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
685 pins_12_13 Select GPIOs 12 & 13 (default)
686 pins_18_19 Select GPIOs 18 & 19
690 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
691 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
692 Load: dtoverlay=balena-fin
696 Name: bmp085_i2c-sensor
697 Info: This overlay is now deprecated - see i2c-sensor
701 Name: camera-mux-2port
702 Info: Configures a 2 port camera multiplexer
703 Note that currently ALL IMX290 modules share a common clock, therefore
704 all modules will need to have the same clock frequency.
705 Load: dtoverlay=camera-mux-2port,<param>=<val>
706 Params: cam0-imx219 Select IMX219 for camera on port 0
707 cam0-imx258 Select IMX258 for camera on port 0
708 cam0-imx290 Select IMX290 for camera on port 0
709 cam0-imx477 Select IMX477 for camera on port 0
710 cam0-ov2311 Select OV2311 for camera on port 0
711 cam0-ov5647 Select OV5647 for camera on port 0
712 cam0-ov7251 Select OV7251 for camera on port 0
713 cam0-ov9281 Select OV9281 for camera on port 0
714 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
715 cam1-imx219 Select IMX219 for camera on port 1
716 cam1-imx258 Select IMX258 for camera on port 1
717 cam1-imx290 Select IMX290 for camera on port 1
718 cam1-imx477 Select IMX477 for camera on port 1
719 cam1-ov2311 Select OV2311 for camera on port 1
720 cam1-ov5647 Select OV5647 for camera on port 1
721 cam1-ov7251 Select OV7251 for camera on port 1
722 cam1-ov9281 Select OV9281 for camera on port 1
723 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
726 Name: camera-mux-4port
727 Info: Configures a 4 port camera multiplexer
728 Note that currently ALL IMX290 modules share a common clock, therefore
729 all modules will need to have the same clock frequency.
730 Load: dtoverlay=camera-mux-4port,<param>=<val>
731 Params: cam0-imx219 Select IMX219 for camera on port 0
732 cam0-imx258 Select IMX258 for camera on port 0
733 cam0-imx290 Select IMX290 for camera on port 0
734 cam0-imx477 Select IMX477 for camera on port 0
735 cam0-ov2311 Select OV2311 for camera on port 0
736 cam0-ov5647 Select OV5647 for camera on port 0
737 cam0-ov7251 Select OV7251 for camera on port 0
738 cam0-ov9281 Select OV9281 for camera on port 0
739 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0
740 cam1-imx219 Select IMX219 for camera on port 1
741 cam1-imx258 Select IMX258 for camera on port 1
742 cam1-imx290 Select IMX290 for camera on port 1
743 cam1-imx477 Select IMX477 for camera on port 1
744 cam1-ov2311 Select OV2311 for camera on port 1
745 cam1-ov5647 Select OV5647 for camera on port 1
746 cam1-ov7251 Select OV7251 for camera on port 1
747 cam1-ov9281 Select OV9281 for camera on port 1
748 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
749 cam2-imx219 Select IMX219 for camera on port 2
750 cam2-imx258 Select IMX258 for camera on port 2
751 cam2-imx290 Select IMX290 for camera on port 2
752 cam2-imx477 Select IMX477 for camera on port 2
753 cam2-ov2311 Select OV2311 for camera on port 2
754 cam2-ov5647 Select OV5647 for camera on port 2
755 cam2-ov7251 Select OV7251 for camera on port 2
756 cam2-ov9281 Select OV9281 for camera on port 2
757 cam2-imx290-clk-freq Set clock frequency for an IMX290 on port 2
758 cam3-imx219 Select IMX219 for camera on port 3
759 cam3-imx258 Select IMX258 for camera on port 3
760 cam3-imx290 Select IMX290 for camera on port 3
761 cam3-imx477 Select IMX477 for camera on port 3
762 cam3-ov2311 Select OV2311 for camera on port 3
763 cam3-ov5647 Select OV5647 for camera on port 3
764 cam3-ov7251 Select OV7251 for camera on port 3
765 cam3-ov9281 Select OV9281 for camera on port 3
766 cam3-imx290-clk-freq Set clock frequency for an IMX290 on port 3
770 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
771 Load: dtoverlay=cap1106,<param>=<val>
772 Params: int_pin GPIO pin for interrupt signal (default 23)
776 Info: Configures Chip Dip audio cards.
777 Load: dtoverlay=chipdip-dac
782 Info: Configures the Cirrus Logic Audio Card
783 Load: dtoverlay=cirrus-wm5102
788 Info: Set custom CMA sizes, only use if you know what you are doing, might
789 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
790 Load: dtoverlay=cma,<param>=<val>
791 Params: cma-512 CMA is 512MB (needs 1GB)
792 cma-448 CMA is 448MB (needs 1GB)
793 cma-384 CMA is 384MB (needs 1GB)
794 cma-320 CMA is 320MB (needs 1GB)
795 cma-256 CMA is 256MB (needs 1GB)
796 cma-192 CMA is 192MB (needs 1GB)
800 cma-size CMA size in bytes, 4MB aligned
801 cma-default Use upstream's default value
805 Info: 8" TFT LCD display and touch panel used by cutiepi.io
806 Load: dtoverlay=cutiepi-panel
811 Info: Configures the dacberry400 add on soundcard
812 Load: dtoverlay=dacberry400
817 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
818 Also sometimes found with the part number(s) AM230x.
819 Load: dtoverlay=dht11,<param>=<val>
820 Params: gpiopin GPIO connected to the sensor's DATA output.
825 Info: Configures the Dion Audio KIWI STREAMER
826 Load: dtoverlay=dionaudio-kiwi
831 Info: Configures the Dion Audio LOCO DAC-AMP
832 Load: dtoverlay=dionaudio-loco
836 Name: dionaudio-loco-v2
837 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
838 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
839 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
840 Digital volume control. Enable with
841 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
842 (The default behaviour is that the Digital
843 volume control is limited to a maximum of
844 0dB. ie. it can attenuate but not provide
845 gain. For most users, this will be desired
846 as it will prevent clipping. By appending
847 the 24dB_digital_gain parameter, the Digital
848 volume control will allow up to 24dB of
849 gain. If this parameter is enabled, it is the
850 responsibility of the user to ensure that
851 the Digital volume control is set to a value
852 that does not result in clipping/distortion!)
856 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
857 UART0/ttyAMA0 over GPIOs 14 & 15.
858 N.B. To disable the systemd service that initialises the modem so it
859 doesn't use the UART, use 'sudo systemctl disable hciuart'.
860 Load: dtoverlay=disable-bt
865 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
866 Load: dtoverlay=disable-wifi
871 Info: Overlay for a generic 18-bit DPI display
872 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
873 2-3 seconds after the kernel has started.
874 Load: dtoverlay=dpi18
879 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
880 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
881 the output 3-3 seconds after the kernel has started.
882 Load: dtoverlay=dpi18cpadhi
887 Info: Overlay for a generic 24-bit DPI display
888 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
889 2-3 seconds after the kernel has started.
890 Load: dtoverlay=dpi24
895 Info: Configures the NW Digital Radio DRAWS Hat
897 The board includes an ADC to measure various board values and also
898 provides two analog user inputs on the expansion header. The ADC
899 can be configured for various sample rates and gain values to adjust
900 the input range. Tables describing the two parameters follow.
917 4 = 1600sps (default)
921 Load: dtoverlay=draws,<param>=<val>
922 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
923 input voltage sensor (default 1)
925 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
928 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
929 5V rail voltage sensor (default 1)
931 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
934 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
935 AIN2 input (default 2)
937 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
939 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
940 AIN3 input (default 2)
942 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
944 alsaname Name of the ALSA audio device (default "draws")
948 Info: Selects the dwc_otg USB controller driver which has fiq support. This
949 is the default on all except the Pi Zero which defaults to dwc2.
950 Load: dtoverlay=dwc-otg
955 Info: Selects the dwc2 USB controller driver
956 Load: dtoverlay=dwc2,<param>=<val>
957 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
959 g-rx-fifo-size Size of rx fifo size in gadget mode
961 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
965 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
969 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
970 This works with the Raspberry Pi 7" touchscreen when not being polled
972 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
973 config.txt to stop the firmware polling the touchscreen.
974 Load: dtoverlay=edt-ft5406,<param>=<val>
975 Params: sizex Touchscreen size x (default 800)
976 sizey Touchscreen size y (default 480)
977 invx Touchscreen inverted x axis
978 invy Touchscreen inverted y axis
979 swapxy Touchscreen swapped x y axis
983 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
984 Load: dtoverlay=enc28j60,<param>=<val>
985 Params: int_pin GPIO used for INT (default 25)
987 speed SPI bus speed (default 12000000)
991 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
992 Load: dtoverlay=enc28j60-spi2,<param>=<val>
993 Params: int_pin GPIO used for INT (default 39)
995 speed SPI bus speed (default 12000000)
999 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
1000 GPIO 4 (pin 7 on GPIO header) for interrupt.
1001 Load: dtoverlay=exc3000,<param>=<val>
1002 Params: interrupt GPIO used for interrupt (default 4)
1003 sizex Touchscreen size x (default 4096)
1004 sizey Touchscreen size y (default 4096)
1005 invx Touchscreen inverted x axis
1006 invy Touchscreen inverted y axis
1007 swapxy Touchscreen swapped x y axis
1011 Info: Overlay for SPI-connected displays using the fbtft drivers.
1013 This overlay seeks to replace the functionality provided by fbtft_device
1014 which is now gone from the kernel.
1016 Most displays from fbtft_device have been ported over.
1018 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1020 It is also possible to specify the controller (this will use the default
1021 init sequence in the driver).
1023 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
1025 For devices on spi1 or spi2, the interfaces should be enabled
1026 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
1028 The following features of fbtft_device have not been ported over:
1029 - parallel bus is not supported
1030 - the init property which overrides the controller initialization
1031 sequence is not supported as a parameter due to memory limitations in
1032 the bootloader responsible for applying the overlay.
