense HAT v2
3668 Load: dtoverlay=rpi-sense-v2
3673 Info: Raspberry Pi TV HAT
3674 Load: dtoverlay=rpi-tv
3679 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3680 video decoder driver is enabled by default.
3684 Name: rra-digidac1-wm8741-audio
3685 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3686 Load: dtoverlay=rra-digidac1-wm8741-audio
3691 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3693 Load: dtoverlay=sainsmart18,<param>=<val>
3694 Params: rotate Display rotation {0,90,180,270}
3695 speed SPI bus speed in Hz (default 4000000)
3696 fps Display frame rate in Hz
3697 bgr Enable BGR mode (default off)
3698 debug Debug output level {0-7}
3699 dc_pin GPIO pin for D/C (default 24)
3700 reset_pin GPIO pin for RESET (default 25)
3704 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3705 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3706 select another address, please refer to table 10 in reference manual.
3707 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3708 Params: int_pin GPIO used for IRQ (default 24)
3709 addr Address (default 0x48)
3710 xtal On-board crystal frequency (default 14745600)
3714 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3715 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3716 select another address, please refer to table 10 in reference manual.
3717 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3718 Params: int_pin GPIO used for IRQ (default 24)
3719 addr Address (default 0x48)
3720 xtal On-board crystal frequency (default 14745600)
3723 Name: sc16is752-spi0
3724 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3725 Enables the chip on SPI0.
3726 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3727 Params: int_pin GPIO used for IRQ (default 24)
3728 xtal On-board crystal frequency (default 14745600)
3731 Name: sc16is752-spi1
3732 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3733 Enables the chip on SPI1.
3734 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3735 A+, B+, Zero and PI2 B; as well as the Compute Module.
3737 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3738 Params: int_pin GPIO used for IRQ (default 24)
3739 xtal On-board crystal frequency (default 14745600)
3743 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3744 N.B. This overlay is designed for situations where the mmc driver is
3745 the default, so it disables the other (mmc) interface - this will kill
3746 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3747 overlay or the new sd_* dtparams of the base DTBs.
3748 Load: dtoverlay=sdhost,<param>=<val>
3749 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3752 force_pio Disable DMA support (default off)
3754 pio_limit Number of blocks above which to use DMA
3757 debug Enable debug output (default off)
3761 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3762 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3763 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3764 Load: dtoverlay=sdio,<param>=<val>
3765 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3766 framework requests 50MHz
3768 poll_once Disable SDIO-device polling every second
3769 (default on: polling once at boot-time)
3771 bus_width Set the SDIO host bus width (default 4 bits)
3773 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3774 with bus_width=1. This replaces the sdio-1bit
3775 overlay, which is now deprecated.
3777 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3780 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3781 with bus_width=4 (the default).
3785 Info: This overlay is now deprecated. Use
3786 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3791 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3792 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3793 "dtparam=sd_poll_once".
3797 Name: seeed-can-fd-hat-v1
3798 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3799 channels without RTC. Use this overlay if your HAT has no
3801 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3802 Load: dtoverlay=seeed-can-fd-hat-v1
3806 Name: seeed-can-fd-hat-v2
3807 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3808 channels and an RTC. Use this overlay if your HAT has a
3810 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3811 Load: dtoverlay=seeed-can-fd-hat-v2
3816 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3817 Load: dtoverlay=sh1106-spi,<param>=<val>
3818 Params: speed SPI bus speed (default 4000000)
3819 rotate Display rotation (0, 90, 180 or 270; default 0)
3820 fps Delay between frame updates (default 25)
3821 debug Debug output level (0-7; default 0)
3822 dc_pin GPIO pin for D/C (default 24)
3823 reset_pin GPIO pin for RESET (default 25)
3824 height Display height (32 or 64; default 64)
3828 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3829 The driver is currently out-of-tree at
3830 https://github.com/sunipkmukherjee/silabs.git
3831 Load: dtoverlay=si446x-spi0,<param>=<val>
3832 Params: speed SPI bus speed (default 4000000)
3833 int_pin GPIO pin for interrupts (default 17)
3834 reset_pin GPIO pin for RESET (default 27)
