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
692 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
693 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
694 Load: dtoverlay=balena-fin
698 Name: bmp085_i2c-sensor
699 Info: This overlay is now deprecated - see i2c-sensor
703 Name: camera-mux-2port
704 Info: Configures a 2 port camera multiplexer
705 Note that currently ALL IMX290 modules share a common clock, therefore
706 all modules will need to have the same clock frequency.
707 Load: dtoverlay=camera-mux-2port,<param>=<val>
708 Params: cam0-imx219 Select IMX219 for camera on port 0
709 cam0-imx258 Select IMX258 for camera on port 0
710 cam0-imx290 Select IMX290 for camera on port 0
711 cam0-imx477 Select IMX477 for camera on port 0
712 cam0-ov2311 Select OV2311 for camera on port 0
713 cam0-ov5647 Select OV5647 for camera on port 0
714 cam0-ov7251 Select OV7251 for camera on port 0
715 cam0-ov9281 Select OV9281 for camera on port 0
716 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
717 cam1-imx219 Select IMX219 for camera on port 1
718 cam1-imx258 Select IMX258 for camera on port 1
719 cam1-imx290 Select IMX290 for camera on port 1
720 cam1-imx477 Select IMX477 for camera on port 1
721 cam1-ov2311 Select OV2311 for camera on port 1
722 cam1-ov5647 Select OV5647 for camera on port 1
723 cam1-ov7251 Select OV7251 for camera on port 1
724 cam1-ov9281 Select OV9281 for camera on port 1
725 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
728 Name: camera-mux-4port
729 Info: Configures a 4 port camera multiplexer
730 Note that currently ALL IMX290 modules share a common clock, therefore
731 all modules will need to have the same clock frequency.
732 Load: dtoverlay=camera-mux-4port,<param>=<val>
733 Params: cam0-imx219 Select IMX219 for camera on port 0
734 cam0-imx258 Select IMX258 for camera on port 0
735 cam0-imx290 Select IMX290 for camera on port 0
736 cam0-imx477 Select IMX477 for camera on port 0
737 cam0-ov2311 Select OV2311 for camera on port 0
738 cam0-ov5647 Select OV5647 for camera on port 0
739 cam0-ov7251 Select OV7251 for camera on port 0
740 cam0-ov9281 Select OV9281 for camera on port 0
741 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
742 cam1-imx219 Select IMX219 for camera on port 1
743 cam1-imx258 Select IMX258 for camera on port 1
744 cam1-imx290 Select IMX290 for camera on port 1
745 cam1-imx477 Select IMX477 for camera on port 1
746 cam1-ov2311 Select OV2311 for camera on port 1
747 cam1-ov5647 Select OV5647 for camera on port 1
748 cam1-ov7251 Select OV7251 for camera on port 1
749 cam1-ov9281 Select OV9281 for camera on port 1
750 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
751 cam2-imx219 Select IMX219 for camera on port 2
752 cam2-imx258 Select IMX258 for camera on port 2
753 cam2-imx290 Select IMX290 for camera on port 2
754 cam2-imx477 Select IMX477 for camera on port 2
755 cam2-ov2311 Select OV2311 for camera on port 2
756 cam2-ov5647 Select OV5647 for camera on port 2
757 cam2-ov7251 Select OV7251 for camera on port 2
758 cam2-ov9281 Select OV9281 for camera on port 2
759 cam2-imx290-clk-freq Set clock frequency for an IMX290 on port 2
760 cam3-imx219 Select IMX219 for camera on port 3
761 cam3-imx258 Select IMX258 for camera on port 3
762 cam3-imx290 Select IMX290 for camera on port 3
763 cam3-imx477 Select IMX477 for camera on port 3
764 cam3-ov2311 Select OV2311 for camera on port 3
765 cam3-ov5647 Select OV5647 for camera on port 3
766 cam3-ov7251 Select OV7251 for camera on port 3
767 cam3-ov9281 Select OV9281 for camera on port 3
768 cam3-imx290-clk-freq Set clock frequency for an IMX290 on port 3
772 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
773 Load: dtoverlay=cap1106,<param>=<val>
774 Params: int_pin GPIO pin for interrupt signal (default 23)
778 Info: Configures Chip Dip audio cards.
779 Load: dtoverlay=chipdip-dac
784 Info: Configures the Cirrus Logic Audio Card
785 Load: dtoverlay=cirrus-wm5102
790 Info: Set custom CMA sizes, only use if you know what you are doing, might
791 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
792 Load: dtoverlay=cma,<param>=<val>
793 Params: cma-512 CMA is 512MB (needs 1GB)
794 cma-448 CMA is 448MB (needs 1GB)
795 cma-384 CMA is 384MB (needs 1GB)
796 cma-320 CMA is 320MB (needs 1GB)
797 cma-256 CMA is 256MB (needs 1GB)
798 cma-192 CMA is 192MB (needs 1GB)
802 cma-size CMA size in bytes, 4MB aligned
803 cma-default Use upstream's default value
807 Info: 8" TFT LCD display and touch panel used by cutiepi.io
808 Load: dtoverlay=cutiepi-panel
813 Info: Configures the dacberry400 add on soundcard
814 Load: dtoverlay=dacberry400
819 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
820 Also sometimes found with the part number(s) AM230x.
821 Load: dtoverlay=dht11,<param>=<val>
822 Params: gpiopin GPIO connected to the sensor's DATA output.
827 Info: Configures the Dion Audio KIWI STREAMER
828 Load: dtoverlay=dionaudio-kiwi
833 Info: Configures the Dion Audio LOCO DAC-AMP
834 Load: dtoverlay=dionaudio-loco
838 Name: dionaudio-loco-v2
839 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
840 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
841 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
842 Digital volume control. Enable with
843 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
844 (The default behaviour is that the Digital
845 volume control is limited to a maximum of
846 0dB. ie. it can attenuate but not provide
847 gain. For most users, this will be desired
848 as it will prevent clipping. By appending
849 the 24dB_digital_gain parameter, the Digital
850 volume control will allow up to 24dB of
851 gain. If this parameter is enabled, it is the
852 responsibility of the user to ensure that
853 the Digital volume control is set to a value
854 that does not result in clipping/distortion!)
858 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
859 UART0/ttyAMA0 over GPIOs 14 & 15.
860 N.B. To disable the systemd service that initialises the modem so it
861 doesn't use the UART, use 'sudo systemctl disable hciuart'.
862 Load: dtoverlay=disable-bt
867 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
868 Load: dtoverlay=disable-wifi
873 Info: Overlay for a generic 18-bit DPI display
874 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
875 2-3 seconds after the kernel has started.
876 Load: dtoverlay=dpi18
881 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
882 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
883 the output 3-3 seconds after the kernel has started.
884 Load: dtoverlay=dpi18cpadhi
889 Info: Overlay for a generic 24-bit DPI display
890 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
891 2-3 seconds after the kernel has started.
892 Load: dtoverlay=dpi24
897 Info: Configures the NW Digital Radio DRAWS Hat
899 The board includes an ADC to measure various board values and also
900 provides two analog user inputs on the expansion header. The ADC
901 can be configured for various sample rates and gain values to adjust
902 the input range. Tables describing the two parameters follow.
919 4 = 1600sps (default)
923 Load: dtoverlay=draws,<param>=<val>
924 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
925 input voltage sensor (default 1)
927 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
930 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
931 5V rail voltage sensor (default 1)
933 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
936 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
937 AIN2 input (default 2)
939 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
941 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
942 AIN3 input (default 2)
944 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
946 alsaname Name of the ALSA audio device (default "draws")
950 Info: Selects the dwc_otg USB controller driver which has fiq support. This
951 is the default on all except the Pi Zero which defaults to dwc2.
952 Load: dtoverlay=dwc-otg
957 Info: Selects the dwc2 USB controller driver
958 Load: dtoverlay=dwc2,<param>=<val>
959 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
961 g-rx-fifo-size Size of rx fifo size in gadget mode
963 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
967 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
971 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
972 This works with the Raspberry Pi 7" touchscreen when not being polled
974 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
975 config.txt to stop the firmware polling the touchscreen.
976 Load: dtoverlay=edt-ft5406,<param>=<val>
977 Params: sizex Touchscreen size x (default 800)
978 sizey Touchscreen size y (default 480)
979 invx Touchscreen inverted x axis
980 invy Touchscreen inverted y axis
981 swapxy Touchscreen swapped x y axis
985 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
986 Load: dtoverlay=enc28j60,<param>=<val>
987 Params: int_pin GPIO used for INT (default 25)
989 speed SPI bus speed (default 12000000)
993 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
994 Load: dtoverlay=enc28j60-spi2,<param>=<val>
995 Params: int_pin GPIO used for INT (default 39)
997 speed SPI bus speed (default 12000000)
1001 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
1002 GPIO 4 (pin 7 on GPIO header) for interrupt.
1003 Load: dtoverlay=exc3000,<param>=<val>
1004 Params: interrupt GPIO used for interrupt (default 4)
1005 sizex Touchscreen size x (default 4096)
1006 sizey Touchscreen size y (default 4096)
1007 invx Touchscreen inverted x axis
1008 invy Touchscreen inverted y axis
1009 swapxy Touchscreen swapped x y axis
1013 Info: Overlay for SPI-connected displays using the fbtft drivers.
1015 This overlay seeks to replace the functionality provided by fbtft_device
1016 which is now gone from the kernel.
1018 Most displays from fbtft_device have been ported over.
1020 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1022 It is also possible to specify the controller (this will use the default
1023 init sequence in the driver).
1025 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1027 For devices on spi1 or spi2, the interfaces should be enabled
1028 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
1030 The following features of fbtft_device have not been ported over:
1031 - parallel bus is not supported
1032 - the init property which overrides the controller initialization
1033 sequence is not supported as a parameter due to memory limitations in
1034 the bootloader responsible for applying the overlay.
1036 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
1039 Load: dtoverlay=fbtft,<param>=<val>
1041 spi<n>-<m> Configure device at spi<n>, cs<m>
1043 speed SPI bus speed in Hz (default 32000000)
1044 cpha Shifted clock phase (CPHA) mode
1045 cpol Inverse clock polarity (CPOL) mode
1047 adafruit18 Adafruit 1.8
1048 adafruit22 Adafruit 2.2 (old)
1049 adafruit22a Adafruit 2.2
1050 adafruit28 Adafruit 2.8
1051 adafruit13m Adafruit 1.3 OLED
1052 admatec_c-berry28 C-Berry28
1054 er_tftm050_2 ER-TFTM070-2
1055 er_tftm070_5 ER-TFTM070-5
1057 ew24ha0_9bit EW24HA0 in 9-bit mode
1058 freetronicsoled128 Freetronics OLED128
1061 itdb28_spi ITDB02-2.8 with SPI interface circuit
1062 mi0283qt-2 Watterott MI0283QT-2
1063 mi0283qt-9a Watterott MI0283QT-9A
1064 nokia3310 Nokia 3310
1065 nokia3310a Nokia 3310a
1066 nokia5110 Nokia 5110
1068 pitft Adafruit PiTFT 2.8
1070 rpi-display Watterott rpi-display
1071 sainsmart18 Sainsmart 1.8
1072 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
1073 tinylcd35 TinyLCD 3.5
1074 tm022hdh26 Tianma TM022HDH26
1075 tontec35_9481 Tontect 3.5 with ILI9481 controller
1076 tontec35_9486 Tontect 3.5 with ILI9486 controller
1077 waveshare32b Waveshare 3.2
1078 waveshare22 Waveshare 2.2
1080 bd663474 BD663474 display controller
1081 hx8340bn HX8340BN display controller
1082 hx8347d HX8347D display controller
1083 hx8353d HX8353D display controller
1084 hx8357d HX8357D display controller
1085 ili9163 ILI9163 display controller
1086 ili9320 ILI9320 display controller
1087 ili9325 ILI9325 display controller
1088 ili9340 ILI9340 display controller
1089 ili9341 ILI9341 display controller
1090 ili9481 ILI9481 display controller
1091 ili9486 ILI9486 display controller
1092 pcd8544 PCD8544 display controller
1093 ra8875 RA8875 display controller
1094 s6d02a1 S6D02A1 display controller
1095 s6d1121 S6D1121 display controller
1096 seps525 SEPS525 display controller
1097 sh1106 SH1106 display controller
1098 ssd1289 SSD1289 display controller
1099 ssd1305 SSD1305 display controller
1100 ssd1306 SSD1306 display controller
1101 ssd1325 SSD1325 display controller
1102 ssd1331 SSD1331 display controller
1103 ssd1351 SSD1351 display controller
1104 st7735r ST7735R display controller
1105 st7789v ST7789V display controller
1106 tls8204 TLS8204 display controller
1107 uc1611 UC1611 display controller
1108 uc1701 UC1701 display controller
1109 upd161704 UPD161704 display controller
1111 width Display width in pixels
1112 height Display height in pixels
1113 regwidth Display controller register width (default is
1115 buswidth Display bus interface width (default 8)
1116 debug Debug output level {0-7}
1117 rotate Display rotation {0, 90, 180, 270} (counter
1118 clockwise). Not supported by all drivers.
1119 bgr Enable BGR mode (default off). Use if Red and
1120 Blue are swapped. Not supported by all drivers.
1121 fps Frames per second (default 30). In effect this
1122 states how long the driver will wait after video
1123 memory has been changed until display update
1124 transfer is started.
1125 txbuflen Length of the FBTFT transmit buffer
1127 startbyte Sets the Start byte used by fb_ili9320,
1128 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1129 gamma String representation of Gamma Curve(s). Driver
1130 specific. Not supported by all drivers.
1131 reset_pin GPIO pin for RESET
1132 dc_pin GPIO pin for D/C
1133 led_pin GPIO pin for LED backlight
1137 Info: Configures the Fe-Pi Audio Sound Card
1138 Load: dtoverlay=fe-pi-audio
1143 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1144 nicely with a "traffic-light" display of red, amber and green LEDs on
1145 GPIOs 7, 8 and 25 respectively.
1146 Load: dtoverlay=fsm-demo,<param>=<val>
1147 Params: fsm_debug Enable debug logging (default off)
1151 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on
1152 SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical
1153 GPIO header pins 22, 13 and 12 respectively) in addition to the
1154 SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19,
1155 23 and 24 respectively).