1034 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
1037 Load: dtoverlay=fbtft,<param>=<val>
1039 spi<n>-<m> Configure device at spi<n>, cs<m>
1041 speed SPI bus speed in Hz (default 32000000)
1042 cpha Shifted clock phase (CPHA) mode
1043 cpol Inverse clock polarity (CPOL) mode
1045 adafruit18 Adafruit 1.8
1046 adafruit22 Adafruit 2.2 (old)
1047 adafruit22a Adafruit 2.2
1048 adafruit28 Adafruit 2.8
1049 adafruit13m Adafruit 1.3 OLED
1050 admatec_c-berry28 C-Berry28
1052 er_tftm050_2 ER-TFTM070-2
1053 er_tftm070_5 ER-TFTM070-5
1055 ew24ha0_9bit EW24HA0 in 9-bit mode
1056 freetronicsoled128 Freetronics OLED128
1059 itdb28_spi ITDB02-2.8 with SPI interface circuit
1060 mi0283qt-2 Watterott MI0283QT-2
1061 mi0283qt-9a Watterott MI0283QT-9A
1062 nokia3310 Nokia 3310
1063 nokia3310a Nokia 3310a
1064 nokia5110 Nokia 5110
1066 pitft Adafruit PiTFT 2.8
1068 rpi-display Watterott rpi-display
1069 sainsmart18 Sainsmart 1.8
1070 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
1071 tinylcd35 TinyLCD 3.5
1072 tm022hdh26 Tianma TM022HDH26
1073 tontec35_9481 Tontect 3.5 with ILI9481 controller
1074 tontec35_9486 Tontect 3.5 with ILI9486 controller
1075 waveshare32b Waveshare 3.2
1076 waveshare22 Waveshare 2.2
1078 bd663474 BD663474 display controller
1079 hx8340bn HX8340BN display controller
1080 hx8347d HX8347D display controller
1081 hx8353d HX8353D display controller
1082 hx8357d HX8357D display controller
1083 ili9163 ILI9163 display controller
1084 ili9320 ILI9320 display controller
1085 ili9325 ILI9325 display controller
1086 ili9340 ILI9340 display controller
1087 ili9341 ILI9341 display controller
1088 ili9481 ILI9481 display controller
1089 ili9486 ILI9486 display controller
1090 pcd8544 PCD8544 display controller
1091 ra8875 RA8875 display controller
1092 s6d02a1 S6D02A1 display controller
1093 s6d1121 S6D1121 display controller
1094 seps525 SEPS525 display controller
1095 sh1106 SH1106 display controller
1096 ssd1289 SSD1289 display controller
1097 ssd1305 SSD1305 display controller
1098 ssd1306 SSD1306 display controller
1099 ssd1325 SSD1325 display controller
1100 ssd1331 SSD1331 display controller
1101 ssd1351 SSD1351 display controller
1102 st7735r ST7735R display controller
1103 st7789v ST7789V display controller
1104 tls8204 TLS8204 display controller
1105 uc1611 UC1611 display controller
1106 uc1701 UC1701 display controller
1107 upd161704 UPD161704 display controller
1109 width Display width in pixels
1110 height Display height in pixels
1111 regwidth Display controller register width (default is
1113 buswidth Display bus interface width (default 8)
1114 debug Debug output level {0-7}
1115 rotate Display rotation {0, 90, 180, 270} (counter
1116 clockwise). Not supported by all drivers.
1117 bgr Enable BGR mode (default off). Use if Red and
1118 Blue are swapped. Not supported by all drivers.
1119 fps Frames per second (default 30). In effect this
1120 states how long the driver will wait after video
1121 memory has been changed until display update
1122 transfer is started.
1123 txbuflen Length of the FBTFT transmit buffer
1125 startbyte Sets the Start byte used by fb_ili9320,
1126 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1127 gamma String representation of Gamma Curve(s). Driver
1128 specific. Not supported by all drivers.
1129 reset_pin GPIO pin for RESET
1130 dc_pin GPIO pin for D/C
1131 led_pin GPIO pin for LED backlight
1135 Info: Configures the Fe-Pi Audio Sound Card
1136 Load: dtoverlay=fe-pi-audio
1141 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1142 nicely with a "traffic-light" display of red, amber and green LEDs on
1143 GPIOs 7, 8 and 25 respectively.
1144 Load: dtoverlay=fsm-demo,<param>=<val>
1145 Params: fsm_debug Enable debug logging (default off)
1149 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on
1150 SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical
1151 GPIO header pins 22, 13 and 12 respectively) in addition to the
1152 SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19,
1153 23 and 24 respectively).
1154 Load: dtoverlay=gc9a01,<param>=<val>
1155 Params: speed Display SPI bus speed
1157 rotate Display rotation {0,90,180,270}
1159 width Width of the display
1161 height Height of the display
1163 fps Delay between frame updates
1165 debug Debug output level {0-7}
1169 Info: An overlay for the Ghost amplifier.
1170 Load: dtoverlay=ghost-amp,<param>=<val>
1171 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1176 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1177 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1178 Load: dtoverlay=goodix,<param>=<val>
1179 Params: interrupt GPIO used for interrupt (default 4)
1180 reset GPIO used for reset (default 17)
1183 Name: googlevoicehat-soundcard
1184 Info: Configures the Google voiceHAT soundcard
1185 Load: dtoverlay=googlevoicehat-soundcard
1190 Info: Configure a GPIO pin to control a cooling fan.
1191 Load: dtoverlay=gpio-fan,<param>=<val>
1192 Params: gpiopin GPIO used to control the fan (default 12)
1193 temp Temperature at which the fan switches on, in
1194 millicelcius (default 55000)
1195 hyst Temperature delta (in millicelcius) below
1196 temp at which the fan will drop to minrpm
1201 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1202 an output, driven low or high as indicated by the presence or absence
1203 of the active_low parameter. Note that a hogged GPIO is not available
1204 to other drivers or for gpioset/gpioget.
1205 Load: dtoverlay=gpio-hog,<param>=<val>
1206 Params: gpio GPIO pin to hog (default 26)
1207 active_low If set, the hog drives the GPIO low (defaults
1208 to off - the GPIO is driven high)
1212 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1213 based gpio_ir_recv driver maps received keys directly to a
1214 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1215 not required! The key mapping and other decoding parameters can be
1216 configured by "ir-keytable" tool.
1217 Load: dtoverlay=gpio-ir,<param>=<val>
1218 Params: gpio_pin Input pin number. Default is 18.
1220 gpio_pull Desired pull-up/down state (off, down, up)
1223 invert "1" = invert the input (active-low signalling).
1224 "0" = non-inverted input (active-high
1225 signalling). Default is "1".
1227 rc-map-name Default rc keymap (can also be changed by
1228 ir-keytable), defaults to "rc-rc6-mce"
1232 Info: Use GPIO pin as bit-banged infrared transmitter output.
1233 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1234 a PWM so it can be used together with onboard analog audio.
1235 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1236 Params: gpio_pin Output GPIO (default 18)
1238 invert "1" = invert the output (make it active-low).
1239 Default is "0" (active-high).
1243 Info: This is a generic overlay for activating GPIO keypresses using
1244 the gpio-keys library and this dtoverlay. Multiple keys can be
1245 set up using multiple calls to the overlay for configuring
1246 additional buttons or joysticks. You can see available keycodes
1247 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1248 linux/input-event-codes.h#L64
1249 Load: dtoverlay=gpio-key,<param>=<val>
1250 Params: gpio GPIO pin to trigger on (default 3)
1251 active_low When this is 1 (active low), a falling
1252 edge generates a key down event and a
1253 rising edge generates a key up event.
1254 When this is 0 (active high), this is
1255 reversed. The default is 1 (active low)
1256 gpio_pull Desired pull-up/down state (off, down, up)
1257 Default is "up". Note that the default pin
1258 (GPIO3) has an external pullup
1259 label Set a label for the key
1260 keycode Set the key code for the button
1265 Info: This is a generic overlay for activating LEDs (or any other component)
1266 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1267 overlay. While there are many existing methods to activate LEDs on the
1268 RPi, this method offers some advantages:
1269 1) Does not require any userspace programs.
1270 2) LEDs can be connected to the kernel's led-trigger framework,
1271 and drive the LED based on triggers such as cpu load, heartbeat,
1272 kernel panic, key input, timers and others.
1273 3) LED can be tied to the input state of another GPIO pin.
1274 4) The LED is setup early during the kernel boot process (useful
1275 for cpu/heartbeat/panic triggers).
1277 Typical electrical connection is:
1278 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1279 The GPIO pin number can be changed with the 'gpio=' parameter.
1281 To control an LED from userspace, write a 0 or 1 value:
1282 echo 1 > /sys/class/leds/myled1/brightness
1283 The 'myled1' name can be changed with the 'label=' parameter.
1285 To connect the LED to a kernel trigger from userspace:
1286 echo cpu > /sys/class/leds/myled1/trigger
1287 echo heartbeat > /sys/class/leds/myled1/trigger
1288 echo none > /sys/class/leds/myled1/trigger
1289 To connect the LED to GPIO.26 pin (physical pin 37):
1290 echo gpio > /sys/class/leds/myled1/trigger
1291 echo 26 > /sys/class/leds/myled1/gpio
1293 cat /sys/class/leds/myled1/trigger
1295 More information about the Linux kernel LED/Trigger system:
1296 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1297 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1298 Load: dtoverlay=gpio-led,<param>=<val>
1299 Params: gpio GPIO pin connected to the LED (default 19)
1300 label The label for this LED. It will appear under
1301 /sys/class/leds/<label> . Default 'myled1'.
1302 trigger Set the led-trigger to connect to this LED.
1303 default 'none' (LED is user-controlled).
1304 Some possible triggers:
1305 cpu - CPU load (all CPUs)
1306 cpu0 - CPU load of first CPU.
1307 mmc - disk activity (all disks)
1308 panic - turn on on kernel panic
1309 heartbeat - indicate system health
1310 gpio - connect to a GPIO input pin (note:
1311 currently the GPIO PIN can not be set
1312 using overlay parameters, must be
1313 done in userspace, see examples above.
1314 active_low Set to 1 to turn invert the LED control
1315 (writing 0 to /sys/class/leds/XXX/brightness
1316 will turn on the GPIO/LED). Default '0'.
1319 Name: gpio-no-bank0-irq
1320 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1321 which can be useful for UIO drivers.
1322 N.B. Using this overlay will trigger a kernel WARN during booting, but
1323 this can safely be ignored - the system should work as expected.
1324 Load: dtoverlay=gpio-no-bank0-irq
1329 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1330 for user-space GPIO edge detection systems.
1331 Load: dtoverlay=gpio-no-irq
1336 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1337 overlay interferes with the normal power-down sequence, preventing the
1338 kernel from resetting the SoC (a necessary step in a normal power-off
1339 or reboot). This also disables the ability to trigger a boot by driving
1342 The GPIO starts in an inactive state. At poweroff time it is driven
1343 active for 100ms, then inactive for 100ms, then active again. It is
1344 safe to remove the power at any point after the initial activation of
1347 Users of this overlay are required to provide an external mechanism to
1348 switch off the power supply when signalled - failure to do so results
1349 in a kernel BUG, increased power consumption and undefined behaviour.
1350 Load: dtoverlay=gpio-poweroff,<param>=<val>
1351 Params: gpiopin GPIO for signalling (default 26)
1353 active_low Set if the power control device requires a
1354 high->low transition to trigger a power-down.
1355 Note that this will require the support of a
1356 custom dt-blob.bin to prevent a power-down
1357 during the boot process, and that a reboot
1358 will also cause the pin to go low.
1359 input Set if the gpio pin should be configured as
1361 export Set to export the configured pin to sysfs
1362 active_delay_ms Initial GPIO active period (default 100)
1363 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1364 timeout_ms Specify (in ms) how long the kernel waits for
1365 power-down before issuing a WARN (default 3000).
1369 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1370 is configured as an input key that generates KEY_POWER events.