3838 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3844 Info: Enables the userspace interface for the SMI driver
3845 Load: dtoverlay=smi-dev
3850 Info: Enables access to NAND flash via the SMI interface
3851 Load: dtoverlay=smi-nand
3856 Info: Move SPI function block to GPIO 35 to 39
3857 Load: dtoverlay=spi-gpio35-39
3862 Info: Move SPI function block to GPIOs 40 to 45
3863 Load: dtoverlay=spi-gpio40-45
3868 Info: Adds support for a number of SPI Real Time Clock devices
3869 Load: dtoverlay=spi-rtc,<param>=<val>
3870 Params: ds3232 Select the DS3232 device
3871 ds3234 Select the DS3234 device
3872 pcf2123 Select the PCF2123 device
3874 spi0_0 Use spi0.0 (default)
3880 cs_high This device requires an active-high CS
3884 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3885 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3886 Load: dtoverlay=spi0-0cs,<param>=<val>
3887 Params: no_miso Don't claim and use the MISO pin (9), freeing
3892 Info: Only use one CS pin for SPI0
3893 Load: dtoverlay=spi0-1cs,<param>=<val>
3894 Params: cs0_pin GPIO pin for CS0 (default 8)
3895 no_miso Don't claim and use the MISO pin (9), freeing
3900 Info: Change the CS pins for SPI0
3901 Load: dtoverlay=spi0-2cs,<param>=<val>
3902 Params: cs0_pin GPIO pin for CS0 (default 8)
3903 cs1_pin GPIO pin for CS1 (default 7)
3904 no_miso Don't claim and use the MISO pin (9), freeing
3909 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3910 alias for backwards compatibility.
3915 Info: This overlay has been deprecated and removed because it is no longer
3916 necessary and has been seen to prevent spi0 from working.
3921 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3922 dev node. The gpio pin number for the CS line and spidev device node
3923 creation are configurable.
3924 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3925 A+, B+, Zero and PI2 B; as well as the Compute Module.
3926 Load: dtoverlay=spi1-1cs,<param>=<val>
3927 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3928 cs0_spidev Set to 'disabled' to stop the creation of a
3929 userspace device node /dev/spidev1.0 (default
3930 is 'okay' or enabled).
3934 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3935 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3936 creation are configurable.
3937 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3938 A+, B+, Zero and PI2 B; as well as the Compute Module.
3939 Load: dtoverlay=spi1-2cs,<param>=<val>
3940 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3941 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3942 cs0_spidev Set to 'disabled' to stop the creation of a
3943 userspace device node /dev/spidev1.0 (default
3944 is 'okay' or enabled).
3945 cs1_spidev Set to 'disabled' to stop the creation of a
3946 userspace device node /dev/spidev1.1 (default
3947 is 'okay' or enabled).
3951 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3952 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3953 creation are configurable.
3954 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3955 A+, B+, Zero and PI2 B; as well as the Compute Module.
3956 Load: dtoverlay=spi1-3cs,<param>=<val>
3957 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3958 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3959 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3960 cs0_spidev Set to 'disabled' to stop the creation of a
3961 userspace device node /dev/spidev1.0 (default
3962 is 'okay' or enabled).
3963 cs1_spidev Set to 'disabled' to stop the creation of a
3964 userspace device node /dev/spidev1.1 (default
3965 is 'okay' or enabled).
3966 cs2_spidev Set to 'disabled' to stop the creation of a
3967 userspace device node /dev/spidev1.2 (default
3968 is 'okay' or enabled).
3972 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3973 dev node. The gpio pin number for the CS line and spidev device node
3974 creation are configurable.
3975 N.B.: spi2 is only accessible with the Compute Module.
3976 Load: dtoverlay=spi2-1cs,<param>=<val>
3977 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3978 cs0_spidev Set to 'disabled' to stop the creation of a
3979 userspace device node /dev/spidev2.0 (default
3980 is 'okay' or enabled).
3984 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3985 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3986 creation are configurable.
3987 N.B.: spi2 is only accessible with the Compute Module.
3988 Load: dtoverlay=spi2-2cs,<param>=<val>
3989 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3990 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3991 cs0_spidev Set to 'disabled' to stop the creation of a
3992 userspace device node /dev/spidev2.0 (default
3993 is 'okay' or enabled).
3994 cs1_spidev Set to 'disabled' to stop the creation of a
3995 userspace device node /dev/spidev2.1 (default
3996 is 'okay' or enabled).
4000 Info: Enables spi2 with three chip select (CS) lines and associated spidev
4001 dev nodes. The gpio pin numbers for the CS lines and spidev device node
4002 creation are configurable.