1156 Load: dtoverlay=gc9a01,<param>=<val>
1157 Params: speed Display SPI bus speed
1159 rotate Display rotation {0,90,180,270}
1161 width Width of the display
1163 height Height of the display
1165 fps Delay between frame updates
1167 debug Debug output level {0-7}
1171 Info: An overlay for the Ghost amplifier.
1172 Load: dtoverlay=ghost-amp,<param>=<val>
1173 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1178 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1179 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1180 Load: dtoverlay=goodix,<param>=<val>
1181 Params: interrupt GPIO used for interrupt (default 4)
1182 reset GPIO used for reset (default 17)
1185 Name: googlevoicehat-soundcard
1186 Info: Configures the Google voiceHAT soundcard
1187 Load: dtoverlay=googlevoicehat-soundcard
1192 Info: Configure a GPIO pin to control a cooling fan.
1193 Load: dtoverlay=gpio-fan,<param>=<val>
1194 Params: gpiopin GPIO used to control the fan (default 12)
1195 temp Temperature at which the fan switches on, in
1196 millicelcius (default 55000)
1197 hyst Temperature delta (in millicelcius) below
1198 temp at which the fan will drop to minrpm
1203 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1204 an output, driven low or high as indicated by the presence or absence
1205 of the active_low parameter. Note that a hogged GPIO is not available
1206 to other drivers or for gpioset/gpioget.
1207 Load: dtoverlay=gpio-hog,<param>=<val>
1208 Params: gpio GPIO pin to hog (default 26)
1209 active_low If set, the hog drives the GPIO low (defaults
1210 to off - the GPIO is driven high)
1214 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1215 based gpio_ir_recv driver maps received keys directly to a
1216 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1217 not required! The key mapping and other decoding parameters can be
1218 configured by "ir-keytable" tool.
1219 Load: dtoverlay=gpio-ir,<param>=<val>
1220 Params: gpio_pin Input pin number. Default is 18.
1222 gpio_pull Desired pull-up/down state (off, down, up)
1225 invert "1" = invert the input (active-low signalling).
1226 "0" = non-inverted input (active-high
1227 signalling). Default is "1".
1229 rc-map-name Default rc keymap (can also be changed by
1230 ir-keytable), defaults to "rc-rc6-mce"
1234 Info: Use GPIO pin as bit-banged infrared transmitter output.
1235 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1236 a PWM so it can be used together with onboard analog audio.
1237 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1238 Params: gpio_pin Output GPIO (default 18)
1240 invert "1" = invert the output (make it active-low).
1241 Default is "0" (active-high).
1245 Info: This is a generic overlay for activating GPIO keypresses using
1246 the gpio-keys library and this dtoverlay. Multiple keys can be
1247 set up using multiple calls to the overlay for configuring
1248 additional buttons or joysticks. You can see available keycodes
1249 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1250 linux/input-event-codes.h#L64
1251 Load: dtoverlay=gpio-key,<param>=<val>
1252 Params: gpio GPIO pin to trigger on (default 3)
1253 active_low When this is 1 (active low), a falling
1254 edge generates a key down event and a
1255 rising edge generates a key up event.
1256 When this is 0 (active high), this is
1257 reversed. The default is 1 (active low)
1258 gpio_pull Desired pull-up/down state (off, down, up)
1259 Default is "up". Note that the default pin
1260 (GPIO3) has an external pullup
1261 label Set a label for the key
1262 keycode Set the key code for the button
1267 Info: This is a generic overlay for activating LEDs (or any other component)
1268 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1269 overlay. While there are many existing methods to activate LEDs on the
1270 RPi, this method offers some advantages:
1271 1) Does not require any userspace programs.
1272 2) LEDs can be connected to the kernel's led-trigger framework,
1273 and drive the LED based on triggers such as cpu load, heartbeat,
1274 kernel panic, key input, timers and others.
1275 3) LED can be tied to the input state of another GPIO pin.
1276 4) The LED is setup early during the kernel boot process (useful
1277 for cpu/heartbeat/panic triggers).
1279 Typical electrical connection is:
1280 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1281 The GPIO pin number can be changed with the 'gpio=' parameter.
1283 To control an LED from userspace, write a 0 or 1 value:
1284 echo 1 > /sys/class/leds/myled1/brightness
1285 The 'myled1' name can be changed with the 'label=' parameter.
1287 To connect the LED to a kernel trigger from userspace:
1288 echo cpu > /sys/class/leds/myled1/trigger
1289 echo heartbeat > /sys/class/leds/myled1/trigger
1290 echo none > /sys/class/leds/myled1/trigger
1291 To connect the LED to GPIO.26 pin (physical pin 37):
1292 echo gpio > /sys/class/leds/myled1/trigger
1293 echo 26 > /sys/class/leds/myled1/gpio
1295 cat /sys/class/leds/myled1/trigger
1297 More information about the Linux kernel LED/Trigger system:
1298 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1299 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1300 Load: dtoverlay=gpio-led,<param>=<val>
1301 Params: gpio GPIO pin connected to the LED (default 19)
1302 label The label for this LED. It will appear under
1303 /sys/class/leds/<label> . Default 'myled1'.
1304 trigger Set the led-trigger to connect to this LED.
1305 default 'none' (LED is user-controlled).
1306 Some possible triggers:
1307 cpu - CPU load (all CPUs)
1308 cpu0 - CPU load of first CPU.
1309 mmc - disk activity (all disks)
1310 panic - turn on on kernel panic
1311 heartbeat - indicate system health
1312 gpio - connect to a GPIO input pin (note:
1313 currently the GPIO PIN can not be set
1314 using overlay parameters, must be
1315 done in userspace, see examples above.
1316 active_low Set to 1 to turn invert the LED control
1317 (writing 0 to /sys/class/leds/XXX/brightness
1318 will turn on the GPIO/LED). Default '0'.
1321 Name: gpio-no-bank0-irq
1322 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1323 which can be useful for UIO drivers.
1324 N.B. Using this overlay will trigger a kernel WARN during booting, but
1325 this can safely be ignored - the system should work as expected.
1326 Load: dtoverlay=gpio-no-bank0-irq
1331 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1332 for user-space GPIO edge detection systems.
1333 Load: dtoverlay=gpio-no-irq
1338 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1339 overlay interferes with the normal power-down sequence, preventing the
1340 kernel from resetting the SoC (a necessary step in a normal power-off
1341 or reboot). This also disables the ability to trigger a boot by driving
1344 The GPIO starts in an inactive state. At poweroff time it is driven
1345 active for 100ms, then inactive for 100ms, then active again. It is
1346 safe to remove the power at any point after the initial activation of
1349 Users of this overlay are required to provide an external mechanism to
1350 switch off the power supply when signalled - failure to do so results
1351 in a kernel BUG, increased power consumption and undefined behaviour.
1352 Load: dtoverlay=gpio-poweroff,<param>=<val>
1353 Params: gpiopin GPIO for signalling (default 26)
1355 active_low Set if the power control device requires a
1356 high->low transition to trigger a power-down.
1357 Note that this will require the support of a
1358 custom dt-blob.bin to prevent a power-down
1359 during the boot process, and that a reboot
1360 will also cause the pin to go low.
1361 input Set if the gpio pin should be configured as
1363 export Set to export the configured pin to sysfs
1364 active_delay_ms Initial GPIO active period (default 100)
1365 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1366 timeout_ms Specify (in ms) how long the kernel waits for
1367 power-down before issuing a WARN (default 3000).
1371 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1372 is configured as an input key that generates KEY_POWER events.
1374 This event is handled by systemd-logind by initiating a
1375 shutdown. Systemd versions older than 225 need an udev rule
1376 enable listening to the input device:
1378 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1379 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1380 ATTRS{keys}=="116", TAG+="power-switch"
1382 Alternatively this event can be handled also on systems without
1383 systemd, just by traditional SysV init daemon. KEY_POWER event
1384 (keycode 116) needs to be mapped to KeyboardSignal on console
1385 and then kb::kbrequest inittab action which is triggered by
1386 KeyboardSignal from console can be configured to issue system
1387 shutdown. Steps for this configuration are:
1389 Add following lines to the /etc/console-setup/remap.inc file:
1391 # Key Power as special keypress
1392 keycode 116 = KeyboardSignal
1394 Then add following lines to /etc/inittab file:
1396 # Action on special keypress (Key Power)
1397 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1399 And finally reload configuration by calling following commands:
1401 # dpkg-reconfigure console-setup
1402 # service console-setup reload
1405 This overlay only handles shutdown. After shutdown, the system
1406 can be powered up again by driving GPIO3 low. The default
1407 configuration uses GPIO3 with a pullup, so if you connect a
1408 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1409 you get a shutdown and power-up button. Please note that
1410 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1411 Load: dtoverlay=gpio-shutdown,<param>=<val>
1412 Params: gpio_pin GPIO pin to trigger on (default 3)
1413 For Raspberry Pi 1 Model B rev 1 set this
1414 explicitly to value 1, e.g.:
1416 dtoverlay=gpio-shutdown,gpio_pin=1
1418 active_low When this is 1 (active low), a falling
1419 edge generates a key down event and a
1420 rising edge generates a key up event.
1421 When this is 0 (active high), this is
1422 reversed. The default is 1 (active low).
1424 gpio_pull Desired pull-up/down state (off, down, up)
1427 Note that the default pin (GPIO3) has an
1428 external pullup. Same applies for GPIO1
1429 on Raspberry Pi 1 Model B rev 1.
1431 debounce Specify the debounce interval in milliseconds
1436 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1437 data, 2 gpio pins for enable and register select and 1 optional pin
1438 for enabling/disabling the backlight display.
1439 Load: dtoverlay=hd44780-lcd,<param>=<val>
1440 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1442 pin_d5 GPIO pin for data pin D5 (default 13)
1444 pin_d6 GPIO pin for data pin D6 (default 19)
1446 pin_d7 GPIO pin for data pin D7 (default 26)
1448 pin_en GPIO pin for "Enable" (default 21)
1450 pin_rs GPIO pin for "Register Select" (default 20)
1452 pin_bl Optional pin for enabling/disabling the
1453 display backlight. (default disabled)
1455 display_height Height of the display in characters
1457 display_width Width of the display in characters
1460 Name: hdmi-backlight-hwhack-gpio
1461 Info: Devicetree overlay for GPIO based backlight on/off capability.
1462 Use this if you have one of those HDMI displays whose backlight cannot
1463 be controlled via DPMS over HDMI and plan to do a little soldering to
1464 use an RPi gpio pin for on/off switching. See:
1465 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1466 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1467 Params: gpio_pin GPIO pin used (default 17)
1468 active_low Set this to 1 if the display backlight is
1469 switched on when the wire goes low.
1470 Leave the default (value 0) if the backlight
1471 expects a high to switch it on.
1475 Info: Configures the HifiBerry Amp and Amp+ audio cards
1476 Load: dtoverlay=hifiberry-amp
1480 Name: hifiberry-amp100
1481 Info: Configures the HifiBerry AMP100 audio card
1482 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1483 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1484 Digital volume control. Enable with
1485 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1486 (The default behaviour is that the Digital
1487 volume control is limited to a maximum of
1488 0dB. ie. it can attenuate but not provide
1489 gain. For most users, this will be desired
1490 as it will prevent clipping. By appending
1491 the 24dB_digital_gain parameter, the Digital
1492 volume control will allow up to 24dB of
1493 gain. If this parameter is enabled, it is the
1494 responsibility of the user to ensure that
1495 the Digital volume control is set to a value
1496 that does not result in clipping/distortion!)
1497 slave Force DAC+ Pro into slave mode, using Pi as
1498 master for bit clock and frame clock.
1499 leds_off If set to 'true' the onboard indicator LEDs
1500 are switched off at all times.
1501 auto_mute If set to 'true' the amplifier is automatically
1502 muted when the DAC is not playing.
1503 mute_ext_ctl The amplifier's HW mute control is enabled
1504 in ALSA mixer and set to <val>.
1505 Will be overwritten by ALSA user settings.
1508 Name: hifiberry-amp3
1509 Info: Configures the HifiBerry Amp3 audio card
1510 Load: dtoverlay=hifiberry-amp3
1515 Info: Configures the HifiBerry DAC audio cards
1516 Load: dtoverlay=hifiberry-dac
1520 Name: hifiberry-dacplus
1521 Info: Configures the HifiBerry DAC+ audio card
1522 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1523 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1524 Digital volume control. Enable with
1525 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1526 (The default behaviour is that the Digital
1527 volume control is limited to a maximum of
1528 0dB. ie. it can attenuate but not provide
1529 gain. For most users, this will be desired
1530 as it will prevent clipping. By appending
1531 the 24dB_digital_gain parameter, the Digital
1532 volume control will allow up to 24dB of
1533 gain. If this parameter is enabled, it is the
1534 responsibility of the user to ensure that
1535 the Digital volume control is set to a value
1536 that does not result in clipping/distortion!)
1537 slave Force DAC+ Pro into slave mode, using Pi as
1538 master for bit clock and frame clock.
1539 leds_off If set to 'true' the onboard indicator LEDs
1540 are switched off at all times.
1543 Name: hifiberry-dacplusadc
1544 Info: Configures the HifiBerry DAC+ADC audio card
1545 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1546 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1547 Digital volume control. Enable with
1548 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1549 (The default behaviour is that the Digital
1550 volume control is limited to a maximum of
1551 0dB. ie. it can attenuate but not provide
1552 gain. For most users, this will be desired
1553 as it will prevent clipping. By appending
1554 the 24dB_digital_gain parameter, the Digital
1555 volume control will allow up to 24dB of
1556 gain. If this parameter is enabled, it is the
1557 responsibility of the user to ensure that
1558 the Digital volume control is set to a value
1559 that does not result in clipping/distortion!)
1560 slave Force DAC+ Pro into slave mode, using Pi as
1561 master for bit clock and frame clock.
1562 leds_off If set to 'true' the onboard indicator LEDs
1563 are switched off at all times.
1566 Name: hifiberry-dacplusadcpro
1567 Info: Configures the HifiBerry DAC+ADC PRO audio card
1568 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1569 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1570 Digital volume control. Enable with
1571 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1572 (The default behaviour is that the Digital
1573 volume control is limited to a maximum of
1574 0dB. ie. it can attenuate but not provide
1575 gain. For most users, this will be desired
1576 as it will prevent clipping. By appending
1577 the 24dB_digital_gain parameter, the Digital
1578 volume control will allow up to 24dB of
1579 gain. If this parameter is enabled, it is the
1580 responsibility of the user to ensure that
1581 the Digital volume control is set to a value
1582 that does not result in clipping/distortion!)