1372 This event is handled by systemd-logind by initiating a
1373 shutdown. Systemd versions older than 225 need an udev rule
1374 enable listening to the input device:
1376 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1377 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1378 ATTRS{keys}=="116", TAG+="power-switch"
1380 Alternatively this event can be handled also on systems without
1381 systemd, just by traditional SysV init daemon. KEY_POWER event
1382 (keycode 116) needs to be mapped to KeyboardSignal on console
1383 and then kb::kbrequest inittab action which is triggered by
1384 KeyboardSignal from console can be configured to issue system
1385 shutdown. Steps for this configuration are:
1387 Add following lines to the /etc/console-setup/remap.inc file:
1389 # Key Power as special keypress
1390 keycode 116 = KeyboardSignal
1392 Then add following lines to /etc/inittab file:
1394 # Action on special keypress (Key Power)
1395 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1397 And finally reload configuration by calling following commands:
1399 # dpkg-reconfigure console-setup
1400 # service console-setup reload
1403 This overlay only handles shutdown. After shutdown, the system
1404 can be powered up again by driving GPIO3 low. The default
1405 configuration uses GPIO3 with a pullup, so if you connect a
1406 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1407 you get a shutdown and power-up button. Please note that
1408 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1409 Load: dtoverlay=gpio-shutdown,<param>=<val>
1410 Params: gpio_pin GPIO pin to trigger on (default 3)
1411 For Raspberry Pi 1 Model B rev 1 set this
1412 explicitly to value 1, e.g.:
1414 dtoverlay=gpio-shutdown,gpio_pin=1
1416 active_low When this is 1 (active low), a falling
1417 edge generates a key down event and a
1418 rising edge generates a key up event.
1419 When this is 0 (active high), this is
1420 reversed. The default is 1 (active low).
1422 gpio_pull Desired pull-up/down state (off, down, up)
1425 Note that the default pin (GPIO3) has an
1426 external pullup. Same applies for GPIO1
1427 on Raspberry Pi 1 Model B rev 1.
1429 debounce Specify the debounce interval in milliseconds
1434 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1435 data, 2 gpio pins for enable and register select and 1 optional pin
1436 for enabling/disabling the backlight display.
1437 Load: dtoverlay=hd44780-lcd,<param>=<val>
1438 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1440 pin_d5 GPIO pin for data pin D5 (default 13)
1442 pin_d6 GPIO pin for data pin D6 (default 19)
1444 pin_d7 GPIO pin for data pin D7 (default 26)
1446 pin_en GPIO pin for "Enable" (default 21)
1448 pin_rs GPIO pin for "Register Select" (default 20)
1450 pin_bl Optional pin for enabling/disabling the
1451 display backlight. (default disabled)
1453 display_height Height of the display in characters
1455 display_width Width of the display in characters
1458 Name: hdmi-backlight-hwhack-gpio
1459 Info: Devicetree overlay for GPIO based backlight on/off capability.
1460 Use this if you have one of those HDMI displays whose backlight cannot
1461 be controlled via DPMS over HDMI and plan to do a little soldering to
1462 use an RPi gpio pin for on/off switching. See:
1463 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1464 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1465 Params: gpio_pin GPIO pin used (default 17)
1466 active_low Set this to 1 if the display backlight is
1467 switched on when the wire goes low.
1468 Leave the default (value 0) if the backlight
1469 expects a high to switch it on.
1473 Info: Configures the HifiBerry Amp and Amp+ audio cards
1474 Load: dtoverlay=hifiberry-amp
1478 Name: hifiberry-amp100
1479 Info: Configures the HifiBerry AMP100 audio card
1480 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1481 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1482 Digital volume control. Enable with
1483 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1484 (The default behaviour is that the Digital
1485 volume control is limited to a maximum of
1486 0dB. ie. it can attenuate but not provide
1487 gain. For most users, this will be desired
1488 as it will prevent clipping. By appending
1489 the 24dB_digital_gain parameter, the Digital
1490 volume control will allow up to 24dB of
1491 gain. If this parameter is enabled, it is the
1492 responsibility of the user to ensure that
1493 the Digital volume control is set to a value
1494 that does not result in clipping/distortion!)
1495 slave Force DAC+ Pro into slave mode, using Pi as
1496 master for bit clock and frame clock.
1497 leds_off If set to 'true' the onboard indicator LEDs
1498 are switched off at all times.
1499 auto_mute If set to 'true' the amplifier is automatically
1500 muted when the DAC is not playing.
1501 mute_ext_ctl The amplifier's HW mute control is enabled
1502 in ALSA mixer and set to <val>.
1503 Will be overwritten by ALSA user settings.
1506 Name: hifiberry-amp3
1507 Info: Configures the HifiBerry Amp3 audio card
1508 Load: dtoverlay=hifiberry-amp3
1513 Info: Configures the HifiBerry DAC audio cards
1514 Load: dtoverlay=hifiberry-dac
1518 Name: hifiberry-dacplus
1519 Info: Configures the HifiBerry DAC+ audio card
1520 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1521 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1522 Digital volume control. Enable with
1523 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1524 (The default behaviour is that the Digital
1525 volume control is limited to a maximum of
1526 0dB. ie. it can attenuate but not provide
1527 gain. For most users, this will be desired
1528 as it will prevent clipping. By appending
1529 the 24dB_digital_gain parameter, the Digital
1530 volume control will allow up to 24dB of
1531 gain. If this parameter is enabled, it is the
1532 responsibility of the user to ensure that
1533 the Digital volume control is set to a value
1534 that does not result in clipping/distortion!)
1535 slave Force DAC+ Pro into slave mode, using Pi as
1536 master for bit clock and frame clock.
1537 leds_off If set to 'true' the onboard indicator LEDs
1538 are switched off at all times.
1541 Name: hifiberry-dacplusadc
1542 Info: Configures the HifiBerry DAC+ADC audio card
1543 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1544 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1545 Digital volume control. Enable with
1546 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1547 (The default behaviour is that the Digital
1548 volume control is limited to a maximum of
1549 0dB. ie. it can attenuate but not provide
1550 gain. For most users, this will be desired
1551 as it will prevent clipping. By appending
1552 the 24dB_digital_gain parameter, the Digital
1553 volume control will allow up to 24dB of
1554 gain. If this parameter is enabled, it is the
1555 responsibility of the user to ensure that
1556 the Digital volume control is set to a value
1557 that does not result in clipping/distortion!)
1558 slave Force DAC+ Pro into slave mode, using Pi as
1559 master for bit clock and frame clock.
1560 leds_off If set to 'true' the onboard indicator LEDs
1561 are switched off at all times.
1564 Name: hifiberry-dacplusadcpro
1565 Info: Configures the HifiBerry DAC+ADC PRO audio card
1566 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1567 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1568 Digital volume control. Enable with
1569 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1570 (The default behaviour is that the Digital
1571 volume control is limited to a maximum of
1572 0dB. ie. it can attenuate but not provide
1573 gain. For most users, this will be desired
1574 as it will prevent clipping. By appending
1575 the 24dB_digital_gain parameter, the Digital
1576 volume control will allow up to 24dB of
1577 gain. If this parameter is enabled, it is the
1578 responsibility of the user to ensure that
1579 the Digital volume control is set to a value
1580 that does not result in clipping/distortion!)
1581 slave Force DAC+ADC Pro into slave mode, using Pi as
1582 master for bit clock and frame clock.
1583 leds_off If set to 'true' the onboard indicator LEDs
1584 are switched off at all times.
1587 Name: hifiberry-dacplusdsp
1588 Info: Configures the HifiBerry DAC+DSP audio card
1589 Load: dtoverlay=hifiberry-dacplusdsp
1593 Name: hifiberry-dacplushd
1594 Info: Configures the HifiBerry DAC+ HD audio card
1595 Load: dtoverlay=hifiberry-dacplushd
1599 Name: hifiberry-digi
1600 Info: Configures the HifiBerry Digi and Digi+ audio card
1601 Load: dtoverlay=hifiberry-digi
1605 Name: hifiberry-digi-pro
1606 Info: Configures the HifiBerry Digi+ Pro audio card
1607 Load: dtoverlay=hifiberry-digi-pro
1612 Info: Enables "High Peripheral" mode
1613 Load: dtoverlay=highperi
1618 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1619 Default values match Texy's display shield
1620 Load: dtoverlay=hy28a,<param>=<val>
1621 Params: speed Display SPI bus speed
1623 rotate Display rotation {0,90,180,270}
1625 fps Delay between frame updates
1627 debug Debug output level {0-7}
1629 xohms Touchpanel sensitivity (X-plate resistance)
1631 resetgpio GPIO used to reset controller
1633 ledgpio GPIO used to control backlight
1637 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1638 Default values match Texy's display shield
1639 Load: dtoverlay=hy28b,<param>=<val>
1640 Params: speed Display SPI bus speed
1642 rotate Display rotation {0,90,180,270}
1644 fps Delay between frame updates
1646 debug Debug output level {0-7}
1648 xohms Touchpanel sensitivity (X-plate resistance)
1650 resetgpio GPIO used to reset controller
1652 ledgpio GPIO used to control backlight
1656 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1657 Default values match Texy's display shield
1658 Load: dtoverlay=hy28b-2017,<param>=<val>
1659 Params: speed Display SPI bus speed
1661 rotate Display rotation {0,90,180,270}
1663 fps Delay between frame updates
1665 debug Debug output level {0-7}
1667 xohms Touchpanel sensitivity (X-plate resistance)
1669 resetgpio GPIO used to reset controller
1671 ledgpio GPIO used to control backlight
1675 Info: Configures the Audiophonics I-SABRE Q2M DAC
1676 Load: dtoverlay=i-sabre-q2m
1681 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1682 Load: dtoverlay=i2c-bcm2708
1687 Info: Adds support for a number of I2C fan controllers
1688 Load: dtoverlay=i2c-fan,<param>=<val>
1689 Params: addr Sets the address for the fan controller. Note
1690 that the device must be configured to use the
1693 i2c0 Choose the I2C0 bus on GPIOs 0&1
1695 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1697 i2c3 Choose the I2C3 bus (configure with the i2c3
1698 overlay - BCM2711 only)
1700 i2c4 Choose the I2C3 bus (configure with the i2c3
1701 overlay - BCM2711 only)
1703 i2c5 Choose the I2C5 bus (configure with the i2c4
1704 overlay - BCM2711 only)
1706 i2c6 Choose the I2C6 bus (configure with the i2c6
1707 overlay - BCM2711 only)
1709 minpwm PWM setting for the fan when the SoC is below
1710 mintemp (range 0-255. default 0)
1711 maxpwm PWM setting for the fan when the SoC is above
1712 maxtemp (range 0-255. default 255)
1713 midtemp Temperature (in millicelcius) at which the fan
1714 begins to speed up (default 50000)
1716 midtemp_hyst Temperature delta (in millicelcius) below
1717 mintemp at which the fan will drop to minrpm
1720 maxtemp Temperature (in millicelcius) at which the fan
1721 will be held at maxrpm (default 70000)
1723 maxtemp_hyst Temperature delta (in millicelcius) below
1724 maxtemp at which the fan begins to slow down
1727 emc2301 Select the Microchip EMC230x controller family
1728 - EMC2301, EMC2302, EMC2303, EMC2305.
