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 cam0_reg Enables CAM 0 regulator. CM1 & 3 only.
149 cam0_reg_gpio Set GPIO for CAM 0 regulator. Default 30.
152 cam1_reg Enables CAM 1 regulator. CM1 & 3 only.
154 cam1_reg_gpio Set GPIO for CAM 1 regulator. Default 2.
157 eee Enable Energy Efficient Ethernet support for
158 compatible devices (default "on"). See also
159 "tx_lpi_timer". Pi3B+ only.
161 eth_downshift_after Set the number of auto-negotiation failures
162 after which the 1000Mbps modes are disabled.
163 Legal values are 2, 3, 4, 5 and 0, where
164 0 means never downshift (default 2). Pi3B+ only.
166 eth_led0 Set mode of LED0 - amber on Pi3B+ (default "1"),
167 green on Pi4 (default "0").
168 The legal values are:
172 0=link/activity 1=link1000/activity
173 2=link100/activity 3=link10/activity
174 4=link100/1000/activity 5=link10/1000/activity
175 6=link10/100/activity 14=off 15=on
179 0=Speed/Activity 1=Speed
180 2=Flash activity 3=FDX
185 eth_led1 Set mode of LED1 - green on Pi3B+ (default "6"),
186 amber on Pi4 (default "8"). See eth_led0 for
189 eth_max_speed Set the maximum speed a link is allowed
190 to negotiate. Legal values are 10, 100 and
191 1000 (default 1000). Pi3B+ only.
193 hdmi Set to "off" to disable the HDMI interface
196 i2c_arm Set to "on" to enable the ARM's i2c interface
199 i2c_vc Set to "on" to enable the i2c interface
200 usually reserved for the VideoCore processor
203 i2c An alias for i2c_arm
205 i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
208 i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
211 i2c_baudrate An alias for i2c_arm_baudrate
213 i2s Set to "on" to enable the i2s interface
216 krnbt Set to "on" to enable autoprobing of Bluetooth
217 driver without need of hciattach/btattach
220 krnbt_baudrate Set the baudrate of the PL011 UART when used
223 pcie Set to "off" to disable the PCIe interface
225 (2711 only, but not applicable on CM4S)
226 N.B. USB-A ports on 4B are subsequently disabled
228 spi Set to "on" to enable the spi interfaces
231 spi_dma4 Use to enable 40-bit DMA on spi interfaces
232 (the assigned value doesn't matter)
235 random Set to "on" to enable the hardware random
236 number generator (default "on")
238 sd Set to "off" to disable the SD card (or eMMC on
239 non-lite SKU of CM4).
242 sd_overclock Clock (in MHz) to use when the MMC framework
245 sd_poll_once Looks for a card once after booting. Useful
246 for network booting scenarios to avoid the
247 overhead of continuous polling. N.B. Using
248 this option restricts the system to using a
249 single card per boot (or none at all).
252 sd_force_pio Disable DMA support for SD driver (default off)
254 sd_pio_limit Number of blocks above which to use DMA for
257 sd_debug Enable debug output from SD driver (default off)
259 sdio_overclock Clock (in MHz) to use when the MMC framework
260 requests 50MHz for the SDIO/WLAN interface.
262 tx_lpi_timer Set the delay in microseconds between going idle
263 and entering the low power state (default 600).
264 Requires EEE to be enabled - see "eee".
266 uart0 Set to "off" to disable uart0 (default "on")
268 uart1 Set to "on" or "off" to enable or disable uart1
271 watchdog Set to "on" to enable the hardware watchdog
274 act_led_trigger Choose which activity the LED tracks.
275 Use "heartbeat" for a nice load indicator.
278 act_led_activelow Set to "on" to invert the sense of the LED
280 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
283 act_led_gpio Set which GPIO to use for the activity LED
284 (in case you want to connect it to an external
286 (default "16" on a non-Plus board, "47" on a
288 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
294 As for act_led_*, but using the PWR LED.
295 Not available on Model A/B boards.
297 N.B. It is recommended to only enable those interfaces that are needed.
298 Leaving all interfaces enabled can lead to unwanted behaviour (i2c_vc
299 interfering with Pi Camera, I2S and SPI hogging GPIO pins, etc.)
300 Note also that i2c, i2c_arm and i2c_vc are aliases for the physical
301 interfaces i2c0 and i2c1. Use of the numeric variants is still possible
302 but deprecated because the ARM/VC assignments differ between board
303 revisions. The same board-specific mapping applies to i2c_baudrate,
304 and the other i2c baudrate parameters.
308 Info: Pi 3B, 3B+, 3A+ and 4B use a GPIO expander to drive the LEDs which can
309 only be accessed from the VPU. There is a special driver for this with a
310 separate DT node, which has the unfortunate consequence of breaking the
311 act_led_gpio and act_led_activelow dtparams.
312 This overlay changes the GPIO controller back to the standard one and
313 restores the dtparams.
314 Load: dtoverlay=act-led,<param>=<val>
315 Params: activelow Set to "on" to invert the sense of the LED
318 gpio Set which GPIO to use for the activity LED
319 (in case you want to connect it to an external
324 Name: adafruit-st7735r
325 Info: Overlay for the SPI-connected Adafruit 1.8" 160x128 or 128x128 displays,
326 based on the ST7735R chip.
327 This overlay uses the newer DRM/KMS "Tiny" driver.
328 Load: dtoverlay=adafruit-st7735r,<param>=<val>
329 Params: 128x128 Select the 128x128 driver (default 160x128)
330 rotate Display rotation {0,90,180,270} (default 90)
331 speed SPI bus speed in Hz (default 4000000)
332 dc_pin GPIO pin for D/C (default 24)
333 reset_pin GPIO pin for RESET (default 25)
334 led_pin GPIO used to control backlight (default 18)
338 Info: Overlay for the SPI-connected Adafruit 1.8" display (based on the
339 ST7735R chip). It includes support for the "green tab" version.
340 This overlay uses the older fbtft driver.
341 Load: dtoverlay=adafruit18,<param>=<val>
342 Params: green Use the adafruit18_green variant.
343 rotate Display rotation {0,90,180,270}
344 speed SPI bus speed in Hz (default 4000000)
345 fps Display frame rate in Hz
346 bgr Enable BGR mode (default off)
347 debug Debug output level {0-7}
348 dc_pin GPIO pin for D/C (default 24)
349 reset_pin GPIO pin for RESET (default 25)
350 led_pin GPIO used to control backlight (default 18)
354 Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
356 Load: dtoverlay=adau1977-adc
360 Name: adau7002-simple
361 Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter.
362 Load: dtoverlay=adau7002-simple,<param>=<val>
363 Params: card-name Override the default, "adau7002", card name.
367 Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
368 Load: dtoverlay=ads1015,<param>=<val>
369 Params: addr I2C bus address of device. Set based on how the
370 addr pin is wired. (default=0x48 assumes addr
372 cha_enable Enable virtual channel a. (default=true)
373 cha_cfg Set the configuration for virtual channel a.
374 (default=4 configures this channel for the
375 voltage at A0 with respect to GND)
376 cha_datarate Set the datarate (samples/sec) for this channel.
377 (default=4 sets 1600 sps)
378 cha_gain Set the gain of the Programmable Gain
379 Amplifier for this channel. (default=2 sets the
380 full scale of the channel to 2.048 Volts)
382 Channel (ch) parameters can be set for each enabled channel.
383 A maximum of 4 channels can be enabled (letters a thru d).
384 For more information refer to the device datasheet at:
385 http://www.ti.com/lit/ds/symlink/ads1015.pdf
389 Info: Texas Instruments ADS1115 ADC
390 Load: dtoverlay=ads1115,<param>[=<val>]
391 Params: addr I2C bus address of device. Set based on how the
392 addr pin is wired. (default=0x48 assumes addr
394 cha_enable Enable virtual channel a.
395 cha_cfg Set the configuration for virtual channel a.
396 (default=4 configures this channel for the
397 voltage at A0 with respect to GND)
398 cha_datarate Set the datarate (samples/sec) for this channel.
399 (default=7 sets 860 sps)
400 cha_gain Set the gain of the Programmable Gain
401 Amplifier for this channel. (Default 1 sets the
402 full scale of the channel to 4.096 Volts)
404 Channel parameters can be set for each enabled channel.
405 A maximum of 4 channels can be enabled (letters a thru d).
406 For more information refer to the device datasheet at:
407 http://www.ti.com/lit/ds/symlink/ads1115.pdf
411 Info: ADS7846 Touch controller
412 Load: dtoverlay=ads7846,<param>=<val>
413 Params: cs SPI bus Chip Select (default 1)
414 speed SPI bus speed (default 2MHz, max 3.25MHz)
415 penirq GPIO used for PENIRQ. REQUIRED
416 penirq_pull Set GPIO pull (default 0=none, 2=pullup)
417 swapxy Swap x and y axis
418 xmin Minimum value on the X axis (default 0)
419 ymin Minimum value on the Y axis (default 0)
420 xmax Maximum value on the X axis (default 4095)
421 ymax Maximum value on the Y axis (default 4095)
422 pmin Minimum reported pressure value (default 0)
423 pmax Maximum reported pressure value (default 65535)
424 xohms Touchpanel sensitivity (X-plate resistance)
427 penirq is required and usually xohms (60-100) has to be set as well.
428 Apart from that, pmax (255) and swapxy are also common.
429 The rest of the calibration can be done with xinput-calibrator.
430 See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
431 Device Tree binding document:
432 www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
436 Info: Analog Devices ADV7282M analogue video to CSI2 bridge.
437 Uses Unicam1, which is the standard camera connector on most Pi
439 Load: dtoverlay=adv7282m,<param>=<val>
440 Params: addr Overrides the I2C address (default 0x21)
441 media-controller Configure use of Media Controller API for
442 configuring the sensor (default off)
446 Info: Analog Devices ADV728[0|1|2]-M analogue video to CSI2 bridges.
447 This is a wrapper for adv7282m, and defaults to ADV7282M.
448 Load: dtoverlay=adv728x-m,<param>=<val>
449 Params: addr Overrides the I2C address (default 0x21)
450 adv7280m Select ADV7280-M.
451 adv7281m Select ADV7281-M.
452 adv7281ma Select ADV7281-MA.
453 media-controller Configure use of Media Controller API for
454 configuring the sensor (default off)
457 Name: akkordion-iqdacplus
458 Info: Configures the Digital Dreamtime Akkordion Music Player (based on the
459 OEM IQAudIO DAC+ or DAC Zero module).
460 Load: dtoverlay=akkordion-iqdacplus,<param>=<val>
461 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
462 Digital volume control. Enable with
463 dtoverlay=akkordion-iqdacplus,24db_digital_gain
464 (The default behaviour is that the Digital
465 volume control is limited to a maximum of
466 0dB. ie. it can attenuate but not provide
467 gain. For most users, this will be desired
468 as it will prevent clipping. By appending
469 the 24db_digital_gain parameter, the Digital
470 volume control will allow up to 24dB of
471 gain. If this parameter is enabled, it is the
472 responsibility of the user to ensure that
473 the Digital volume control is set to a value
474 that does not result in clipping/distortion!)
477 Name: allo-boss-dac-pcm512x-audio
478 Info: Configures the Allo Boss DAC audio cards.
479 Load: dtoverlay=allo-boss-dac-pcm512x-audio,<param>
480 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
481 Digital volume control. Enable with
482 "dtoverlay=allo-boss-dac-pcm512x-audio,
484 (The default behaviour is that the Digital
485 volume control is limited to a maximum of
486 0dB. ie. it can attenuate but not provide
487 gain. For most users, this will be desired
488 as it will prevent clipping. By appending
489 the 24db_digital_gain parameter, the Digital
490 volume control will allow up to 24dB of
491 gain. If this parameter is enabled, it is the
492 responsibility of the user to ensure that
493 the Digital volume control is set to a value
494 that does not result in clipping/distortion!)
495 slave Force Boss DAC into slave mode, using Pi a
496 master for bit clock and frame clock. Enable
497 with "dtoverlay=allo-boss-dac-pcm512x-audio,
501 Name: allo-boss2-dac-audio
502 Info: Configures the Allo Boss2 DAC audio card
503 Load: dtoverlay=allo-boss2-dac-audio
508 Info: Configures the Allo Digione audio card
509 Load: dtoverlay=allo-digione
513 Name: allo-katana-dac-audio
514 Info: Configures the Allo Katana DAC audio card
515 Load: dtoverlay=allo-katana-dac-audio
519 Name: allo-piano-dac-pcm512x-audio
520 Info: Configures the Allo Piano DAC (2.0/2.1) audio cards.
521 (NB. This initial support is for 2.0 channel audio ONLY! ie. stereo.
522 The subwoofer outputs on the Piano 2.1 are not currently supported!)
523 Load: dtoverlay=allo-piano-dac-pcm512x-audio,<param>
524 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
525 Digital volume control.
526 (The default behaviour is that the Digital
527 volume control is limited to a maximum of
528 0dB. ie. it can attenuate but not provide
529 gain. For most users, this will be desired
530 as it will prevent clipping. By appending
531 the 24db_digital_gain parameter, the Digital
532 volume control will allow up to 24dB of
533 gain. If this parameter is enabled, it is the
534 responsibility of the user to ensure that
535 the Digital volume control is set to a value
536 that does not result in clipping/distortion!)
539 Name: allo-piano-dac-plus-pcm512x-audio
540 Info: Configures the Allo Piano DAC (2.1) audio cards.
541 Load: dtoverlay=allo-piano-dac-plus-pcm512x-audio,<param>
542 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
543 Digital volume control.
544 (The default behaviour is that the Digital
545 volume control is limited to a maximum of
546 0dB. ie. it can attenuate but not provide
547 gain. For most users, this will be desired
548 as it will prevent clipping. By appending
549 the 24db_digital_gain parameter, the Digital
550 volume control will allow up to 24dB of
551 gain. If this parameter is enabled, it is the
552 responsibility of the user to ensure that
553 the Digital volume control is set to a value
554 that does not result in clipping/distortion!)
555 glb_mclk This option is only with Kali board. If enabled,
556 MCLK for Kali is used and PLL is disabled for
557 better voice quality. (default Off)
561 Info: Universal device tree overlay for SPI devices
563 Just specify the SPI address and device name ("compatible" property).
564 This overlay lacks any device-specific parameter support!
566 For devices on spi1 or spi2, the interfaces should be enabled
567 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
570 1. SPI NOR flash on spi0.1, maximum SPI clock frequency 45MHz:
571 dtoverlay=anyspi:spi0-1,dev="jedec,spi-nor",speed=45000000
572 2. MCP3204 ADC on spi1.2, maximum SPI clock frequency 500kHz:
573 dtoverlay=anyspi:spi1-2,dev="microchip,mcp3204"
574 Load: dtoverlay=anyspi,<param>=<val>
575 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
577 dev Set device name to search compatible module
579 speed Set SPI clock frequency in Hz
580 (integer, optional, default 500000)
584 Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and
586 Load: dtoverlay=apds9960,<param>=<val>
587 Params: gpiopin GPIO used for INT (default 4)
588 noints Disable the interrupt GPIO line.
592 Info: Configures the Orchard Audio ApplePi-DAC audio card
593 Load: dtoverlay=applepi-dac
598 Info: Arducam 64MP camera module.
599 Uses Unicam 1, which is the standard camera connector on most Pi
601 Load: dtoverlay=arducam-64mp,<param>=<val>
602 Params: rotation Mounting rotation of the camera sensor (0 or
604 orientation Sensor orientation (0 = front, 1 = rear,
605 2 = external, default external)
606 media-controller Configure use of Media Controller API for
607 configuring the sensor (default on)
608 cam0 Adopt the default configuration for CAM0 on a
609 Compute Module (CSI0, i2c_vc, and cam0_reg).
612 Name: arducam-pivariety
613 Info: Arducam Pivariety camera module.
614 Uses Unicam 1, which is the standard camera connector on most Pi
616 Load: dtoverlay=arducam-pivariety,<param>=<val>
617 Params: rotation Mounting rotation of the camera sensor (0 or
619 orientation Sensor orientation (0 = front, 1 = rear,
620 2 = external, default external)
621 media-controller Configure use of Media Controller API for
622 configuring the sensor (default on)
623 cam0 Adopt the default configuration for CAM0 on a
624 Compute Module (CSI0, i2c_vc, and cam0_reg).
628 Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
630 Load: dtoverlay=at86rf233,<param>=<val>
631 Params: interrupt GPIO used for INT (default 23)
632 reset GPIO used for Reset (default 24)
633 sleep GPIO used for Sleep (default 25)
634 speed SPI bus speed in Hz (default 3000000)
635 trim Fine tuning of the internal capacitance
636 arrays (0=+0pF, 15=+4.5pF, default 15)
639 Name: audioinjector-addons
640 Info: Configures the audioinjector.net audio add on soundcards
641 Load: dtoverlay=audioinjector-addons,<param>=<val>
642 Params: non-stop-clocks Keeps the clocks running even when the stream
643 is paused or stopped (default off)
646 Name: audioinjector-bare-i2s
647 Info: Configures the audioinjector.net audio bare i2s soundcard
648 Load: dtoverlay=audioinjector-bare-i2s
652 Name: audioinjector-isolated-soundcard
653 Info: Configures the audioinjector.net isolated soundcard
654 Load: dtoverlay=audioinjector-isolated-soundcard
658 Name: audioinjector-ultra
659 Info: Configures the audioinjector.net ultra soundcard
660 Load: dtoverlay=audioinjector-ultra
664 Name: audioinjector-wm8731-audio
665 Info: Configures the audioinjector.net audio add on soundcard
666 Load: dtoverlay=audioinjector-wm8731-audio
671 Info: Configures the audiosense-pi add on soundcard
672 For more information refer to
673 https://gitlab.com/kakar0t/audiosense-pi
674 Load: dtoverlay=audiosense-pi
679 Info: Switches PWM sound output to GPIOs on the 40-pin header
680 Load: dtoverlay=audremap,<param>=<val>
681 Params: swap_lr Reverse the channel allocation, which will also
682 swap the audio jack outputs (default off)
683 enable_jack Don't switch off the audio jack output. Does
684 nothing on BCM2711 (default off)
685 pins_12_13 Select GPIOs 12 & 13 (default)
686 pins_18_19 Select GPIOs 18 & 19
687 pins_40_41 Select GPIOs 40 & 41
688 pins_40_45 Select GPIOs 40 & 45 (don't use on BCM2711 - the
689 pins are on different controllers)
693 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
694 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
695 Load: dtoverlay=balena-fin
699 Name: bmp085_i2c-sensor
700 Info: This overlay is now deprecated - see i2c-sensor
704 Name: camera-mux-2port
705 Info: Configures a 2 port camera multiplexer
706 Note that currently ALL IMX290 modules share a common clock, therefore
707 all modules will need to have the same clock frequency.