1583 slave Force DAC+ADC Pro into slave mode, using Pi as
1584 master for bit clock and frame clock.
1585 leds_off If set to 'true' the onboard indicator LEDs
1586 are switched off at all times.
1589 Name: hifiberry-dacplusdsp
1590 Info: Configures the HifiBerry DAC+DSP audio card
1591 Load: dtoverlay=hifiberry-dacplusdsp
1595 Name: hifiberry-dacplushd
1596 Info: Configures the HifiBerry DAC+ HD audio card
1597 Load: dtoverlay=hifiberry-dacplushd
1601 Name: hifiberry-digi
1602 Info: Configures the HifiBerry Digi and Digi+ audio card
1603 Load: dtoverlay=hifiberry-digi
1607 Name: hifiberry-digi-pro
1608 Info: Configures the HifiBerry Digi+ Pro audio card
1609 Load: dtoverlay=hifiberry-digi-pro
1614 Info: Enables "High Peripheral" mode
1615 Load: dtoverlay=highperi
1620 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1621 Default values match Texy's display shield
1622 Load: dtoverlay=hy28a,<param>=<val>
1623 Params: speed Display SPI bus speed
1625 rotate Display rotation {0,90,180,270}
1627 fps Delay between frame updates
1629 debug Debug output level {0-7}
1631 xohms Touchpanel sensitivity (X-plate resistance)
1633 resetgpio GPIO used to reset controller
1635 ledgpio GPIO used to control backlight
1639 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1640 Default values match Texy's display shield
1641 Load: dtoverlay=hy28b,<param>=<val>
1642 Params: speed Display SPI bus speed
1644 rotate Display rotation {0,90,180,270}
1646 fps Delay between frame updates
1648 debug Debug output level {0-7}
1650 xohms Touchpanel sensitivity (X-plate resistance)
1652 resetgpio GPIO used to reset controller
1654 ledgpio GPIO used to control backlight
1658 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1659 Default values match Texy's display shield
1660 Load: dtoverlay=hy28b-2017,<param>=<val>
1661 Params: speed Display SPI bus speed
1663 rotate Display rotation {0,90,180,270}
1665 fps Delay between frame updates
1667 debug Debug output level {0-7}
1669 xohms Touchpanel sensitivity (X-plate resistance)
1671 resetgpio GPIO used to reset controller
1673 ledgpio GPIO used to control backlight
1677 Info: Configures the Audiophonics I-SABRE Q2M DAC
1678 Load: dtoverlay=i-sabre-q2m
1683 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1684 Load: dtoverlay=i2c-bcm2708
1689 Info: Adds support for a number of I2C fan controllers
1690 Load: dtoverlay=i2c-fan,<param>=<val>
1691 Params: addr Sets the address for the fan controller. Note
1692 that the device must be configured to use the
1695 i2c0 Choose the I2C0 bus on GPIOs 0&1
1697 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1699 i2c3 Choose the I2C3 bus (configure with the i2c3
1700 overlay - BCM2711 only)
1702 i2c4 Choose the I2C3 bus (configure with the i2c3
1703 overlay - BCM2711 only)
1705 i2c5 Choose the I2C5 bus (configure with the i2c4
1706 overlay - BCM2711 only)
1708 i2c6 Choose the I2C6 bus (configure with the i2c6
1709 overlay - BCM2711 only)
1711 minpwm PWM setting for the fan when the SoC is below
1712 mintemp (range 0-255. default 0)
1713 maxpwm PWM setting for the fan when the SoC is above
1714 maxtemp (range 0-255. default 255)
1715 midtemp Temperature (in millicelcius) at which the fan
1716 begins to speed up (default 50000)
1718 midtemp_hyst Temperature delta (in millicelcius) below
1719 mintemp at which the fan will drop to minrpm
1722 maxtemp Temperature (in millicelcius) at which the fan
1723 will be held at maxrpm (default 70000)
1725 maxtemp_hyst Temperature delta (in millicelcius) below
1726 maxtemp at which the fan begins to slow down
1729 emc2301 Select the Microchip EMC230x controller family
1730 - EMC2301, EMC2302, EMC2303, EMC2305.
1734 Info: Adds support for software i2c controller on gpio pins
1735 Load: dtoverlay=i2c-gpio,<param>=<val>
1736 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1738 i2c_gpio_scl GPIO used for I2C clock (default "24")
1740 i2c_gpio_delay_us Clock delay in microseconds
1741 (default "2" = ~100kHz)
1743 bus Set to a unique, non-zero value if wanting
1744 multiple i2c-gpio busses. If set, will be used
1745 as the preferred bus number (/dev/i2c-<n>). If
1746 not set, the default value is 0, but the bus
1747 number will be dynamically assigned - probably
1752 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1753 Load: dtoverlay=i2c-mux,<param>=<val>
1754 Params: pca9542 Select the NXP PCA9542 device
1756 pca9545 Select the NXP PCA9545 device
1758 pca9548 Select the NXP PCA9548 device
1760 addr Change I2C address of the device (default 0x70)
1763 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1766 Name: i2c-pwm-pca9685a
1767 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1768 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1769 Params: addr I2C address of PCA9685A (default 0x40)
1773 Info: Adds support for a number of I2C Real Time Clock devices
1774 Load: dtoverlay=i2c-rtc,<param>=<val>
1775 Params: abx80x Select one of the ABx80x family:
1776 AB0801, AB0803, AB0804, AB0805,
1777 AB1801, AB1803, AB1804, AB1805
1779 bq32000 Select the TI BQ32000 device
1781 ds1307 Select the DS1307 device
1783 ds1339 Select the DS1339 device
1785 ds1340 Select the DS1340 device
1787 ds3231 Select the DS3231 device
1789 m41t62 Select the M41T62 device
1791 mcp7940x Select the MCP7940x device
1793 mcp7941x Select the MCP7941x device
1795 pcf2127 Select the PCF2127 device
1797 pcf2129 Select the PCF2129 device
1799 pcf85063 Select the PCF85063 device
1801 pcf85063a Select the PCF85063A device
1803 pcf8523 Select the PCF8523 device
1805 pcf85363 Select the PCF85363 device
1807 pcf8563 Select the PCF8563 device
1809 rv1805 Select the Micro Crystal RV1805 device
1811 rv3028 Select the Micro Crystal RV3028 device
1813 rv3032 Select the Micro Crystal RV3032 device
1815 rv8803 Select the Micro Crystal RV8803 device
1817 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1819 s35390a Select the ABLIC S35390A device
1821 i2c0 Choose the I2C0 bus on GPIOs 0&1
1823 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1825 i2c3 Choose the I2C3 bus (configure with the i2c3
1826 overlay - BCM2711 only)
1828 i2c4 Choose the I2C3 bus (configure with the i2c3
1829 overlay - BCM2711 only)
1831 i2c5 Choose the I2C5 bus (configure with the i2c4
1832 overlay - BCM2711 only)
1834 i2c6 Choose the I2C6 bus (configure with the i2c6
1835 overlay - BCM2711 only)
1837 addr Sets the address for the RTC. Note that the
1838 device must be configured to use the specified
1841 trickle-diode-disable Do not use the internal trickle charger diode
1844 trickle-diode-type Diode type for trickle charge - "standard" or
1845 "schottky" (ABx80x and RV1805 only)
1847 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1848 ABx80x, RV1805, RV3028)
1850 wakeup-source Specify that the RTC can be used as a wakeup
1853 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1854 off or 1 for Vdd < VBackup (RV3028 only)
1858 Info: Adds support for a number of I2C Real Time Clock devices
1859 using the software i2c controller
1860 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1861 Params: abx80x Select one of the ABx80x family:
1862 AB0801, AB0803, AB0804, AB0805,
1863 AB1801, AB1803, AB1804, AB1805
1865 bq32000 Select the TI BQ32000 device
1867 ds1307 Select the DS1307 device
1869 ds1339 Select the DS1339 device
1871 ds1340 Select the DS1340 device
1873 ds3231 Select the DS3231 device
1875 m41t62 Select the M41T62 device
1877 mcp7940x Select the MCP7940x device
1879 mcp7941x Select the MCP7941x device
1881 pcf2127 Select the PCF2127 device
1883 pcf2129 Select the PCF2129 device
1885 pcf85063 Select the PCF85063 device
1887 pcf85063a Select the PCF85063A device
1889 pcf8523 Select the PCF8523 device
1891 pcf85363 Select the PCF85363 device
1893 pcf8563 Select the PCF8563 device
1895 rv1805 Select the Micro Crystal RV1805 device
1897 rv3028 Select the Micro Crystal RV3028 device
1899 rv3032 Select the Micro Crystal RV3032 device
1901 rv8803 Select the Micro Crystal RV8803 device
1903 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1905 s35390a Select the ABLIC S35390A device
1907 addr Sets the address for the RTC. Note that the
1908 device must be configured to use the specified
1911 trickle-diode-disable Do not use the internal trickle charger diode
1914 trickle-diode-type Diode type for trickle charge - "standard" or
1915 "schottky" (ABx80x and RV1805 only)
1917 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1918 ABx80x, RV1805, RV3028)
1920 wakeup-source Specify that the RTC can be used as a wakeup
1923 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1924 off or 1 for Vdd < VBackup (RV3028 only)
1926 i2c_gpio_sda GPIO used for I2C data (default "23")
1928 i2c_gpio_scl GPIO used for I2C clock (default "24")
1930 i2c_gpio_delay_us Clock delay in microseconds
1931 (default "2" = ~100kHz)
1935 Info: Adds support for a number of I2C barometric pressure, temperature,
1936 light level and chemical sensors on i2c_arm
1937 Load: dtoverlay=i2c-sensor,<param>=<val>
1938 Params: addr Set the address for the BH1750, BME280, BME680,
1939 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1942 aht10 Select the Aosong AHT10 temperature and humidity
1945 bh1750 Select the Rohm BH1750 ambient light sensor
1946 Valid addresses 0x23 or 0x5c, default 0x23
1948 bme280 Select the Bosch Sensortronic BME280
1949 Valid addresses 0x76-0x77, default 0x76
1951 bme680 Select the Bosch Sensortronic BME680
1952 Valid addresses 0x76-0x77, default 0x76
1954 bmp085 Select the Bosch Sensortronic BMP085
1956 bmp180 Select the Bosch Sensortronic BMP180
1958 bmp280 Select the Bosch Sensortronic BMP280
1959 Valid addresses 0x76-0x77, default 0x76
1961 ccs811 Select the AMS CCS811 digital gas sensor
1962 Valid addresses 0x5a-0x5b, default 0x5b
1964 ds1621 Select the Dallas Semiconductors DS1621 temp
1965 sensor. Valid addresses 0x48-0x4f, default 0x48
1967 hdc100x Select the Texas Instruments HDC100x temp sensor
1968 Valid addresses 0x40-0x43, default 0x40
1970 htu21 Select the HTU21 temperature and humidity sensor
1972 int_pin Set the GPIO to use for interrupts (max30102
1975 jc42 Select any of the many JEDEC JC42.4-compliant
1976 temperature sensors, including:
1977 ADT7408, AT30TS00, CAT34TS02, CAT6095,
1978 MAX6604, MCP9804, MCP9805, MCP9808,
1979 MCP98242, MCP98243, MCP98244, MCP9843,
1980 SE97, SE98, STTS424(E), STTS2002, STTS3000,
1981 TSE2002, TSE2004, TS3000, and TS3001.
1982 The default address is 0x18.
1984 lm75 Select the Maxim LM75 temperature sensor
1985 Valid addresses 0x48-0x4f, default 0x4f
1987 lm75addr Deprecated - use addr parameter instead
1989 max17040 Select the Maxim Integrated MAX17040 battery
1992 max30102 Select the Maxim Integrated MAX30102 heart-rate
1993 and blood-oxygen sensor
1995 mcp980x Select the Maxim MCP980x range of temperature
1996 sensors (i.e. MCP9800, MCP9801, MCP9802 and
1997 MCP9803). N.B. For MCP9804, MCP9805 and MCP9808,
1998 use the "jc42" option.
1999 Valid addresses are 0x18-0x1f (default 0x18)
2001 sht3x Select the Sensiron SHT3x temperature and
2002 humidity sensor. Valid addresses 0x44-0x45,
2005 si7020 Select the Silicon Labs Si7013/20/21 humidity/
2008 sps30 Select the Sensirion SPS30 particulate matter
2009 sensor. Fixed address 0x69.
2011 sgp30 Select the Sensirion SGP30 VOC sensor.
2014 tmp102 Select the Texas Instruments TMP102 temp sensor
2015 Valid addresses 0x48-0x4b, default 0x48
2017 tsl4531 Select the AMS TSL4531 digital ambient light
2020 veml6070 Select the Vishay VEML6070 ultraviolet light
2023 i2c0 Choose the I2C0 bus on GPIOs 0&1
2025 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
2027 i2c3 Choose the I2C3 bus (configure with the i2c3
2028 overlay - BCM2711 only)
2030 i2c4 Choose the I2C3 bus (configure with the i2c3
2031 overlay - BCM2711 only)
2033 i2c5 Choose the I2C5 bus (configure with the i2c4
2034 overlay - BCM2711 only)
2036 i2c6 Choose the I2C6 bus (configure with the i2c6
2037 overlay - BCM2711 only)
2041 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
2042 platforms - platforms other then Compute Modules can only use this
2043 to disable transaction combining.
2044 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
2045 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
2046 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
2047 camera and display connectors. This overlay disables that mux and
2048 configures /dev/i2c0 to point at whichever set of pins is requested.
2049 dtparam=i2c_vc=on will try and enable the mux, so combining the two
2050 will cause conflicts.
2051 Load: dtoverlay=i2c0,<param>=<val>
2052 Params: pins_0_1 Use pins 0 and 1 (default)
2053 pins_28_29 Use pins 28 and 29
2054 pins_44_45 Use pins 44 and 45
2055 pins_46_47 Use pins 46 and 47
2056 combine Allow transactions to be combined (default
2061 Info: Deprecated, legacy version of i2c0.
2066 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
2067 platforms - platforms other then Compute Modules can only use this
2068 to disable transaction combining.