1732 Info: Adds support for software i2c controller on gpio pins
1733 Load: dtoverlay=i2c-gpio,<param>=<val>
1734 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1736 i2c_gpio_scl GPIO used for I2C clock (default "24")
1738 i2c_gpio_delay_us Clock delay in microseconds
1739 (default "2" = ~100kHz)
1741 bus Set to a unique, non-zero value if wanting
1742 multiple i2c-gpio busses. If set, will be used
1743 as the preferred bus number (/dev/i2c-<n>). If
1744 not set, the default value is 0, but the bus
1745 number will be dynamically assigned - probably
1750 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1751 Load: dtoverlay=i2c-mux,<param>=<val>
1752 Params: pca9542 Select the NXP PCA9542 device
1754 pca9545 Select the NXP PCA9545 device
1756 pca9548 Select the NXP PCA9548 device
1758 addr Change I2C address of the device (default 0x70)
1761 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1764 Name: i2c-pwm-pca9685a
1765 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1766 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1767 Params: addr I2C address of PCA9685A (default 0x40)
1771 Info: Adds support for a number of I2C Real Time Clock devices
1772 Load: dtoverlay=i2c-rtc,<param>=<val>
1773 Params: abx80x Select one of the ABx80x family:
1774 AB0801, AB0803, AB0804, AB0805,
1775 AB1801, AB1803, AB1804, AB1805
1777 bq32000 Select the TI BQ32000 device
1779 ds1307 Select the DS1307 device
1781 ds1339 Select the DS1339 device
1783 ds1340 Select the DS1340 device
1785 ds3231 Select the DS3231 device
1787 m41t62 Select the M41T62 device
1789 mcp7940x Select the MCP7940x device
1791 mcp7941x Select the MCP7941x device
1793 pcf2127 Select the PCF2127 device
1795 pcf2129 Select the PCF2129 device
1797 pcf85063 Select the PCF85063 device
1799 pcf85063a Select the PCF85063A device
1801 pcf8523 Select the PCF8523 device
1803 pcf85363 Select the PCF85363 device
1805 pcf8563 Select the PCF8563 device
1807 rv1805 Select the Micro Crystal RV1805 device
1809 rv3028 Select the Micro Crystal RV3028 device
1811 rv8803 Select the Micro Crystal RV8803 device
1813 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1815 s35390a Select the ABLIC S35390A device
1817 i2c0 Choose the I2C0 bus on GPIOs 0&1
1819 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1821 i2c3 Choose the I2C3 bus (configure with the i2c3
1822 overlay - BCM2711 only)
1824 i2c4 Choose the I2C3 bus (configure with the i2c3
1825 overlay - BCM2711 only)
1827 i2c5 Choose the I2C5 bus (configure with the i2c4
1828 overlay - BCM2711 only)
1830 i2c6 Choose the I2C6 bus (configure with the i2c6
1831 overlay - BCM2711 only)
1833 addr Sets the address for the RTC. Note that the
1834 device must be configured to use the specified
1837 trickle-diode-disable Do not use the internal trickle charger diode
1840 trickle-diode-type Diode type for trickle charge - "standard" or
1841 "schottky" (ABx80x and RV1805 only)
1843 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1844 ABx80x, RV1805, RV3028)
1846 wakeup-source Specify that the RTC can be used as a wakeup
1849 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1850 off or 1 for Vdd < VBackup (RV3028 only)
1854 Info: Adds support for a number of I2C Real Time Clock devices
1855 using the software i2c controller
1856 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1857 Params: abx80x Select one of the ABx80x family:
1858 AB0801, AB0803, AB0804, AB0805,
1859 AB1801, AB1803, AB1804, AB1805
1861 bq32000 Select the TI BQ32000 device
1863 ds1307 Select the DS1307 device
1865 ds1339 Select the DS1339 device
1867 ds1340 Select the DS1340 device
1869 ds3231 Select the DS3231 device
1871 m41t62 Select the M41T62 device
1873 mcp7940x Select the MCP7940x device
1875 mcp7941x Select the MCP7941x device
1877 pcf2127 Select the PCF2127 device
1879 pcf2129 Select the PCF2129 device
1881 pcf85063 Select the PCF85063 device
1883 pcf85063a Select the PCF85063A device
1885 pcf8523 Select the PCF8523 device
1887 pcf85363 Select the PCF85363 device
1889 pcf8563 Select the PCF8563 device
1891 rv1805 Select the Micro Crystal RV1805 device
1893 rv3028 Select the Micro Crystal RV3028 device
1895 rv8803 Select the Micro Crystal RV8803 device
1897 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1899 s35390a Select the ABLIC S35390A device
1901 addr Sets the address for the RTC. Note that the
1902 device must be configured to use the specified
1905 trickle-diode-disable Do not use the internal trickle charger diode
1908 trickle-diode-type Diode type for trickle charge - "standard" or
1909 "schottky" (ABx80x and RV1805 only)
1911 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1912 ABx80x, RV1805, RV3028)
1914 wakeup-source Specify that the RTC can be used as a wakeup
1917 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1918 off or 1 for Vdd < VBackup (RV3028 only)
1920 i2c_gpio_sda GPIO used for I2C data (default "23")
1922 i2c_gpio_scl GPIO used for I2C clock (default "24")
1924 i2c_gpio_delay_us Clock delay in microseconds
1925 (default "2" = ~100kHz)
1929 Info: Adds support for a number of I2C barometric pressure, temperature,
1930 light level and chemical sensors on i2c_arm
1931 Load: dtoverlay=i2c-sensor,<param>=<val>
1932 Params: addr Set the address for the BH1750, BME280, BME680,
1933 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1936 bh1750 Select the Rohm BH1750 ambient light sensor
1937 Valid addresses 0x23 or 0x5c, default 0x23
1939 bme280 Select the Bosch Sensortronic BME280
1940 Valid addresses 0x76-0x77, default 0x76
1942 bme680 Select the Bosch Sensortronic BME680
1943 Valid addresses 0x76-0x77, default 0x76
1945 bmp085 Select the Bosch Sensortronic BMP085
1947 bmp180 Select the Bosch Sensortronic BMP180
1949 bmp280 Select the Bosch Sensortronic BMP280
1950 Valid addresses 0x76-0x77, default 0x76
1952 ccs811 Select the AMS CCS811 digital gas sensor
1953 Valid addresses 0x5a-0x5b, default 0x5b
1955 ds1621 Select the Dallas Semiconductors DS1621 temp
1956 sensor. Valid addresses 0x48-0x4f, default 0x48
1958 hdc100x Select the Texas Instruments HDC100x temp sensor
1959 Valid addresses 0x40-0x43, default 0x40
1961 htu21 Select the HTU21 temperature and humidity sensor
1963 int_pin Set the GPIO to use for interrupts (max30102
1966 lm75 Select the Maxim LM75 temperature sensor
1967 Valid addresses 0x48-0x4f, default 0x4f
1969 lm75addr Deprecated - use addr parameter instead
1971 max17040 Select the Maxim Integrated MAX17040 battery
1974 max30102 Select the Maxim Integrated MAX30102 heart-rate
1975 and blood-oxygen sensor
1977 sht3x Select the Sensiron SHT3x temperature and
1978 humidity sensor. Valid addresses 0x44-0x45,
1981 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1984 sps30 Select the Sensirion SPS30 particulate matter
1985 sensor. Fixed address 0x69.
1987 sgp30 Select the Sensirion SGP30 VOC sensor.
1990 tmp102 Select the Texas Instruments TMP102 temp sensor
1991 Valid addresses 0x48-0x4b, default 0x48
1993 tsl4531 Select the AMS TSL4531 digital ambient light
1996 veml6070 Select the Vishay VEML6070 ultraviolet light
1999 i2c0 Choose the I2C0 bus on GPIOs 0&1
2001 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
2003 i2c3 Choose the I2C3 bus (configure with the i2c3
2004 overlay - BCM2711 only)
2006 i2c4 Choose the I2C3 bus (configure with the i2c3
2007 overlay - BCM2711 only)
2009 i2c5 Choose the I2C5 bus (configure with the i2c4
2010 overlay - BCM2711 only)
2012 i2c6 Choose the I2C6 bus (configure with the i2c6
2013 overlay - BCM2711 only)
2017 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
2018 platforms - platforms other then Compute Modules can only use this
2019 to disable transaction combining.
2020 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
2021 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
2022 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
2023 camera and display connectors. This overlay disables that mux and
2024 configures /dev/i2c0 to point at whichever set of pins is requested.
2025 dtparam=i2c_vc=on will try and enable the mux, so combining the two
2026 will cause conflicts.
2027 Load: dtoverlay=i2c0,<param>=<val>
2028 Params: pins_0_1 Use pins 0 and 1 (default)
2029 pins_28_29 Use pins 28 and 29
2030 pins_44_45 Use pins 44 and 45
2031 pins_46_47 Use pins 46 and 47
2032 combine Allow transactions to be combined (default
2037 Info: Deprecated, legacy version of i2c0.
2042 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
2043 platforms - platforms other then Compute Modules can only use this
2044 to disable transaction combining.
2045 Load: dtoverlay=i2c1,<param>=<val>
2046 Params: pins_2_3 Use pins 2 and 3 (default)
2047 pins_44_45 Use pins 44 and 45
2048 combine Allow transactions to be combined (default
2053 Info: Deprecated, legacy version of i2c1.
2058 Info: Enable the i2c3 bus. BCM2711 only.
2059 Load: dtoverlay=i2c3,<param>
2060 Params: pins_2_3 Use GPIOs 2 and 3
2061 pins_4_5 Use GPIOs 4 and 5 (default)
2062 baudrate Set the baudrate for the interface (default
2067 Info: Enable the i2c4 bus. BCM2711 only.
2068 Load: dtoverlay=i2c4,<param>
2069 Params: pins_6_7 Use GPIOs 6 and 7
2070 pins_8_9 Use GPIOs 8 and 9 (default)
2071 baudrate Set the baudrate for the interface (default
2076 Info: Enable the i2c5 bus. BCM2711 only.
2077 Load: dtoverlay=i2c5,<param>
2078 Params: pins_10_11 Use GPIOs 10 and 11
2079 pins_12_13 Use GPIOs 12 and 13 (default)
2080 baudrate Set the baudrate for the interface (default
2085 Info: Enable the i2c6 bus. BCM2711 only.
2086 Load: dtoverlay=i2c6,<param>
2087 Params: pins_0_1 Use GPIOs 0 and 1
2088 pins_22_23 Use GPIOs 22 and 23 (default)
2089 baudrate Set the baudrate for the interface (default
2094 Info: Configures any passive I2S DAC soundcard.
2095 Load: dtoverlay=i2s-dac
2100 Info: move I2S function block to GPIO 28 to 31
2101 Load: dtoverlay=i2s-gpio28-31
2106 Info: Enables I2C connected Ilitek 251x multiple touch controller using
2107 GPIO 4 (pin 7 on GPIO header) for interrupt.
2108 Load: dtoverlay=ilitek251x,<param>=<val>
2109 Params: interrupt GPIO used for interrupt (default 4)
2110 sizex Touchscreen size x, horizontal resolution of
2111 touchscreen (in pixels)
2112 sizey Touchscreen size y, vertical resolution of
2113 touchscreen (in pixels)
2117 Info: Sony IMX219 camera module.
2118 Uses Unicam 1, which is the standard camera connector on most Pi
2120 Load: dtoverlay=imx219,<param>=<val>
2121 Params: rotation Mounting rotation of the camera sensor (0 or
2123 orientation Sensor orientation (0 = front, 1 = rear,
2124 2 = external, default external)
2125 media-controller Configure use of Media Controller API for
2126 configuring the sensor (default on)
2127 cam0 Adopt the default configuration for CAM0 on a
2128 Compute Module (CSI0, i2c_vc, and cam0_reg).
2129 vcm Configure a VCM focus drive on the sensor.