4003 N.B.: spi2 is only accessible with the Compute Module.
4004 Load: dtoverlay=spi2-3cs,<param>=<val>
4005 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
4006 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
4007 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
4008 cs0_spidev Set to 'disabled' to stop the creation of a
4009 userspace device node /dev/spidev2.0 (default
4010 is 'okay' or enabled).
4011 cs1_spidev Set to 'disabled' to stop the creation of a
4012 userspace device node /dev/spidev2.1 (default
4013 is 'okay' or enabled).
4014 cs2_spidev Set to 'disabled' to stop the creation of a
4015 userspace device node /dev/spidev2.2 (default
4016 is 'okay' or enabled).
4020 Info: Enables spi3 with a single chip select (CS) line and associated spidev
4021 dev node. The gpio pin number for the CS line and spidev device node
4022 creation are configurable. BCM2711 only.
4023 Load: dtoverlay=spi3-1cs,<param>=<val>
4024 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
4025 cs0_spidev Set to 'off' to prevent the creation of a
4026 userspace device node /dev/spidev3.0 (default
4027 is 'on' or enabled).
4031 Info: Enables spi3 with two chip select (CS) lines and associated spidev
4032 dev nodes. The gpio pin numbers for the CS lines and spidev device node
4033 creation are configurable. BCM2711 only.
4034 Load: dtoverlay=spi3-2cs,<param>=<val>
4035 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
4036 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
4037 cs0_spidev Set to 'off' to prevent the creation of a
4038 userspace device node /dev/spidev3.0 (default
4039 is 'on' or enabled).
4040 cs1_spidev Set to 'off' to prevent the creation of a
4041 userspace device node /dev/spidev3.1 (default
4042 is 'on' or enabled).
4046 Info: Enables spi4 with a single chip select (CS) line and associated spidev
4047 dev node. The gpio pin number for the CS line and spidev device node
4048 creation are configurable. BCM2711 only.
4049 Load: dtoverlay=spi4-1cs,<param>=<val>
4050 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
4051 cs0_spidev Set to 'off' to prevent the creation of a
4052 userspace device node /dev/spidev4.0 (default
4053 is 'on' or enabled).
4057 Info: Enables spi4 with two chip select (CS) lines and associated spidev
4058 dev nodes. The gpio pin numbers for the CS lines and spidev device node
4059 creation are configurable. BCM2711 only.
4060 Load: dtoverlay=spi4-2cs,<param>=<val>
4061 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
4062 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
4063 cs0_spidev Set to 'off' to prevent the creation of a
4064 userspace device node /dev/spidev4.0 (default
4065 is 'on' or enabled).
4066 cs1_spidev Set to 'off' to prevent the creation of a
4067 userspace device node /dev/spidev4.1 (default
4068 is 'on' or enabled).
4072 Info: Enables spi5 with a single chip select (CS) line and associated spidev
4073 dev node. The gpio pin numbers for the CS lines and spidev device node
4074 creation are configurable. BCM2711 only.
4075 Load: dtoverlay=spi5-1cs,<param>=<val>
4076 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
4077 cs0_spidev Set to 'off' to prevent the creation of a
4078 userspace device node /dev/spidev5.0 (default
4079 is 'on' or enabled).
4083 Info: Enables spi5 with two chip select (CS) lines and associated spidev
4084 dev nodes. The gpio pin numbers for the CS lines and spidev device node
4085 creation are configurable. BCM2711 only.
4086 Load: dtoverlay=spi5-2cs,<param>=<val>
4087 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
4088 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
4089 cs0_spidev Set to 'off' to prevent the creation of a
4090 userspace device node /dev/spidev5.0 (default
4091 is 'on' or enabled).
4092 cs1_spidev Set to 'off' to prevent the creation of a
4093 userspace device node /dev/spidev5.1 (default
4094 is 'on' or enabled).
4098 Info: Enables spi6 with a single chip select (CS) line and associated spidev
4099 dev node. The gpio pin number for the CS line and spidev device node
4100 creation are configurable. BCM2711 only.
4101 Load: dtoverlay=spi6-1cs,<param>=<val>
4102 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
4103 cs0_spidev Set to 'off' to prevent the creation of a
4104 userspace device node /dev/spidev6.0 (default
4105 is 'on' or enabled).