2069 Load: dtoverlay=i2c1,<param>=<val>
2070 Params: pins_2_3 Use pins 2 and 3 (default)
2071 pins_44_45 Use pins 44 and 45
2072 combine Allow transactions to be combined (default
2077 Info: Deprecated, legacy version of i2c1.
2082 Info: Enable the i2c3 bus. BCM2711 only.
2083 Load: dtoverlay=i2c3,<param>
2084 Params: pins_2_3 Use GPIOs 2 and 3
2085 pins_4_5 Use GPIOs 4 and 5 (default)
2086 baudrate Set the baudrate for the interface (default
2091 Info: Enable the i2c4 bus. BCM2711 only.
2092 Load: dtoverlay=i2c4,<param>
2093 Params: pins_6_7 Use GPIOs 6 and 7
2094 pins_8_9 Use GPIOs 8 and 9 (default)
2095 baudrate Set the baudrate for the interface (default
2100 Info: Enable the i2c5 bus. BCM2711 only.
2101 Load: dtoverlay=i2c5,<param>
2102 Params: pins_10_11 Use GPIOs 10 and 11
2103 pins_12_13 Use GPIOs 12 and 13 (default)
2104 baudrate Set the baudrate for the interface (default
2109 Info: Enable the i2c6 bus. BCM2711 only.
2110 Load: dtoverlay=i2c6,<param>
2111 Params: pins_0_1 Use GPIOs 0 and 1
2112 pins_22_23 Use GPIOs 22 and 23 (default)
2113 baudrate Set the baudrate for the interface (default
2118 Info: Configures any passive I2S DAC soundcard.
2119 Load: dtoverlay=i2s-dac
2124 Info: move I2S function block to GPIO 28 to 31
2125 Load: dtoverlay=i2s-gpio28-31
2130 Info: Enables I2C connected Ilitek 251x multiple touch controller using
2131 GPIO 4 (pin 7 on GPIO header) for interrupt.
2132 Load: dtoverlay=ilitek251x,<param>=<val>
2133 Params: interrupt GPIO used for interrupt (default 4)
2134 sizex Touchscreen size x, horizontal resolution of
2135 touchscreen (in pixels)
2136 sizey Touchscreen size y, vertical resolution of
2137 touchscreen (in pixels)
2141 Info: Sony IMX219 camera module.
2142 Uses Unicam 1, which is the standard camera connector on most Pi
2144 Load: dtoverlay=imx219,<param>=<val>
2145 Params: rotation Mounting rotation of the camera sensor (0 or
2147 orientation Sensor orientation (0 = front, 1 = rear,
2148 2 = external, default external)
2149 media-controller Configure use of Media Controller API for
2150 configuring the sensor (default on)
2151 cam0 Adopt the default configuration for CAM0 on a
2152 Compute Module (CSI0, i2c_vc, and cam0_reg).
2153 vcm Configure a VCM focus drive on the sensor.
2157 Info: Sony IMX258 camera module.
2158 Uses Unicam 1, which is the standard camera connector on most Pi
2160 Load: dtoverlay=imx258,<param>=<val>
2161 Params: rotation Mounting rotation of the camera sensor (0 or
2163 orientation Sensor orientation (0 = front, 1 = rear,
2164 2 = external, default external)
2165 media-controller Configure use of Media Controller API for
2166 configuring the sensor (default on)
2167 cam0 Adopt the default configuration for CAM0 on a
2168 Compute Module (CSI0, i2c_vc, and cam0_reg).
2169 vcm Configure a VCM focus drive on the sensor.
2170 4lane Enable 4 CSI2 lanes. This requires a Compute
2171 Module (1, 3, or 4).
2175 Info: Sony IMX290 camera module.
2176 Uses Unicam 1, which is the standard camera connector on most Pi
2178 Load: dtoverlay=imx290,<param>
2179 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2180 Module (1, 3, or 4).
2181 clock-frequency Sets the clock frequency to match that used on
2183 Modules from Vision Components use 37.125MHz
2184 (the default), whilst those from Innomaker use
2186 mono Denote that the module is a mono sensor.
2187 orientation Sensor orientation (0 = front, 1 = rear,
2188 2 = external, default external)
2189 rotation Mounting rotation of the camera sensor (0 or
2191 media-controller Configure use of Media Controller API for
2192 configuring the sensor (default on)
2193 cam0 Adopt the default configuration for CAM0 on a
2194 Compute Module (CSI0, i2c_vc, and cam0_reg).
2198 Info: Sony IMX296 camera module.
2199 Uses Unicam 1, which is the standard camera connector on most Pi
2201 Load: dtoverlay=imx296,<param>=<val>
2202 Params: rotation Mounting rotation of the camera sensor (0 or
2204 orientation Sensor orientation (0 = front, 1 = rear,
2205 2 = external, default external)
2206 media-controller Configure use of Media Controller API for
2207 configuring the sensor (default on)
2208 cam0 Adopt the default configuration for CAM0 on a
2209 Compute Module (CSI0, i2c_vc, and cam0_reg).
2210 clock-frequency Sets the clock frequency to match that used on
2211 the board, which should be one of 54000000
2212 (the default), 37125000 or 74250000.
2216 Info: Sony IMX327 camera module.
2217 Uses Unicam 1, which is the standard camera connector on most Pi
2219 Load: dtoverlay=imx327,<param>
2220 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2221 Module (1, 3, or 4).
2222 clock-frequency Sets the clock frequency to match that used on
2224 Modules from Vision Components use 37.125MHz
2225 (the default), whilst those from Innomaker use
2227 mono Denote that the module is a mono sensor.
2228 orientation Sensor orientation (0 = front, 1 = rear,
2229 2 = external, default external)
2230 rotation Mounting rotation of the camera sensor (0 or
2232 media-controller Configure use of Media Controller API for
2233 configuring the sensor (default on)
2234 cam0 Adopt the default configuration for CAM0 on a
2235 Compute Module (CSI0, i2c_vc, and cam0_reg).
2239 Info: Sony IMX378 camera module.
2240 Uses Unicam 1, which is the standard camera connector on most Pi
2242 Load: dtoverlay=imx378,<param>=<val>
2243 Params: rotation Mounting rotation of the camera sensor (0 or
2245 orientation Sensor orientation (0 = front, 1 = rear,
2246 2 = external, default external)
2247 media-controller Configure use of Media Controller API for
2248 configuring the sensor (default on)
2249 cam0 Adopt the default configuration for CAM0 on a
2250 Compute Module (CSI0, i2c_vc, and cam0_reg).
2254 Info: Sony IMX462 camera module.
2255 Uses Unicam 1, which is the standard camera connector on most Pi
2257 Load: dtoverlay=imx462,<param>
2258 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2259 Module (1, 3, or 4).
2260 clock-frequency Sets the clock frequency to match that used on
2262 Modules from Vision Components use 37.125MHz
2263 (the default), whilst those from Innomaker use
2265 mono Denote that the module is a mono sensor.
2266 orientation Sensor orientation (0 = front, 1 = rear,
2267 2 = external, default external)
2268 rotation Mounting rotation of the camera sensor (0 or
2270 media-controller Configure use of Media Controller API for
2271 configuring the sensor (default on)
2272 cam0 Adopt the default configuration for CAM0 on a
2273 Compute Module (CSI0, i2c_vc, and cam0_reg).
2277 Info: Sony IMX477 camera module.
2278 Uses Unicam 1, which is the standard camera connector on most Pi
2280 Load: dtoverlay=imx477,<param>=<val>
2281 Params: rotation Mounting rotation of the camera sensor (0 or
2283 orientation Sensor orientation (0 = front, 1 = rear,
2284 2 = external, default external)
2285 media-controller Configure use of Media Controller API for
2286 configuring the sensor (default on)
2287 cam0 Adopt the default configuration for CAM0 on a
2288 Compute Module (CSI0, i2c_vc, and cam0_reg).
2292 Info: Sony IMX519 camera module.
2293 Uses Unicam 1, which is the standard camera connector on most Pi
2295 Load: dtoverlay=imx519,<param>=<val>
2296 Params: rotation Mounting rotation of the camera sensor (0 or
2298 orientation Sensor orientation (0 = front, 1 = rear,
2299 2 = external, default external)
2300 media-controller Configure use of Media Controller API for
2301 configuring the sensor (default on)
2302 cam0 Adopt the default configuration for CAM0 on a
2303 Compute Module (CSI0, i2c_vc, and cam0_reg).
2307 Info: Configures the IQaudio Codec audio card
2308 Load: dtoverlay=iqaudio-codec
2313 Info: Configures the IQaudio DAC audio card
2314 Load: dtoverlay=iqaudio-dac,<param>
2315 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2316 Digital volume control. Enable with
2317 "dtoverlay=iqaudio-dac,24db_digital_gain"
2318 (The default behaviour is that the Digital
2319 volume control is limited to a maximum of
2320 0dB. ie. it can attenuate but not provide
2321 gain. For most users, this will be desired
2322 as it will prevent clipping. By appending
2323 the 24db_digital_gain parameter, the Digital
2324 volume control will allow up to 24dB of
2325 gain. If this parameter is enabled, it is the
2326 responsibility of the user to ensure that
2327 the Digital volume control is set to a value
2328 that does not result in clipping/distortion!)
2331 Name: iqaudio-dacplus
2332 Info: Configures the IQaudio DAC+ audio card
2333 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2334 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2335 Digital volume control. Enable with
2336 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2337 (The default behaviour is that the Digital
2338 volume control is limited to a maximum of
2339 0dB. ie. it can attenuate but not provide
2340 gain. For most users, this will be desired
2341 as it will prevent clipping. By appending
2342 the 24db_digital_gain parameter, the Digital
2343 volume control will allow up to 24dB of
2344 gain. If this parameter is enabled, it is the
2345 responsibility of the user to ensure that
2346 the Digital volume control is set to a value
2347 that does not result in clipping/distortion!)
2348 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2349 starting/stopping audio playback.
2350 unmute_amp If specified, unmute the IQaudIO amp once when
2351 the DAC driver module loads.
2354 Name: iqaudio-digi-wm8804-audio
2355 Info: Configures the IQAudIO Digi WM8804 audio card
2356 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2357 Params: card_name Override the default, "IQAudIODigi", card name.
2358 dai_name Override the default, "IQAudIO Digi", dai name.
2359 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2364 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2365 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2366 Load: dtoverlay=iqs550,<param>=<val>
2367 Params: interrupt GPIO used for interrupt (default 4)
2368 reset GPIO used for reset (optional)
2369 sizex Touchscreen size x (default 800)
2370 sizey Touchscreen size y (default 480)
2371 invx Touchscreen inverted x axis
2372 invy Touchscreen inverted y axis
2373 swapxy Touchscreen swapped x y axis
2377 Info: Infineon irs1125 TOF camera module.
2378 Uses Unicam 1, which is the standard camera connector on most Pi
2380 Load: dtoverlay=irs1125,<param>=<val>
2381 Params: media-controller Configure use of Media Controller API for
2382 configuring the sensor (default off)
2383 cam0 Adopt the default configuration for CAM0 on a
2384 Compute Module (CSI0, i2c_vc, and cam0_reg).
2388 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2389 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2390 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2391 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2392 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2397 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2399 Load: dtoverlay=justboom-both,<param>=<val>
2400 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2401 Digital volume control. Enable with
2402 "dtoverlay=justboom-dac,24db_digital_gain"
2403 (The default behaviour is that the Digital
2404 volume control is limited to a maximum of
2405 0dB. ie. it can attenuate but not provide
2406 gain. For most users, this will be desired
2407 as it will prevent clipping. By appending
2408 the 24dB_digital_gain parameter, the Digital
2409 volume control will allow up to 24dB of
2410 gain. If this parameter is enabled, it is the
2411 responsibility of the user to ensure that
2412 the Digital volume control is set to a value
2413 that does not result in clipping/distortion!)
2417 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2419 Load: dtoverlay=justboom-dac,<param>=<val>
2420 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2421 Digital volume control. Enable with
2422 "dtoverlay=justboom-dac,24db_digital_gain"
2423 (The default behaviour is that the Digital
2424 volume control is limited to a maximum of
2425 0dB. ie. it can attenuate but not provide
2426 gain. For most users, this will be desired
2427 as it will prevent clipping. By appending
2428 the 24dB_digital_gain parameter, the Digital
2429 volume control will allow up to 24dB of
2430 gain. If this parameter is enabled, it is the
2431 responsibility of the user to ensure that
2432 the Digital volume control is set to a value
2433 that does not result in clipping/distortion!)
2437 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2438 Load: dtoverlay=justboom-digi
2443 Info: This overlay has been deprecated and removed - see gpio-ir
2448 Info: Adds support for the ltc294x family of battery gauges
2449 Load: dtoverlay=ltc294x,<param>=<val>
2450 Params: ltc2941 Select the ltc2941 device
2452 ltc2942 Select the ltc2942 device
2454 ltc2943 Select the ltc2943 device
2456 ltc2944 Select the ltc2944 device
2458 resistor-sense The sense resistor value in milli-ohms.
2459 Can be a 32-bit negative value when the battery
2460 has been connected to the wrong end of the
2463 prescaler-exponent Range and accuracy of the gauge. The value is
2464 programmed into the chip only if it differs
2465 from the current setting.
2467 - Default value is 128
2468 - the exponent is in the range 0-7 (default 7)
2469 See the datasheet for more information.
2473 Info: Configures the Maxim MAX98357A I2S DAC
2474 Load: dtoverlay=max98357a,<param>=<val>
2475 Params: no-sdmode Driver does not manage the state of the DAC's
2476 SD_MODE pin (i.e. chip is always on).
2477 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2478 of the DAC (default GPIO4 if parameter omitted).
2482 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2484 For devices on spi1 or spi2, the interfaces should be enabled
2485 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2486 The overlay expects to disable the relevant spidev node, so also using
2487 e.g. cs0_spidev=off is unnecessary.
2490 MAX31855 on /dev/spidev0.0
2491 dtoverlay=maxtherm,spi0-0,max31855
2492 MAX31856 using a type J thermocouple on /dev/spidev2.1
2494 dtoverlay=maxtherm,spi2-1,max31856,type_j
2496 Load: dtoverlay=maxtherm,<param>=<val>
2497 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2499 max6675 Enable support for the MAX6675 (default)
2500 max31855 Enable support for the MAX31855
2501 max31855e Enable support for the MAX31855E
2502 max31855j Enable support for the MAX31855J
2503 max31855k Enable support for the MAX31855K
2504 max31855n Enable support for the MAX31855N
2505 max31855r Enable support for the MAX31855R
2506 max31855s Enable support for the MAX31855S
2507 max31855t Enable support for the MAX31855T
2508 max31856 Enable support for the MAX31856 (with type K)
2509 type_b Select a type B sensor for max31856
2510 type_e Select a type E sensor for max31856
2511 type_j Select a type J sensor for max31856
2512 type_k Select a type K sensor for max31856
2513 type_n Select a type N sensor for max31856
2514 type_r Select a type R sensor for max31856
2515 type_s Select a type S sensor for max31856
2516 type_t Select a type T sensor for max31856
2520 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2521 Load: dtoverlay=mbed-dac
2526 Info: Configures the MCP23017 I2C GPIO expander
2527 Load: dtoverlay=mcp23017,<param>=<val>
2528 Params: gpiopin Gpio pin connected to the INTA output of the
2529 MCP23017 (default: 4)
2531 addr I2C address of the MCP23017 (default: 0x20)
2533 mcp23008 Configure an MCP23008 instead.