2133 Info: Sony IMX258 camera module.
2134 Uses Unicam 1, which is the standard camera connector on most Pi
2136 Load: dtoverlay=imx258,<param>=<val>
2137 Params: rotation Mounting rotation of the camera sensor (0 or
2139 orientation Sensor orientation (0 = front, 1 = rear,
2140 2 = external, default external)
2141 media-controller Configure use of Media Controller API for
2142 configuring the sensor (default on)
2143 cam0 Adopt the default configuration for CAM0 on a
2144 Compute Module (CSI0, i2c_vc, and cam0_reg).
2145 vcm Configure a VCM focus drive on the sensor.
2146 4lane Enable 4 CSI2 lanes. This requires a Compute
2147 Module (1, 3, or 4).
2151 Info: Sony IMX290 camera module.
2152 Uses Unicam 1, which is the standard camera connector on most Pi
2154 Load: dtoverlay=imx290,<param>
2155 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2156 Module (1, 3, or 4).
2157 clock-frequency Sets the clock frequency to match that used on
2159 Modules from Vision Components use 37.125MHz
2160 (the default), whilst those from Innomaker use
2162 mono Denote that the module is a mono sensor.
2163 orientation Sensor orientation (0 = front, 1 = rear,
2164 2 = external, default external)
2165 rotation Mounting rotation of the camera sensor (0 or
2167 media-controller Configure use of Media Controller API for
2168 configuring the sensor (default on)
2169 cam0 Adopt the default configuration for CAM0 on a
2170 Compute Module (CSI0, i2c_vc, and cam0_reg).
2174 Info: Sony IMX296 camera module.
2175 Uses Unicam 1, which is the standard camera connector on most Pi
2177 Load: dtoverlay=imx296,<param>=<val>
2178 Params: rotation Mounting rotation of the camera sensor (0 or
2180 orientation Sensor orientation (0 = front, 1 = rear,
2181 2 = external, default external)
2182 media-controller Configure use of Media Controller API for
2183 configuring the sensor (default on)
2184 cam0 Adopt the default configuration for CAM0 on a
2185 Compute Module (CSI0, i2c_vc, and cam0_reg).
2189 Info: Sony IMX327 camera module.
2190 Uses Unicam 1, which is the standard camera connector on most Pi
2192 Load: dtoverlay=imx327,<param>
2193 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2194 Module (1, 3, or 4).
2195 clock-frequency Sets the clock frequency to match that used on
2197 Modules from Vision Components use 37.125MHz
2198 (the default), whilst those from Innomaker use
2200 mono Denote that the module is a mono sensor.
2201 orientation Sensor orientation (0 = front, 1 = rear,
2202 2 = external, default external)
2203 rotation Mounting rotation of the camera sensor (0 or
2205 media-controller Configure use of Media Controller API for
2206 configuring the sensor (default on)
2207 cam0 Adopt the default configuration for CAM0 on a
2208 Compute Module (CSI0, i2c_vc, and cam0_reg).
2212 Info: Sony IMX378 camera module.
2213 Uses Unicam 1, which is the standard camera connector on most Pi
2215 Load: dtoverlay=imx378,<param>=<val>
2216 Params: rotation Mounting rotation of the camera sensor (0 or
2218 orientation Sensor orientation (0 = front, 1 = rear,
2219 2 = external, default external)
2220 media-controller Configure use of Media Controller API for
2221 configuring the sensor (default on)
2222 cam0 Adopt the default configuration for CAM0 on a
2223 Compute Module (CSI0, i2c_vc, and cam0_reg).
2227 Info: Sony IMX462 camera module.
2228 Uses Unicam 1, which is the standard camera connector on most Pi
2230 Load: dtoverlay=imx462,<param>
2231 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2232 Module (1, 3, or 4).
2233 clock-frequency Sets the clock frequency to match that used on
2235 Modules from Vision Components use 37.125MHz
2236 (the default), whilst those from Innomaker use
2238 mono Denote that the module is a mono sensor.
2239 orientation Sensor orientation (0 = front, 1 = rear,
2240 2 = external, default external)
2241 rotation Mounting rotation of the camera sensor (0 or
2243 media-controller Configure use of Media Controller API for
2244 configuring the sensor (default on)
2245 cam0 Adopt the default configuration for CAM0 on a
2246 Compute Module (CSI0, i2c_vc, and cam0_reg).
2250 Info: Sony IMX477 camera module.
2251 Uses Unicam 1, which is the standard camera connector on most Pi
2253 Load: dtoverlay=imx477,<param>=<val>
2254 Params: rotation Mounting rotation of the camera sensor (0 or
2256 orientation Sensor orientation (0 = front, 1 = rear,
2257 2 = external, default external)
2258 media-controller Configure use of Media Controller API for
2259 configuring the sensor (default on)
2260 cam0 Adopt the default configuration for CAM0 on a
2261 Compute Module (CSI0, i2c_vc, and cam0_reg).
2265 Info: Sony IMX519 camera module.
2266 Uses Unicam 1, which is the standard camera connector on most Pi
2268 Load: dtoverlay=imx519,<param>=<val>
2269 Params: rotation Mounting rotation of the camera sensor (0 or
2271 orientation Sensor orientation (0 = front, 1 = rear,
2272 2 = external, default external)
2273 media-controller Configure use of Media Controller API for
2274 configuring the sensor (default on)
2275 cam0 Adopt the default configuration for CAM0 on a
2276 Compute Module (CSI0, i2c_vc, and cam0_reg).
2280 Info: Configures the IQaudio Codec audio card
2281 Load: dtoverlay=iqaudio-codec
2286 Info: Configures the IQaudio DAC audio card
2287 Load: dtoverlay=iqaudio-dac,<param>
2288 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2289 Digital volume control. Enable with
2290 "dtoverlay=iqaudio-dac,24db_digital_gain"
2291 (The default behaviour is that the Digital
2292 volume control is limited to a maximum of
2293 0dB. ie. it can attenuate but not provide
2294 gain. For most users, this will be desired
2295 as it will prevent clipping. By appending
2296 the 24db_digital_gain parameter, the Digital
2297 volume control will allow up to 24dB of
2298 gain. If this parameter is enabled, it is the
2299 responsibility of the user to ensure that
2300 the Digital volume control is set to a value
2301 that does not result in clipping/distortion!)
2304 Name: iqaudio-dacplus
2305 Info: Configures the IQaudio DAC+ audio card
2306 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2307 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2308 Digital volume control. Enable with
2309 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2310 (The default behaviour is that the Digital
2311 volume control is limited to a maximum of
2312 0dB. ie. it can attenuate but not provide
2313 gain. For most users, this will be desired
2314 as it will prevent clipping. By appending
2315 the 24db_digital_gain parameter, the Digital
2316 volume control will allow up to 24dB of
2317 gain. If this parameter is enabled, it is the
2318 responsibility of the user to ensure that
2319 the Digital volume control is set to a value
2320 that does not result in clipping/distortion!)
2321 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2322 starting/stopping audio playback.
2323 unmute_amp If specified, unmute the IQaudIO amp once when
2324 the DAC driver module loads.
2327 Name: iqaudio-digi-wm8804-audio
2328 Info: Configures the IQAudIO Digi WM8804 audio card
2329 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2330 Params: card_name Override the default, "IQAudIODigi", card name.
2331 dai_name Override the default, "IQAudIO Digi", dai name.
2332 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2337 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2338 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2339 Load: dtoverlay=iqs550,<param>=<val>
2340 Params: interrupt GPIO used for interrupt (default 4)
2341 reset GPIO used for reset (optional)
2342 sizex Touchscreen size x (default 800)
2343 sizey Touchscreen size y (default 480)
2344 invx Touchscreen inverted x axis
2345 invy Touchscreen inverted y axis
2346 swapxy Touchscreen swapped x y axis
2350 Info: Infineon irs1125 TOF camera module.
2351 Uses Unicam 1, which is the standard camera connector on most Pi
2353 Load: dtoverlay=irs1125,<param>=<val>
2354 Params: media-controller Configure use of Media Controller API for
2355 configuring the sensor (default off)
2356 cam0 Adopt the default configuration for CAM0 on a
2357 Compute Module (CSI0, i2c_vc, and cam0_reg).
2361 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2362 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2363 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2364 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2365 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2370 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2372 Load: dtoverlay=justboom-both,<param>=<val>
2373 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2374 Digital volume control. Enable with
2375 "dtoverlay=justboom-dac,24db_digital_gain"
2376 (The default behaviour is that the Digital
2377 volume control is limited to a maximum of
2378 0dB. ie. it can attenuate but not provide
2379 gain. For most users, this will be desired
2380 as it will prevent clipping. By appending
2381 the 24dB_digital_gain parameter, the Digital
2382 volume control will allow up to 24dB of
2383 gain. If this parameter is enabled, it is the
2384 responsibility of the user to ensure that
2385 the Digital volume control is set to a value
2386 that does not result in clipping/distortion!)
2390 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2392 Load: dtoverlay=justboom-dac,<param>=<val>
2393 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2394 Digital volume control. Enable with
2395 "dtoverlay=justboom-dac,24db_digital_gain"
2396 (The default behaviour is that the Digital
2397 volume control is limited to a maximum of
2398 0dB. ie. it can attenuate but not provide
2399 gain. For most users, this will be desired
2400 as it will prevent clipping. By appending
2401 the 24dB_digital_gain parameter, the Digital
2402 volume control will allow up to 24dB of
2403 gain. If this parameter is enabled, it is the
2404 responsibility of the user to ensure that
2405 the Digital volume control is set to a value
2406 that does not result in clipping/distortion!)
2410 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2411 Load: dtoverlay=justboom-digi
2416 Info: This overlay has been deprecated and removed - see gpio-ir
2421 Info: Adds support for the ltc294x family of battery gauges
2422 Load: dtoverlay=ltc294x,<param>=<val>
2423 Params: ltc2941 Select the ltc2941 device
2425 ltc2942 Select the ltc2942 device
2427 ltc2943 Select the ltc2943 device
2429 ltc2944 Select the ltc2944 device
2431 resistor-sense The sense resistor value in milli-ohms.
2432 Can be a 32-bit negative value when the battery
2433 has been connected to the wrong end of the
2436 prescaler-exponent Range and accuracy of the gauge. The value is
2437 programmed into the chip only if it differs
2438 from the current setting.
2440 - Default value is 128
2441 - the exponent is in the range 0-7 (default 7)
2442 See the datasheet for more information.
2446 Info: Configures the Maxim MAX98357A I2S DAC
2447 Load: dtoverlay=max98357a,<param>=<val>
2448 Params: no-sdmode Driver does not manage the state of the DAC's
2449 SD_MODE pin (i.e. chip is always on).
2450 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2451 of the DAC (default GPIO4 if parameter omitted).
2455 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2457 For devices on spi1 or spi2, the interfaces should be enabled
2458 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2459 The overlay expects to disable the relevant spidev node, so also using
2460 e.g. cs0_spidev=off is unnecessary.