708 Load: dtoverlay=camera-mux-2port,<param>=<val>
709 Params: cam0-imx219 Select IMX219 for camera on port 0
710 cam0-imx258 Select IMX258 for camera on port 0
711 cam0-imx290 Select IMX290 for camera on port 0
712 cam0-imx477 Select IMX477 for camera on port 0
713 cam0-imx708 Select IMX708 for camera on port 0
714 cam0-ov2311 Select OV2311 for camera on port 0
715 cam0-ov5647 Select OV5647 for camera on port 0
716 cam0-ov7251 Select OV7251 for camera on port 0
717 cam0-ov9281 Select OV9281 for camera on port 0
718 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
719 cam1-imx219 Select IMX219 for camera on port 1
720 cam1-imx258 Select IMX258 for camera on port 1
721 cam1-imx290 Select IMX290 for camera on port 1
722 cam1-imx477 Select IMX477 for camera on port 1
723 cam1-imx708 Select IMX708 for camera on port 1
724 cam1-ov2311 Select OV2311 for camera on port 1
725 cam1-ov5647 Select OV5647 for camera on port 1
726 cam1-ov7251 Select OV7251 for camera on port 1
727 cam1-ov9281 Select OV9281 for camera on port 1
728 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
731 Name: camera-mux-4port
732 Info: Configures a 4 port camera multiplexer
733 Note that currently ALL IMX290 modules share a common clock, therefore
734 all modules will need to have the same clock frequency.
735 Load: dtoverlay=camera-mux-4port,<param>=<val>
736 Params: cam0-imx219 Select IMX219 for camera on port 0
737 cam0-imx258 Select IMX258 for camera on port 0
738 cam0-imx290 Select IMX290 for camera on port 0
739 cam0-imx477 Select IMX477 for camera on port 0
740 cam0-imx708 Select IMX708 for camera on port 0
741 cam0-ov2311 Select OV2311 for camera on port 0
742 cam0-ov5647 Select OV5647 for camera on port 0
743 cam0-ov7251 Select OV7251 for camera on port 0
744 cam0-ov9281 Select OV9281 for camera on port 0
745 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
746 cam1-imx219 Select IMX219 for camera on port 1
747 cam1-imx258 Select IMX258 for camera on port 1
748 cam1-imx290 Select IMX290 for camera on port 1
749 cam1-imx477 Select IMX477 for camera on port 1
750 cam1-imx708 Select IMX708 for camera on port 1
751 cam1-ov2311 Select OV2311 for camera on port 1
752 cam1-ov5647 Select OV5647 for camera on port 1
753 cam1-ov7251 Select OV7251 for camera on port 1
754 cam1-ov9281 Select OV9281 for camera on port 1
755 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
756 cam2-imx219 Select IMX219 for camera on port 2
757 cam2-imx258 Select IMX258 for camera on port 2
758 cam2-imx290 Select IMX290 for camera on port 2
759 cam2-imx477 Select IMX477 for camera on port 2
760 cam2-imx708 Select IMX708 for camera on port 2
761 cam2-ov2311 Select OV2311 for camera on port 2
762 cam2-ov5647 Select OV5647 for camera on port 2
763 cam2-ov7251 Select OV7251 for camera on port 2
764 cam2-ov9281 Select OV9281 for camera on port 2
765 cam2-imx290-clk-freq Set clock frequency for an IMX290 on port 2
766 cam3-imx219 Select IMX219 for camera on port 3
767 cam3-imx258 Select IMX258 for camera on port 3
768 cam3-imx290 Select IMX290 for camera on port 3
769 cam3-imx477 Select IMX477 for camera on port 3
770 cam3-imx708 Select IMX708 for camera on port 3
771 cam3-ov2311 Select OV2311 for camera on port 3
772 cam3-ov5647 Select OV5647 for camera on port 3
773 cam3-ov7251 Select OV7251 for camera on port 3
774 cam3-ov9281 Select OV9281 for camera on port 3
775 cam3-imx290-clk-freq Set clock frequency for an IMX290 on port 3
779 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
780 Load: dtoverlay=cap1106,<param>=<val>
781 Params: int_pin GPIO pin for interrupt signal (default 23)
785 Info: Configures Chip Dip audio cards.
786 Load: dtoverlay=chipdip-dac
791 Info: Configures the Cirrus Logic Audio Card
792 Load: dtoverlay=cirrus-wm5102
797 Info: Set custom CMA sizes, only use if you know what you are doing, might
798 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
799 Load: dtoverlay=cma,<param>=<val>
800 Params: cma-512 CMA is 512MB (needs 1GB)
801 cma-448 CMA is 448MB (needs 1GB)
802 cma-384 CMA is 384MB (needs 1GB)
803 cma-320 CMA is 320MB (needs 1GB)
804 cma-256 CMA is 256MB (needs 1GB)
805 cma-192 CMA is 192MB (needs 1GB)
809 cma-size CMA size in bytes, 4MB aligned
810 cma-default Use upstream's default value
814 Info: 8" TFT LCD display and touch panel used by cutiepi.io
815 Load: dtoverlay=cutiepi-panel
820 Info: Configures the dacberry400 add on soundcard
821 Load: dtoverlay=dacberry400
826 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
827 Also sometimes found with the part number(s) AM230x.
828 Load: dtoverlay=dht11,<param>=<val>
829 Params: gpiopin GPIO connected to the sensor's DATA output.
834 Info: Configures the Dion Audio KIWI STREAMER
835 Load: dtoverlay=dionaudio-kiwi
840 Info: Configures the Dion Audio LOCO DAC-AMP
841 Load: dtoverlay=dionaudio-loco
845 Name: dionaudio-loco-v2
846 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
847 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
848 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
849 Digital volume control. Enable with
850 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
851 (The default behaviour is that the Digital
852 volume control is limited to a maximum of
853 0dB. ie. it can attenuate but not provide
854 gain. For most users, this will be desired
855 as it will prevent clipping. By appending
856 the 24dB_digital_gain parameter, the Digital
857 volume control will allow up to 24dB of
858 gain. If this parameter is enabled, it is the
859 responsibility of the user to ensure that
860 the Digital volume control is set to a value
861 that does not result in clipping/distortion!)
865 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
866 UART0/ttyAMA0 over GPIOs 14 & 15.
867 N.B. To disable the systemd service that initialises the modem so it
868 doesn't use the UART, use 'sudo systemctl disable hciuart'.
869 Load: dtoverlay=disable-bt
874 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
875 Load: dtoverlay=disable-wifi
880 Info: Overlay for a generic 18-bit DPI display
881 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
882 2-3 seconds after the kernel has started.
883 Load: dtoverlay=dpi18
888 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
889 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
890 the output 3-3 seconds after the kernel has started.
891 Load: dtoverlay=dpi18cpadhi
896 Info: Overlay for a generic 24-bit DPI display
897 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
898 2-3 seconds after the kernel has started.
899 Load: dtoverlay=dpi24
904 Info: Configures the NW Digital Radio DRAWS Hat
906 The board includes an ADC to measure various board values and also
907 provides two analog user inputs on the expansion header. The ADC
908 can be configured for various sample rates and gain values to adjust
909 the input range. Tables describing the two parameters follow.
926 4 = 1600sps (default)
930 Load: dtoverlay=draws,<param>=<val>
931 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
932 input voltage sensor (default 1)
934 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
937 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
938 5V rail voltage sensor (default 1)
940 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
943 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
944 AIN2 input (default 2)
946 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
948 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
949 AIN3 input (default 2)
951 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
953 alsaname Name of the ALSA audio device (default "draws")
957 Info: Selects the dwc_otg USB controller driver which has fiq support. This
958 is the default on all except the Pi Zero which defaults to dwc2.
959 Load: dtoverlay=dwc-otg
964 Info: Selects the dwc2 USB controller driver
965 Load: dtoverlay=dwc2,<param>=<val>
966 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
968 g-rx-fifo-size Size of rx fifo size in gadget mode
970 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
974 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
978 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
979 This works with the Raspberry Pi 7" touchscreen when not being polled
981 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
982 config.txt to stop the firmware polling the touchscreen.
983 Load: dtoverlay=edt-ft5406,<param>=<val>
984 Params: sizex Touchscreen size x (default 800)
985 sizey Touchscreen size y (default 480)
986 invx Touchscreen inverted x axis
987 invy Touchscreen inverted y axis
988 swapxy Touchscreen swapped x y axis
992 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
993 Load: dtoverlay=enc28j60,<param>=<val>
994 Params: int_pin GPIO used for INT (default 25)
996 speed SPI bus speed (default 12000000)
1000 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
1001 Load: dtoverlay=enc28j60-spi2,<param>=<val>
1002 Params: int_pin GPIO used for INT (default 39)
1004 speed SPI bus speed (default 12000000)
1008 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
1009 GPIO 4 (pin 7 on GPIO header) for interrupt.
1010 Load: dtoverlay=exc3000,<param>=<val>
1011 Params: interrupt GPIO used for interrupt (default 4)
1012 sizex Touchscreen size x (default 4096)
1013 sizey Touchscreen size y (default 4096)
1014 invx Touchscreen inverted x axis
1015 invy Touchscreen inverted y axis
1016 swapxy Touchscreen swapped x y axis
1020 Info: Overlay for SPI-connected displays using the fbtft drivers.
1022 This overlay seeks to replace the functionality provided by fbtft_device
1023 which is now gone from the kernel.
1025 Most displays from fbtft_device have been ported over.
1027 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1029 It is also possible to specify the controller (this will use the default
1030 init sequence in the driver).
1032 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1034 For devices on spi1 or spi2, the interfaces should be enabled
1035 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
1037 The following features of fbtft_device have not been ported over:
1038 - parallel bus is not supported
1039 - the init property which overrides the controller initialization
1040 sequence is not supported as a parameter due to memory limitations in
1041 the bootloader responsible for applying the overlay.
1043 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
1046 Load: dtoverlay=fbtft,<param>=<val>
1048 spi<n>-<m> Configure device at spi<n>, cs<m>
1050 speed SPI bus speed in Hz (default 32000000)
1051 cpha Shifted clock phase (CPHA) mode
1052 cpol Inverse clock polarity (CPOL) mode
1054 adafruit18 Adafruit 1.8
1055 adafruit22 Adafruit 2.2 (old)
1056 adafruit22a Adafruit 2.2
1057 adafruit28 Adafruit 2.8
1058 adafruit13m Adafruit 1.3 OLED
1059 admatec_c-berry28 C-Berry28
1061 er_tftm050_2 ER-TFTM070-2
1062 er_tftm070_5 ER-TFTM070-5
1064 ew24ha0_9bit EW24HA0 in 9-bit mode
1065 freetronicsoled128 Freetronics OLED128
1068 itdb28_spi ITDB02-2.8 with SPI interface circuit
1069 mi0283qt-2 Watterott MI0283QT-2
1070 mi0283qt-9a Watterott MI0283QT-9A
1071 nokia3310 Nokia 3310
1072 nokia3310a Nokia 3310a
1073 nokia5110 Nokia 5110
1075 pitft Adafruit PiTFT 2.8
1077 rpi-display Watterott rpi-display
1078 sainsmart18 Sainsmart 1.8
1079 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
1080 tinylcd35 TinyLCD 3.5
1081 tm022hdh26 Tianma TM022HDH26
1082 tontec35_9481 Tontect 3.5 with ILI9481 controller
1083 tontec35_9486 Tontect 3.5 with ILI9486 controller
1084 waveshare32b Waveshare 3.2
1085 waveshare22 Waveshare 2.2
1087 bd663474 BD663474 display controller
1088 hx8340bn HX8340BN display controller
1089 hx8347d HX8347D display controller
1090 hx8353d HX8353D display controller
1091 hx8357d HX8357D display controller
1092 ili9163 ILI9163 display controller
1093 ili9320 ILI9320 display controller
1094 ili9325 ILI9325 display controller
1095 ili9340 ILI9340 display controller
1096 ili9341 ILI9341 display controller
1097 ili9481 ILI9481 display controller
1098 ili9486 ILI9486 display controller
1099 pcd8544 PCD8544 display controller
1100 ra8875 RA8875 display controller
1101 s6d02a1 S6D02A1 display controller
1102 s6d1121 S6D1121 display controller
1103 seps525 SEPS525 display controller
1104 sh1106 SH1106 display controller
1105 ssd1289 SSD1289 display controller
1106 ssd1305 SSD1305 display controller
1107 ssd1306 SSD1306 display controller
1108 ssd1325 SSD1325 display controller
1109 ssd1331 SSD1331 display controller
1110 ssd1351 SSD1351 display controller
1111 st7735r ST7735R display controller
1112 st7789v ST7789V display controller
1113 tls8204 TLS8204 display controller
1114 uc1611 UC1611 display controller
1115 uc1701 UC1701 display controller
1116 upd161704 UPD161704 display controller
1118 width Display width in pixels
1119 height Display height in pixels
1120 regwidth Display controller register width (default is
1122 buswidth Display bus interface width (default 8)
1123 debug Debug output level {0-7}
1124 rotate Display rotation {0, 90, 180, 270} (counter
1125 clockwise). Not supported by all drivers.
1126 bgr Enable BGR mode (default off). Use if Red and
1127 Blue are swapped. Not supported by all drivers.
1128 fps Frames per second (default 30). In effect this
1129 states how long the driver will wait after video
1130 memory has been changed until display update
1131 transfer is started.
1132 txbuflen Length of the FBTFT transmit buffer
1134 startbyte Sets the Start byte used by fb_ili9320,
1135 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1136 gamma String representation of Gamma Curve(s). Driver
1137 specific. Not supported by all drivers.
1138 reset_pin GPIO pin for RESET
1139 dc_pin GPIO pin for D/C
1140 led_pin GPIO pin for LED backlight
1144 Info: Configures the Fe-Pi Audio Sound Card
1145 Load: dtoverlay=fe-pi-audio
1150 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1151 nicely with a "traffic-light" display of red, amber and green LEDs on
1152 GPIOs 7, 8 and 25 respectively.
1153 Load: dtoverlay=fsm-demo,<param>=<val>
1154 Params: fsm_debug Enable debug logging (default off)
1158 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on
1159 SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical
1160 GPIO header pins 22, 13 and 12 respectively) in addition to the
1161 SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19,
1162 23 and 24 respectively).
1163 Load: dtoverlay=gc9a01,<param>=<val>
1164 Params: speed Display SPI bus speed
1166 rotate Display rotation {0,90,180,270}
1168 width Width of the display
1170 height Height of the display
1172 fps Delay between frame updates
1174 debug Debug output level {0-7}
1178 Info: An overlay for the Ghost amplifier.
1179 Load: dtoverlay=ghost-amp,<param>=<val>
1180 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1185 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1186 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1187 Load: dtoverlay=goodix,<param>=<val>
1188 Params: interrupt GPIO used for interrupt (default 4)
1189 reset GPIO used for reset (default 17)
1192 Name: googlevoicehat-soundcard
1193 Info: Configures the Google voiceHAT soundcard
1194 Load: dtoverlay=googlevoicehat-soundcard
1199 Info: Configure a GPIO pin to control a cooling fan.
1200 Load: dtoverlay=gpio-fan,<param>=<val>
1201 Params: gpiopin GPIO used to control the fan (default 12)
1202 temp Temperature at which the fan switches on, in
1203 millicelcius (default 55000)
1204 hyst Temperature delta (in millicelcius) below
1205 temp at which the fan will drop to minrpm
1210 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1211 an output, driven low or high as indicated by the presence or absence
1212 of the active_low parameter. Note that a hogged GPIO is not available
1213 to other drivers or for gpioset/gpioget.