2534 noints Disable the interrupt GPIO line.
2538 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2539 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2540 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2541 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2542 device must be the only one present on that SPI bus/CS#.
2543 Load: dtoverlay=mcp23s17,<param>=<val>
2544 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2545 devices present on SPI<n>, CS#<m>
2547 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2548 devices present on SPI<n>, CS#<m>
2550 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2551 MCP23S08 device on SPI<n>, CS#<m>, specifies
2552 the GPIO pin to which INT output of MCP23S08
2555 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2556 single MCP23S17 device on SPI<n>, CS#<m>,
2557 specifies the GPIO pin to which either INTA
2558 or INTB output of MCP23S17 is connected.
2562 Info: Configures the MCP2515 CAN controller on spi0/1/2
2563 For devices on spi1 or spi2, the interfaces should be enabled
2564 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2565 Load: dtoverlay=mcp2515,<param>=<val>
2566 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2569 oscillator Clock frequency for the CAN controller (Hz)
2571 speed Maximum SPI frequence (Hz)
2573 interrupt GPIO for interrupt signal
2577 Info: Configures the MCP2515 CAN controller on spi0.0
2578 Load: dtoverlay=mcp2515-can0,<param>=<val>
2579 Params: oscillator Clock frequency for the CAN controller (Hz)
2581 spimaxfrequency Maximum SPI frequence (Hz)
2583 interrupt GPIO for interrupt signal
2587 Info: Configures the MCP2515 CAN controller on spi0.1
2588 Load: dtoverlay=mcp2515-can1,<param>=<val>
2589 Params: oscillator Clock frequency for the CAN controller (Hz)
2591 spimaxfrequency Maximum SPI frequence (Hz)
2593 interrupt GPIO for interrupt signal
2597 Info: Configures the MCP251XFD CAN controller family
2598 For devices on spi1 or spi2, the interfaces should be enabled
2599 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2600 Load: dtoverlay=mcp251xfd,<param>=<val>
2601 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2604 oscillator Clock frequency for the CAN controller (Hz)
2606 speed Maximum SPI frequence (Hz)
2608 interrupt GPIO for interrupt signal
2610 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2612 xceiver_enable GPIO for CAN transceiver enable (optional)
2614 xceiver_active_high specifiy if CAN transceiver enable pin is
2615 active high (optional, default: active low)
2619 Info: Configures MCP3008 A/D converters
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=mcp3008,<param>[=<val>]
2623 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2624 spi<n>-<m>-speed integer, set the spi bus speed for this device
2628 Info: Configures MCP3202 A/D converters
2629 For devices on spi1 or spi2, the interfaces should be enabled
2630 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2631 Load: dtoverlay=mcp3202,<param>[=<val>]
2632 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2633 spi<n>-<m>-speed integer, set the spi bus speed for this device
2637 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2638 Load: dtoverlay=mcp342x,<param>=<val>
2639 Params: addr I2C bus address of device, for devices with
2640 addresses that are configurable, e.g. by
2641 hardware links (default=0x68)
2642 mcp3421 The device is an MCP3421
2643 mcp3422 The device is an MCP3422
2644 mcp3423 The device is an MCP3423
2645 mcp3424 The device is an MCP3424
2646 mcp3425 The device is an MCP3425
2647 mcp3426 The device is an MCP3426
2648 mcp3427 The device is an MCP3427
2649 mcp3428 The device is an MCP3428
2653 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2654 Load: dtoverlay=media-center,<param>=<val>
2655 Params: speed Display SPI bus speed
2656 rotate Display rotation {0,90,180,270}
2657 fps Delay between frame updates
2658 xohms Touchpanel sensitivity (X-plate resistance)
2659 swapxy Swap x and y axis
2660 backlight Change backlight GPIO pin {e.g. 12, 18}
2661 gpio_out_pin GPIO for output (default "17")
2662 gpio_in_pin GPIO for input (default "18")
2663 gpio_in_pull Pull up/down/off on the input pin
2665 sense Override the IR receive auto-detection logic:
2666 "0" = force active-high
2667 "1" = force active-low
2668 "-1" = use auto-detection
2670 softcarrier Turn the software carrier "on" or "off"
2672 invert "on" = invert the output pin (default "off")
2673 debug "on" = enable additional debug messages
2678 Info: Configures the merus-amp audio card
2679 Load: dtoverlay=merus-amp
2684 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2685 31.25kbaud, the frequency required for MIDI
2686 Load: dtoverlay=midi-uart0
2691 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2692 31.25kbaud, the frequency required for MIDI
2693 Load: dtoverlay=midi-uart1
2698 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2699 31.25kbaud, the frequency required for MIDI
2700 Load: dtoverlay=midi-uart2
2705 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2706 31.25kbaud, the frequency required for MIDI
2707 Load: dtoverlay=midi-uart3
2712 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2713 31.25kbaud, the frequency required for MIDI
2714 Load: dtoverlay=midi-uart4
2719 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2720 31.25kbaud, the frequency required for MIDI
2721 Load: dtoverlay=midi-uart5
2726 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2727 Load: dtoverlay=minipitft13,<param>=<val>
2728 Params: speed SPI bus speed (default 32000000)
2729 rotate Display rotation (0, 90, 180 or 270; default 0)
2730 width Display width (default 240)
2731 height Display height (default 240)
2732 fps Delay between frame updates (default 25)
2733 debug Debug output level (0-7; default 0)
2737 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2738 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2739 15. Note that this may reduce the maximum usable baudrate.
2740 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2741 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2742 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2743 in which case use /dev/serial1 instead because it will always be
2744 correct. Furthermore, you must also set core_freq and core_freq_min to
2745 the same value in config.txt or the miniuart will not work.
2746 Load: dtoverlay=miniuart-bt,<param>=<val>
2747 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2748 driver without need of hciattach/btattach
2752 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2753 driver. The driver will load a file /lib/firmware/panel.bin containing
2754 the initialisation commands.
2757 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2758 dtparam=width=320,height=240
2759 dtparam=reset-gpio=23,dc-gpio=24
2760 dtparam=backlight-gpio=18
2762 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2763 and init commands at 10MHz. This makes it possible to push the envelope
2764 without messing up the controller configuration due to command
2765 transmission errors.
2767 For devices on spi1 or spi2, the interfaces should be enabled
2768 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2770 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2772 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2774 compatible Set the compatible string to load a different
2775 firmware file. Both the panel compatible value
2776 used to load the firmware file and the value
2777 used to load the driver has to be set having a
2778 NUL (\0) separator between them.
2780 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2781 spi<n>-<m> Configure device at spi<n>, cs<m>
2783 speed SPI bus speed in Hz (default 32000000)
2784 cpha Shifted SPI clock phase (CPHA) mode
2785 cpol Inverse SPI clock polarity (CPOL) mode
2786 write-only Controller is not readable
2787 (ie. MISO is not wired up).
2789 width Panel width in pixels (required)
2790 height Panel height in pixels (required)
2791 width-mm Panel width in mm
2792 height-mm Panel height in mm
2793 x-offset Panel x-offset in controller RAM
2794 y-offset Panel y-offset in controller RAM
2796 clock-frequency Panel clock frequency in Hz
2797 (optional, just informational).
2799 reset-gpio GPIO pin to be used for RESET
2800 dc-gpio GPIO pin to be used for D/C
2802 backlight-gpio GPIO pin to be used for backlight control
2804 backlight-pwm PWM channel to be used for backlight control
2805 (default of none). NB Disables audio headphone
2806 output as that also uses PWM.
2807 backlight-pwm-chan Choose channel on &pwm node for backlight
2808 control (default 0).
2809 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2810 pwm-2chan for valid options (default 18).
2811 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2812 See pwm-2chan for valid options (default 2).
2813 backlight-def-brightness
2814 Set the default brightness. Normal range 1-16.
2819 Info: Overlay for i2c connected mlx90640 thermal camera
2820 Load: dtoverlay=mlx90640
2825 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2826 Load: dtoverlay=mmc,<param>=<val>
2827 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2832 Info: Overlay for i2c connected mpu6050 imu
2833 Load: dtoverlay=mpu6050,<param>=<val>
2834 Params: interrupt GPIO pin for interrupt (default 4)
2835 addr I2C address of the device (default 0x68)
2839 Info: MZ61581 display by Tontec
2840 Load: dtoverlay=mz61581,<param>=<val>
2841 Params: speed Display SPI bus speed
2843 rotate Display rotation {0,90,180,270}
2845 fps Delay between frame updates
2847 txbuflen Transmit buffer length (default 32768)
2849 debug Debug output level {0-7}
2851 xohms Touchpanel sensitivity (X-plate resistance)
2855 Info: Omnivision OV2311 camera module.
2856 Uses Unicam 1, which is the standard camera connector on most Pi
2858 Load: dtoverlay=ov2311,<param>=<val>
2859 Params: rotation Mounting rotation of the camera sensor (0 or
2861 orientation Sensor orientation (0 = front, 1 = rear,
2862 2 = external, default external)
2863 media-controller Configure use of Media Controller API for
2864 configuring the sensor (default on)
2865 cam0 Adopt the default configuration for CAM0 on a
2866 Compute Module (CSI0, i2c_vc, and cam0_reg).
2870 Info: Omnivision OV5647 camera module.
2871 Uses Unicam 1, which is the standard camera connector on most Pi
2873 Load: dtoverlay=ov5647,<param>=<val>
2874 Params: rotation Mounting rotation of the camera sensor (0 or
2876 orientation Sensor orientation (0 = front, 1 = rear,
2877 2 = external, default external)
2878 media-controller Configure use of Media Controller API for
2879 configuring the sensor (default on)
2880 cam0 Adopt the default configuration for CAM0 on a
2881 Compute Module (CSI0, i2c_vc, and cam0_reg).
2882 vcm Configure a VCM focus drive on the sensor.
2886 Info: Omnivision OV7251 camera module.
2887 Uses Unicam 1, which is the standard camera connector on most Pi
2889 Load: dtoverlay=ov7251,<param>=<val>
2890 Params: rotation Mounting rotation of the camera sensor (0 or
2892 orientation Sensor orientation (0 = front, 1 = rear,
2893 2 = external, default external)
2894 media-controller Configure use of Media Controller API for
2895 configuring the sensor (default off)
2896 cam0 Adopt the default configuration for CAM0 on a
2897 Compute Module (CSI0, i2c_vc, and cam0_reg).
2901 Info: Omnivision OV9281 camera module.
2902 Uses Unicam 1, which is the standard camera connector on most Pi
2904 Load: dtoverlay=ov9281,<param>=<val>
2905 Params: rotation Mounting rotation of the camera sensor (0 or
2907 orientation Sensor orientation (0 = front, 1 = rear,
2908 2 = external, default external)
2909 media-controller Configure use of Media Controller API for
2910 configuring the sensor (default on)
2911 cam0 Adopt the default configuration for CAM0 on a
2912 Compute Module (CSI0, i2c_vc, and cam0_reg).
2916 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2917 Load: dtoverlay=papirus,<param>=<val>
2918 Params: panel Display panel (required):
2923 speed Display SPI bus speed
2927 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2928 Load: dtoverlay=pca953x,<param>=<val>
2929 Params: addr I2C address of expander. Default 0x20.
2930 pca6416 Select the NXP PCA6416 (16 bit)
2931 pca9505 Select the NXP PCA9505 (40 bit)
2932 pca9535 Select the NXP PCA9535 (16 bit)
2933 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2934 pca9537 Select the NXP PCA9537 (4 bit)
2935 pca9538 Select the NXP PCA9538 (8 bit)
2936 pca9539 Select the NXP PCA9539 (16 bit)
2937 pca9554 Select the NXP PCA9554 (8 bit)
2938 pca9555 Select the NXP PCA9555 (16 bit)
2939 pca9556 Select the NXP PCA9556 (8 bit)
2940 pca9557 Select the NXP PCA9557 (8 bit)
2941 pca9574 Select the NXP PCA9574 (8 bit)
2942 pca9575 Select the NXP PCA9575 (16 bit)
2943 pca9698 Select the NXP PCA9698 (40 bit)
2944 pca16416 Select the NXP PCA16416 (16 bit)
2945 pca16524 Select the NXP PCA16524 (24 bit)
2946 pca19555a Select the NXP PCA19555A (16 bit)
2947 max7310 Select the Maxim MAX7310 (8 bit)
2948 max7312 Select the Maxim MAX7312 (16 bit)
2949 max7313 Select the Maxim MAX7313 (16 bit)
2950 max7315 Select the Maxim MAX7315 (8 bit)
2951 pca6107 Select the TI PCA6107 (8 bit)
2952 tca6408 Select the TI TCA6408 (8 bit)
2953 tca6416 Select the TI TCA6416 (16 bit)
2954 tca6424 Select the TI TCA6424 (24 bit)
2955 tca9539 Select the TI TCA9539 (16 bit)
2956 tca9554 Select the TI TCA9554 (8 bit)
2957 cat9554 Select the Onnn CAT9554 (8 bit)
2958 pca9654 Select the Onnn PCA9654 (8 bit)
2959 xra1202 Select the Exar XRA1202 (8 bit)
2962 Name: pcie-32bit-dma
2963 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2964 having to bounce buffers.
2965 Load: dtoverlay=pcie-32bit-dma
2969 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2972 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2975 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2979 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2980 for backwards compatibility.
2984 Name: pi3-disable-bt
2985 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2986 alias for backwards compatibility.
2990 Name: pi3-disable-wifi
2991 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2992 an alias for backwards compatibility.
2996 Name: pi3-miniuart-bt
2997 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2998 an alias for backwards compatibility.