2463 MAX31855 on /dev/spidev0.0
2464 dtoverlay=maxtherm,spi0-0,max31855
2465 MAX31856 using a type J thermocouple on /dev/spidev2.1
2467 dtoverlay=maxtherm,spi2-1,max31856,type_j
2469 Load: dtoverlay=maxtherm,<param>=<val>
2470 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2472 max6675 Enable support for the MAX6675 (default)
2473 max31855 Enable support for the MAX31855
2474 max31855e Enable support for the MAX31855E
2475 max31855j Enable support for the MAX31855J
2476 max31855k Enable support for the MAX31855K
2477 max31855n Enable support for the MAX31855N
2478 max31855r Enable support for the MAX31855R
2479 max31855s Enable support for the MAX31855S
2480 max31855t Enable support for the MAX31855T
2481 max31856 Enable support for the MAX31856 (with type K)
2482 type_b Select a type B sensor for max31856
2483 type_e Select a type E sensor for max31856
2484 type_j Select a type J sensor for max31856
2485 type_k Select a type K sensor for max31856
2486 type_n Select a type N sensor for max31856
2487 type_r Select a type R sensor for max31856
2488 type_s Select a type S sensor for max31856
2489 type_t Select a type T sensor for max31856
2493 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2494 Load: dtoverlay=mbed-dac
2499 Info: Configures the MCP23017 I2C GPIO expander
2500 Load: dtoverlay=mcp23017,<param>=<val>
2501 Params: gpiopin Gpio pin connected to the INTA output of the
2502 MCP23017 (default: 4)
2504 addr I2C address of the MCP23017 (default: 0x20)
2506 mcp23008 Configure an MCP23008 instead.
2507 noints Disable the interrupt GPIO line.
2511 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2512 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2513 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2514 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2515 device must be the only one present on that SPI bus/CS#.
2516 Load: dtoverlay=mcp23s17,<param>=<val>
2517 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2518 devices present on SPI<n>, CS#<m>
2520 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2521 devices present on SPI<n>, CS#<m>
2523 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2524 MCP23S08 device on SPI<n>, CS#<m>, specifies
2525 the GPIO pin to which INT output of MCP23S08
2528 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2529 single MCP23S17 device on SPI<n>, CS#<m>,
2530 specifies the GPIO pin to which either INTA
2531 or INTB output of MCP23S17 is connected.
2535 Info: Configures the MCP2515 CAN controller on spi0/1/2
2536 For devices on spi1 or spi2, the interfaces should be enabled
2537 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2538 Load: dtoverlay=mcp2515,<param>=<val>
2539 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2542 oscillator Clock frequency for the CAN controller (Hz)
2544 speed Maximum SPI frequence (Hz)
2546 interrupt GPIO for interrupt signal
2550 Info: Configures the MCP2515 CAN controller on spi0.0
2551 Load: dtoverlay=mcp2515-can0,<param>=<val>
2552 Params: oscillator Clock frequency for the CAN controller (Hz)
2554 spimaxfrequency Maximum SPI frequence (Hz)
2556 interrupt GPIO for interrupt signal
2560 Info: Configures the MCP2515 CAN controller on spi0.1
2561 Load: dtoverlay=mcp2515-can1,<param>=<val>
2562 Params: oscillator Clock frequency for the CAN controller (Hz)
2564 spimaxfrequency Maximum SPI frequence (Hz)
2566 interrupt GPIO for interrupt signal
2570 Info: Configures the MCP251XFD CAN controller family
2571 For devices on spi1 or spi2, the interfaces should be enabled
2572 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2573 Load: dtoverlay=mcp251xfd,<param>=<val>
2574 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2577 oscillator Clock frequency for the CAN controller (Hz)
2579 speed Maximum SPI frequence (Hz)
2581 interrupt GPIO for interrupt signal
2583 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2585 xceiver_enable GPIO for CAN transceiver enable (optional)
2587 xceiver_active_high specifiy if CAN transceiver enable pin is
2588 active high (optional, default: active low)
2592 Info: Configures MCP3008 A/D converters
2593 For devices on spi1 or spi2, the interfaces should be enabled
2594 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2595 Load: dtoverlay=mcp3008,<param>[=<val>]
2596 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2597 spi<n>-<m>-speed integer, set the spi bus speed for this device
2601 Info: Configures MCP3202 A/D converters
2602 For devices on spi1 or spi2, the interfaces should be enabled
2603 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2604 Load: dtoverlay=mcp3202,<param>[=<val>]
2605 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2606 spi<n>-<m>-speed integer, set the spi bus speed for this device
2610 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2611 Load: dtoverlay=mcp342x,<param>=<val>
2612 Params: addr I2C bus address of device, for devices with
2613 addresses that are configurable, e.g. by
2614 hardware links (default=0x68)
2615 mcp3421 The device is an MCP3421
2616 mcp3422 The device is an MCP3422
2617 mcp3423 The device is an MCP3423
2618 mcp3424 The device is an MCP3424
2619 mcp3425 The device is an MCP3425
2620 mcp3426 The device is an MCP3426
2621 mcp3427 The device is an MCP3427
2622 mcp3428 The device is an MCP3428
2626 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2627 Load: dtoverlay=media-center,<param>=<val>
2628 Params: speed Display SPI bus speed
2629 rotate Display rotation {0,90,180,270}
2630 fps Delay between frame updates
2631 xohms Touchpanel sensitivity (X-plate resistance)
2632 swapxy Swap x and y axis
2633 backlight Change backlight GPIO pin {e.g. 12, 18}
2634 gpio_out_pin GPIO for output (default "17")
2635 gpio_in_pin GPIO for input (default "18")
2636 gpio_in_pull Pull up/down/off on the input pin
2638 sense Override the IR receive auto-detection logic:
2639 "0" = force active-high
2640 "1" = force active-low
2641 "-1" = use auto-detection
2643 softcarrier Turn the software carrier "on" or "off"
2645 invert "on" = invert the output pin (default "off")
2646 debug "on" = enable additional debug messages
2651 Info: Configures the merus-amp audio card
2652 Load: dtoverlay=merus-amp
2657 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2658 31.25kbaud, the frequency required for MIDI
2659 Load: dtoverlay=midi-uart0
2664 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2665 31.25kbaud, the frequency required for MIDI
2666 Load: dtoverlay=midi-uart1
2671 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2672 31.25kbaud, the frequency required for MIDI
2673 Load: dtoverlay=midi-uart2
2678 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2679 31.25kbaud, the frequency required for MIDI
2680 Load: dtoverlay=midi-uart3
2685 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2686 31.25kbaud, the frequency required for MIDI
2687 Load: dtoverlay=midi-uart4
2692 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2693 31.25kbaud, the frequency required for MIDI
2694 Load: dtoverlay=midi-uart5
2699 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2700 Load: dtoverlay=minipitft13,<param>=<val>
2701 Params: speed SPI bus speed (default 32000000)
2702 rotate Display rotation (0, 90, 180 or 270; default 0)
2703 width Display width (default 240)
2704 height Display height (default 240)
2705 fps Delay between frame updates (default 25)
2706 debug Debug output level (0-7; default 0)
2710 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2711 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2712 15. Note that this may reduce the maximum usable baudrate.
2713 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2714 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2715 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2716 in which case use /dev/serial1 instead because it will always be
2717 correct. Furthermore, you must also set core_freq and core_freq_min to
2718 the same value in config.txt or the miniuart will not work.
2719 Load: dtoverlay=miniuart-bt,<param>=<val>
2720 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2721 driver without need of hciattach/btattach
2725 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2726 driver. The driver will load a file /lib/firmware/panel.bin containing
2727 the initialisation commands.
2730 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2731 dtparam=width=320,height=240
2732 dtparam=reset-gpio=23,dc-gpio=24
2733 dtparam=backlight-gpio=18
2735 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2736 and init commands at 10MHz. This makes it possible to push the envelope
2737 without messing up the controller configuration due to command
2738 transmission errors.
2740 For devices on spi1 or spi2, the interfaces should be enabled
2741 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2743 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2745 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2747 compatible Set the compatible string to load a different
2748 firmware file. Both the panel compatible value
2749 used to load the firmware file and the value
2750 used to load the driver has to be set having a
2751 NUL (\0) separator between them.
2753 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2754 spi<n>-<m> Configure device at spi<n>, cs<m>
2756 speed SPI bus speed in Hz (default 32000000)
2757 cpha Shifted SPI clock phase (CPHA) mode
2758 cpol Inverse SPI clock polarity (CPOL) mode
2759 write-only Controller is not readable
2760 (ie. MISO is not wired up).
2762 width Panel width in pixels (required)
2763 height Panel height in pixels (required)
2764 width-mm Panel width in mm
2765 height-mm Panel height in mm
2766 x-offset Panel x-offset in controller RAM
2767 y-offset Panel y-offset in controller RAM
2769 clock-frequency Panel clock frequency in Hz
2770 (optional, just informational).
2772 reset-gpio GPIO pin to be used for RESET
2773 dc-gpio GPIO pin to be used for D/C
2775 backlight-gpio GPIO pin to be used for backlight control
2777 backlight-pwm PWM channel to be used for backlight control
2778 (default of none). NB Disables audio headphone
2779 output as that also uses PWM.
2780 backlight-pwm-chan Choose channel on &pwm node for backlight
2781 control (default 0).
2782 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2783 pwm-2chan for valid options (default 18).
2784 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2785 See pwm-2chan for valid options (default 2).
2786 backlight-def-brightness
2787 Set the default brightness. Normal range 1-16.
2792 Info: Overlay for i2c connected mlx90640 thermal camera
2793 Load: dtoverlay=mlx90640
2798 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2799 Load: dtoverlay=mmc,<param>=<val>
2800 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2805 Info: Overlay for i2c connected mpu6050 imu
2806 Load: dtoverlay=mpu6050,<param>=<val>
2807 Params: interrupt GPIO pin for interrupt (default 4)
2808 addr I2C address of the device (default 0x68)
2812 Info: MZ61581 display by Tontec
2813 Load: dtoverlay=mz61581,<param>=<val>
2814 Params: speed Display SPI bus speed
2816 rotate Display rotation {0,90,180,270}
2818 fps Delay between frame updates
2820 txbuflen Transmit buffer length (default 32768)
2822 debug Debug output level {0-7}
2824 xohms Touchpanel sensitivity (X-plate resistance)
2828 Info: Omnivision OV2311 camera module.
2829 Uses Unicam 1, which is the standard camera connector on most Pi
2831 Load: dtoverlay=ov2311,<param>=<val>
2832 Params: rotation Mounting rotation of the camera sensor (0 or
2834 orientation Sensor orientation (0 = front, 1 = rear,
2835 2 = external, default external)
2836 media-controller Configure use of Media Controller API for
2837 configuring the sensor (default on)
2838 cam0 Adopt the default configuration for CAM0 on a
2839 Compute Module (CSI0, i2c_vc, and cam0_reg).
2843 Info: Omnivision OV5647 camera module.
2844 Uses Unicam 1, which is the standard camera connector on most Pi
2846 Load: dtoverlay=ov5647,<param>=<val>
2847 Params: rotation Mounting rotation of the camera sensor (0 or
2849 orientation Sensor orientation (0 = front, 1 = rear,
2850 2 = external, default external)
2851 media-controller Configure use of Media Controller API for
2852 configuring the sensor (default on)
2853 cam0 Adopt the default configuration for CAM0 on a
2854 Compute Module (CSI0, i2c_vc, and cam0_reg).
2855 vcm Configure a VCM focus drive on the sensor.