1214 Load: dtoverlay=gpio-hog,<param>=<val>
1215 Params: gpio GPIO pin to hog (default 26)
1216 active_low If set, the hog drives the GPIO low (defaults
1217 to off - the GPIO is driven high)
1221 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1222 based gpio_ir_recv driver maps received keys directly to a
1223 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1224 not required! The key mapping and other decoding parameters can be
1225 configured by "ir-keytable" tool.
1226 Load: dtoverlay=gpio-ir,<param>=<val>
1227 Params: gpio_pin Input pin number. Default is 18.
1229 gpio_pull Desired pull-up/down state (off, down, up)
1232 invert "1" = invert the input (active-low signalling).
1233 "0" = non-inverted input (active-high
1234 signalling). Default is "1".
1236 rc-map-name Default rc keymap (can also be changed by
1237 ir-keytable), defaults to "rc-rc6-mce"
1241 Info: Use GPIO pin as bit-banged infrared transmitter output.
1242 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1243 a PWM so it can be used together with onboard analog audio.
1244 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1245 Params: gpio_pin Output GPIO (default 18)
1247 invert "1" = invert the output (make it active-low).
1248 Default is "0" (active-high).
1252 Info: This is a generic overlay for activating GPIO keypresses using
1253 the gpio-keys library and this dtoverlay. Multiple keys can be
1254 set up using multiple calls to the overlay for configuring
1255 additional buttons or joysticks. You can see available keycodes
1256 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1257 linux/input-event-codes.h#L64
1258 Load: dtoverlay=gpio-key,<param>=<val>
1259 Params: gpio GPIO pin to trigger on (default 3)
1260 active_low When this is 1 (active low), a falling
1261 edge generates a key down event and a
1262 rising edge generates a key up event.
1263 When this is 0 (active high), this is
1264 reversed. The default is 1 (active low)
1265 gpio_pull Desired pull-up/down state (off, down, up)
1266 Default is "up". Note that the default pin
1267 (GPIO3) has an external pullup
1268 label Set a label for the key
1269 keycode Set the key code for the button
1274 Info: This is a generic overlay for activating LEDs (or any other component)
1275 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1276 overlay. While there are many existing methods to activate LEDs on the
1277 RPi, this method offers some advantages:
1278 1) Does not require any userspace programs.
1279 2) LEDs can be connected to the kernel's led-trigger framework,
1280 and drive the LED based on triggers such as cpu load, heartbeat,
1281 kernel panic, key input, timers and others.
1282 3) LED can be tied to the input state of another GPIO pin.
1283 4) The LED is setup early during the kernel boot process (useful
1284 for cpu/heartbeat/panic triggers).
1286 Typical electrical connection is:
1287 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1288 The GPIO pin number can be changed with the 'gpio=' parameter.
1290 To control an LED from userspace, write a 0 or 1 value:
1291 echo 1 > /sys/class/leds/myled1/brightness
1292 The 'myled1' name can be changed with the 'label=' parameter.
1294 To connect the LED to a kernel trigger from userspace:
1295 echo cpu > /sys/class/leds/myled1/trigger
1296 echo heartbeat > /sys/class/leds/myled1/trigger
1297 echo none > /sys/class/leds/myled1/trigger
1298 To connect the LED to GPIO.26 pin (physical pin 37):
1299 echo gpio > /sys/class/leds/myled1/trigger
1300 echo 26 > /sys/class/leds/myled1/gpio
1302 cat /sys/class/leds/myled1/trigger
1304 More information about the Linux kernel LED/Trigger system:
1305 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1306 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1307 Load: dtoverlay=gpio-led,<param>=<val>
1308 Params: gpio GPIO pin connected to the LED (default 19)
1309 label The label for this LED. It will appear under
1310 /sys/class/leds/<label> . Default 'myled1'.
1311 trigger Set the led-trigger to connect to this LED.
1312 default 'none' (LED is user-controlled).
1313 Some possible triggers:
1314 cpu - CPU load (all CPUs)
1315 cpu0 - CPU load of first CPU.
1316 mmc - disk activity (all disks)
1317 panic - turn on on kernel panic
1318 heartbeat - indicate system health
1319 gpio - connect to a GPIO input pin (note:
1320 currently the GPIO PIN can not be set
1321 using overlay parameters, must be
1322 done in userspace, see examples above.
1323 active_low Set to 1 to turn invert the LED control
1324 (writing 0 to /sys/class/leds/XXX/brightness
1325 will turn on the GPIO/LED). Default '0'.
1328 Name: gpio-no-bank0-irq
1329 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1330 which can be useful for UIO drivers.
1331 N.B. Using this overlay will trigger a kernel WARN during booting, but
1332 this can safely be ignored - the system should work as expected.
1333 Load: dtoverlay=gpio-no-bank0-irq
1338 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1339 for user-space GPIO edge detection systems.
1340 Load: dtoverlay=gpio-no-irq
1345 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1346 overlay interferes with the normal power-down sequence, preventing the
1347 kernel from resetting the SoC (a necessary step in a normal power-off
1348 or reboot). This also disables the ability to trigger a boot by driving
1351 The GPIO starts in an inactive state. At poweroff time it is driven
1352 active for 100ms, then inactive for 100ms, then active again. It is
1353 safe to remove the power at any point after the initial activation of
1356 Users of this overlay are required to provide an external mechanism to
1357 switch off the power supply when signalled - failure to do so results
1358 in a kernel BUG, increased power consumption and undefined behaviour.
1359 Load: dtoverlay=gpio-poweroff,<param>=<val>
1360 Params: gpiopin GPIO for signalling (default 26)
1362 active_low Set if the power control device requires a
1363 high->low transition to trigger a power-down.
1364 Note that this will require the support of a
1365 custom dt-blob.bin to prevent a power-down
1366 during the boot process, and that a reboot
1367 will also cause the pin to go low.
1368 input Set if the gpio pin should be configured as
1370 export Set to export the configured pin to sysfs
1371 active_delay_ms Initial GPIO active period (default 100)
1372 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1373 timeout_ms Specify (in ms) how long the kernel waits for
1374 power-down before issuing a WARN (default 3000).
1378 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1379 is configured as an input key that generates KEY_POWER events.
1381 This event is handled by systemd-logind by initiating a
1382 shutdown. Systemd versions older than 225 need an udev rule
1383 enable listening to the input device:
1385 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1386 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1387 ATTRS{keys}=="116", TAG+="power-switch"
1389 Alternatively this event can be handled also on systems without
1390 systemd, just by traditional SysV init daemon. KEY_POWER event
1391 (keycode 116) needs to be mapped to KeyboardSignal on console
1392 and then kb::kbrequest inittab action which is triggered by
1393 KeyboardSignal from console can be configured to issue system
1394 shutdown. Steps for this configuration are:
1396 Add following lines to the /etc/console-setup/remap.inc file:
1398 # Key Power as special keypress
1399 keycode 116 = KeyboardSignal
1401 Then add following lines to /etc/inittab file:
1403 # Action on special keypress (Key Power)
1404 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1406 And finally reload configuration by calling following commands:
1408 # dpkg-reconfigure console-setup
1409 # service console-setup reload
1412 This overlay only handles shutdown. After shutdown, the system
1413 can be powered up again by driving GPIO3 low. The default
1414 configuration uses GPIO3 with a pullup, so if you connect a
1415 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1416 you get a shutdown and power-up button. Please note that
1417 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1418 Load: dtoverlay=gpio-shutdown,<param>=<val>
1419 Params: gpio_pin GPIO pin to trigger on (default 3)
1420 For Raspberry Pi 1 Model B rev 1 set this
1421 explicitly to value 1, e.g.:
1423 dtoverlay=gpio-shutdown,gpio_pin=1
1425 active_low When this is 1 (active low), a falling
1426 edge generates a key down event and a
1427 rising edge generates a key up event.
1428 When this is 0 (active high), this is
1429 reversed. The default is 1 (active low).
1431 gpio_pull Desired pull-up/down state (off, down, up)
1434 Note that the default pin (GPIO3) has an
1435 external pullup. Same applies for GPIO1
1436 on Raspberry Pi 1 Model B rev 1.
1438 debounce Specify the debounce interval in milliseconds
1443 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1444 data, 2 gpio pins for enable and register select and 1 optional pin
1445 for enabling/disabling the backlight display.
1446 Load: dtoverlay=hd44780-lcd,<param>=<val>
1447 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1449 pin_d5 GPIO pin for data pin D5 (default 13)
1451 pin_d6 GPIO pin for data pin D6 (default 19)
1453 pin_d7 GPIO pin for data pin D7 (default 26)
1455 pin_en GPIO pin for "Enable" (default 21)
1457 pin_rs GPIO pin for "Register Select" (default 20)
1459 pin_bl Optional pin for enabling/disabling the
1460 display backlight. (default disabled)
1462 display_height Height of the display in characters
1464 display_width Width of the display in characters
1467 Name: hdmi-backlight-hwhack-gpio
1468 Info: Devicetree overlay for GPIO based backlight on/off capability.
1469 Use this if you have one of those HDMI displays whose backlight cannot
1470 be controlled via DPMS over HDMI and plan to do a little soldering to
1471 use an RPi gpio pin for on/off switching. See:
1472 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1473 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1474 Params: gpio_pin GPIO pin used (default 17)
1475 active_low Set this to 1 if the display backlight is
1476 switched on when the wire goes low.
1477 Leave the default (value 0) if the backlight
1478 expects a high to switch it on.
1482 Info: Configures the HifiBerry Amp and Amp+ audio cards
1483 Load: dtoverlay=hifiberry-amp
1487 Name: hifiberry-amp100
1488 Info: Configures the HifiBerry AMP100 audio card
1489 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1490 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1491 Digital volume control. Enable with
1492 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1493 (The default behaviour is that the Digital
1494 volume control is limited to a maximum of
1495 0dB. ie. it can attenuate but not provide
1496 gain. For most users, this will be desired
1497 as it will prevent clipping. By appending
1498 the 24dB_digital_gain parameter, the Digital
1499 volume control will allow up to 24dB of
1500 gain. If this parameter is enabled, it is the
1501 responsibility of the user to ensure that
1502 the Digital volume control is set to a value
1503 that does not result in clipping/distortion!)
1504 slave Force DAC+ Pro into slave mode, using Pi as
1505 master for bit clock and frame clock.
1506 leds_off If set to 'true' the onboard indicator LEDs
1507 are switched off at all times.
1508 auto_mute If set to 'true' the amplifier is automatically
1509 muted when the DAC is not playing.
1510 mute_ext_ctl The amplifier's HW mute control is enabled
1511 in ALSA mixer and set to <val>.
1512 Will be overwritten by ALSA user settings.
1515 Name: hifiberry-amp3
1516 Info: Configures the HifiBerry Amp3 audio card
1517 Load: dtoverlay=hifiberry-amp3
1522 Info: Configures the HifiBerry DAC audio cards
1523 Load: dtoverlay=hifiberry-dac
1527 Name: hifiberry-dacplus
1528 Info: Configures the HifiBerry DAC+ audio card
1529 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1530 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1531 Digital volume control. Enable with
1532 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1533 (The default behaviour is that the Digital
1534 volume control is limited to a maximum of
1535 0dB. ie. it can attenuate but not provide
1536 gain. For most users, this will be desired
1537 as it will prevent clipping. By appending
1538 the 24dB_digital_gain parameter, the Digital
1539 volume control will allow up to 24dB of
1540 gain. If this parameter is enabled, it is the
1541 responsibility of the user to ensure that
1542 the Digital volume control is set to a value
1543 that does not result in clipping/distortion!)
1544 slave Force DAC+ Pro into slave mode, using Pi as
1545 master for bit clock and frame clock.
1546 leds_off If set to 'true' the onboard indicator LEDs
1547 are switched off at all times.
1550 Name: hifiberry-dacplusadc
1551 Info: Configures the HifiBerry DAC+ADC audio card
1552 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1553 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1554 Digital volume control. Enable with
1555 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1556 (The default behaviour is that the Digital
1557 volume control is limited to a maximum of
1558 0dB. ie. it can attenuate but not provide
1559 gain. For most users, this will be desired
1560 as it will prevent clipping. By appending
1561 the 24dB_digital_gain parameter, the Digital
1562 volume control will allow up to 24dB of
1563 gain. If this parameter is enabled, it is the
1564 responsibility of the user to ensure that
1565 the Digital volume control is set to a value
1566 that does not result in clipping/distortion!)
1567 slave Force DAC+ Pro into slave mode, using Pi as
1568 master for bit clock and frame clock.
1569 leds_off If set to 'true' the onboard indicator LEDs
1570 are switched off at all times.
1573 Name: hifiberry-dacplusadcpro
1574 Info: Configures the HifiBerry DAC+ADC PRO audio card
1575 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1576 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1577 Digital volume control. Enable with
1578 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1579 (The default behaviour is that the Digital
1580 volume control is limited to a maximum of
1581 0dB. ie. it can attenuate but not provide
1582 gain. For most users, this will be desired
1583 as it will prevent clipping. By appending
1584 the 24dB_digital_gain parameter, the Digital
1585 volume control will allow up to 24dB of
1586 gain. If this parameter is enabled, it is the
1587 responsibility of the user to ensure that
1588 the Digital volume control is set to a value
1589 that does not result in clipping/distortion!)
1590 slave Force DAC+ADC Pro into slave mode, using Pi as
1591 master for bit clock and frame clock.
1592 leds_off If set to 'true' the onboard indicator LEDs
1593 are switched off at all times.
1596 Name: hifiberry-dacplusdsp
1597 Info: Configures the HifiBerry DAC+DSP audio card
1598 Load: dtoverlay=hifiberry-dacplusdsp
1602 Name: hifiberry-dacplushd
1603 Info: Configures the HifiBerry DAC+ HD audio card
1604 Load: dtoverlay=hifiberry-dacplushd
1608 Name: hifiberry-digi
1609 Info: Configures the HifiBerry Digi and Digi+ audio card
1610 Load: dtoverlay=hifiberry-digi
1614 Name: hifiberry-digi-pro
1615 Info: Configures the HifiBerry Digi+ Pro audio card
1616 Load: dtoverlay=hifiberry-digi-pro
1621 Info: Enables "High Peripheral" mode
1622 Load: dtoverlay=highperi
1627 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1628 Default values match Texy's display shield
1629 Load: dtoverlay=hy28a,<param>=<val>
1630 Params: speed Display SPI bus speed
1632 rotate Display rotation {0,90,180,270}
1634 fps Delay between frame updates
1636 debug Debug output level {0-7}
1638 xohms Touchpanel sensitivity (X-plate resistance)
1640 resetgpio GPIO used to reset controller
1642 ledgpio GPIO used to control backlight
1646 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1647 Default values match Texy's display shield
1648 Load: dtoverlay=hy28b,<param>=<val>
1649 Params: speed Display SPI bus speed
1651 rotate Display rotation {0,90,180,270}
1653 fps Delay between frame updates
1655 debug Debug output level {0-7}
1657 xohms Touchpanel sensitivity (X-plate resistance)
1659 resetgpio GPIO used to reset controller
1661 ledgpio GPIO used to control backlight
1665 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1666 Default values match Texy's display shield
1667 Load: dtoverlay=hy28b-2017,<param>=<val>
1668 Params: speed Display SPI bus speed
1670 rotate Display rotation {0,90,180,270}
1672 fps Delay between frame updates
1674 debug Debug output level {0-7}
1676 xohms Touchpanel sensitivity (X-plate resistance)
1678 resetgpio GPIO used to reset controller
1680 ledgpio GPIO used to control backlight
1684 Info: Configures the Audiophonics I-SABRE Q2M DAC
1685 Load: dtoverlay=i-sabre-q2m
1690 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1691 Load: dtoverlay=i2c-bcm2708
1696 Info: Adds support for a number of I2C fan controllers
1697 Load: dtoverlay=i2c-fan,<param>=<val>
1698 Params: addr Sets the address for the fan controller. Note
1699 that the device must be configured to use the
1702 i2c0 Choose the I2C0 bus on GPIOs 0&1
1704 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1706 i2c3 Choose the I2C3 bus (configure with the i2c3
1707 overlay - BCM2711 only)
1709 i2c4 Choose the I2C3 bus (configure with the i2c3
1710 overlay - BCM2711 only)
1712 i2c5 Choose the I2C5 bus (configure with the i2c4
1713 overlay - BCM2711 only)
1715 i2c6 Choose the I2C6 bus (configure with the i2c6
1716 overlay - BCM2711 only)
1718 minpwm PWM setting for the fan when the SoC is below
1719 mintemp (range 0-255. default 0)
1720 maxpwm PWM setting for the fan when the SoC is above
1721 maxtemp (range 0-255. default 255)
1722 midtemp Temperature (in millicelcius) at which the fan
1723 begins to speed up (default 50000)
1725 midtemp_hyst Temperature delta (in millicelcius) below
1726 mintemp at which the fan will drop to minrpm
1729 maxtemp Temperature (in millicelcius) at which the fan
1730 will be held at maxrpm (default 70000)
1732 maxtemp_hyst Temperature delta (in millicelcius) below
1733 maxtemp at which the fan begins to slow down
1736 emc2301 Select the Microchip EMC230x controller family
1737 - EMC2301, EMC2302, EMC2303, EMC2305.