4109 Info: Enables spi6 with two chip select (CS) lines and associated spidev
4110 dev nodes. The gpio pin numbers for the CS lines and spidev device node
4111 creation are configurable. BCM2711 only.
4112 Load: dtoverlay=spi6-2cs,<param>=<val>
4113 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
4114 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
4115 cs0_spidev Set to 'off' to prevent the creation of a
4116 userspace device node /dev/spidev6.0 (default
4117 is 'on' or enabled).
4118 cs1_spidev Set to 'off' to prevent the creation of a
4119 userspace device node /dev/spidev6.1 (default
4120 is 'on' or enabled).
4124 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
4125 Load: dtoverlay=ssd1306,<param>=<val>
4126 Params: address Location in display memory of first character.
4128 width Width of display. (default=128)
4129 height Height of display. (default=64)
4130 offset virtual channel a. (default=0)
4131 normal Has no effect on displays tested. (default=not
4133 sequential Set this if every other scan line is missing.
4135 remapped Set this if display is garbled. (default=not
4137 inverted Set this if display is inverted and mirrored.
4141 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
4143 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
4145 i2c_baudrate=400000 will speed up the display.
4147 i2c_baudrate=1000000 seems to work even though it's not officially
4148 supported by the hardware, and is faster still.
4150 For more information refer to the device datasheet at:
4151 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
4155 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
4156 Load: dtoverlay=ssd1306-spi,<param>=<val>
4157 Params: speed SPI bus speed (default 10000000)
4158 rotate Display rotation (0, 90, 180 or 270; default 0)
4159 fps Delay between frame updates (default 25)
4160 debug Debug output level (0-7; default 0)
4161 dc_pin GPIO pin for D/C (default 24)
4162 reset_pin GPIO pin for RESET (default 25)
4163 height Display height (32 or 64; default 64)
4164 inverted Set this if display is inverted and mirrored.
4169 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
4170 Load: dtoverlay=ssd1331-spi,<param>=<val>
4171 Params: speed SPI bus speed (default 4500000)
4172 rotate Display rotation (0, 90, 180 or 270; default 0)
4173 fps Delay between frame updates (default 25)
4174 debug Debug output level (0-7; default 0)
4175 dc_pin GPIO pin for D/C (default 24)
4176 reset_pin GPIO pin for RESET (default 25)
4180 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
4181 Load: dtoverlay=ssd1351-spi,<param>=<val>
4182 Params: speed SPI bus speed (default 4500000)
4183 rotate Display rotation (0, 90, 180 or 270; default 0)
4184 fps Delay between frame updates (default 25)
4185 debug Debug output level (0-7; default 0)
4186 dc_pin GPIO pin for D/C (default 24)
4187 reset_pin GPIO pin for RESET (default 25)
4190 Name: superaudioboard
4191 Info: Configures the SuperAudioBoard sound card
4192 Load: dtoverlay=superaudioboard,<param>=<val>
4193 Params: gpiopin GPIO pin for codec reset
4197 Info: Configures the Semtech SX150X I2C GPIO expanders.
4198 Load: dtoverlay=sx150x,<param>=<val>
4199 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
4200 address <m>. <x> may be 1-9. <n> may be 0 or 1.
4201 Permissible values of <m> (which is denoted in
4202 hex) depend on the device variant. For SX1501,
4203 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
4204 For SX1503 and SX1506, <m> may be 20. For
4205 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
4206 For SX1508, <m> may be 20, 21, 22 or 23.
4208 sx150<x>-<n>-<m>-int-gpio
4209 Integer, enables interrupts on SX150X device on
4210 I2C#<n> with slave address <m>, specifies
4211 the GPIO pin to which NINT output of SX150X is
4216 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
4217 Uses Unicam 1, which is the standard camera connector on most Pi
4219 Load: dtoverlay=tc358743,<param>=<val>
4220 Params: 4lane Use 4 lanes (only applicable to Compute Modules
4223 link-frequency Set the link frequency. Only values of 297000000
4224 (574Mbit/s) and 486000000 (972Mbit/s - default)
4225 are supported by the driver.
4226 media-controller Configure use of Media Controller API for
4227 configuring the sensor (default off)
4228 cam0 Adopt the default configuration for CAM0 on a
4229 Compute Module (CSI0, i2c_vc, and cam0_reg).
4232 Name: tc358743-audio
4233 Info: Used in combination with the tc358743-fast overlay to route the audio
4234 from the TC358743 over I2S to the Pi.