2859 Info: Omnivision OV7251 camera module.
2860 Uses Unicam 1, which is the standard camera connector on most Pi
2862 Load: dtoverlay=ov7251,<param>=<val>
2863 Params: rotation Mounting rotation of the camera sensor (0 or
2865 orientation Sensor orientation (0 = front, 1 = rear,
2866 2 = external, default external)
2867 media-controller Configure use of Media Controller API for
2868 configuring the sensor (default off)
2869 cam0 Adopt the default configuration for CAM0 on a
2870 Compute Module (CSI0, i2c_vc, and cam0_reg).
2874 Info: Omnivision OV9281 camera module.
2875 Uses Unicam 1, which is the standard camera connector on most Pi
2877 Load: dtoverlay=ov9281,<param>=<val>
2878 Params: rotation Mounting rotation of the camera sensor (0 or
2880 orientation Sensor orientation (0 = front, 1 = rear,
2881 2 = external, default external)
2882 media-controller Configure use of Media Controller API for
2883 configuring the sensor (default on)
2884 cam0 Adopt the default configuration for CAM0 on a
2885 Compute Module (CSI0, i2c_vc, and cam0_reg).
2889 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2890 Load: dtoverlay=papirus,<param>=<val>
2891 Params: panel Display panel (required):
2896 speed Display SPI bus speed
2900 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2901 Load: dtoverlay=pca953x,<param>=<val>
2902 Params: addr I2C address of expander. Default 0x20.
2903 pca6416 Select the NXP PCA6416 (16 bit)
2904 pca9505 Select the NXP PCA9505 (40 bit)
2905 pca9535 Select the NXP PCA9535 (16 bit)
2906 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2907 pca9537 Select the NXP PCA9537 (4 bit)
2908 pca9538 Select the NXP PCA9538 (8 bit)
2909 pca9539 Select the NXP PCA9539 (16 bit)
2910 pca9554 Select the NXP PCA9554 (8 bit)
2911 pca9555 Select the NXP PCA9555 (16 bit)
2912 pca9556 Select the NXP PCA9556 (8 bit)
2913 pca9557 Select the NXP PCA9557 (8 bit)
2914 pca9574 Select the NXP PCA9574 (8 bit)
2915 pca9575 Select the NXP PCA9575 (16 bit)
2916 pca9698 Select the NXP PCA9698 (40 bit)
2917 pca16416 Select the NXP PCA16416 (16 bit)
2918 pca16524 Select the NXP PCA16524 (24 bit)
2919 pca19555a Select the NXP PCA19555A (16 bit)
2920 max7310 Select the Maxim MAX7310 (8 bit)
2921 max7312 Select the Maxim MAX7312 (16 bit)
2922 max7313 Select the Maxim MAX7313 (16 bit)
2923 max7315 Select the Maxim MAX7315 (8 bit)
2924 pca6107 Select the TI PCA6107 (8 bit)
2925 tca6408 Select the TI TCA6408 (8 bit)
2926 tca6416 Select the TI TCA6416 (16 bit)
2927 tca6424 Select the TI TCA6424 (24 bit)
2928 tca9539 Select the TI TCA9539 (16 bit)
2929 tca9554 Select the TI TCA9554 (8 bit)
2930 cat9554 Select the Onnn CAT9554 (8 bit)
2931 pca9654 Select the Onnn PCA9654 (8 bit)
2932 xra1202 Select the Exar XRA1202 (8 bit)
2935 Name: pcie-32bit-dma
2936 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2937 having to bounce buffers.
2938 Load: dtoverlay=pcie-32bit-dma
2942 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2945 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2948 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2952 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2953 for backwards compatibility.
2957 Name: pi3-disable-bt
2958 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2959 alias for backwards compatibility.
2963 Name: pi3-disable-wifi
2964 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2965 an alias for backwards compatibility.
2969 Name: pi3-miniuart-bt
2970 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2971 an alias for backwards compatibility.
2976 Info: Configures the pibell audio card.
2977 Load: dtoverlay=pibell,<param>=<val>
2978 Params: alsaname Set the name as it appears in ALSA (default
2983 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2984 Load: dtoverlay=pifacedigital,<param>=<val>
2985 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2986 CS0 address. PiFace Digital supports addresses
2987 0-3, which can be configured with JP1 and JP2.
2991 Info: Configures the PiFi 40W stereo amplifier
2992 Load: dtoverlay=pifi-40
2997 Info: Configures the PiFi DAC HD
2998 Load: dtoverlay=pifi-dac-hd
3003 Info: Configures the PiFi DAC Zero
3004 Load: dtoverlay=pifi-dac-zero
3009 Info: Configures the PiFi Mini stereo amplifier
3010 Load: dtoverlay=pifi-mini-210
3015 Info: Configures the PiGlow by pimoroni.com
3016 Load: dtoverlay=piglow
3021 Info: PiScreen display by OzzMaker.com
3022 Load: dtoverlay=piscreen,<param>=<val>
3023 Params: speed Display SPI bus speed
3025 rotate Display rotation {0,90,180,270}
3027 fps Delay between frame updates
3029 debug Debug output level {0-7}
3031 xohms Touchpanel sensitivity (X-plate resistance)
3035 Info: PiScreen 2 with resistive TP display by OzzMaker.com
3036 Load: dtoverlay=piscreen2r,<param>=<val>
3037 Params: speed Display SPI bus speed
3039 rotate Display rotation {0,90,180,270}
3041 fps Delay between frame updates
3043 debug Debug output level {0-7}
3045 xohms Touchpanel sensitivity (X-plate resistance)
3049 Info: Configures the Blokas Labs pisound card
3050 Load: dtoverlay=pisound
3055 Info: Adafruit PiTFT 2.2" screen
3056 Load: dtoverlay=pitft22,<param>=<val>
3057 Params: speed Display SPI bus speed
3059 rotate Display rotation {0,90,180,270}
3061 fps Delay between frame updates
3063 debug Debug output level {0-7}
3066 Name: pitft28-capacitive
3067 Info: Adafruit PiTFT 2.8" capacitive touch screen
3068 Load: dtoverlay=pitft28-capacitive,<param>=<val>
3069 Params: speed Display SPI bus speed
3071 rotate Display rotation {0,90,180,270}
3073 fps Delay between frame updates
3075 debug Debug output level {0-7}
3077 touch-sizex Touchscreen size x (default 240)
3079 touch-sizey Touchscreen size y (default 320)
3081 touch-invx Touchscreen inverted x axis
3083 touch-invy Touchscreen inverted y axis
3085 touch-swapxy Touchscreen swapped x y axis
3088 Name: pitft28-resistive
3089 Info: Adafruit PiTFT 2.8" resistive touch screen
3090 Load: dtoverlay=pitft28-resistive,<param>=<val>
3091 Params: speed Display SPI bus speed
3093 rotate Display rotation {0,90,180,270}
3095 fps Delay between frame updates
3097 debug Debug output level {0-7}
3099 drm Force the use of the mi0283qt DRM driver (by
3100 default the ili9340 framebuffer driver will
3101 be used in preference if available)
3104 Name: pitft35-resistive
3105 Info: Adafruit PiTFT 3.5" resistive touch screen
3106 Load: dtoverlay=pitft35-resistive,<param>=<val>
3107 Params: speed Display SPI bus speed
3109 rotate Display rotation {0,90,180,270}
3111 fps Delay between frame updates
3113 debug Debug output level {0-7}
3115 drm Force the use of the hx8357d DRM driver (by
3116 default the fb_hx8357d framebuffer driver will
3117 be used in preference if available)
3121 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
3122 Load: dtoverlay=pps-gpio,<param>=<val>
3123 Params: gpiopin Input GPIO (default "18")
3124 assert_falling_edge When present, assert is indicated by a falling
3125 edge, rather than by a rising edge (default
3127 capture_clear Generate clear events on the trailing edge
3129 pull Desired pull-up/down state (off, down, up)
3134 Info: Configures the PROTO Audio Codec card
3135 Load: dtoverlay=proto-codec
3140 Info: Configures a single PWM channel
3141 Legal pin,function combinations for each channel:
3142 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3143 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3145 1) Pin 18 is the only one available on all platforms, and
3146 it is the one used by the I2S audio interface.
3147 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3148 2) The onboard analogue audio output uses both PWM channels.
3149 3) So be careful mixing audio and PWM.
3150 4) Currently the clock must have been enabled and configured
3152 Load: dtoverlay=pwm,<param>=<val>
3153 Params: pin Output pin (default 18) - see table
3154 func Pin function (default 2 = Alt5) - see above
3155 clock PWM clock frequency (informational)
3159 Info: Configures both PWM channels
3160 Legal pin,function combinations for each channel:
3161 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3162 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3164 1) Pin 18 is the only one available on all platforms, and
3165 it is the one used by the I2S audio interface.
3166 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3167 2) The onboard analogue audio output uses both PWM channels.
3168 3) So be careful mixing audio and PWM.
3169 4) Currently the clock must have been enabled and configured
3171 Load: dtoverlay=pwm-2chan,<param>=<val>
3172 Params: pin Output pin (default 18) - see table
3173 pin2 Output pin for other channel (default 19)
3174 func Pin function (default 2 = Alt5) - see above
3175 func2 Function for pin2 (default 2 = Alt5)
3176 clock PWM clock frequency (informational)
3180 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
3181 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
3182 of PWM0 to reduce the CPU load during transmission compared to
3183 gpio-ir-tx which uses bit-banging.
3184 Legal pin,function combinations are:
3185 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3186 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3187 Params: gpio_pin Output GPIO (default 18)
3189 func Pin function (default 2 = Alt5)
3193 Info: in-tech's Evaluation Board for PLC Stamp micro
3194 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3195 Load: dtoverlay=qca7000,<param>=<val>
3196 Params: int_pin GPIO pin for interrupt signal (default 23)
3198 speed SPI bus speed (default 12 MHz)
3202 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3203 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3204 But it requires disabling of onboard Bluetooth on
3205 Pi 3B, 3B+, 3A+, 4B and Zero W.
3206 Load: dtoverlay=qca7000-uart0,<param>=<val>
3207 Params: baudrate Set the baudrate for the UART (default
3212 Info: Enable the preservation of crash logs across a reboot. With
3213 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3214 are moved to /var/lib/systemd/pstore/ on reboot.
3215 Load: dtoverlay=ramoops,<param>=<val>
3216 Params: base-addr Where to place the capture buffer (default
3218 total-size How much memory to allocate altogether (in
3219 bytes - default 64kB)
3220 record-size How much space to use for each capture, i.e.
3221 total-size / record-size = number of captures
3223 console-size Size of non-panic dmesg captures (default 0)
3227 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3228 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3229 Load: dtoverlay=ramoops-pi4,<param>=<val>
3230 Params: base-addr Where to place the capture buffer (default
3232 total-size How much memory to allocate altogether (in
3233 bytes - default 64kB)
3234 record-size How much space to use for each capture, i.e.