3003 Info: Configures the pibell audio card.
3004 Load: dtoverlay=pibell,<param>=<val>
3005 Params: alsaname Set the name as it appears in ALSA (default
3010 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
3011 Load: dtoverlay=pifacedigital,<param>=<val>
3012 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
3013 CS0 address. PiFace Digital supports addresses
3014 0-3, which can be configured with JP1 and JP2.
3018 Info: Configures the PiFi 40W stereo amplifier
3019 Load: dtoverlay=pifi-40
3024 Info: Configures the PiFi DAC HD
3025 Load: dtoverlay=pifi-dac-hd
3030 Info: Configures the PiFi DAC Zero
3031 Load: dtoverlay=pifi-dac-zero
3036 Info: Configures the PiFi Mini stereo amplifier
3037 Load: dtoverlay=pifi-mini-210
3042 Info: Configures the PiGlow by pimoroni.com
3043 Load: dtoverlay=piglow
3048 Info: PiScreen display by OzzMaker.com
3049 Load: dtoverlay=piscreen,<param>=<val>
3050 Params: speed Display SPI bus speed
3052 rotate Display rotation {0,90,180,270}
3054 fps Delay between frame updates
3056 debug Debug output level {0-7}
3058 xohms Touchpanel sensitivity (X-plate resistance)
3062 Info: PiScreen 2 with resistive TP display by OzzMaker.com
3063 Load: dtoverlay=piscreen2r,<param>=<val>
3064 Params: speed Display SPI bus speed
3066 rotate Display rotation {0,90,180,270}
3068 fps Delay between frame updates
3070 debug Debug output level {0-7}
3072 xohms Touchpanel sensitivity (X-plate resistance)
3076 Info: Configures the Blokas Labs pisound card
3077 Load: dtoverlay=pisound
3082 Info: Adafruit PiTFT 2.2" screen
3083 Load: dtoverlay=pitft22,<param>=<val>
3084 Params: speed Display SPI bus speed
3086 rotate Display rotation {0,90,180,270}
3088 fps Delay between frame updates
3090 debug Debug output level {0-7}
3093 Name: pitft28-capacitive
3094 Info: Adafruit PiTFT 2.8" capacitive touch screen
3095 Load: dtoverlay=pitft28-capacitive,<param>=<val>
3096 Params: speed Display SPI bus speed
3098 rotate Display rotation {0,90,180,270}
3100 fps Delay between frame updates
3102 debug Debug output level {0-7}
3104 touch-sizex Touchscreen size x (default 240)
3106 touch-sizey Touchscreen size y (default 320)
3108 touch-invx Touchscreen inverted x axis
3110 touch-invy Touchscreen inverted y axis
3112 touch-swapxy Touchscreen swapped x y axis
3115 Name: pitft28-resistive
3116 Info: Adafruit PiTFT 2.8" resistive touch screen
3117 Load: dtoverlay=pitft28-resistive,<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 drm Force the use of the mi0283qt DRM driver (by
3127 default the ili9340 framebuffer driver will
3128 be used in preference if available)
3131 Name: pitft35-resistive
3132 Info: Adafruit PiTFT 3.5" resistive touch screen
3133 Load: dtoverlay=pitft35-resistive,<param>=<val>
3134 Params: speed Display SPI bus speed
3136 rotate Display rotation {0,90,180,270}
3138 fps Delay between frame updates
3140 debug Debug output level {0-7}
3142 drm Force the use of the hx8357d DRM driver (by
3143 default the fb_hx8357d framebuffer driver will
3144 be used in preference if available)
3148 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
3149 Load: dtoverlay=pps-gpio,<param>=<val>
3150 Params: gpiopin Input GPIO (default "18")
3151 assert_falling_edge When present, assert is indicated by a falling
3152 edge, rather than by a rising edge (default
3154 capture_clear Generate clear events on the trailing edge
3156 pull Desired pull-up/down state (off, down, up)
3161 Info: Configures the PROTO Audio Codec card
3162 Load: dtoverlay=proto-codec
3167 Info: Configures a single PWM channel
3168 Legal pin,function combinations for each channel:
3169 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3170 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3172 1) Pin 18 is the only one available on all platforms, and
3173 it is the one used by the I2S audio interface.
3174 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3175 2) The onboard analogue audio output uses both PWM channels.
3176 3) So be careful mixing audio and PWM.
3177 4) Currently the clock must have been enabled and configured
3179 Load: dtoverlay=pwm,<param>=<val>
3180 Params: pin Output pin (default 18) - see table
3181 func Pin function (default 2 = Alt5) - see above
3182 clock PWM clock frequency (informational)
3186 Info: Configures both PWM channels
3187 Legal pin,function combinations for each channel:
3188 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3189 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3191 1) Pin 18 is the only one available on all platforms, and
3192 it is the one used by the I2S audio interface.
3193 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3194 2) The onboard analogue audio output uses both PWM channels.
3195 3) So be careful mixing audio and PWM.
3196 4) Currently the clock must have been enabled and configured
3198 Load: dtoverlay=pwm-2chan,<param>=<val>
3199 Params: pin Output pin (default 18) - see table
3200 pin2 Output pin for other channel (default 19)
3201 func Pin function (default 2 = Alt5) - see above
3202 func2 Function for pin2 (default 2 = Alt5)
3203 clock PWM clock frequency (informational)
3207 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
3208 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
3209 of PWM0 to reduce the CPU load during transmission compared to
3210 gpio-ir-tx which uses bit-banging.
3211 Legal pin,function combinations are:
3212 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3213 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3214 Params: gpio_pin Output GPIO (default 18)
3216 func Pin function (default 2 = Alt5)
3220 Info: in-tech's Evaluation Board for PLC Stamp micro
3221 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3222 Load: dtoverlay=qca7000,<param>=<val>
3223 Params: int_pin GPIO pin for interrupt signal (default 23)
3225 speed SPI bus speed (default 12 MHz)
3229 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3230 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3231 But it requires disabling of onboard Bluetooth on
3232 Pi 3B, 3B+, 3A+, 4B and Zero W.
3233 Load: dtoverlay=qca7000-uart0,<param>=<val>
3234 Params: baudrate Set the baudrate for the UART (default
3239 Info: Enable the preservation of crash logs across a reboot. With
3240 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3241 are moved to /var/lib/systemd/pstore/ on reboot.
3242 Load: dtoverlay=ramoops,<param>=<val>
3243 Params: base-addr Where to place the capture buffer (default
3245 total-size How much memory to allocate altogether (in
3246 bytes - default 64kB)
3247 record-size How much space to use for each capture, i.e.
3248 total-size / record-size = number of captures
3250 console-size Size of non-panic dmesg captures (default 0)
3254 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3255 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3256 Load: dtoverlay=ramoops-pi4,<param>=<val>
3257 Params: base-addr Where to place the capture buffer (default
3259 total-size How much memory to allocate altogether (in
3260 bytes - default 64kB)
3261 record-size How much space to use for each capture, i.e.
3262 total-size / record-size = number of captures
3264 console-size Size of non-panic dmesg captures (default 0)
3267 Name: rotary-encoder
3268 Info: Overlay for GPIO connected rotary encoder.
3269 Load: dtoverlay=rotary-encoder,<param>=<val>
3270 Params: pin_a GPIO connected to rotary encoder channel A
3272 pin_b GPIO connected to rotary encoder channel B
3274 relative_axis register a relative axis rather than an
3275 absolute one. Relative axis will only
3276 generate +1/-1 events on the input device,
3277 hence no steps need to be passed.
3278 linux_axis the input subsystem axis to map to this
3279 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3280 rollover Automatic rollover when the rotary value
3281 becomes greater than the specified steps or
3282 smaller than 0. For absolute axis only.
3283 steps-per-period Number of steps (stable states) per period.
3284 The values have the following meaning:
3285 1: Full-period mode (default)
3287 4: Quarter-period mode
3288 steps Number of steps in a full turnaround of the
3289 encoder. Only relevant for absolute axis.
3290 Defaults to 24 which is a typical value for
3292 wakeup Boolean, rotary encoder can wake up the
3294 encoding String, the method used to encode steps.
3295 Supported are "gray" (the default and more
3296 common) and "binary".
3300 Info: Raspberry Pi official display backlight driver
3301 Load: dtoverlay=rpi-backlight
3305 Name: rpi-cirrus-wm5102
3306 Info: This overlay has been renamed to cirrus-wm5102
3311 Info: Configures the Raspberry Pi Codec Zero sound card
3312 Load: dtoverlay=rpi-codeczero
3317 Info: This overlay has been renaamed to i2s-dac.
3322 Info: Configures the Raspberry Pi DAC+ card
3323 Load: dtoverlay=rpi-dacplus,<param>=<val>
3324 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3325 digital volume control. Enable by adding
3326 "dtparam=24db_digital_gain" to config.txt
3327 before any "dtoverlay" lines.
3328 The default behaviour is that the digital
3329 volume control is limited to a maximum of
3330 0dB. ie. it can attenuate but not provide
3331 gain. For most users, this will be desired
3332 as it will prevent clipping. By appending
3333 the 24db_digital_gain parameter, the digital
3334 volume control will allow up to 24dB of
3335 gain. If this parameter is enabled, it is the
3336 responsibility of the user to ensure that
3337 the digital volume control is set to a value
3338 that does not result in clipping/distortion!
3342 Info: Configures the Raspberry Pi DAC Pro sound card
3343 Load: dtoverlay=rpi-dacpro,<param>=<val>
3344 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3345 digital volume control. Enable by adding
3346 "dtparam=24db_digital_gain" to config.txt
3347 before any "dtoverlay" lines.
3348 The default behaviour is that the digital
3349 volume control is limited to a maximum of
3350 0dB. ie. it can attenuate but not provide
3351 gain. For most users, this will be desired
3352 as it will prevent clipping. By appending
3353 the 24db_digital_gain parameter, the digital
3354 volume control will allow up to 24dB of
3355 gain. If this parameter is enabled, it is the
3356 responsibility of the user to ensure that
3357 the digital volume control is set to a value
3358 that does not result in clipping/distortion!
3361 Name: rpi-digiampplus
3362 Info: Configures the Raspberry Pi DigiAMP+ sound card
3363 Load: dtoverlay=rpi-digiampplus,<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!
3379 auto_mute_amp If specified, unmute/mute the DigiAMP+ when
3380 starting/stopping audio playback (default "on").
3381 unmute_amp If specified, unmute the DigiAMP+ amp once when
3382 the DAC driver module loads (default "off").
3386 Info: This overlay has been renamed to watterott-display
3391 Info: Official Raspberry Pi display touchscreen
3392 Load: dtoverlay=rpi-ft5406,<param>=<val>
3393 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3394 touchscreen-size-y Touchscreen Y resolution (default 600);
3395 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3396 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3397 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3401 Info: Raspberry Pi PoE HAT fan
3402 Load: dtoverlay=rpi-poe,<param>[=<val>]
3403 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3404 turns on (default 40000)
3405 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3406 the fan turns off (default 2000)
3407 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3408 speeds up (default 45000)
3409 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3410 the fan slows down (default 2000)
3411 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3412 speeds up (default 50000)
3413 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3414 the fan slows down (default 2000)
3415 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3416 speeds up (default 55000)
3417 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3418 the fan slows down (default 5000)
3419 i2c Control the fan via Linux I2C drivers instead of
3424 Info: Raspberry Pi PoE+ HAT fan
3425 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3426 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3427 turns on (default 40000)
3428 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3429 the fan turns off (default 2000)
3430 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3431 speeds up (default 45000)
3432 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3433 the fan slows down (default 2000)
3434 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3435 speeds up (default 50000)
3436 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3437 the fan slows down (default 2000)
3438 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3439 speeds up (default 55000)
3440 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3441 the fan slows down (default 5000)
3442 i2c Control the fan via Linux I2C drivers instead of
3447 Info: This overlay has been renamaed to proto-codec.
3452 Info: Raspberry Pi Sense HAT
3453 Load: dtoverlay=rpi-sense
3458 Info: Raspberry Pi Sense HAT v2
3459 Load: dtoverlay=rpi-sense-v2
3464 Info: Raspberry Pi TV HAT
3465 Load: dtoverlay=rpi-tv
3470 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3471 video decoder driver is enabled by default.
3475 Name: rra-digidac1-wm8741-audio
3476 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3477 Load: dtoverlay=rra-digidac1-wm8741-audio
3482 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3484 Load: dtoverlay=sainsmart18,<param>=<val>
3485 Params: rotate Display rotation {0,90,180,270}
3486 speed SPI bus speed in Hz (default 4000000)
3487 fps Display frame rate in Hz
3488 bgr Enable BGR mode (default off)
3489 debug Debug output level {0-7}
3490 dc_pin GPIO pin for D/C (default 24)
3491 reset_pin GPIO pin for RESET (default 25)
3495 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3496 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3497 select another address, please refer to table 10 in reference manual.
3498 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3499 Params: int_pin GPIO used for IRQ (default 24)
3500 addr Address (default 0x48)
3501 xtal On-board crystal frequency (default 14745600)
3505 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3506 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3507 select another address, please refer to table 10 in reference manual.
3508 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3509 Params: int_pin GPIO used for IRQ (default 24)
3510 addr Address (default 0x48)
3511 xtal On-board crystal frequency (default 14745600)
3514 Name: sc16is752-spi0
3515 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3516 Enables the chip on SPI0.
3517 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3518 Params: int_pin GPIO used for IRQ (default 24)
3519 xtal On-board crystal frequency (default 14745600)
3522 Name: sc16is752-spi1
3523 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3524 Enables the chip on SPI1.
3525 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3526 A+, B+, Zero and PI2 B; as well as the Compute Module.
3528 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3529 Params: int_pin GPIO used for IRQ (default 24)
3530 xtal On-board crystal frequency (default 14745600)
3534 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3535 N.B. This overlay is designed for situations where the mmc driver is
3536 the default, so it disables the other (mmc) interface - this will kill
3537 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3538 overlay or the new sd_* dtparams of the base DTBs.
3539 Load: dtoverlay=sdhost,<param>=<val>
3540 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3543 force_pio Disable DMA support (default off)
3545 pio_limit Number of blocks above which to use DMA
3548 debug Enable debug output (default off)
3552 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3553 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3554 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3555 Load: dtoverlay=sdio,<param>=<val>
3556 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3557 framework requests 50MHz
3559 poll_once Disable SDIO-device polling every second
3560 (default on: polling once at boot-time)
3562 bus_width Set the SDIO host bus width (default 4 bits)
3564 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3565 with bus_width=1. This replaces the sdio-1bit
3566 overlay, which is now deprecated.