4235 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
4237 Load: dtoverlay=tc358743-audio,<param>=<val>
4238 Params: card-name Override the default, "tc358743", card name.
4242 Info: 3.5" Color TFT Display by www.tinylcd.com
4243 Options: Touch, RTC, keypad
4244 Load: dtoverlay=tinylcd35,<param>=<val>
4245 Params: speed Display SPI bus speed
4247 rotate Display rotation {0,90,180,270}
4249 fps Delay between frame updates
4251 debug Debug output level {0-7}
4253 touch Enable touch panel
4255 touchgpio Touch controller IRQ GPIO
4257 xohms Touchpanel: Resistance of X-plate in ohms
4259 rtc-pcf PCF8563 Real Time Clock
4261 rtc-ds DS1307 Real Time Clock
4263 keypad Enable keypad
4266 Display with touchpanel, PCF8563 RTC and keypad:
4267 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
4269 dtoverlay=tinylcd35,touch,touchgpio=3
4273 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
4274 boards, which can be used as a secure key storage and hwrng,
4275 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
4276 Load: dtoverlay=tpm-slb9670
4281 Info: Enables support for Infineon SLB9673 Trusted Platform Module add-on
4282 boards, which can be used as a secure key storage and hwrng
4283 via the I2C protocol.
4284 Load: dtoverlay=tpm-slb9673
4289 Info: Change the pin usage of uart0
4290 Load: dtoverlay=uart0,<param>=<val>
4291 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
4293 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
4295 pin_func Alternative pin function - 4(Alt0) for 14&15,
4296 7(Alt3) for 32&33, 6(Alt2) for 36&37
4300 Info: Change the pin usage of uart1
4301 Load: dtoverlay=uart1,<param>=<val>
4302 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
4304 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
4308 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
4309 Load: dtoverlay=uart2,<param>
4310 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
4314 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
4315 Load: dtoverlay=uart3,<param>
4316 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
4320 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
4321 Load: dtoverlay=uart4,<param>
4322 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
4326 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
4327 Load: dtoverlay=uart5,<param>
4328 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
4332 Info: Configures the NW Digital Radio UDRC Hat
4333 Load: dtoverlay=udrc,<param>=<val>
4334 Params: alsaname Name of the ALSA audio device (default "udrc")
4337 Name: ugreen-dabboard
4338 Info: Configures the ugreen-dabboard I2S overlay
4339 This is a simple overlay based on the simple-audio-card and the dmic
4340 codec. It has the speciality that it is configured to use the codec
4341 as a master I2S device. It works for example with the Si468x DAB
4342 receiver on the uGreen DABBoard.
4343 Load: dtoverlay=ugreen-dabboard,<param>=<val>
4344 Params: card-name Override the default, "dabboard", card name.
4348 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
4349 vc4-kms-v3d and dwc2 overlays.
4350 Load: dtoverlay=upstream
4354 Name: upstream-aux-interrupt
4355 Info: This overlay has been deprecated and removed because it is no longer
4361 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
4362 the vc4-kms-v3d-pi4 and dwc2 overlays.
4363 Load: dtoverlay=upstream-pi4
4368 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4370 Load: dtoverlay=vc4-fkms-v3d,<param>
4371 Params: cma-512 CMA is 512MB (needs 1GB)
4372 cma-448 CMA is 448MB (needs 1GB)
4373 cma-384 CMA is 384MB (needs 1GB)
4374 cma-320 CMA is 320MB (needs 1GB)
4375 cma-256 CMA is 256MB (needs 1GB)
4376 cma-192 CMA is 192MB (needs 1GB)
4377 cma-128 CMA is 128MB
4380 cma-size CMA size in bytes, 4MB aligned
4381 cma-default Use upstream's default value
4384 Name: vc4-fkms-v3d-pi4
4385 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4387 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
4388 Params: cma-512 CMA is 512MB (needs 1GB)
4389 cma-448 CMA is 448MB (needs 1GB)
4390 cma-384 CMA is 384MB (needs 1GB)
4391 cma-320 CMA is 320MB (needs 1GB)
4392 cma-256 CMA is 256MB (needs 1GB)
4393 cma-192 CMA is 192MB (needs 1GB)