1741 Info: Adds support for software i2c controller on gpio pins
1742 Load: dtoverlay=i2c-gpio,<param>=<val>
1743 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1745 i2c_gpio_scl GPIO used for I2C clock (default "24")
1747 i2c_gpio_delay_us Clock delay in microseconds
1748 (default "2" = ~100kHz)
1750 bus Set to a unique, non-zero value if wanting
1751 multiple i2c-gpio busses. If set, will be used
1752 as the preferred bus number (/dev/i2c-<n>). If
1753 not set, the default value is 0, but the bus
1754 number will be dynamically assigned - probably
1759 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1760 Load: dtoverlay=i2c-mux,<param>=<val>
1761 Params: pca9542 Select the NXP PCA9542 device
1763 pca9545 Select the NXP PCA9545 device
1765 pca9548 Select the NXP PCA9548 device
1767 addr Change I2C address of the device (default 0x70)
1770 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1773 Name: i2c-pwm-pca9685a
1774 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1775 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1776 Params: addr I2C address of PCA9685A (default 0x40)
1780 Info: Adds support for a number of I2C Real Time Clock devices
1781 Load: dtoverlay=i2c-rtc,<param>=<val>
1782 Params: abx80x Select one of the ABx80x family:
1783 AB0801, AB0803, AB0804, AB0805,
1784 AB1801, AB1803, AB1804, AB1805
1786 bq32000 Select the TI BQ32000 device
1788 ds1307 Select the DS1307 device
1790 ds1339 Select the DS1339 device
1792 ds1340 Select the DS1340 device
1794 ds3231 Select the DS3231 device
1796 m41t62 Select the M41T62 device
1798 mcp7940x Select the MCP7940x device
1800 mcp7941x Select the MCP7941x device
1802 pcf2127 Select the PCF2127 device
1804 pcf2129 Select the PCF2129 device
1806 pcf85063 Select the PCF85063 device
1808 pcf85063a Select the PCF85063A device
1810 pcf8523 Select the PCF8523 device
1812 pcf85363 Select the PCF85363 device
1814 pcf8563 Select the PCF8563 device
1816 rv1805 Select the Micro Crystal RV1805 device
1818 rv3028 Select the Micro Crystal RV3028 device
1820 rv3032 Select the Micro Crystal RV3032 device
1822 rv8803 Select the Micro Crystal RV8803 device
1824 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1826 s35390a Select the ABLIC S35390A device
1828 i2c0 Choose the I2C0 bus on GPIOs 0&1
1830 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1832 i2c3 Choose the I2C3 bus (configure with the i2c3
1833 overlay - BCM2711 only)
1835 i2c4 Choose the I2C3 bus (configure with the i2c3
1836 overlay - BCM2711 only)
1838 i2c5 Choose the I2C5 bus (configure with the i2c4
1839 overlay - BCM2711 only)
1841 i2c6 Choose the I2C6 bus (configure with the i2c6
1842 overlay - BCM2711 only)
1844 addr Sets the address for the RTC. Note that the
1845 device must be configured to use the specified
1848 trickle-diode-disable Do not use the internal trickle charger diode
1851 trickle-diode-type Diode type for trickle charge - "standard" or
1852 "schottky" (ABx80x and RV1805 only)
1854 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1855 ABx80x, RV1805, RV3028)
1857 wakeup-source Specify that the RTC can be used as a wakeup
1860 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1861 off or 1 for Vdd < VBackup (RV3028 only)
1865 Info: Adds support for a number of I2C Real Time Clock devices
1866 using the software i2c controller
1867 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1868 Params: abx80x Select one of the ABx80x family:
1869 AB0801, AB0803, AB0804, AB0805,
1870 AB1801, AB1803, AB1804, AB1805
1872 bq32000 Select the TI BQ32000 device
1874 ds1307 Select the DS1307 device
1876 ds1339 Select the DS1339 device
1878 ds1340 Select the DS1340 device
1880 ds3231 Select the DS3231 device
1882 m41t62 Select the M41T62 device
1884 mcp7940x Select the MCP7940x device
1886 mcp7941x Select the MCP7941x device
1888 pcf2127 Select the PCF2127 device
1890 pcf2129 Select the PCF2129 device
1892 pcf85063 Select the PCF85063 device
1894 pcf85063a Select the PCF85063A device
1896 pcf8523 Select the PCF8523 device
1898 pcf85363 Select the PCF85363 device
1900 pcf8563 Select the PCF8563 device
1902 rv1805 Select the Micro Crystal RV1805 device
1904 rv3028 Select the Micro Crystal RV3028 device
1906 rv3032 Select the Micro Crystal RV3032 device
1908 rv8803 Select the Micro Crystal RV8803 device
1910 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1912 s35390a Select the ABLIC S35390A device
1914 addr Sets the address for the RTC. Note that the
1915 device must be configured to use the specified
1918 trickle-diode-disable Do not use the internal trickle charger diode
1921 trickle-diode-type Diode type for trickle charge - "standard" or
1922 "schottky" (ABx80x and RV1805 only)
1924 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1925 ABx80x, RV1805, RV3028)
1927 wakeup-source Specify that the RTC can be used as a wakeup
1930 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1931 off or 1 for Vdd < VBackup (RV3028 only)
1933 i2c_gpio_sda GPIO used for I2C data (default "23")
1935 i2c_gpio_scl GPIO used for I2C clock (default "24")
1937 i2c_gpio_delay_us Clock delay in microseconds
1938 (default "2" = ~100kHz)
1942 Info: Adds support for a number of I2C barometric pressure, temperature,
1943 light level and chemical sensors on i2c_arm
1944 Load: dtoverlay=i2c-sensor,<param>=<val>
1945 Params: addr Set the address for the BH1750, BME280, BME680,
1946 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1949 aht10 Select the Aosong AHT10 temperature and humidity
1952 bh1750 Select the Rohm BH1750 ambient light sensor
1953 Valid addresses 0x23 or 0x5c, default 0x23
1955 bme280 Select the Bosch Sensortronic BME280
1956 Valid addresses 0x76-0x77, default 0x76
1958 bme680 Select the Bosch Sensortronic BME680
1959 Valid addresses 0x76-0x77, default 0x76
1961 bmp085 Select the Bosch Sensortronic BMP085
1963 bmp180 Select the Bosch Sensortronic BMP180
1965 bmp280 Select the Bosch Sensortronic BMP280
1966 Valid addresses 0x76-0x77, default 0x76
1968 ccs811 Select the AMS CCS811 digital gas sensor
1969 Valid addresses 0x5a-0x5b, default 0x5b
1971 ds1621 Select the Dallas Semiconductors DS1621 temp
1972 sensor. Valid addresses 0x48-0x4f, default 0x48
1974 hdc100x Select the Texas Instruments HDC100x temp sensor
1975 Valid addresses 0x40-0x43, default 0x40
1977 htu21 Select the HTU21 temperature and humidity sensor
1979 int_pin Set the GPIO to use for interrupts (max30102
1982 jc42 Select any of the many JEDEC JC42.4-compliant
1983 temperature sensors, including:
1984 ADT7408, AT30TS00, CAT34TS02, CAT6095,
1985 MAX6604, MCP9804, MCP9805, MCP9808,
1986 MCP98242, MCP98243, MCP98244, MCP9843,
1987 SE97, SE98, STTS424(E), STTS2002, STTS3000,
1988 TSE2002, TSE2004, TS3000, and TS3001.
1989 The default address is 0x18.
1991 lm75 Select the Maxim LM75 temperature sensor
1992 Valid addresses 0x48-0x4f, default 0x4f
1994 lm75addr Deprecated - use addr parameter instead
1996 max17040 Select the Maxim Integrated MAX17040 battery
1999 max30102 Select the Maxim Integrated MAX30102 heart-rate
2000 and blood-oxygen sensor
2002 mcp980x Select the Maxim MCP980x range of temperature
2003 sensors (i.e. MCP9800, MCP9801, MCP9802 and
2004 MCP9803). N.B. For MCP9804, MCP9805 and MCP9808,
2005 use the "jc42" option.
2006 Valid addresses are 0x18-0x1f (default 0x18)
2008 sht3x Select the Sensiron SHT3x temperature and
2009 humidity sensor. Valid addresses 0x44-0x45,
2012 si7020 Select the Silicon Labs Si7013/20/21 humidity/
2015 sps30 Select the Sensirion SPS30 particulate matter
2016 sensor. Fixed address 0x69.
2018 sgp30 Select the Sensirion SGP30 VOC sensor.
2021 tmp102 Select the Texas Instruments TMP102 temp sensor
2022 Valid addresses 0x48-0x4b, default 0x48
2024 tsl4531 Select the AMS TSL4531 digital ambient light
2027 veml6070 Select the Vishay VEML6070 ultraviolet light
2030 i2c0 Choose the I2C0 bus on GPIOs 0&1
2032 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
2034 i2c3 Choose the I2C3 bus (configure with the i2c3
2035 overlay - BCM2711 only)
2037 i2c4 Choose the I2C3 bus (configure with the i2c3
2038 overlay - BCM2711 only)
2040 i2c5 Choose the I2C5 bus (configure with the i2c4
2041 overlay - BCM2711 only)
2043 i2c6 Choose the I2C6 bus (configure with the i2c6
2044 overlay - BCM2711 only)
2048 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
2049 platforms - platforms other then Compute Modules can only use this
2050 to disable transaction combining.
2051 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
2052 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
2053 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
2054 camera and display connectors. This overlay disables that mux and
2055 configures /dev/i2c0 to point at whichever set of pins is requested.
2056 dtparam=i2c_vc=on will try and enable the mux, so combining the two
2057 will cause conflicts.
2058 Load: dtoverlay=i2c0,<param>=<val>
2059 Params: pins_0_1 Use pins 0 and 1 (default)
2060 pins_28_29 Use pins 28 and 29
2061 pins_44_45 Use pins 44 and 45
2062 pins_46_47 Use pins 46 and 47
2063 combine Allow transactions to be combined (default
2068 Info: Deprecated, legacy version of i2c0.
2073 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
2074 platforms - platforms other then Compute Modules can only use this
2075 to disable transaction combining.
2076 Load: dtoverlay=i2c1,<param>=<val>
2077 Params: pins_2_3 Use pins 2 and 3 (default)
2078 pins_44_45 Use pins 44 and 45
2079 combine Allow transactions to be combined (default
2084 Info: Deprecated, legacy version of i2c1.
2089 Info: Enable the i2c3 bus. BCM2711 only.
2090 Load: dtoverlay=i2c3,<param>
2091 Params: pins_2_3 Use GPIOs 2 and 3
2092 pins_4_5 Use GPIOs 4 and 5 (default)
2093 baudrate Set the baudrate for the interface (default
2098 Info: Enable the i2c4 bus. BCM2711 only.
2099 Load: dtoverlay=i2c4,<param>
2100 Params: pins_6_7 Use GPIOs 6 and 7
2101 pins_8_9 Use GPIOs 8 and 9 (default)
2102 baudrate Set the baudrate for the interface (default
2107 Info: Enable the i2c5 bus. BCM2711 only.
2108 Load: dtoverlay=i2c5,<param>
2109 Params: pins_10_11 Use GPIOs 10 and 11
2110 pins_12_13 Use GPIOs 12 and 13 (default)
2111 baudrate Set the baudrate for the interface (default
2116 Info: Enable the i2c6 bus. BCM2711 only.
2117 Load: dtoverlay=i2c6,<param>
2118 Params: pins_0_1 Use GPIOs 0 and 1
2119 pins_22_23 Use GPIOs 22 and 23 (default)
2120 baudrate Set the baudrate for the interface (default
2125 Info: Configures any passive I2S DAC soundcard.
2126 Load: dtoverlay=i2s-dac
2131 Info: move I2S function block to GPIO 28 to 31
2132 Load: dtoverlay=i2s-gpio28-31
2137 Info: Enables I2C connected Ilitek 251x multiple touch controller using
2138 GPIO 4 (pin 7 on GPIO header) for interrupt.
2139 Load: dtoverlay=ilitek251x,<param>=<val>
2140 Params: interrupt GPIO used for interrupt (default 4)
2141 sizex Touchscreen size x, horizontal resolution of
2142 touchscreen (in pixels)
2143 sizey Touchscreen size y, vertical resolution of
2144 touchscreen (in pixels)
2148 Info: Sony IMX219 camera module.
2149 Uses Unicam 1, which is the standard camera connector on most Pi
2151 Load: dtoverlay=imx219,<param>=<val>
2152 Params: rotation Mounting rotation of the camera sensor (0 or
2154 orientation Sensor orientation (0 = front, 1 = rear,
2155 2 = external, default external)
2156 media-controller Configure use of Media Controller API for
2157 configuring the sensor (default on)
2158 cam0 Adopt the default configuration for CAM0 on a
2159 Compute Module (CSI0, i2c_vc, and cam0_reg).
2160 vcm Configure a VCM focus drive on the sensor.
2164 Info: Sony IMX258 camera module.
2165 Uses Unicam 1, which is the standard camera connector on most Pi
2167 Load: dtoverlay=imx258,<param>=<val>
2168 Params: rotation Mounting rotation of the camera sensor (0 or
2170 orientation Sensor orientation (0 = front, 1 = rear,
2171 2 = external, default external)
2172 media-controller Configure use of Media Controller API for
2173 configuring the sensor (default on)
2174 cam0 Adopt the default configuration for CAM0 on a
2175 Compute Module (CSI0, i2c_vc, and cam0_reg).
2176 vcm Configure a VCM focus drive on the sensor.
2177 4lane Enable 4 CSI2 lanes. This requires a Compute
2178 Module (1, 3, or 4).
2182 Info: Sony IMX290 camera module.
2183 Uses Unicam 1, which is the standard camera connector on most Pi
2185 Load: dtoverlay=imx290,<param>
2186 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2187 Module (1, 3, or 4).
2188 clock-frequency Sets the clock frequency to match that used on
2190 Modules from Vision Components use 37.125MHz
2191 (the default), whilst those from Innomaker use
2193 mono Denote that the module is a mono sensor.
2194 orientation Sensor orientation (0 = front, 1 = rear,
2195 2 = external, default external)
2196 rotation Mounting rotation of the camera sensor (0 or
2198 media-controller Configure use of Media Controller API for
2199 configuring the sensor (default on)
2200 cam0 Adopt the default configuration for CAM0 on a
2201 Compute Module (CSI0, i2c_vc, and cam0_reg).
2205 Info: Sony IMX296 camera module.
2206 Uses Unicam 1, which is the standard camera connector on most Pi
2208 Load: dtoverlay=imx296,<param>=<val>
2209 Params: rotation Mounting rotation of the camera sensor (0 or
2211 orientation Sensor orientation (0 = front, 1 = rear,
2212 2 = external, default external)
2213 media-controller Configure use of Media Controller API for
2214 configuring the sensor (default on)
2215 cam0 Adopt the default configuration for CAM0 on a
2216 Compute Module (CSI0, i2c_vc, and cam0_reg).
2217 clock-frequency Sets the clock frequency to match that used on
2218 the board, which should be one of 54000000
2219 (the default), 37125000 or 74250000.
2223 Info: Sony IMX327 camera module.
2224 Uses Unicam 1, which is the standard camera connector on most Pi
2226 Load: dtoverlay=imx327,<param>
2227 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2228 Module (1, 3, or 4).
2229 clock-frequency Sets the clock frequency to match that used on
2231 Modules from Vision Components use 37.125MHz
2232 (the default), whilst those from Innomaker use
2234 mono Denote that the module is a mono sensor.
2235 orientation Sensor orientation (0 = front, 1 = rear,
2236 2 = external, default external)
2237 rotation Mounting rotation of the camera sensor (0 or
2239 media-controller Configure use of Media Controller API for
2240 configuring the sensor (default on)
2241 cam0 Adopt the default configuration for CAM0 on a
2242 Compute Module (CSI0, i2c_vc, and cam0_reg).
2246 Info: Sony IMX378 camera module.
2247 Uses Unicam 1, which is the standard camera connector on most Pi
2249 Load: dtoverlay=imx378,<param>=<val>
2250 Params: rotation Mounting rotation of the camera sensor (0 or
2252 orientation Sensor orientation (0 = front, 1 = rear,
2253 2 = external, default external)
2254 media-controller Configure use of Media Controller API for
2255 configuring the sensor (default on)
2256 cam0 Adopt the default configuration for CAM0 on a
2257 Compute Module (CSI0, i2c_vc, and cam0_reg).
2261 Info: Sony IMX462 camera module.
2262 Uses Unicam 1, which is the standard camera connector on most Pi
2264 Load: dtoverlay=imx462,<param>
2265 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2266 Module (1, 3, or 4).