3568 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3571 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3572 with bus_width=4 (the default).
3576 Info: This overlay is now deprecated. Use
3577 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3582 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3583 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3584 "dtparam=sd_poll_once".
3588 Name: seeed-can-fd-hat-v1
3589 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3590 channels without RTC. Use this overlay if your HAT has no
3592 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3593 Load: dtoverlay=seeed-can-fd-hat-v1
3597 Name: seeed-can-fd-hat-v2
3598 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3599 channels and an RTC. Use this overlay if your HAT has a
3601 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3602 Load: dtoverlay=seeed-can-fd-hat-v2
3607 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3608 Load: dtoverlay=sh1106-spi,<param>=<val>
3609 Params: speed SPI bus speed (default 4000000)
3610 rotate Display rotation (0, 90, 180 or 270; default 0)
3611 fps Delay between frame updates (default 25)
3612 debug Debug output level (0-7; default 0)
3613 dc_pin GPIO pin for D/C (default 24)
3614 reset_pin GPIO pin for RESET (default 25)
3615 height Display height (32 or 64; default 64)
3619 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3620 The driver is currently out-of-tree at
3621 https://github.com/sunipkmukherjee/silabs.git
3622 Load: dtoverlay=si446x-spi0,<param>=<val>
3623 Params: speed SPI bus speed (default 4000000)
3624 int_pin GPIO pin for interrupts (default 17)
3625 reset_pin GPIO pin for RESET (default 27)
3629 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3635 Info: Enables the userspace interface for the SMI driver
3636 Load: dtoverlay=smi-dev
3641 Info: Enables access to NAND flash via the SMI interface
3642 Load: dtoverlay=smi-nand
3647 Info: Move SPI function block to GPIO 35 to 39
3648 Load: dtoverlay=spi-gpio35-39
3653 Info: Move SPI function block to GPIOs 40 to 45
3654 Load: dtoverlay=spi-gpio40-45
3659 Info: Adds support for a number of SPI Real Time Clock devices
3660 Load: dtoverlay=spi-rtc,<param>=<val>
3661 Params: ds3232 Select the DS3232 device
3662 ds3234 Select the DS3234 device
3663 pcf2123 Select the PCF2123 device
3665 spi0_0 Use spi0.0 (default)
3671 cs_high This device requires an active-high CS
3675 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3676 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3677 Load: dtoverlay=spi0-0cs,<param>=<val>
3678 Params: no_miso Don't claim and use the MISO pin (9), freeing
3683 Info: Only use one CS pin for SPI0
3684 Load: dtoverlay=spi0-1cs,<param>=<val>
3685 Params: cs0_pin GPIO pin for CS0 (default 8)
3686 no_miso Don't claim and use the MISO pin (9), freeing
3691 Info: Change the CS pins for SPI0
3692 Load: dtoverlay=spi0-2cs,<param>=<val>
3693 Params: cs0_pin GPIO pin for CS0 (default 8)
3694 cs1_pin GPIO pin for CS1 (default 7)
3695 no_miso Don't claim and use the MISO pin (9), freeing
3700 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3701 alias for backwards compatibility.
3706 Info: This overlay has been deprecated and removed because it is no longer
3707 necessary and has been seen to prevent spi0 from working.
3712 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3713 dev node. The gpio pin number for the CS line and spidev device node
3714 creation are configurable.
3715 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3716 A+, B+, Zero and PI2 B; as well as the Compute Module.
3717 Load: dtoverlay=spi1-1cs,<param>=<val>
3718 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3719 cs0_spidev Set to 'disabled' to stop the creation of a
3720 userspace device node /dev/spidev1.0 (default
3721 is 'okay' or enabled).
3725 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3726 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3727 creation are configurable.
3728 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3729 A+, B+, Zero and PI2 B; as well as the Compute Module.
3730 Load: dtoverlay=spi1-2cs,<param>=<val>
3731 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3732 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3733 cs0_spidev Set to 'disabled' to stop the creation of a
3734 userspace device node /dev/spidev1.0 (default
3735 is 'okay' or enabled).
3736 cs1_spidev Set to 'disabled' to stop the creation of a
3737 userspace device node /dev/spidev1.1 (default
3738 is 'okay' or enabled).
3742 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3743 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3744 creation are configurable.
3745 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3746 A+, B+, Zero and PI2 B; as well as the Compute Module.
3747 Load: dtoverlay=spi1-3cs,<param>=<val>
3748 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3749 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3750 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3751 cs0_spidev Set to 'disabled' to stop the creation of a
3752 userspace device node /dev/spidev1.0 (default
3753 is 'okay' or enabled).
3754 cs1_spidev Set to 'disabled' to stop the creation of a
3755 userspace device node /dev/spidev1.1 (default
3756 is 'okay' or enabled).
3757 cs2_spidev Set to 'disabled' to stop the creation of a
3758 userspace device node /dev/spidev1.2 (default
3759 is 'okay' or enabled).
3763 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3764 dev node. The gpio pin number for the CS line and spidev device node
3765 creation are configurable.
3766 N.B.: spi2 is only accessible with the Compute Module.
3767 Load: dtoverlay=spi2-1cs,<param>=<val>
3768 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3769 cs0_spidev Set to 'disabled' to stop the creation of a
3770 userspace device node /dev/spidev2.0 (default
3771 is 'okay' or enabled).
3775 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3776 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3777 creation are configurable.
3778 N.B.: spi2 is only accessible with the Compute Module.
3779 Load: dtoverlay=spi2-2cs,<param>=<val>
3780 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3781 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3782 cs0_spidev Set to 'disabled' to stop the creation of a
3783 userspace device node /dev/spidev2.0 (default
3784 is 'okay' or enabled).
3785 cs1_spidev Set to 'disabled' to stop the creation of a
3786 userspace device node /dev/spidev2.1 (default
3787 is 'okay' or enabled).
3791 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3792 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3793 creation are configurable.
3794 N.B.: spi2 is only accessible with the Compute Module.
3795 Load: dtoverlay=spi2-3cs,<param>=<val>
3796 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3797 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3798 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3799 cs0_spidev Set to 'disabled' to stop the creation of a
3800 userspace device node /dev/spidev2.0 (default
3801 is 'okay' or enabled).
3802 cs1_spidev Set to 'disabled' to stop the creation of a
3803 userspace device node /dev/spidev2.1 (default
3804 is 'okay' or enabled).
3805 cs2_spidev Set to 'disabled' to stop the creation of a
3806 userspace device node /dev/spidev2.2 (default
3807 is 'okay' or enabled).
3811 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3812 dev node. The gpio pin number for the CS line and spidev device node
3813 creation are configurable. BCM2711 only.
3814 Load: dtoverlay=spi3-1cs,<param>=<val>
3815 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3816 cs0_spidev Set to 'off' to prevent the creation of a
3817 userspace device node /dev/spidev3.0 (default
3818 is 'on' or enabled).
3822 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3823 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3824 creation are configurable. BCM2711 only.
3825 Load: dtoverlay=spi3-2cs,<param>=<val>
3826 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3827 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3828 cs0_spidev Set to 'off' to prevent the creation of a
3829 userspace device node /dev/spidev3.0 (default
3830 is 'on' or enabled).
3831 cs1_spidev Set to 'off' to prevent the creation of a
3832 userspace device node /dev/spidev3.1 (default
3833 is 'on' or enabled).
3837 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3838 dev node. The gpio pin number for the CS line and spidev device node
3839 creation are configurable. BCM2711 only.
3840 Load: dtoverlay=spi4-1cs,<param>=<val>
3841 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3842 cs0_spidev Set to 'off' to prevent the creation of a
3843 userspace device node /dev/spidev4.0 (default
3844 is 'on' or enabled).
3848 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3849 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3850 creation are configurable. BCM2711 only.
3851 Load: dtoverlay=spi4-2cs,<param>=<val>
3852 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3853 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3854 cs0_spidev Set to 'off' to prevent the creation of a
3855 userspace device node /dev/spidev4.0 (default
3856 is 'on' or enabled).
3857 cs1_spidev Set to 'off' to prevent the creation of a
3858 userspace device node /dev/spidev4.1 (default
3859 is 'on' or enabled).
3863 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3864 dev node. The gpio pin numbers for the CS lines and spidev device node
3865 creation are configurable. BCM2711 only.
3866 Load: dtoverlay=spi5-1cs,<param>=<val>
3867 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3868 cs0_spidev Set to 'off' to prevent the creation of a
3869 userspace device node /dev/spidev5.0 (default
3870 is 'on' or enabled).
3874 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3875 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3876 creation are configurable. BCM2711 only.
3877 Load: dtoverlay=spi5-2cs,<param>=<val>
3878 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3879 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3880 cs0_spidev Set to 'off' to prevent the creation of a
3881 userspace device node /dev/spidev5.0 (default
3882 is 'on' or enabled).
3883 cs1_spidev Set to 'off' to prevent the creation of a
3884 userspace device node /dev/spidev5.1 (default
3885 is 'on' or enabled).
3889 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3890 dev node. The gpio pin number for the CS line and spidev device node
3891 creation are configurable. BCM2711 only.
3892 Load: dtoverlay=spi6-1cs,<param>=<val>
3893 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3894 cs0_spidev Set to 'off' to prevent the creation of a
3895 userspace device node /dev/spidev6.0 (default
3896 is 'on' or enabled).
3900 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3901 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3902 creation are configurable. BCM2711 only.
3903 Load: dtoverlay=spi6-2cs,<param>=<val>
3904 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3905 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3906 cs0_spidev Set to 'off' to prevent the creation of a
3907 userspace device node /dev/spidev6.0 (default
3908 is 'on' or enabled).
3909 cs1_spidev Set to 'off' to prevent the creation of a
3910 userspace device node /dev/spidev6.1 (default
3911 is 'on' or enabled).
3915 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3916 Load: dtoverlay=ssd1306,<param>=<val>
3917 Params: address Location in display memory of first character.
3919 width Width of display. (default=128)
3920 height Height of display. (default=64)
3921 offset virtual channel a. (default=0)
3922 normal Has no effect on displays tested. (default=not
3924 sequential Set this if every other scan line is missing.
3926 remapped Set this if display is garbled. (default=not
3928 inverted Set this if display is inverted and mirrored.
3932 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3934 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3936 i2c_baudrate=400000 will speed up the display.
3938 i2c_baudrate=1000000 seems to work even though it's not officially
3939 supported by the hardware, and is faster still.
3941 For more information refer to the device datasheet at:
3942 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3946 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3947 Load: dtoverlay=ssd1306-spi,<param>=<val>
3948 Params: speed SPI bus speed (default 10000000)
3949 rotate Display rotation (0, 90, 180 or 270; default 0)
3950 fps Delay between frame updates (default 25)
3951 debug Debug output level (0-7; default 0)
3952 dc_pin GPIO pin for D/C (default 24)
3953 reset_pin GPIO pin for RESET (default 25)
3954 height Display height (32 or 64; default 64)
3958 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3959 Load: dtoverlay=ssd1331-spi,<param>=<val>
3960 Params: speed SPI bus speed (default 4500000)
3961 rotate Display rotation (0, 90, 180 or 270; default 0)
3962 fps Delay between frame updates (default 25)
3963 debug Debug output level (0-7; default 0)
3964 dc_pin GPIO pin for D/C (default 24)
3965 reset_pin GPIO pin for RESET (default 25)
3969 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3970 Load: dtoverlay=ssd1351-spi,<param>=<val>
3971 Params: speed SPI bus speed (default 4500000)
3972 rotate Display rotation (0, 90, 180 or 270; default 0)
3973 fps Delay between frame updates (default 25)
3974 debug Debug output level (0-7; default 0)
3975 dc_pin GPIO pin for D/C (default 24)
3976 reset_pin GPIO pin for RESET (default 25)
3979 Name: superaudioboard
3980 Info: Configures the SuperAudioBoard sound card
3981 Load: dtoverlay=superaudioboard,<param>=<val>
3982 Params: gpiopin GPIO pin for codec reset
3986 Info: Configures the Semtech SX150X I2C GPIO expanders.
3987 Load: dtoverlay=sx150x,<param>=<val>
3988 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3989 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3990 Permissible values of <m> (which is denoted in
3991 hex) depend on the device variant. For SX1501,
3992 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3993 For SX1503 and SX1506, <m> may be 20. For
3994 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3995 For SX1508, <m> may be 20, 21, 22 or 23.
3997 sx150<x>-<n>-<m>-int-gpio
3998 Integer, enables interrupts on SX150X device on
3999 I2C#<n> with slave address <m>, specifies
4000 the GPIO pin to which NINT output of SX150X is
4005 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
4006 Uses Unicam 1, which is the standard camera connector on most Pi
4008 Load: dtoverlay=tc358743,<param>=<val>
4009 Params: 4lane Use 4 lanes (only applicable to Compute Modules
4012 link-frequency Set the link frequency. Only values of 297000000
4013 (574Mbit/s) and 486000000 (972Mbit/s - default)
4014 are supported by the driver.
4015 media-controller Configure use of Media Controller API for
4016 configuring the sensor (default off)
4017 cam0 Adopt the default configuration for CAM0 on a
4018 Compute Module (CSI0, i2c_vc, and cam0_reg).
4021 Name: tc358743-audio
4022 Info: Used in combination with the tc358743-fast overlay to route the audio
4023 from the TC358743 over I2S to the Pi.