4394 cma-128 CMA is 128MB
4397 cma-size CMA size in bytes, 4MB aligned
4398 cma-default Use upstream's default value
4401 Name: vc4-kms-dpi-at056tn53v1
4402 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
4406 Name: vc4-kms-dpi-generic
4407 Info: Enable a generic DPI display under KMS. Default timings are for the
4408 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
4409 Requires vc4-kms-v3d to be loaded.
4410 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
4411 Params: clock-frequency Display clock frequency (Hz)
4412 hactive Horizontal active pixels
4413 hfp Horizontal front porch
4414 hsync Horizontal sync pulse width
4415 hbp Horizontal back porch
4416 vactive Vertical active lines
4417 vfp Vertical front porch
4418 vsync Vertical sync pulse width
4419 vbp Vertical back porch
4420 hsync-invert Horizontal sync active low
4421 vsync-invert Vertical sync active low
4422 de-invert Data Enable active low
4423 pixclk-invert Negative edge pixel clock
4424 width-mm Define the screen width in mm
4425 height-mm Define the screen height in mm
4426 rgb565 Change to RGB565 output on GPIOs 0-19
4427 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
4429 bgr666 Change to BGR666 output on GPIOs 0-21.
4430 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
4432 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
4434 bgr888 Change to BGR888 output on GPIOs 0-27
4435 rgb888 Change to RGB888 output on GPIOs 0-27
4436 bus-format Override the bus format for a MEDIA_BUS_FMT_*
4437 value. NB also overridden by rgbXXX overrides.
4438 backlight-gpio Defines a GPIO to be used for backlight control
4440 backlight-pwm Defines a PWM channel to be used for backlight
4441 control (default of none). NB Disables audio
4442 headphone output as that also uses PWM.
4443 backlight-pwm-chan Choose channel on &pwm node for backlight
4446 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4447 pwm-2chan for valid options.
4448 (default 18 - note this can only work with
4450 backlight-pwm-func Pin function of GPIO used for the PWM
4452 See pwm-2chan for valid options.
4454 backlight-def-brightness
4455 Set the default brightness. Normal range 1-16.
4457 rotate Display rotation {0,90,180,270} (default 0)
4460 Name: vc4-kms-dpi-hyperpixel2r
4461 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
4462 Requires vc4-kms-v3d to be loaded.
4463 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
4464 Params: disable-touch Disables the touch controller
4465 touchscreen-inverted-x Inverts X direction of touch controller
4466 touchscreen-inverted-y Inverts Y direction of touch controller
4467 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4468 rotate Display rotation {0,90,180,270} (default 0)
4471 Name: vc4-kms-dpi-hyperpixel4
4472 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
4473 Requires vc4-kms-v3d to be loaded.
4474 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
4475 Params: disable-touch Disables the touch controller
4476 touchscreen-inverted-x Inverts X direction of touch controller
4477 touchscreen-inverted-y Inverts Y direction of touch controller
4478 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4479 rotate Display rotation {0,90,180,270} (default 0)
4482 Name: vc4-kms-dpi-hyperpixel4sq
4483 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4484 Requires vc4-kms-v3d to be loaded.
4485 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4486 Params: disable-touch Disables the touch controller
4487 touchscreen-inverted-x Inverts X direction of touch controller
4488 touchscreen-inverted-y Inverts Y direction of touch controller
4489 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4490 rotate Display rotation {0,90,180,270} (default 0)
4493 Name: vc4-kms-dpi-panel
4494 Info: Enable a preconfigured KMS DPI panel.
4495 Requires vc4-kms-v3d to be loaded.
4496 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4497 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4498 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4499 mzp280 Enable a Geekworm MZP280 panel.
4500 backlight-gpio Defines a GPIO to be used for backlight control
4502 backlight-pwm Defines a PWM channel to be used for backlight
4503 control (default of none). NB Disables audio
4504 headphone output as that also uses PWM.
4505 backlight-pwm-chan Choose channel on &pwm node for backlight
4508 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4509 pwm-2chan for valid options.