2267 clock-frequency Sets the clock frequency to match that used on
2269 Modules from Vision Components use 37.125MHz
2270 (the default), whilst those from Innomaker use
2272 mono Denote that the module is a mono sensor.
2273 orientation Sensor orientation (0 = front, 1 = rear,
2274 2 = external, default external)
2275 rotation Mounting rotation of the camera sensor (0 or
2277 media-controller Configure use of Media Controller API for
2278 configuring the sensor (default on)
2279 cam0 Adopt the default configuration for CAM0 on a
2280 Compute Module (CSI0, i2c_vc, and cam0_reg).
2284 Info: Sony IMX477 camera module.
2285 Uses Unicam 1, which is the standard camera connector on most Pi
2287 Load: dtoverlay=imx477,<param>=<val>
2288 Params: rotation Mounting rotation of the camera sensor (0 or
2290 orientation Sensor orientation (0 = front, 1 = rear,
2291 2 = external, default external)
2292 media-controller Configure use of Media Controller API for
2293 configuring the sensor (default on)
2294 cam0 Adopt the default configuration for CAM0 on a
2295 Compute Module (CSI0, i2c_vc, and cam0_reg).
2299 Info: Sony IMX519 camera module.
2300 Uses Unicam 1, which is the standard camera connector on most Pi
2302 Load: dtoverlay=imx519,<param>=<val>
2303 Params: rotation Mounting rotation of the camera sensor (0 or
2305 orientation Sensor orientation (0 = front, 1 = rear,
2306 2 = external, default external)
2307 media-controller Configure use of Media Controller API for
2308 configuring the sensor (default on)
2309 cam0 Adopt the default configuration for CAM0 on a
2310 Compute Module (CSI0, i2c_vc, and cam0_reg).
2314 Info: Sony IMX708 camera module.
2315 Uses Unicam 1, which is the standard camera connector on most Pi
2317 Load: dtoverlay=imx708,<param>=<val>
2318 Params: rotation Mounting rotation of the camera sensor (0 or
2320 vcm Select lens driver state. Default is enabled,
2321 but vcm=off will disable.
2322 media-controller Configure use of Media Controller API for
2323 configuring the sensor (default on)
2324 cam0 Adopt the default configuration for CAM0 on a
2325 Compute Module (CSI0, i2c_vc, and cam0_reg).
2329 Info: Configures the IQaudio Codec audio card
2330 Load: dtoverlay=iqaudio-codec
2335 Info: Configures the IQaudio DAC audio card
2336 Load: dtoverlay=iqaudio-dac,<param>
2337 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2338 Digital volume control. Enable with
2339 "dtoverlay=iqaudio-dac,24db_digital_gain"
2340 (The default behaviour is that the Digital
2341 volume control is limited to a maximum of
2342 0dB. ie. it can attenuate but not provide
2343 gain. For most users, this will be desired
2344 as it will prevent clipping. By appending
2345 the 24db_digital_gain parameter, the Digital
2346 volume control will allow up to 24dB of
2347 gain. If this parameter is enabled, it is the
2348 responsibility of the user to ensure that
2349 the Digital volume control is set to a value
2350 that does not result in clipping/distortion!)
2353 Name: iqaudio-dacplus
2354 Info: Configures the IQaudio DAC+ audio card
2355 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2356 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2357 Digital volume control. Enable with
2358 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2359 (The default behaviour is that the Digital
2360 volume control is limited to a maximum of
2361 0dB. ie. it can attenuate but not provide
2362 gain. For most users, this will be desired
2363 as it will prevent clipping. By appending
2364 the 24db_digital_gain parameter, the Digital
2365 volume control will allow up to 24dB of
2366 gain. If this parameter is enabled, it is the
2367 responsibility of the user to ensure that
2368 the Digital volume control is set to a value
2369 that does not result in clipping/distortion!)
2370 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2371 starting/stopping audio playback.
2372 unmute_amp If specified, unmute the IQaudIO amp once when
2373 the DAC driver module loads.
2376 Name: iqaudio-digi-wm8804-audio
2377 Info: Configures the IQAudIO Digi WM8804 audio card
2378 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2379 Params: card_name Override the default, "IQAudIODigi", card name.
2380 dai_name Override the default, "IQAudIO Digi", dai name.
2381 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2386 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2387 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2388 Load: dtoverlay=iqs550,<param>=<val>
2389 Params: interrupt GPIO used for interrupt (default 4)
2390 reset GPIO used for reset (optional)
2391 sizex Touchscreen size x (default 800)
2392 sizey Touchscreen size y (default 480)
2393 invx Touchscreen inverted x axis
2394 invy Touchscreen inverted y axis
2395 swapxy Touchscreen swapped x y axis
2399 Info: Infineon irs1125 TOF camera module.
2400 Uses Unicam 1, which is the standard camera connector on most Pi
2402 Load: dtoverlay=irs1125,<param>=<val>
2403 Params: media-controller Configure use of Media Controller API for
2404 configuring the sensor (default off)
2405 cam0 Adopt the default configuration for CAM0 on a
2406 Compute Module (CSI0, i2c_vc, and cam0_reg).
2410 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2411 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2412 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2413 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2414 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2419 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2421 Load: dtoverlay=justboom-both,<param>=<val>
2422 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2423 Digital volume control. Enable with
2424 "dtoverlay=justboom-dac,24db_digital_gain"
2425 (The default behaviour is that the Digital
2426 volume control is limited to a maximum of
2427 0dB. ie. it can attenuate but not provide
2428 gain. For most users, this will be desired
2429 as it will prevent clipping. By appending
2430 the 24dB_digital_gain parameter, the Digital
2431 volume control will allow up to 24dB of
2432 gain. If this parameter is enabled, it is the
2433 responsibility of the user to ensure that
2434 the Digital volume control is set to a value
2435 that does not result in clipping/distortion!)
2439 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2441 Load: dtoverlay=justboom-dac,<param>=<val>
2442 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2443 Digital volume control. Enable with
2444 "dtoverlay=justboom-dac,24db_digital_gain"
2445 (The default behaviour is that the Digital
2446 volume control is limited to a maximum of
2447 0dB. ie. it can attenuate but not provide
2448 gain. For most users, this will be desired
2449 as it will prevent clipping. By appending
2450 the 24dB_digital_gain parameter, the Digital
2451 volume control will allow up to 24dB of
2452 gain. If this parameter is enabled, it is the
2453 responsibility of the user to ensure that
2454 the Digital volume control is set to a value
2455 that does not result in clipping/distortion!)
2459 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2460 Load: dtoverlay=justboom-digi
2465 Info: This overlay has been deprecated and removed - see gpio-ir
2470 Info: Adds support for the ltc294x family of battery gauges
2471 Load: dtoverlay=ltc294x,<param>=<val>
2472 Params: ltc2941 Select the ltc2941 device
2474 ltc2942 Select the ltc2942 device
2476 ltc2943 Select the ltc2943 device
2478 ltc2944 Select the ltc2944 device
2480 resistor-sense The sense resistor value in milli-ohms.
2481 Can be a 32-bit negative value when the battery
2482 has been connected to the wrong end of the
2485 prescaler-exponent Range and accuracy of the gauge. The value is
2486 programmed into the chip only if it differs
2487 from the current setting.
2489 - Default value is 128
2490 - the exponent is in the range 0-7 (default 7)
2491 See the datasheet for more information.
2495 Info: Configures the Maxim MAX98357A I2S DAC
2496 Load: dtoverlay=max98357a,<param>=<val>
2497 Params: no-sdmode Driver does not manage the state of the DAC's
2498 SD_MODE pin (i.e. chip is always on).
2499 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2500 of the DAC (default GPIO4 if parameter omitted).
2504 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2506 For devices on spi1 or spi2, the interfaces should be enabled
2507 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2508 The overlay expects to disable the relevant spidev node, so also using
2509 e.g. cs0_spidev=off is unnecessary.
2512 MAX31855 on /dev/spidev0.0
2513 dtoverlay=maxtherm,spi0-0,max31855
2514 MAX31856 using a type J thermocouple on /dev/spidev2.1
2516 dtoverlay=maxtherm,spi2-1,max31856,type_j
2518 Load: dtoverlay=maxtherm,<param>=<val>
2519 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2521 max6675 Enable support for the MAX6675 (default)
2522 max31855 Enable support for the MAX31855
2523 max31855e Enable support for the MAX31855E
2524 max31855j Enable support for the MAX31855J
2525 max31855k Enable support for the MAX31855K
2526 max31855n Enable support for the MAX31855N
2527 max31855r Enable support for the MAX31855R
2528 max31855s Enable support for the MAX31855S
2529 max31855t Enable support for the MAX31855T
2530 max31856 Enable support for the MAX31856 (with type K)
2531 type_b Select a type B sensor for max31856
2532 type_e Select a type E sensor for max31856
2533 type_j Select a type J sensor for max31856
2534 type_k Select a type K sensor for max31856
2535 type_n Select a type N sensor for max31856
2536 type_r Select a type R sensor for max31856
2537 type_s Select a type S sensor for max31856
2538 type_t Select a type T sensor for max31856
2542 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2543 Load: dtoverlay=mbed-dac
2548 Info: Configures the MCP23017 I2C GPIO expander
2549 Load: dtoverlay=mcp23017,<param>=<val>
2550 Params: gpiopin Gpio pin connected to the INTA output of the
2551 MCP23017 (default: 4)
2553 addr I2C address of the MCP23017 (default: 0x20)
2555 mcp23008 Configure an MCP23008 instead.
2556 noints Disable the interrupt GPIO line.
2560 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2561 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2562 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2563 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2564 device must be the only one present on that SPI bus/CS#.
2565 Load: dtoverlay=mcp23s17,<param>=<val>
2566 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2567 devices present on SPI<n>, CS#<m>
2569 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2570 devices present on SPI<n>, CS#<m>
2572 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2573 MCP23S08 device on SPI<n>, CS#<m>, specifies
2574 the GPIO pin to which INT output of MCP23S08
2577 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2578 single MCP23S17 device on SPI<n>, CS#<m>,
2579 specifies the GPIO pin to which either INTA
2580 or INTB output of MCP23S17 is connected.
2584 Info: Configures the MCP2515 CAN controller on spi0/1/2
2585 For devices on spi1 or spi2, the interfaces should be enabled
2586 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2587 Load: dtoverlay=mcp2515,<param>=<val>
2588 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2591 oscillator Clock frequency for the CAN controller (Hz)
2593 speed Maximum SPI frequence (Hz)
2595 interrupt GPIO for interrupt signal
2599 Info: Configures the MCP2515 CAN controller on spi0.0
2600 Load: dtoverlay=mcp2515-can0,<param>=<val>
2601 Params: oscillator Clock frequency for the CAN controller (Hz)
2603 spimaxfrequency Maximum SPI frequence (Hz)
2605 interrupt GPIO for interrupt signal
2609 Info: Configures the MCP2515 CAN controller on spi0.1
2610 Load: dtoverlay=mcp2515-can1,<param>=<val>
2611 Params: oscillator Clock frequency for the CAN controller (Hz)
2613 spimaxfrequency Maximum SPI frequence (Hz)
2615 interrupt GPIO for interrupt signal
2619 Info: Configures the MCP251XFD CAN controller family
2620 For devices on spi1 or spi2, the interfaces should be enabled
2621 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2622 Load: dtoverlay=mcp251xfd,<param>=<val>
2623 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2626 oscillator Clock frequency for the CAN controller (Hz)
2628 speed Maximum SPI frequence (Hz)
2630 interrupt GPIO for interrupt signal
2632 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2634 xceiver_enable GPIO for CAN transceiver enable (optional)
2636 xceiver_active_high specifiy if CAN transceiver enable pin is
2637 active high (optional, default: active low)
2641 Info: Configures MCP3008 A/D converters
2642 For devices on spi1 or spi2, the interfaces should be enabled
2643 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2644 Load: dtoverlay=mcp3008,<param>[=<val>]
2645 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2646 spi<n>-<m>-speed integer, set the spi bus speed for this device
2650 Info: Configures MCP3202 A/D converters
2651 For devices on spi1 or spi2, the interfaces should be enabled
2652 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2653 Load: dtoverlay=mcp3202,<param>[=<val>]
2654 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2655 spi<n>-<m>-speed integer, set the spi bus speed for this device
2659 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2660 Load: dtoverlay=mcp342x,<param>=<val>
2661 Params: addr I2C bus address of device, for devices with
2662 addresses that are configurable, e.g. by
2663 hardware links (default=0x68)
2664 mcp3421 The device is an MCP3421
2665 mcp3422 The device is an MCP3422
2666 mcp3423 The device is an MCP3423
2667 mcp3424 The device is an MCP3424
2668 mcp3425 The device is an MCP3425
2669 mcp3426 The device is an MCP3426
2670 mcp3427 The device is an MCP3427
2671 mcp3428 The device is an MCP3428
2675 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2676 Load: dtoverlay=media-center,<param>=<val>
2677 Params: speed Display SPI bus speed
2678 rotate Display rotation {0,90,180,270}
2679 fps Delay between frame updates
2680 xohms Touchpanel sensitivity (X-plate resistance)
2681 swapxy Swap x and y axis
2682 backlight Change backlight GPIO pin {e.g. 12, 18}
2683 gpio_out_pin GPIO for output (default "17")
2684 gpio_in_pin GPIO for input (default "18")
2685 gpio_in_pull Pull up/down/off on the input pin
2687 sense Override the IR receive auto-detection logic:
2688 "0" = force active-high
2689 "1" = force active-low
2690 "-1" = use auto-detection
2692 softcarrier Turn the software carrier "on" or "off"
2694 invert "on" = invert the output pin (default "off")
2695 debug "on" = enable additional debug messages
2700 Info: Configures the merus-amp audio card
2701 Load: dtoverlay=merus-amp
2706 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2707 31.25kbaud, the frequency required for MIDI
2708 Load: dtoverlay=midi-uart0
2713 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2714 31.25kbaud, the frequency required for MIDI
2715 Load: dtoverlay=midi-uart1
2720 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2721 31.25kbaud, the frequency required for MIDI
2722 Load: dtoverlay=midi-uart2
2727 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2728 31.25kbaud, the frequency required for MIDI
2729 Load: dtoverlay=midi-uart3
2734 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2735 31.25kbaud, the frequency required for MIDI
2736 Load: dtoverlay=midi-uart4
2741 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2742 31.25kbaud, the frequency required for MIDI
2743 Load: dtoverlay=midi-uart5
2748 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2749 Load: dtoverlay=minipitft13,<param>=<val>
2750 Params: speed SPI bus speed (default 32000000)
2751 rotate Display rotation (0, 90, 180 or 270; default 0)
2752 width Display width (default 240)
2753 height Display height (default 240)
2754 fps Delay between frame updates (default 25)
2755 debug Debug output level (0-7; default 0)
2759 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2760 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2761 15. Note that this may reduce the maximum usable baudrate.
2762 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2763 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2764 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2765 in which case use /dev/serial1 instead because it will always be
2766 correct. Furthermore, you must also set core_freq and core_freq_min to
2767 the same value in config.txt or the miniuart will not work.
2768 Load: dtoverlay=miniuart-bt,<param>=<val>
2769 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2770 driver without need of hciattach/btattach
2774 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2775 driver. The driver will load a file /lib/firmware/panel.bin containing
2776 the initialisation commands.
2779 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2780 dtparam=width=320,height=240
2781 dtparam=reset-gpio=23,dc-gpio=24
2782 dtparam=backlight-gpio=18
2784 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2785 and init commands at 10MHz. This makes it possible to push the envelope
2786 without messing up the controller configuration due to command
2787 transmission errors.
2789 For devices on spi1 or spi2, the interfaces should be enabled
2790 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2792 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2794 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2796 compatible Set the compatible string to load a different
2797 firmware file. Both the panel compatible value
2798 used to load the firmware file and the value
2799 used to load the driver has to be set having a
2800 NUL (\0) separator between them.
2802 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2803 spi<n>-<m> Configure device at spi<n>, cs<m>
2805 speed SPI bus speed in Hz (default 32000000)
2806 cpha Shifted SPI clock phase (CPHA) mode
2807 cpol Inverse SPI clock polarity (CPOL) mode
2808 write-only Controller is not readable
2809 (ie. MISO is not wired up).
2811 width Panel width in pixels (required)
2812 height Panel height in pixels (required)
2813 width-mm Panel width in mm
2814 height-mm Panel height in mm
2815 x-offset Panel x-offset in controller RAM
2816 y-offset Panel y-offset in controller RAM
2818 clock-frequency Panel clock frequency in Hz
2819 (optional, just informational).
2821 reset-gpio GPIO pin to be used for RESET
2822 dc-gpio GPIO pin to be used for D/C
2824 backlight-gpio GPIO pin to be used for backlight control
2826 backlight-pwm PWM channel to be used for backlight control
2827 (default of none). NB Disables audio headphone
2828 output as that also uses PWM.