4024 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
4026 Load: dtoverlay=tc358743-audio,<param>=<val>
4027 Params: card-name Override the default, "tc358743", card name.
4031 Info: 3.5" Color TFT Display by www.tinylcd.com
4032 Options: Touch, RTC, keypad
4033 Load: dtoverlay=tinylcd35,<param>=<val>
4034 Params: speed Display SPI bus speed
4036 rotate Display rotation {0,90,180,270}
4038 fps Delay between frame updates
4040 debug Debug output level {0-7}
4042 touch Enable touch panel
4044 touchgpio Touch controller IRQ GPIO
4046 xohms Touchpanel: Resistance of X-plate in ohms
4048 rtc-pcf PCF8563 Real Time Clock
4050 rtc-ds DS1307 Real Time Clock
4052 keypad Enable keypad
4055 Display with touchpanel, PCF8563 RTC and keypad:
4056 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
4058 dtoverlay=tinylcd35,touch,touchgpio=3
4062 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
4063 boards, which can be used as a secure key storage and hwrng,
4064 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
4065 Load: dtoverlay=tpm-slb9670
4070 Info: Change the pin usage of uart0
4071 Load: dtoverlay=uart0,<param>=<val>
4072 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
4074 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
4076 pin_func Alternative pin function - 4(Alt0) for 14&15,
4077 7(Alt3) for 32&33, 6(Alt2) for 36&37
4081 Info: Change the pin usage of uart1
4082 Load: dtoverlay=uart1,<param>=<val>
4083 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
4085 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
4089 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
4090 Load: dtoverlay=uart2,<param>
4091 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
4095 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
4096 Load: dtoverlay=uart3,<param>
4097 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
4101 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
4102 Load: dtoverlay=uart4,<param>
4103 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
4107 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
4108 Load: dtoverlay=uart5,<param>
4109 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
4113 Info: Configures the NW Digital Radio UDRC Hat
4114 Load: dtoverlay=udrc,<param>=<val>
4115 Params: alsaname Name of the ALSA audio device (default "udrc")
4118 Name: ugreen-dabboard
4119 Info: Configures the ugreen-dabboard I2S overlay
4120 This is a simple overlay based on the simple-audio-card and the dmic
4121 codec. It has the speciality that it is configured to use the codec
4122 as a master I2S device. It works for example with the Si468x DAB
4123 receiver on the uGreen DABBoard.
4124 Load: dtoverlay=ugreen-dabboard,<param>=<val>
4125 Params: card-name Override the default, "dabboard", card name.
4129 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
4130 vc4-kms-v3d and dwc2 overlays.
4131 Load: dtoverlay=upstream
4135 Name: upstream-aux-interrupt
4136 Info: This overlay has been deprecated and removed because it is no longer
4142 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
4143 the vc4-kms-v3d-pi4 and dwc2 overlays.
4144 Load: dtoverlay=upstream-pi4
4149 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4151 Load: dtoverlay=vc4-fkms-v3d,<param>
4152 Params: cma-512 CMA is 512MB (needs 1GB)
4153 cma-448 CMA is 448MB (needs 1GB)
4154 cma-384 CMA is 384MB (needs 1GB)
4155 cma-320 CMA is 320MB (needs 1GB)
4156 cma-256 CMA is 256MB (needs 1GB)
4157 cma-192 CMA is 192MB (needs 1GB)
4158 cma-128 CMA is 128MB
4161 cma-size CMA size in bytes, 4MB aligned
4162 cma-default Use upstream's default value
4165 Name: vc4-fkms-v3d-pi4
4166 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4168 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
4169 Params: cma-512 CMA is 512MB (needs 1GB)
4170 cma-448 CMA is 448MB (needs 1GB)
4171 cma-384 CMA is 384MB (needs 1GB)
4172 cma-320 CMA is 320MB (needs 1GB)
4173 cma-256 CMA is 256MB (needs 1GB)
4174 cma-192 CMA is 192MB (needs 1GB)
4175 cma-128 CMA is 128MB
4178 cma-size CMA size in bytes, 4MB aligned
4179 cma-default Use upstream's default value
4182 Name: vc4-kms-dpi-at056tn53v1
4183 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
4187 Name: vc4-kms-dpi-generic
4188 Info: Enable a generic DPI display under KMS. Default timings are for the
4189 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
4190 Requires vc4-kms-v3d to be loaded.
4191 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
4192 Params: clock-frequency Display clock frequency (Hz)
4193 hactive Horizontal active pixels
4194 hfp Horizontal front porch
4195 hsync Horizontal sync pulse width
4196 hbp Horizontal back porch
4197 vactive Vertical active lines
4198 vfp Vertical front porch
4199 vsync Vertical sync pulse width
4200 vbp Vertical back porch
4201 hsync-invert Horizontal sync active low
4202 vsync-invert Vertical sync active low
4203 de-invert Data Enable active low
4204 pixclk-invert Negative edge pixel clock
4205 width-mm Define the screen width in mm
4206 height-mm Define the screen height in mm
4207 rgb565 Change to RGB565 output on GPIOs 0-19
4208 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
4210 bgr666 Change to BGR666 output on GPIOs 0-21.
4211 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
4213 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
4215 bgr888 Change to BGR888 output on GPIOs 0-27
4216 rgb888 Change to RGB888 output on GPIOs 0-27
4217 bus-format Override the bus format for a MEDIA_BUS_FMT_*
4218 value. NB also overridden by rgbXXX overrides.
4219 backlight-gpio Defines a GPIO to be used for backlight control
4221 backlight-pwm Defines a PWM channel to be used for backlight
4222 control (default of none). NB Disables audio
4223 headphone output as that also uses PWM.
4224 backlight-pwm-chan Choose channel on &pwm node for backlight
4227 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4228 pwm-2chan for valid options.
4229 (default 18 - note this can only work with
4231 backlight-pwm-func Pin function of GPIO used for the PWM
4233 See pwm-2chan for valid options.
4235 backlight-def-brightness
4236 Set the default brightness. Normal range 1-16.
4238 rotate Display rotation {0,90,180,270} (default 0)
4241 Name: vc4-kms-dpi-hyperpixel2r
4242 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
4243 Requires vc4-kms-v3d to be loaded.
4244 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
4245 Params: disable-touch Disables the touch controller
4246 touchscreen-inverted-x Inverts X direction of touch controller
4247 touchscreen-inverted-y Inverts Y direction of touch controller
4248 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4249 rotate Display rotation {0,90,180,270} (default 0)
4252 Name: vc4-kms-dpi-hyperpixel4
4253 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
4254 Requires vc4-kms-v3d to be loaded.
4255 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
4256 Params: disable-touch Disables the touch controller
4257 touchscreen-inverted-x Inverts X direction of touch controller
4258 touchscreen-inverted-y Inverts Y direction of touch controller
4259 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4260 rotate Display rotation {0,90,180,270} (default 0)
4263 Name: vc4-kms-dpi-hyperpixel4sq
4264 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4265 Requires vc4-kms-v3d to be loaded.
4266 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4267 Params: disable-touch Disables the touch controller
4268 touchscreen-inverted-x Inverts X direction of touch controller
4269 touchscreen-inverted-y Inverts Y direction of touch controller
4270 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4271 rotate Display rotation {0,90,180,270} (default 0)
4274 Name: vc4-kms-dpi-panel
4275 Info: Enable a preconfigured KMS DPI panel.
4276 Requires vc4-kms-v3d to be loaded.
4277 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4278 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4279 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4280 mzp280 Enable a Geekworm MZP280 panel.
4281 backlight-gpio Defines a GPIO to be used for backlight control
4283 backlight-pwm Defines a PWM channel to be used for backlight
4284 control (default of none). NB Disables audio
4285 headphone output as that also uses PWM.
4286 backlight-pwm-chan Choose channel on &pwm node for backlight
4289 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4290 pwm-2chan for valid options.
4291 (default 18 - note this can only work with
4293 backlight-pwm-func Pin function of GPIO used for the PWM
4295 See pwm-2chan for valid options.
4297 backlight-def-brightness
4298 Set the default brightness. Normal range 1-16.
4300 rotate Display rotation {0,90,180,270} (default 0)
4303 Name: vc4-kms-dsi-7inch
4304 Info: Enable the Raspberry Pi DSI 7" screen.
4305 Includes the edt-ft5406 for the touchscreen element.
4306 Requires vc4-kms-v3d to be loaded.
4307 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4308 Params: sizex Touchscreen size x (default 800)
4309 sizey Touchscreen size y (default 480)
4310 invx Touchscreen inverted x axis
4311 invy Touchscreen inverted y axis
4312 swapxy Touchscreen swapped x y axis
4313 disable_touch Disables the touch screen overlay driver
4316 Name: vc4-kms-dsi-lt070me05000
4317 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4318 Note that this is a 4 lane DSI device, so it will only work on a Compute
4320 Requires vc4-kms-v3d to be loaded.
4321 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4322 Params: reset GPIO for the reset signal (default 17)
4323 enable GPIO for the enable signal (default 4)
4324 dcdc-en GPIO for the DC-DC converter enable (default 5)
4327 Name: vc4-kms-dsi-lt070me05000-v2
4328 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4330 Note that this is a 4 lane DSI device, so it will only work on a Compute
4332 Requires vc4-kms-v3d to be loaded.
4333 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4337 Name: vc4-kms-kippah-7inch
4338 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4343 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4344 Load: dtoverlay=vc4-kms-v3d,<param>
4345 Params: cma-512 CMA is 512MB (needs 1GB)
4346 cma-448 CMA is 448MB (needs 1GB)
4347 cma-384 CMA is 384MB (needs 1GB)
4348 cma-320 CMA is 320MB (needs 1GB)
4349 cma-256 CMA is 256MB (needs 1GB)
4350 cma-192 CMA is 192MB (needs 1GB)
4351 cma-128 CMA is 128MB
4354 cma-size CMA size in bytes, 4MB aligned
4355 cma-default Use upstream's default value
4356 audio Enable or disable audio over HDMI (default "on")
4357 noaudio Disable all HDMI audio (default "off")
4358 composite Enable the composite output (default "off")
4359 N.B. Disables all other outputs on a Pi 4.
4360 nohdmi Disable HDMI output
4363 Name: vc4-kms-v3d-pi4
4364 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4365 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4366 Params: cma-512 CMA is 512MB
4367 cma-448 CMA is 448MB
4368 cma-384 CMA is 384MB
4369 cma-320 CMA is 320MB
4370 cma-256 CMA is 256MB
4371 cma-192 CMA is 192MB
4372 cma-128 CMA is 128MB
4375 cma-size CMA size in bytes, 4MB aligned
4376 cma-default Use upstream's default value
4377 audio Enable or disable audio over HDMI0 (default
4379 audio1 Enable or disable audio over HDMI1 (default
4381 noaudio Disable all HDMI audio (default "off")
4382 composite Enable the composite output (disables all other
4384 nohdmi Disable both HDMI 0 & 1 outputs
4385 nohdmi0 Disable HDMI 0 output
4386 nohdmi1 Disable HDMI 1 output
4390 Name: vc4-kms-vga666
4391 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4392 Requires vc4-kms-v3d to be loaded.
4393 Load: dtoverlay=vc4-kms-vga666,<param>
4394 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4395 from the display. NB These are NOT 5V tolerant
4396 GPIOs, therefore level shifters are required.
4400 Info: Overlay for the Fen Logic VGA666 board
4401 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4402 after the kernel has started.
4403 NOT for use with vc4-kms-v3d.
4404 Load: dtoverlay=vga666
4409 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4410 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4411 set in the EEPROM config.
4412 Load: dtoverlay=vl805
4417 Info: Configures the w1-gpio Onewire interface module.
4418 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4419 Load: dtoverlay=w1-gpio,<param>=<val>
4420 Params: gpiopin GPIO for I/O (default "4")
4421 pullup Now enabled by default (ignored)
4424 Name: w1-gpio-pullup
4425 Info: Configures the w1-gpio Onewire interface module.
4426 Use this overlay if you *do* need a GPIO to drive an external pullup.
4427 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4428 Params: gpiopin GPIO for I/O (default "4")
4429 extpullup GPIO for external pullup (default "5")
4430 pullup Now enabled by default (ignored)
4434 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4435 Load: dtoverlay=w5500,<param>=<val>
4436 Params: int_pin GPIO used for INT (default 25)
4438 speed SPI bus speed (default 30000000)
4440 cs SPI bus Chip Select (default 0)
4443 Name: watterott-display
4444 Info: Watterott RPi-Display - 2.8" Touch Display
4445 Linux has 2 drivers that support this display and this overlay supports
4449 fbtft/fb_ili9341: dtoverlay=watterott-display
4450 drm/mi0283qt: dtoverlay=watterott-display,drm,backlight-pwm,rotate=180
4452 Some notable differences with the DRM driver compared to fbtft:
4453 - The display is turned on when it's first used and not on driver load
4454 as with fbtft. So if nothing uses the display it stays off.
4455 - Can run with a higher SPI clock increasing framerate. This is possible
4456 since the driver avoids messing up the controller configuration due to
4457 transmission errors by running config commands at 10MHz and only pixel
4458 data at full speed (occasional pixel glitch might occur).
4459 - PWM backlight is supported.
4461 Load: dtoverlay=watterott-display,<param>=<val>
4462 Params: speed Display SPI bus speed
4463 rotate Display rotation {0,90,180,270}
4464 fps Delay between frame updates (fbtft only)
4465 debug Debug output level {0-7} (fbtft only)
4466 xohms Touchpanel sensitivity (X-plate resistance)
4467 swapxy Swap x and y axis
4468 backlight Change backlight GPIO pin {e.g. 12, 18}
4470 drm Use DRM/KMS driver mi0283qt instead of fbtft.
4471 Set the SPI clock to 70MHz.
4472 This has to be the first parameter.
4473 backlight-pwm Use pwm for backlight (drm only). NB: Disables
4474 audio headphone output as that also uses PWM.
4477 Name: waveshare-can-fd-hat-mode-a
4478 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4479 for Raspberry Pi, Multi Protections. Use this overlay when the
4480 HAT is configured in Mode A (Default), with can0 on spi0.0
4482 https://www.waveshare.com/2-ch-can-fd-hat.htm
4483 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4487 Name: waveshare-can-fd-hat-mode-b
4488 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4489 for Raspberry Pi, Multi Protections. Use this overlay when the
4490 HAT is configured in Mode B (requires hardware modification), with
4491 can0 on spi0.0 and can1 on spi0.1.
4492 https://www.waveshare.com/2-ch-can-fd-hat.htm
4493 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4498 Info: Configures the wittypi RTC module.
4499 Load: dtoverlay=wittypi,<param>=<val>
4500 Params: led_gpio GPIO for LED (default "17")
4501 led_trigger Choose which activity the LED tracks (default
4505 Name: wm8960-soundcard
4506 Info: Overlay for the Waveshare wm8960 soundcard
4507 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4508 Params: alsaname Changes the card name in ALSA
4509 compatible Changes the codec compatibility
4515 If you are experiencing problems that you think are DT-related, enable DT
4516 diagnostic output by adding this to /boot/config.txt:
4520 and rebooting. Then run:
4524 and look for relevant messages.
4529 This is only meant to be a quick introduction to the subject of Device Tree on
4530 Raspberry Pi. There is a more complete explanation here:
4532 http://www.raspberrypi.org/documentation/configuration/device-tree.md