4510 (default 18 - note this can only work with
4512 backlight-pwm-func Pin function of GPIO used for the PWM
4514 See pwm-2chan for valid options.
4516 backlight-def-brightness
4517 Set the default brightness. Normal range 1-16.
4519 rotate Display rotation {0,90,180,270} (default 0)
4522 Name: vc4-kms-dsi-7inch
4523 Info: Enable the Raspberry Pi DSI 7" screen.
4524 Includes the edt-ft5406 for the touchscreen element.
4525 Requires vc4-kms-v3d to be loaded.
4526 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4527 Params: sizex Touchscreen size x (default 800)
4528 sizey Touchscreen size y (default 480)
4529 invx Touchscreen inverted x axis
4530 invy Touchscreen inverted y axis
4531 swapxy Touchscreen swapped x y axis
4532 disable_touch Disables the touch screen overlay driver
4535 Name: vc4-kms-dsi-lt070me05000
4536 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4537 Note that this is a 4 lane DSI device, so it will only work on a Compute
4539 Requires vc4-kms-v3d to be loaded.
4540 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4541 Params: reset GPIO for the reset signal (default 17)
4542 enable GPIO for the enable signal (default 4)
4543 dcdc-en GPIO for the DC-DC converter enable (default 5)
4546 Name: vc4-kms-dsi-lt070me05000-v2
4547 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4549 Note that this is a 4 lane DSI device, so it will only work on a Compute
4551 Requires vc4-kms-v3d to be loaded.
4552 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4556 Name: vc4-kms-dsi-waveshare-panel
4557 Info: Enable a Waveshare DSI touchscreen
4558 Includes the Goodix driver for the touchscreen element.
4559 The default is for the display to be using the I2C0 option for control.
4560 Use the i2c1 override if using the I2C1 wiring with jumper wires from
4561 GPIOs 2&3 (pins 3&5).
4562 invx/invy/swapxy should be used with caution as the panel specifier will
4563 set the default inversions for that panel. Always use them after the
4564 panel specifier, and be aware that you may need to set them as =0, not
4566 Requires vc4-kms-v3d to be loaded.
4567 Load: dtoverlay=vc4-kms-dsi-waveshare-panel,<param>=<val>
4568 Params: 2_8_inch 2.8" 480x640
4569 3_4_inch 3.4" 800x800 round
4570 4_0_inch 4.0" 480x800
4571 7_0_inchC 7.0" C 1024x600
4572 7_9_inch 7.9" 400x1280
4573 8_0_inch 8.0" 1280x800
4574 10_1_inch 10.1" 1280x800
4575 11_9_inch 11.9" 320x1480
4576 i2c1 Use i2c-1 with jumper wires from GPIOs 2&3
4577 disable_touch Disable the touch controller
4578 rotation Set the panel orientation property
4579 invx Touchscreen inverted x axis
4580 invy Touchscreen inverted y axis
4581 swapxy Touchscreen swapped x y axis
4584 Name: vc4-kms-kippah-7inch
4585 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4590 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4591 Load: dtoverlay=vc4-kms-v3d,<param>
4592 Params: cma-512 CMA is 512MB (needs 1GB)
4593 cma-448 CMA is 448MB (needs 1GB)
4594 cma-384 CMA is 384MB (needs 1GB)
4595 cma-320 CMA is 320MB (needs 1GB)
4596 cma-256 CMA is 256MB (needs 1GB)
4597 cma-192 CMA is 192MB (needs 1GB)
4598 cma-128 CMA is 128MB
4601 cma-size CMA size in bytes, 4MB aligned
4602 cma-default Use upstream's default value
4603 audio Enable or disable audio over HDMI (default "on")
4604 noaudio Disable all HDMI audio (default "off")
4605 composite Enable the composite output (default "off")
4606 N.B. Disables all other outputs on a Pi 4.
4607 nohdmi Disable HDMI output
4610 Name: vc4-kms-v3d-pi4
4611 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4612 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4613 Params: cma-512 CMA is 512MB
4614 cma-448 CMA is 448MB
4615 cma-384 CMA is 384MB
4616 cma-320 CMA is 320MB
4617 cma-256 CMA is 256MB
4618 cma-192 CMA is 192MB
4619 cma-128 CMA is 128MB
4622 cma-size CMA size in bytes, 4MB aligned
4623 cma-default Use upstream's default value
4624 audio Enable or disable audio over HDMI0 (default
4626 audio1 Enable or disable audio over HDMI1 (default
4628 noaudio Disable all HDMI audio (default "off")
4629 composite Enable the composite output (disables all other
4631 nohdmi Disable both HDMI 0 & 1 outputs
4632 nohdmi0 Disable HDMI 0 output
4633 nohdmi1 Disable HDMI 1 output
4637 Name: vc4-kms-vga666
4638 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4639 Requires vc4-kms-v3d to be loaded.