2829 backlight-pwm-chan Choose channel on &pwm node for backlight
2830 control (default 0).
2831 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2832 pwm-2chan for valid options (default 18).
2833 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2834 See pwm-2chan for valid options (default 2).
2835 backlight-def-brightness
2836 Set the default brightness. Normal range 1-16.
2841 Info: Overlay for i2c connected mlx90640 thermal camera
2842 Load: dtoverlay=mlx90640
2847 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2848 Load: dtoverlay=mmc,<param>=<val>
2849 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2854 Info: Overlay for i2c connected mpu6050 imu
2855 Load: dtoverlay=mpu6050,<param>=<val>
2856 Params: interrupt GPIO pin for interrupt (default 4)
2857 addr I2C address of the device (default 0x68)
2861 Info: MZ61581 display by Tontec
2862 Load: dtoverlay=mz61581,<param>=<val>
2863 Params: speed Display SPI bus speed
2865 rotate Display rotation {0,90,180,270}
2867 fps Delay between frame updates
2869 txbuflen Transmit buffer length (default 32768)
2871 debug Debug output level {0-7}
2873 xohms Touchpanel sensitivity (X-plate resistance)
2877 Info: Omnivision OV2311 camera module.
2878 Uses Unicam 1, which is the standard camera connector on most Pi
2880 Load: dtoverlay=ov2311,<param>=<val>
2881 Params: rotation Mounting rotation of the camera sensor (0 or
2883 orientation Sensor orientation (0 = front, 1 = rear,
2884 2 = external, default external)
2885 media-controller Configure use of Media Controller API for
2886 configuring the sensor (default on)
2887 cam0 Adopt the default configuration for CAM0 on a
2888 Compute Module (CSI0, i2c_vc, and cam0_reg).
2892 Info: Omnivision OV5647 camera module.
2893 Uses Unicam 1, which is the standard camera connector on most Pi
2895 Load: dtoverlay=ov5647,<param>=<val>
2896 Params: rotation Mounting rotation of the camera sensor (0 or
2898 orientation Sensor orientation (0 = front, 1 = rear,
2899 2 = external, default external)
2900 media-controller Configure use of Media Controller API for
2901 configuring the sensor (default on)
2902 cam0 Adopt the default configuration for CAM0 on a
2903 Compute Module (CSI0, i2c_vc, and cam0_reg).
2904 vcm Configure a VCM focus drive on the sensor.
2908 Info: Omnivision OV7251 camera module.
2909 Uses Unicam 1, which is the standard camera connector on most Pi
2911 Load: dtoverlay=ov7251,<param>=<val>
2912 Params: rotation Mounting rotation of the camera sensor (0 or
2914 orientation Sensor orientation (0 = front, 1 = rear,
2915 2 = external, default external)
2916 media-controller Configure use of Media Controller API for
2917 configuring the sensor (default off)
2918 cam0 Adopt the default configuration for CAM0 on a
2919 Compute Module (CSI0, i2c_vc, and cam0_reg).
2923 Info: Omnivision OV9281 camera module.
2924 Uses Unicam 1, which is the standard camera connector on most Pi
2926 Load: dtoverlay=ov9281,<param>=<val>
2927 Params: rotation Mounting rotation of the camera sensor (0 or
2929 orientation Sensor orientation (0 = front, 1 = rear,
2930 2 = external, default external)
2931 media-controller Configure use of Media Controller API for
2932 configuring the sensor (default on)
2933 cam0 Adopt the default configuration for CAM0 on a
2934 Compute Module (CSI0, i2c_vc, and cam0_reg).
2938 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2939 Load: dtoverlay=papirus,<param>=<val>
2940 Params: panel Display panel (required):
2945 speed Display SPI bus speed
2949 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2950 Load: dtoverlay=pca953x,<param>=<val>
2951 Params: addr I2C address of expander. Default 0x20.
2952 pca6416 Select the NXP PCA6416 (16 bit)
2953 pca9505 Select the NXP PCA9505 (40 bit)
2954 pca9535 Select the NXP PCA9535 (16 bit)
2955 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2956 pca9537 Select the NXP PCA9537 (4 bit)
2957 pca9538 Select the NXP PCA9538 (8 bit)
2958 pca9539 Select the NXP PCA9539 (16 bit)
2959 pca9554 Select the NXP PCA9554 (8 bit)
2960 pca9555 Select the NXP PCA9555 (16 bit)
2961 pca9556 Select the NXP PCA9556 (8 bit)
2962 pca9557 Select the NXP PCA9557 (8 bit)
2963 pca9574 Select the NXP PCA9574 (8 bit)
2964 pca9575 Select the NXP PCA9575 (16 bit)
2965 pca9698 Select the NXP PCA9698 (40 bit)
2966 pca16416 Select the NXP PCA16416 (16 bit)
2967 pca16524 Select the NXP PCA16524 (24 bit)
2968 pca19555a Select the NXP PCA19555A (16 bit)
2969 max7310 Select the Maxim MAX7310 (8 bit)
2970 max7312 Select the Maxim MAX7312 (16 bit)
2971 max7313 Select the Maxim MAX7313 (16 bit)
2972 max7315 Select the Maxim MAX7315 (8 bit)
2973 pca6107 Select the TI PCA6107 (8 bit)
2974 tca6408 Select the TI TCA6408 (8 bit)
2975 tca6416 Select the TI TCA6416 (16 bit)
2976 tca6424 Select the TI TCA6424 (24 bit)
2977 tca9539 Select the TI TCA9539 (16 bit)
2978 tca9554 Select the TI TCA9554 (8 bit)
2979 cat9554 Select the Onnn CAT9554 (8 bit)
2980 pca9654 Select the Onnn PCA9654 (8 bit)
2981 xra1202 Select the Exar XRA1202 (8 bit)
2984 Name: pcie-32bit-dma
2985 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2986 having to bounce buffers.
2987 Load: dtoverlay=pcie-32bit-dma
2991 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2994 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2997 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
3001 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
3002 for backwards compatibility.
3006 Name: pi3-disable-bt
3007 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
3008 alias for backwards compatibility.
3012 Name: pi3-disable-wifi
3013 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
3014 an alias for backwards compatibility.
3018 Name: pi3-miniuart-bt
3019 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
3020 an alias for backwards compatibility.
3025 Info: Configures the pibell audio card.
3026 Load: dtoverlay=pibell,<param>=<val>
3027 Params: alsaname Set the name as it appears in ALSA (default
3032 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
3033 Load: dtoverlay=pifacedigital,<param>=<val>
3034 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
3035 CS0 address. PiFace Digital supports addresses
3036 0-3, which can be configured with JP1 and JP2.
3040 Info: Configures the PiFi 40W stereo amplifier
3041 Load: dtoverlay=pifi-40
3046 Info: Configures the PiFi DAC HD
3047 Load: dtoverlay=pifi-dac-hd
3052 Info: Configures the PiFi DAC Zero
3053 Load: dtoverlay=pifi-dac-zero
3058 Info: Configures the PiFi Mini stereo amplifier
3059 Load: dtoverlay=pifi-mini-210
3064 Info: Configures the PiGlow by pimoroni.com
3065 Load: dtoverlay=piglow
3070 Info: PiScreen display by OzzMaker.com
3071 Load: dtoverlay=piscreen,<param>=<val>
3072 Params: speed Display SPI bus speed
3074 rotate Display rotation {0,90,180,270}
3076 fps Delay between frame updates
3078 debug Debug output level {0-7}
3080 xohms Touchpanel sensitivity (X-plate resistance)
3084 Info: PiScreen 2 with resistive TP display by OzzMaker.com
3085 Load: dtoverlay=piscreen2r,<param>=<val>
3086 Params: speed Display SPI bus speed
3088 rotate Display rotation {0,90,180,270}
3090 fps Delay between frame updates
3092 debug Debug output level {0-7}
3094 xohms Touchpanel sensitivity (X-plate resistance)
3098 Info: Configures the Blokas Labs pisound card
3099 Load: dtoverlay=pisound
3104 Info: Adafruit PiTFT 2.2" screen
3105 Load: dtoverlay=pitft22,<param>=<val>
3106 Params: speed Display SPI bus speed
3108 rotate Display rotation {0,90,180,270}
3110 fps Delay between frame updates
3112 debug Debug output level {0-7}
3115 Name: pitft28-capacitive
3116 Info: Adafruit PiTFT 2.8" capacitive touch screen
3117 Load: dtoverlay=pitft28-capacitive,<param>=<val>
3118 Params: speed Display SPI bus speed
3120 rotate Display rotation {0,90,180,270}
3122 fps Delay between frame updates
3124 debug Debug output level {0-7}
3126 touch-sizex Touchscreen size x (default 240)
3128 touch-sizey Touchscreen size y (default 320)
3130 touch-invx Touchscreen inverted x axis
3132 touch-invy Touchscreen inverted y axis
3134 touch-swapxy Touchscreen swapped x y axis
3137 Name: pitft28-resistive
3138 Info: Adafruit PiTFT 2.8" resistive touch screen
3139 Load: dtoverlay=pitft28-resistive,<param>=<val>
3140 Params: speed Display SPI bus speed
3142 rotate Display rotation {0,90,180,270}
3144 fps Delay between frame updates
3146 debug Debug output level {0-7}
3148 drm Force the use of the mi0283qt DRM driver (by
3149 default the ili9340 framebuffer driver will
3150 be used in preference if available)
3153 Name: pitft35-resistive
3154 Info: Adafruit PiTFT 3.5" resistive touch screen
3155 Load: dtoverlay=pitft35-resistive,<param>=<val>
3156 Params: speed Display SPI bus speed
3158 rotate Display rotation {0,90,180,270}
3160 fps Delay between frame updates
3162 debug Debug output level {0-7}
3164 drm Force the use of the hx8357d DRM driver (by
3165 default the fb_hx8357d framebuffer driver will
3166 be used in preference if available)
3170 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
3171 Load: dtoverlay=pps-gpio,<param>=<val>
3172 Params: gpiopin Input GPIO (default "18")
3173 assert_falling_edge When present, assert is indicated by a falling
3174 edge, rather than by a rising edge (default
3176 capture_clear Generate clear events on the trailing edge
3178 pull Desired pull-up/down state (off, down, up)
3183 Info: Configures the PROTO Audio Codec card
3184 Load: dtoverlay=proto-codec
3189 Info: Configures a single PWM channel
3190 Legal pin,function combinations for each channel:
3191 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3192 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3194 1) Pin 18 is the only one available on all platforms, and
3195 it is the one used by the I2S audio interface.
3196 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3197 2) The onboard analogue audio output uses both PWM channels.
3198 3) So be careful mixing audio and PWM.
3199 4) Currently the clock must have been enabled and configured
3201 Load: dtoverlay=pwm,<param>=<val>
3202 Params: pin Output pin (default 18) - see table
3203 func Pin function (default 2 = Alt5) - see above
3204 clock PWM clock frequency (informational)
3208 Info: Configures both PWM channels
3209 Legal pin,function combinations for each channel:
3210 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3211 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3213 1) Pin 18 is the only one available on all platforms, and
3214 it is the one used by the I2S audio interface.
3215 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3216 2) The onboard analogue audio output uses both PWM channels.
3217 3) So be careful mixing audio and PWM.
3218 4) Currently the clock must have been enabled and configured
3220 Load: dtoverlay=pwm-2chan,<param>=<val>
3221 Params: pin Output pin (default 18) - see table
3222 pin2 Output pin for other channel (default 19)
3223 func Pin function (default 2 = Alt5) - see above
3224 func2 Function for pin2 (default 2 = Alt5)
3225 clock PWM clock frequency (informational)
3229 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
3230 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
3231 of PWM0 to reduce the CPU load during transmission compared to
3232 gpio-ir-tx which uses bit-banging.
3233 Legal pin,function combinations are:
3234 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3235 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3236 Params: gpio_pin Output GPIO (default 18)
3238 func Pin function (default 2 = Alt5)
3242 Info: Configures one or two PWM channel on PWM1 (BCM2711 only)
3244 1) The onboard analogue audio output uses both PWM channels.
3245 2) So be careful mixing audio and PWM.
3246 Note that even when only one pin is enabled, both channels are available
3247 from the PWM driver, so be careful to use the correct one.
3248 Load: dtoverlay=pwm1,<param>=<val>
3249 Params: clock PWM clock frequency (informational)
3250 pins_40 Enable channel 0 (PWM1_0) on GPIO 40
3251 pins_41 Enable channel 1 (PWM1_1) on GPIO 41
3252 pins_40_41 Enable channels 0 (PWM1_0) and 1 (PW1_1) on
3253 GPIOs 40 and 41 (default)
3254 pull_up Enable pull-ups on the PWM pins (default)
3255 pull_down Enable pull-downs on the PWM pins
3256 pull_off Disable pulls on the PWM pins
3260 Info: in-tech's Evaluation Board for PLC Stamp micro
3261 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3262 Load: dtoverlay=qca7000,<param>=<val>
3263 Params: int_pin GPIO pin for interrupt signal (default 23)
3265 speed SPI bus speed (default 12 MHz)
3269 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3270 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3271 But it requires disabling of onboard Bluetooth on
3272 Pi 3B, 3B+, 3A+, 4B and Zero W.
3273 Load: dtoverlay=qca7000-uart0,<param>=<val>
3274 Params: baudrate Set the baudrate for the UART (default
3279 Info: Enable the preservation of crash logs across a reboot. With
3280 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3281 are moved to /var/lib/systemd/pstore/ on reboot.
3282 Load: dtoverlay=ramoops,<param>=<val>
3283 Params: base-addr Where to place the capture buffer (default
3285 total-size How much memory to allocate altogether (in
3286 bytes - default 64kB)
3287 record-size How much space to use for each capture, i.e.
3288 total-size / record-size = number of captures
3290 console-size Size of non-panic dmesg captures (default 0)
3294 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3295 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3296 Load: dtoverlay=ramoops-pi4,<param>=<val>
3297 Params: base-addr Where to place the capture buffer (default
3299 total-size How much memory to allocate altogether (in
3300 bytes - default 64kB)
3301 record-size How much space to use for each capture, i.e.
3302 total-size / record-size = number of captures
3304 console-size Size of non-panic dmesg captures (default 0)
3307 Name: rotary-encoder
3308 Info: Overlay for GPIO connected rotary encoder.
3309 Load: dtoverlay=rotary-encoder,<param>=<val>
3310 Params: pin_a GPIO connected to rotary encoder channel A
3312 pin_b GPIO connected to rotary encoder channel B
3314 relative_axis register a relative axis rather than an
3315 absolute one. Relative axis will only
3316 generate +1/-1 events on the input device,
3317 hence no steps need to be passed.
3318 linux_axis the input subsystem axis to map to this
3319 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3320 rollover Automatic rollover when the rotary value
3321 becomes greater than the specified steps or
3322 smaller than 0. For absolute axis only.
3323 steps-per-period Number of steps (stable states) per period.
3324 The values have the following meaning:
3325 1: Full-period mode (default)
3327 4: Quarter-period mode
3328 steps Number of steps in a full turnaround of the
3329 encoder. Only relevant for absolute axis.
3330 Defaults to 24 which is a typical value for
3332 wakeup Boolean, rotary encoder can wake up the
3334 encoding String, the method used to encode steps.
3335 Supported are "gray" (the default and more
3336 common) and "binary".
3340 Info: Raspberry Pi official display backlight driver
3341 Load: dtoverlay=rpi-backlight
3345 Name: rpi-cirrus-wm5102
3346 Info: This overlay has been renamed to cirrus-wm5102
3351 Info: Configures the Raspberry Pi Codec Zero sound card
3352 Load: dtoverlay=rpi-codeczero
3357 Info: This overlay has been renaamed to i2s-dac.
3362 Info: Configures the Raspberry Pi DAC+ card
3363 Load: dtoverlay=rpi-dacplus,<param>=<val>
3364 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3365 digital volume control. Enable by adding
3366 "dtparam=24db_digital_gain" to config.txt
3367 before any "dtoverlay" lines.
3368 The default behaviour is that the digital
3369 volume control is limited to a maximum of
3370 0dB. ie. it can attenuate but not provide
3371 gain. For most users, this will be desired
3372 as it will prevent clipping. By appending
3373 the 24db_digital_gain parameter, the digital
3374 volume control will allow up to 24dB of
3375 gain. If this parameter is enabled, it is the
3376 responsibility of the user to ensure that
3377 the digital volume control is set to a value
3378 that does not result in clipping/distortion!
3382 Info: Configures the Raspberry Pi DAC Pro sound card
3383 Load: dtoverlay=rpi-dacpro,<param>=<val>
3384 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3385 digital volume control. Enable by adding
3386 "dtparam=24db_digital_gain" to config.txt
3387 before any "dtoverlay" lines.
3388 The default behaviour is that the digital
3389 volume control is limited to a maximum of
3390 0dB. ie. it can attenuate but not provide
3391 gain. For most users, this will be desired
3392 as it will prevent clipping. By appending
3393 the 24db_digital_gain parameter, the digital
3394 volume control will allow up to 24dB of
3395 gain. If this parameter is enabled, it is the
3396 responsibility of the user to ensure that
3397 the digital volume control is set to a value
3398 that does not result in clipping/distortion!