4640 Load: dtoverlay=vc4-kms-vga666,<param>
4641 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4642 from the display. NB These are NOT 5V tolerant
4643 GPIOs, therefore level shifters are required.
4647 Info: Overlay for the Fen Logic VGA666 board
4648 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4649 after the kernel has started.
4650 NOT for use with vc4-kms-v3d.
4651 Load: dtoverlay=vga666
4656 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4657 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4658 set in the EEPROM config.
4659 Load: dtoverlay=vl805
4664 Info: Configures the w1-gpio Onewire interface module.
4665 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4666 Load: dtoverlay=w1-gpio,<param>=<val>
4667 Params: gpiopin GPIO for I/O (default "4")
4668 pullup Now enabled by default (ignored)
4671 Name: w1-gpio-pullup
4672 Info: Configures the w1-gpio Onewire interface module.
4673 Use this overlay if you *do* need a GPIO to drive an external pullup.
4674 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4675 Params: gpiopin GPIO for I/O (default "4")
4676 extpullup GPIO for external pullup (default "5")
4677 pullup Now enabled by default (ignored)
4681 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4682 Load: dtoverlay=w5500,<param>=<val>
4683 Params: int_pin GPIO used for INT (default 25)
4685 speed SPI bus speed (default 30000000)
4687 cs SPI bus Chip Select (default 0)
4690 Name: watterott-display
4691 Info: Watterott RPi-Display - 2.8" Touch Display
4692 Linux has 2 drivers that support this display and this overlay supports
4696 fbtft/fb_ili9341: dtoverlay=watterott-display
4697 drm/mi0283qt: dtoverlay=watterott-display,drm,backlight-pwm,rotate=180
4699 Some notable differences with the DRM driver compared to fbtft:
4700 - The display is turned on when it's first used and not on driver load
4701 as with fbtft. So if nothing uses the display it stays off.
4702 - Can run with a higher SPI clock increasing framerate. This is possible
4703 since the driver avoids messing up the controller configuration due to
4704 transmission errors by running config commands at 10MHz and only pixel
4705 data at full speed (occasional pixel glitch might occur).
4706 - PWM backlight is supported.
4708 Load: dtoverlay=watterott-display,<param>=<val>
4709 Params: speed Display SPI bus speed
4710 rotate Display rotation {0,90,180,270}
4711 fps Delay between frame updates (fbtft only)
4712 debug Debug output level {0-7} (fbtft only)
4713 xohms Touchpanel sensitivity (X-plate resistance)
4714 swapxy Swap x and y axis
4715 backlight Change backlight GPIO pin {e.g. 12, 18}
4717 drm Use DRM/KMS driver mi0283qt instead of fbtft.
4718 Set the SPI clock to 70MHz.
4719 This has to be the first parameter.
4720 backlight-pwm Use pwm for backlight (drm only). NB: Disables
4721 audio headphone output as that also uses PWM.
4724 Name: waveshare-can-fd-hat-mode-a
4725 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4726 for Raspberry Pi, Multi Protections. Use this overlay when the
4727 HAT is configured in Mode A (Default), with can0 on spi0.0
4729 https://www.waveshare.com/2-ch-can-fd-hat.htm
4730 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4734 Name: waveshare-can-fd-hat-mode-b
4735 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4736 for Raspberry Pi, Multi Protections. Use this overlay when the
4737 HAT is configured in Mode B (requires hardware modification), with
4738 can0 on spi0.0 and can1 on spi0.1.
4739 https://www.waveshare.com/2-ch-can-fd-hat.htm
4740 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4745 Info: Configures the wittypi RTC module.
4746 Load: dtoverlay=wittypi,<param>=<val>
4747 Params: led_gpio GPIO for LED (default "17")
4748 led_trigger Choose which activity the LED tracks (default
4752 Name: wm8960-soundcard
4753 Info: Overlay for the Waveshare wm8960 soundcard
4754 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4755 Params: alsaname Changes the card name in ALSA
4756 compatible Changes the codec compatibility
4762 If you are experiencing problems that you think are DT-related, enable DT
4763 diagnostic output by adding this to /boot/config.txt:
4767 and rebooting. Then run:
4771 and look for relevant messages.
4776 This is only meant to be a quick introduction to the subject of Device Tree on
4777 Raspberry Pi. There is a more complete explanation here:
4779 http://www.raspberrypi.org/documentation/configuration/device-tree.md
projects / platform / kernel / linux-rpi.git / blob