3401 Name: rpi-digiampplus
3402 Info: Configures the Raspberry Pi DigiAMP+ sound card
3403 Load: dtoverlay=rpi-digiampplus,<param>=<val>
3404 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3405 digital volume control. Enable by adding
3406 "dtparam=24db_digital_gain" to config.txt
3407 before any "dtoverlay" lines.
3408 The default behaviour is that the digital
3409 volume control is limited to a maximum of
3410 0dB. ie. it can attenuate but not provide
3411 gain. For most users, this will be desired
3412 as it will prevent clipping. By appending
3413 the 24db_digital_gain parameter, the digital
3414 volume control will allow up to 24dB of
3415 gain. If this parameter is enabled, it is the
3416 responsibility of the user to ensure that
3417 the digital volume control is set to a value
3418 that does not result in clipping/distortion!
3419 auto_mute_amp If specified, unmute/mute the DigiAMP+ when
3420 starting/stopping audio playback (default "on").
3421 unmute_amp If specified, unmute the DigiAMP+ amp once when
3422 the DAC driver module loads (default "off").
3426 Info: This overlay has been renamed to watterott-display
3431 Info: Official Raspberry Pi display touchscreen
3432 Load: dtoverlay=rpi-ft5406,<param>=<val>
3433 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3434 touchscreen-size-y Touchscreen Y resolution (default 600);
3435 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3436 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3437 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3441 Info: Raspberry Pi PoE HAT fan
3442 Load: dtoverlay=rpi-poe,<param>[=<val>]
3443 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3444 turns on (default 40000)
3445 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3446 the fan turns off (default 2000)
3447 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3448 speeds up (default 45000)
3449 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3450 the fan slows down (default 2000)
3451 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3452 speeds up (default 50000)
3453 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3454 the fan slows down (default 2000)
3455 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3456 speeds up (default 55000)
3457 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3458 the fan slows down (default 5000)
3459 i2c Control the fan via Linux I2C drivers instead of
3464 Info: Raspberry Pi PoE+ HAT fan
3465 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3466 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3467 turns on (default 40000)
3468 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3469 the fan turns off (default 2000)
3470 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3471 speeds up (default 45000)
3472 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3473 the fan slows down (default 2000)
3474 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3475 speeds up (default 50000)
3476 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3477 the fan slows down (default 2000)
3478 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3479 speeds up (default 55000)
3480 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3481 the fan slows down (default 5000)
3482 i2c Control the fan via Linux I2C drivers instead of
3487 Info: This overlay has been renamaed to proto-codec.
3492 Info: Raspberry Pi Sense HAT
3493 Load: dtoverlay=rpi-sense
3498 Info: Raspberry Pi Sense HAT v2
3499 Load: dtoverlay=rpi-sense-v2
3504 Info: Raspberry Pi TV HAT
3505 Load: dtoverlay=rpi-tv
3510 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3511 video decoder driver is enabled by default.
3515 Name: rra-digidac1-wm8741-audio
3516 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3517 Load: dtoverlay=rra-digidac1-wm8741-audio
3522 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3524 Load: dtoverlay=sainsmart18,<param>=<val>
3525 Params: rotate Display rotation {0,90,180,270}
3526 speed SPI bus speed in Hz (default 4000000)
3527 fps Display frame rate in Hz
3528 bgr Enable BGR mode (default off)
3529 debug Debug output level {0-7}
3530 dc_pin GPIO pin for D/C (default 24)
3531 reset_pin GPIO pin for RESET (default 25)
3535 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3536 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3537 select another address, please refer to table 10 in reference manual.
3538 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3539 Params: int_pin GPIO used for IRQ (default 24)
3540 addr Address (default 0x48)
3541 xtal On-board crystal frequency (default 14745600)
3545 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3546 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3547 select another address, please refer to table 10 in reference manual.
3548 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3549 Params: int_pin GPIO used for IRQ (default 24)
3550 addr Address (default 0x48)
3551 xtal On-board crystal frequency (default 14745600)
3554 Name: sc16is752-spi0
3555 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3556 Enables the chip on SPI0.
3557 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3558 Params: int_pin GPIO used for IRQ (default 24)
3559 xtal On-board crystal frequency (default 14745600)
3562 Name: sc16is752-spi1
3563 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3564 Enables the chip on SPI1.
3565 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3566 A+, B+, Zero and PI2 B; as well as the Compute Module.
3568 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3569 Params: int_pin GPIO used for IRQ (default 24)
3570 xtal On-board crystal frequency (default 14745600)
3574 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3575 N.B. This overlay is designed for situations where the mmc driver is
3576 the default, so it disables the other (mmc) interface - this will kill
3577 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3578 overlay or the new sd_* dtparams of the base DTBs.
3579 Load: dtoverlay=sdhost,<param>=<val>
3580 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3583 force_pio Disable DMA support (default off)
3585 pio_limit Number of blocks above which to use DMA
3588 debug Enable debug output (default off)
3592 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3593 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3594 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3595 Load: dtoverlay=sdio,<param>=<val>
3596 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3597 framework requests 50MHz
3599 poll_once Disable SDIO-device polling every second
3600 (default on: polling once at boot-time)
3602 bus_width Set the SDIO host bus width (default 4 bits)
3604 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3605 with bus_width=1. This replaces the sdio-1bit
3606 overlay, which is now deprecated.
3608 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3611 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3612 with bus_width=4 (the default).
3616 Info: This overlay is now deprecated. Use
3617 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3622 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3623 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3624 "dtparam=sd_poll_once".
3628 Name: seeed-can-fd-hat-v1
3629 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3630 channels without RTC. Use this overlay if your HAT has no
3632 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3633 Load: dtoverlay=seeed-can-fd-hat-v1
3637 Name: seeed-can-fd-hat-v2
3638 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3639 channels and an RTC. Use this overlay if your HAT has a
3641 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3642 Load: dtoverlay=seeed-can-fd-hat-v2
3647 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3648 Load: dtoverlay=sh1106-spi,<param>=<val>
3649 Params: speed SPI bus speed (default 4000000)
3650 rotate Display rotation (0, 90, 180 or 270; default 0)
3651 fps Delay between frame updates (default 25)
3652 debug Debug output level (0-7; default 0)
3653 dc_pin GPIO pin for D/C (default 24)
3654 reset_pin GPIO pin for RESET (default 25)
3655 height Display height (32 or 64; default 64)
3659 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3660 The driver is currently out-of-tree at
3661 https://github.com/sunipkmukherjee/silabs.git
3662 Load: dtoverlay=si446x-spi0,<param>=<val>
3663 Params: speed SPI bus speed (default 4000000)
3664 int_pin GPIO pin for interrupts (default 17)
3665 reset_pin GPIO pin for RESET (default 27)
3669 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3675 Info: Enables the userspace interface for the SMI driver
3676 Load: dtoverlay=smi-dev
3681 Info: Enables access to NAND flash via the SMI interface
3682 Load: dtoverlay=smi-nand
3687 Info: Move SPI function block to GPIO 35 to 39
3688 Load: dtoverlay=spi-gpio35-39
3693 Info: Move SPI function block to GPIOs 40 to 45
3694 Load: dtoverlay=spi-gpio40-45
3699 Info: Adds support for a number of SPI Real Time Clock devices
3700 Load: dtoverlay=spi-rtc,<param>=<val>
3701 Params: ds3232 Select the DS3232 device
3702 ds3234 Select the DS3234 device
3703 pcf2123 Select the PCF2123 device
3705 spi0_0 Use spi0.0 (default)
3711 cs_high This device requires an active-high CS
3715 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3716 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3717 Load: dtoverlay=spi0-0cs,<param>=<val>
3718 Params: no_miso Don't claim and use the MISO pin (9), freeing
3723 Info: Only use one CS pin for SPI0
3724 Load: dtoverlay=spi0-1cs,<param>=<val>
3725 Params: cs0_pin GPIO pin for CS0 (default 8)
3726 no_miso Don't claim and use the MISO pin (9), freeing
3731 Info: Change the CS pins for SPI0
3732 Load: dtoverlay=spi0-2cs,<param>=<val>
3733 Params: cs0_pin GPIO pin for CS0 (default 8)
3734 cs1_pin GPIO pin for CS1 (default 7)
3735 no_miso Don't claim and use the MISO pin (9), freeing
3740 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3741 alias for backwards compatibility.
3746 Info: This overlay has been deprecated and removed because it is no longer
3747 necessary and has been seen to prevent spi0 from working.
3752 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3753 dev node. The gpio pin number for the CS line and spidev device node
3754 creation are configurable.
3755 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3756 A+, B+, Zero and PI2 B; as well as the Compute Module.
3757 Load: dtoverlay=spi1-1cs,<param>=<val>
3758 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3759 cs0_spidev Set to 'disabled' to stop the creation of a
3760 userspace device node /dev/spidev1.0 (default
3761 is 'okay' or enabled).
3765 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3766 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3767 creation are configurable.
3768 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3769 A+, B+, Zero and PI2 B; as well as the Compute Module.
3770 Load: dtoverlay=spi1-2cs,<param>=<val>
3771 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3772 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3773 cs0_spidev Set to 'disabled' to stop the creation of a
3774 userspace device node /dev/spidev1.0 (default
3775 is 'okay' or enabled).
3776 cs1_spidev Set to 'disabled' to stop the creation of a
3777 userspace device node /dev/spidev1.1 (default
3778 is 'okay' or enabled).
3782 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3783 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3784 creation are configurable.
3785 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3786 A+, B+, Zero and PI2 B; as well as the Compute Module.
3787 Load: dtoverlay=spi1-3cs,<param>=<val>
3788 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3789 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3790 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3791 cs0_spidev Set to 'disabled' to stop the creation of a
3792 userspace device node /dev/spidev1.0 (default
3793 is 'okay' or enabled).
3794 cs1_spidev Set to 'disabled' to stop the creation of a
3795 userspace device node /dev/spidev1.1 (default
3796 is 'okay' or enabled).
3797 cs2_spidev Set to 'disabled' to stop the creation of a
3798 userspace device node /dev/spidev1.2 (default
3799 is 'okay' or enabled).
3803 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3804 dev node. The gpio pin number for the CS line and spidev device node
3805 creation are configurable.
3806 N.B.: spi2 is only accessible with the Compute Module.
3807 Load: dtoverlay=spi2-1cs,<param>=<val>
3808 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3809 cs0_spidev Set to 'disabled' to stop the creation of a
3810 userspace device node /dev/spidev2.0 (default
3811 is 'okay' or enabled).
3815 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3816 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3817 creation are configurable.
3818 N.B.: spi2 is only accessible with the Compute Module.
3819 Load: dtoverlay=spi2-2cs,<param>=<val>
3820 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3821 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3822 cs0_spidev Set to 'disabled' to stop the creation of a
3823 userspace device node /dev/spidev2.0 (default
3824 is 'okay' or enabled).
3825 cs1_spidev Set to 'disabled' to stop the creation of a
3826 userspace device node /dev/spidev2.1 (default
3827 is 'okay' or enabled).
3831 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3832 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3833 creation are configurable.
3834 N.B.: spi2 is only accessible with the Compute Module.
3835 Load: dtoverlay=spi2-3cs,<param>=<val>
3836 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3837 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3838 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3839 cs0_spidev Set to 'disabled' to stop the creation of a
3840 userspace device node /dev/spidev2.0 (default
3841 is 'okay' or enabled).
3842 cs1_spidev Set to 'disabled' to stop the creation of a
3843 userspace device node /dev/spidev2.1 (default
3844 is 'okay' or enabled).
3845 cs2_spidev Set to 'disabled' to stop the creation of a
3846 userspace device node /dev/spidev2.2 (default
3847 is 'okay' or enabled).
3851 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3852 dev node. The gpio pin number for the CS line and spidev device node
3853 creation are configurable. BCM2711 only.
3854 Load: dtoverlay=spi3-1cs,<param>=<val>
3855 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3856 cs0_spidev Set to 'off' to prevent the creation of a
3857 userspace device node /dev/spidev3.0 (default
3858 is 'on' or enabled).
3862 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3863 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3864 creation are configurable. BCM2711 only.
3865 Load: dtoverlay=spi3-2cs,<param>=<val>
3866 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3867 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3868 cs0_spidev Set to 'off' to prevent the creation of a
3869 userspace device node /dev/spidev3.0 (default
3870 is 'on' or enabled).
3871 cs1_spidev Set to 'off' to prevent the creation of a
3872 userspace device node /dev/spidev3.1 (default
3873 is 'on' or enabled).
3877 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3878 dev node. The gpio pin number for the CS line and spidev device node
3879 creation are configurable. BCM2711 only.
3880 Load: dtoverlay=spi4-1cs,<param>=<val>
3881 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3882 cs0_spidev Set to 'off' to prevent the creation of a
3883 userspace device node /dev/spidev4.0 (default
3884 is 'on' or enabled).
3888 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3889 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3890 creation are configurable. BCM2711 only.
3891 Load: dtoverlay=spi4-2cs,<param>=<val>
3892 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3893 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3894 cs0_spidev Set to 'off' to prevent the creation of a
3895 userspace device node /dev/spidev4.0 (default
3896 is 'on' or enabled).
3897 cs1_spidev Set to 'off' to prevent the creation of a
3898 userspace device node /dev/spidev4.1 (default
3899 is 'on' or enabled).
3903 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3904 dev node. The gpio pin numbers for the CS lines and spidev device node
3905 creation are configurable. BCM2711 only.
3906 Load: dtoverlay=spi5-1cs,<param>=<val>
3907 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3908 cs0_spidev Set to 'off' to prevent the creation of a
3909 userspace device node /dev/spidev5.0 (default
3910 is 'on' or enabled).
3914 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3915 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3916 creation are configurable. BCM2711 only.
3917 Load: dtoverlay=spi5-2cs,<param>=<val>
3918 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3919 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3920 cs0_spidev Set to 'off' to prevent the creation of a
3921 userspace device node /dev/spidev5.0 (default
3922 is 'on' or enabled).
3923 cs1_spidev Set to 'off' to prevent the creation of a
3924 userspace device node /dev/spidev5.1 (default
3925 is 'on' or enabled).
3929 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3930 dev node. The gpio pin number for the CS line and spidev device node
3931 creation are configurable. BCM2711 only.
3932 Load: dtoverlay=spi6-1cs,<param>=<val>
3933 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3934 cs0_spidev Set to 'off' to prevent the creation of a
3935 userspace device node /dev/spidev6.0 (default
3936 is 'on' or enabled).
3940 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3941 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3942 creation are configurable. BCM2711 only.
3943 Load: dtoverlay=spi6-2cs,<param>=<val>
3944 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3945 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3946 cs0_spidev Set to 'off' to prevent the creation of a
3947 userspace device node /dev/spidev6.0 (default
3948 is 'on' or enabled).
3949 cs1_spidev Set to 'off' to prevent the creation of a
3950 userspace device node /dev/spidev6.1 (default
3951 is 'on' or enabled).
3955 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3956 Load: dtoverlay=ssd1306,<param>=<val>
3957 Params: address Location in display memory of first character.
3959 width Width of display. (default=128)
3960 height Height of display. (default=64)
3961 offset virtual channel a. (default=0)
3962 normal Has no effect on displays tested. (default=not
3964 sequential Set this if every other scan line is missing.
3966 remapped Set this if display is garbled. (default=not
3968 inverted Set this if display is inverted and mirrored.
3972 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3974 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3976 i2c_baudrate=400000 will speed up the display.
3978 i2c_baudrate=1000000 seems to work even though it's not officially
3979 supported by the hardware, and is faster still.
3981 For more information refer to the device datasheet at:
3982 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3986 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3987 Load: dtoverlay=ssd1306-spi,<param>=<val>
3988 Params: speed SPI bus speed (default 10000000)
3989 rotate Display rotation (0, 90, 180 or 270; default 0)
3990 fps Delay between frame updates (default 25)
3991 debug Debug output level (0-7; default 0)
3992 dc_pin GPIO pin for D/C (default 24)
3993 reset_pin GPIO pin for RESET (default 25)
3994 height Display height (32 or 64; default 64)
3998 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3999 Load: dtoverlay=ssd1331-spi,<param>=<val>
4000 Params: speed SPI bus speed (default 4500000)
4001 rotate Display rotation (0, 90, 180 or 270; default 0)
4002 fps Delay between frame updates (default 25)
4003 debug Debug output level (0-7; default 0)
4004 dc_pin GPIO pin for D/C (default 24)
4005 reset_pin GPIO pin for RESET (default 25)
4009 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
4010 Load: dtoverlay=ssd1351-spi,<param>=<val>
4011 Params: speed SPI bus speed (default 4500000)
4012 rotate Display rotation (0, 90, 180 or 270; default 0)
4013 fps Delay between frame updates (default 25)
4014 debug Debug output level (0-7; default 0)
4015 dc_pin GPIO pin for D/C (default 24)
4016 reset_pin GPIO pin for RESET (default 25)
4019 Name: superaudioboard
4020 Info: Configures the SuperAudioBoard sound card
4021 Load: dtoverlay=superaudioboard,<param>=<val>
4022 Params: gpiopin GPIO pin for codec reset
4026 Info: Configures the Semtech SX150X I2C GPIO expanders.
4027 Load: dtoverlay=sx150x,<param>=<val>
4028 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
4029 address <m>. <x> may be 1-9. <n> may be 0 or 1.
4030 Permissible values of <m> (which is denoted in
4031 hex) depend on the device variant. For SX1501,
4032 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
4033 For SX1503 and SX1506, <m> may be 20. For
4034 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
4035 For SX1508, <m> may be 20, 21, 22 or 23.
4037 sx150<x>-<n>-<m>-int-gpio
4038 Integer, enables interrupts on SX150X device on
4039 I2C#<n> with slave address <m>, specifies
4040 the GPIO pin to which NINT output of SX150X is
4045 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
4046 Uses Unicam 1, which is the standard camera connector on most Pi
4048 Load: dtoverlay=tc358743,<param>=<val>
4049 Params: 4lane Use 4 lanes (only applicable to Compute Modules
4052 link-frequency Set the link frequency. Only values of 297000000
4053 (574Mbit/s) and 486000000 (972Mbit/s - default)
4054 are supported by the driver.
4055 media-controller Configure use of Media Controller API for
4056 configuring the sensor (default off)
4057 cam0 Adopt the default configuration for CAM0 on a
4058 Compute Module (CSI0, i2c_vc, and cam0_reg).
4061 Name: tc358743-audio
4062 Info: Used in combination with the tc358743-fast overlay to route the audio
4063 from the TC358743 over I2S to the Pi.
4064 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
4066 Load: dtoverlay=tc358743-audio,<param>=<val>
4067 Params: card-name Override the default, "tc358743", card name.
4071 Info: 3.5" Color TFT Display by www.tinylcd.com
4072 Options: Touch, RTC, keypad
4073 Load: dtoverlay=tinylcd35,<param>=<val>
4074 Params: speed Display SPI bus speed
4076 rotate Display rotation {0,90,180,270}
4078 fps Delay between frame updates
4080 debug Debug output level {0-7}
4082 touch Enable touch panel
4084 touchgpio Touch controller IRQ GPIO
4086 xohms Touchpanel: Resistance of X-plate in ohms
4088 rtc-pcf PCF8563 Real Time Clock
4090 rtc-ds DS1307 Real Time Clock
4092 keypad Enable keypad
4095 Display with touchpanel, PCF8563 RTC and keypad:
4096 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
4098 dtoverlay=tinylcd35,touch,touchgpio=3
4102 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
4103 boards, which can be used as a secure key storage and hwrng,
4104 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
4105 Load: dtoverlay=tpm-slb9670
4110 Info: Change the pin usage of uart0
4111 Load: dtoverlay=uart0,<param>=<val>
4112 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
4114 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
4116 pin_func Alternative pin function - 4(Alt0) for 14&15,
4117 7(Alt3) for 32&33, 6(Alt2) for 36&37
4121 Info: Change the pin usage of uart1
4122 Load: dtoverlay=uart1,<param>=<val>
4123 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
4125 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
4129 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
4130 Load: dtoverlay=uart2,<param>
4131 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
4135 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
4136 Load: dtoverlay=uart3,<param>
4137 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
4141 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
4142 Load: dtoverlay=uart4,<param>
4143 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
4147 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
4148 Load: dtoverlay=uart5,<param>
4149 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
4153 Info: Configures the NW Digital Radio UDRC Hat
4154 Load: dtoverlay=udrc,<param>=<val>
4155 Params: alsaname Name of the ALSA audio device (default "udrc")
4158 Name: ugreen-dabboard
4159 Info: Configures the ugreen-dabboard I2S overlay
4160 This is a simple overlay based on the simple-audio-card and the dmic
4161 codec. It has the speciality that it is configured to use the codec
4162 as a master I2S device. It works for example with the Si468x DAB
4163 receiver on the uGreen DABBoard.
4164 Load: dtoverlay=ugreen-dabboard,<param>=<val>
4165 Params: card-name Override the default, "dabboard", card name.
4169 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
4170 vc4-kms-v3d and dwc2 overlays.
4171 Load: dtoverlay=upstream
4175 Name: upstream-aux-interrupt
4176 Info: This overlay has been deprecated and removed because it is no longer
4182 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
4183 the vc4-kms-v3d-pi4 and dwc2 overlays.
4184 Load: dtoverlay=upstream-pi4
4189 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4191 Load: dtoverlay=vc4-fkms-v3d,<param>
4192 Params: cma-512 CMA is 512MB (needs 1GB)
4193 cma-448 CMA is 448MB (needs 1GB)
4194 cma-384 CMA is 384MB (needs 1GB)
4195 cma-320 CMA is 320MB (needs 1GB)
4196 cma-256 CMA is 256MB (needs 1GB)
4197 cma-192 CMA is 192MB (needs 1GB)
4198 cma-128 CMA is 128MB
4201 cma-size CMA size in bytes, 4MB aligned
4202 cma-default Use upstream's default value
4205 Name: vc4-fkms-v3d-pi4
4206 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4208 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
4209 Params: cma-512 CMA is 512MB (needs 1GB)
4210 cma-448 CMA is 448MB (needs 1GB)
4211 cma-384 CMA is 384MB (needs 1GB)
4212 cma-320 CMA is 320MB (needs 1GB)
4213 cma-256 CMA is 256MB (needs 1GB)
4214 cma-192 CMA is 192MB (needs 1GB)
4215 cma-128 CMA is 128MB
4218 cma-size CMA size in bytes, 4MB aligned
4219 cma-default Use upstream's default value
4222 Name: vc4-kms-dpi-at056tn53v1
4223 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
4227 Name: vc4-kms-dpi-generic
4228 Info: Enable a generic DPI display under KMS. Default timings are for the
4229 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
4230 Requires vc4-kms-v3d to be loaded.
4231 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
4232 Params: clock-frequency Display clock frequency (Hz)
4233 hactive Horizontal active pixels
4234 hfp Horizontal front porch
4235 hsync Horizontal sync pulse width
4236 hbp Horizontal back porch
4237 vactive Vertical active lines
4238 vfp Vertical front porch
4239 vsync Vertical sync pulse width
4240 vbp Vertical back porch
4241 hsync-invert Horizontal sync active low
4242 vsync-invert Vertical sync active low
4243 de-invert Data Enable active low
4244 pixclk-invert Negative edge pixel clock
4245 width-mm Define the screen width in mm
4246 height-mm Define the screen height in mm
4247 rgb565 Change to RGB565 output on GPIOs 0-19
4248 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
4250 bgr666 Change to BGR666 output on GPIOs 0-21.
4251 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
4253 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
4255 bgr888 Change to BGR888 output on GPIOs 0-27
4256 rgb888 Change to RGB888 output on GPIOs 0-27
4257 bus-format Override the bus format for a MEDIA_BUS_FMT_*
4258 value. NB also overridden by rgbXXX overrides.
4259 backlight-gpio Defines a GPIO to be used for backlight control
4261 backlight-pwm Defines a PWM channel to be used for backlight
4262 control (default of none). NB Disables audio
4263 headphone output as that also uses PWM.
4264 backlight-pwm-chan Choose channel on &pwm node for backlight
4267 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4268 pwm-2chan for valid options.
4269 (default 18 - note this can only work with
4271 backlight-pwm-func Pin function of GPIO used for the PWM
4273 See pwm-2chan for valid options.
4275 backlight-def-brightness
4276 Set the default brightness. Normal range 1-16.
4278 rotate Display rotation {0,90,180,270} (default 0)
4281 Name: vc4-kms-dpi-hyperpixel2r
4282 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
4283 Requires vc4-kms-v3d to be loaded.
4284 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
4285 Params: disable-touch Disables the touch controller
4286 touchscreen-inverted-x Inverts X direction of touch controller
4287 touchscreen-inverted-y Inverts Y direction of touch controller
4288 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4289 rotate Display rotation {0,90,180,270} (default 0)
4292 Name: vc4-kms-dpi-hyperpixel4
4293 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
4294 Requires vc4-kms-v3d to be loaded.
4295 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
4296 Params: disable-touch Disables the touch controller
4297 touchscreen-inverted-x Inverts X direction of touch controller
4298 touchscreen-inverted-y Inverts Y direction of touch controller
4299 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4300 rotate Display rotation {0,90,180,270} (default 0)
4303 Name: vc4-kms-dpi-hyperpixel4sq
4304 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4305 Requires vc4-kms-v3d to be loaded.
4306 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4307 Params: disable-touch Disables the touch controller
4308 touchscreen-inverted-x Inverts X direction of touch controller
4309 touchscreen-inverted-y Inverts Y direction of touch controller
4310 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4311 rotate Display rotation {0,90,180,270} (default 0)
4314 Name: vc4-kms-dpi-panel
4315 Info: Enable a preconfigured KMS DPI panel.
4316 Requires vc4-kms-v3d to be loaded.
4317 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4318 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4319 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4320 mzp280 Enable a Geekworm MZP280 panel.
4321 backlight-gpio Defines a GPIO to be used for backlight control
4323 backlight-pwm Defines a PWM channel to be used for backlight
4324 control (default of none). NB Disables audio
4325 headphone output as that also uses PWM.
4326 backlight-pwm-chan Choose channel on &pwm node for backlight
4329 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4330 pwm-2chan for valid options.
4331 (default 18 - note this can only work with
4333 backlight-pwm-func Pin function of GPIO used for the PWM
4335 See pwm-2chan for valid options.
4337 backlight-def-brightness
4338 Set the default brightness. Normal range 1-16.
4340 rotate Display rotation {0,90,180,270} (default 0)
4343 Name: vc4-kms-dsi-7inch
4344 Info: Enable the Raspberry Pi DSI 7" screen.
4345 Includes the edt-ft5406 for the touchscreen element.
4346 Requires vc4-kms-v3d to be loaded.
4347 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4348 Params: sizex Touchscreen size x (default 800)
4349 sizey Touchscreen size y (default 480)
4350 invx Touchscreen inverted x axis
4351 invy Touchscreen inverted y axis
4352 swapxy Touchscreen swapped x y axis
4353 disable_touch Disables the touch screen overlay driver
4356 Name: vc4-kms-dsi-lt070me05000
4357 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4358 Note that this is a 4 lane DSI device, so it will only work on a Compute
4360 Requires vc4-kms-v3d to be loaded.
4361 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4362 Params: reset GPIO for the reset signal (default 17)
4363 enable GPIO for the enable signal (default 4)
4364 dcdc-en GPIO for the DC-DC converter enable (default 5)
4367 Name: vc4-kms-dsi-lt070me05000-v2
4368 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4370 Note that this is a 4 lane DSI device, so it will only work on a Compute
4372 Requires vc4-kms-v3d to be loaded.
4373 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4377 Name: vc4-kms-kippah-7inch
4378 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4383 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4384 Load: dtoverlay=vc4-kms-v3d,<param>
4385 Params: cma-512 CMA is 512MB (needs 1GB)
4386 cma-448 CMA is 448MB (needs 1GB)
4387 cma-384 CMA is 384MB (needs 1GB)
4388 cma-320 CMA is 320MB (needs 1GB)
4389 cma-256 CMA is 256MB (needs 1GB)
4390 cma-192 CMA is 192MB (needs 1GB)
4391 cma-128 CMA is 128MB
4394 cma-size CMA size in bytes, 4MB aligned
4395 cma-default Use upstream's default value
4396 audio Enable or disable audio over HDMI (default "on")
4397 noaudio Disable all HDMI audio (default "off")
4398 composite Enable the composite output (default "off")
4399 N.B. Disables all other outputs on a Pi 4.
4400 nohdmi Disable HDMI output
4403 Name: vc4-kms-v3d-pi4
4404 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4405 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4406 Params: cma-512 CMA is 512MB
4407 cma-448 CMA is 448MB
4408 cma-384 CMA is 384MB
4409 cma-320 CMA is 320MB
4410 cma-256 CMA is 256MB
4411 cma-192 CMA is 192MB
4412 cma-128 CMA is 128MB
4415 cma-size CMA size in bytes, 4MB aligned
4416 cma-default Use upstream's default value
4417 audio Enable or disable audio over HDMI0 (default
4419 audio1 Enable or disable audio over HDMI1 (default
4421 noaudio Disable all HDMI audio (default "off")
4422 composite Enable the composite output (disables all other
4424 nohdmi Disable both HDMI 0 & 1 outputs
4425 nohdmi0 Disable HDMI 0 output
4426 nohdmi1 Disable HDMI 1 output
4430 Name: vc4-kms-vga666
4431 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4432 Requires vc4-kms-v3d to be loaded.
4433 Load: dtoverlay=vc4-kms-vga666,<param>
4434 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4435 from the display. NB These are NOT 5V tolerant
4436 GPIOs, therefore level shifters are required.
4440 Info: Overlay for the Fen Logic VGA666 board
4441 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4442 after the kernel has started.
4443 NOT for use with vc4-kms-v3d.
4444 Load: dtoverlay=vga666
4449 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4450 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4451 set in the EEPROM config.
4452 Load: dtoverlay=vl805
4457 Info: Configures the w1-gpio Onewire interface module.
4458 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4459 Load: dtoverlay=w1-gpio,<param>=<val>
4460 Params: gpiopin GPIO for I/O (default "4")
4461 pullup Now enabled by default (ignored)
4464 Name: w1-gpio-pullup
4465 Info: Configures the w1-gpio Onewire interface module.
4466 Use this overlay if you *do* need a GPIO to drive an external pullup.
4467 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4468 Params: gpiopin GPIO for I/O (default "4")
4469 extpullup GPIO for external pullup (default "5")
4470 pullup Now enabled by default (ignored)
4474 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4475 Load: dtoverlay=w5500,<param>=<val>
4476 Params: int_pin GPIO used for INT (default 25)
4478 speed SPI bus speed (default 30000000)
4480 cs SPI bus Chip Select (default 0)
4483 Name: watterott-display
4484 Info: Watterott RPi-Display - 2.8" Touch Display
4485 Linux has 2 drivers that support this display and this overlay supports
4489 fbtft/fb_ili9341: dtoverlay=watterott-display
4490 drm/mi0283qt: dtoverlay=watterott-display,drm,backlight-pwm,rotate=180
4492 Some notable differences with the DRM driver compared to fbtft:
4493 - The display is turned on when it's first used and not on driver load
4494 as with fbtft. So if nothing uses the display it stays off.
4495 - Can run with a higher SPI clock increasing framerate. This is possible
4496 since the driver avoids messing up the controller configuration due to
4497 transmission errors by running config commands at 10MHz and only pixel
4498 data at full speed (occasional pixel glitch might occur).
4499 - PWM backlight is supported.
4501 Load: dtoverlay=watterott-display,<param>=<val>
4502 Params: speed Display SPI bus speed
4503 rotate Display rotation {0,90,180,270}
4504 fps Delay between frame updates (fbtft only)
4505 debug Debug output level {0-7} (fbtft only)
4506 xohms Touchpanel sensitivity (X-plate resistance)
4507 swapxy Swap x and y axis
4508 backlight Change backlight GPIO pin {e.g. 12, 18}
4510 drm Use DRM/KMS driver mi0283qt instead of fbtft.
4511 Set the SPI clock to 70MHz.
4512 This has to be the first parameter.
4513 backlight-pwm Use pwm for backlight (drm only). NB: Disables
4514 audio headphone output as that also uses PWM.
4517 Name: waveshare-can-fd-hat-mode-a
4518 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4519 for Raspberry Pi, Multi Protections. Use this overlay when the
4520 HAT is configured in Mode A (Default), with can0 on spi0.0
4522 https://www.waveshare.com/2-ch-can-fd-hat.htm
4523 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4527 Name: waveshare-can-fd-hat-mode-b
4528 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4529 for Raspberry Pi, Multi Protections. Use this overlay when the
4530 HAT is configured in Mode B (requires hardware modification), with
4531 can0 on spi0.0 and can1 on spi0.1.
4532 https://www.waveshare.com/2-ch-can-fd-hat.htm
4533 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4538 Info: Configures the wittypi RTC module.
4539 Load: dtoverlay=wittypi,<param>=<val>
4540 Params: led_gpio GPIO for LED (default "17")
4541 led_trigger Choose which activity the LED tracks (default
4545 Name: wm8960-soundcard
4546 Info: Overlay for the Waveshare wm8960 soundcard
4547 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4548 Params: alsaname Changes the card name in ALSA
4549 compatible Changes the codec compatibility
4555 If you are experiencing problems that you think are DT-related, enable DT
4556 diagnostic output by adding this to /boot/config.txt:
4560 and rebooting. Then run:
4564 and look for relevant messages.
4569 This is only meant to be a quick introduction to the subject of Device Tree on
4570 Raspberry Pi. There is a more complete explanation here:
4572 http://www.raspberrypi.org/documentation/configuration/device-tree.md