3235 total-size / record-size = number of captures
3237 console-size Size of non-panic dmesg captures (default 0)
3240 Name: rotary-encoder
3241 Info: Overlay for GPIO connected rotary encoder.
3242 Load: dtoverlay=rotary-encoder,<param>=<val>
3243 Params: pin_a GPIO connected to rotary encoder channel A
3245 pin_b GPIO connected to rotary encoder channel B
3247 relative_axis register a relative axis rather than an
3248 absolute one. Relative axis will only
3249 generate +1/-1 events on the input device,
3250 hence no steps need to be passed.
3251 linux_axis the input subsystem axis to map to this
3252 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3253 rollover Automatic rollover when the rotary value
3254 becomes greater than the specified steps or
3255 smaller than 0. For absolute axis only.
3256 steps-per-period Number of steps (stable states) per period.
3257 The values have the following meaning:
3258 1: Full-period mode (default)
3260 4: Quarter-period mode
3261 steps Number of steps in a full turnaround of the
3262 encoder. Only relevant for absolute axis.
3263 Defaults to 24 which is a typical value for
3265 wakeup Boolean, rotary encoder can wake up the
3267 encoding String, the method used to encode steps.
3268 Supported are "gray" (the default and more
3269 common) and "binary".
3273 Info: Raspberry Pi official display backlight driver
3274 Load: dtoverlay=rpi-backlight
3278 Name: rpi-cirrus-wm5102
3279 Info: This overlay has been renamed to cirrus-wm5102
3284 Info: Configures the Raspberry Pi Codec Zero sound card
3285 Load: dtoverlay=rpi-codeczero
3290 Info: This overlay has been renaamed to i2s-dac.
3295 Info: Configures the Raspberry Pi DAC+ card
3296 Load: dtoverlay=rpi-dacplus,<param>=<val>
3297 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3298 digital volume control. Enable by adding
3299 "dtparam=24db_digital_gain" to config.txt
3300 before any "dtoverlay" lines.
3301 The default behaviour is that the digital
3302 volume control is limited to a maximum of
3303 0dB. ie. it can attenuate but not provide
3304 gain. For most users, this will be desired
3305 as it will prevent clipping. By appending
3306 the 24db_digital_gain parameter, the digital
3307 volume control will allow up to 24dB of
3308 gain. If this parameter is enabled, it is the
3309 responsibility of the user to ensure that
3310 the digital volume control is set to a value
3311 that does not result in clipping/distortion!
3315 Info: Configures the Raspberry Pi DAC Pro sound card
3316 Load: dtoverlay=rpi-dacpro,<param>=<val>
3317 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3318 digital volume control. Enable by adding
3319 "dtparam=24db_digital_gain" to config.txt
3320 before any "dtoverlay" lines.
3321 The default behaviour is that the digital
3322 volume control is limited to a maximum of
3323 0dB. ie. it can attenuate but not provide
3324 gain. For most users, this will be desired
3325 as it will prevent clipping. By appending
3326 the 24db_digital_gain parameter, the digital
3327 volume control will allow up to 24dB of
3328 gain. If this parameter is enabled, it is the
3329 responsibility of the user to ensure that
3330 the digital volume control is set to a value
3331 that does not result in clipping/distortion!
3334 Name: rpi-digiampplus
3335 Info: Configures the Raspberry Pi DigiAMP+ sound card
3336 Load: dtoverlay=rpi-digiampplus,<param>=<val>
3337 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
3338 digital volume control. Enable by adding
3339 "dtparam=24db_digital_gain" to config.txt
3340 before any "dtoverlay" lines.
3341 The default behaviour is that the digital
3342 volume control is limited to a maximum of
3343 0dB. ie. it can attenuate but not provide
3344 gain. For most users, this will be desired
3345 as it will prevent clipping. By appending
3346 the 24db_digital_gain parameter, the digital
3347 volume control will allow up to 24dB of
3348 gain. If this parameter is enabled, it is the
3349 responsibility of the user to ensure that
3350 the digital volume control is set to a value
3351 that does not result in clipping/distortion!
3352 auto_mute_amp If specified, unmute/mute the DigiAMP+ when
3353 starting/stopping audio playback (default "on").
3354 unmute_amp If specified, unmute the DigiAMP+ amp once when
3355 the DAC driver module loads (default "off").
3359 Info: This overlay has been renamed to watterott-display
3364 Info: Official Raspberry Pi display touchscreen
3365 Load: dtoverlay=rpi-ft5406,<param>=<val>
3366 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3367 touchscreen-size-y Touchscreen Y resolution (default 600);
3368 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3369 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3370 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3374 Info: Raspberry Pi PoE HAT fan
3375 Load: dtoverlay=rpi-poe,<param>[=<val>]
3376 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3377 turns on (default 40000)
3378 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3379 the fan turns off (default 2000)
3380 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3381 speeds up (default 45000)
3382 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3383 the fan slows down (default 2000)
3384 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3385 speeds up (default 50000)
3386 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3387 the fan slows down (default 2000)
3388 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3389 speeds up (default 55000)
3390 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3391 the fan slows down (default 5000)
3392 i2c Control the fan via Linux I2C drivers instead of
3397 Info: Raspberry Pi PoE+ HAT fan
3398 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3399 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3400 turns on (default 40000)
3401 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3402 the fan turns off (default 2000)
3403 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3404 speeds up (default 45000)
3405 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3406 the fan slows down (default 2000)
3407 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3408 speeds up (default 50000)
3409 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3410 the fan slows down (default 2000)
3411 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3412 speeds up (default 55000)
3413 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3414 the fan slows down (default 5000)
3415 i2c Control the fan via Linux I2C drivers instead of
3420 Info: This overlay has been renamaed to proto-codec.
3425 Info: Raspberry Pi Sense HAT
3426 Load: dtoverlay=rpi-sense
3431 Info: Raspberry Pi Sense HAT v2
3432 Load: dtoverlay=rpi-sense-v2
3437 Info: Raspberry Pi TV HAT
3438 Load: dtoverlay=rpi-tv
3443 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3444 video decoder driver is enabled by default.
3448 Name: rra-digidac1-wm8741-audio
3449 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3450 Load: dtoverlay=rra-digidac1-wm8741-audio
3455 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3457 Load: dtoverlay=sainsmart18,<param>=<val>
3458 Params: rotate Display rotation {0,90,180,270}
3459 speed SPI bus speed in Hz (default 4000000)
3460 fps Display frame rate in Hz
3461 bgr Enable BGR mode (default off)
3462 debug Debug output level {0-7}
3463 dc_pin GPIO pin for D/C (default 24)
3464 reset_pin GPIO pin for RESET (default 25)
3468 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3469 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3470 select another address, please refer to table 10 in reference manual.
3471 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3472 Params: int_pin GPIO used for IRQ (default 24)
3473 addr Address (default 0x48)
3474 xtal On-board crystal frequency (default 14745600)
3478 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3479 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3480 select another address, please refer to table 10 in reference manual.
3481 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3482 Params: int_pin GPIO used for IRQ (default 24)
3483 addr Address (default 0x48)
3484 xtal On-board crystal frequency (default 14745600)
3487 Name: sc16is752-spi0
3488 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3489 Enables the chip on SPI0.
3490 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3491 Params: int_pin GPIO used for IRQ (default 24)
3492 xtal On-board crystal frequency (default 14745600)
3495 Name: sc16is752-spi1
3496 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3497 Enables the chip on SPI1.
3498 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3499 A+, B+, Zero and PI2 B; as well as the Compute Module.
3501 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3502 Params: int_pin GPIO used for IRQ (default 24)
3503 xtal On-board crystal frequency (default 14745600)
3507 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3508 N.B. This overlay is designed for situations where the mmc driver is
3509 the default, so it disables the other (mmc) interface - this will kill
3510 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3511 overlay or the new sd_* dtparams of the base DTBs.
3512 Load: dtoverlay=sdhost,<param>=<val>
3513 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3516 force_pio Disable DMA support (default off)
3518 pio_limit Number of blocks above which to use DMA
3521 debug Enable debug output (default off)
3525 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3526 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3527 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3528 Load: dtoverlay=sdio,<param>=<val>
3529 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3530 framework requests 50MHz
3532 poll_once Disable SDIO-device polling every second
3533 (default on: polling once at boot-time)
3535 bus_width Set the SDIO host bus width (default 4 bits)
3537 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3538 with bus_width=1. This replaces the sdio-1bit
3539 overlay, which is now deprecated.
3541 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3544 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3545 with bus_width=4 (the default).
3549 Info: This overlay is now deprecated. Use
3550 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3555 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3556 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3557 "dtparam=sd_poll_once".
3561 Name: seeed-can-fd-hat-v1
3562 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3563 channels without RTC. Use this overlay if your HAT has no
3565 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3566 Load: dtoverlay=seeed-can-fd-hat-v1
3570 Name: seeed-can-fd-hat-v2
3571 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3572 channels and an RTC. Use this overlay if your HAT has a
3574 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3575 Load: dtoverlay=seeed-can-fd-hat-v2
3580 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3581 Load: dtoverlay=sh1106-spi,<param>=<val>
3582 Params: speed SPI bus speed (default 4000000)
3583 rotate Display rotation (0, 90, 180 or 270; default 0)
3584 fps Delay between frame updates (default 25)
3585 debug Debug output level (0-7; default 0)
3586 dc_pin GPIO pin for D/C (default 24)
3587 reset_pin GPIO pin for RESET (default 25)
3588 height Display height (32 or 64; default 64)
3592 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3593 The driver is currently out-of-tree at
3594 https://github.com/sunipkmukherjee/silabs.git
3595 Load: dtoverlay=si446x-spi0,<param>=<val>
3596 Params: speed SPI bus speed (default 4000000)
3597 int_pin GPIO pin for interrupts (default 17)
3598 reset_pin GPIO pin for RESET (default 27)
3602 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3608 Info: Enables the userspace interface for the SMI driver
3609 Load: dtoverlay=smi-dev
3614 Info: Enables access to NAND flash via the SMI interface
3615 Load: dtoverlay=smi-nand
3620 Info: Move SPI function block to GPIO 35 to 39
3621 Load: dtoverlay=spi-gpio35-39
3626 Info: Move SPI function block to GPIOs 40 to 45
3627 Load: dtoverlay=spi-gpio40-45
3632 Info: Adds support for a number of SPI Real Time Clock devices
3633 Load: dtoverlay=spi-rtc,<param>=<val>
3634 Params: ds3232 Select the DS3232 device
3635 ds3234 Select the DS3234 device
3636 pcf2123 Select the PCF2123 device
3638 spi0_0 Use spi0.0 (default)
3644 cs_high This device requires an active-high CS
3648 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3649 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3650 Load: dtoverlay=spi0-0cs,<param>=<val>
3651 Params: no_miso Don't claim and use the MISO pin (9), freeing
3656 Info: Only use one CS pin for SPI0
3657 Load: dtoverlay=spi0-1cs,<param>=<val>
3658 Params: cs0_pin GPIO pin for CS0 (default 8)
3659 no_miso Don't claim and use the MISO pin (9), freeing
3664 Info: Change the CS pins for SPI0
3665 Load: dtoverlay=spi0-2cs,<param>=<val>
3666 Params: cs0_pin GPIO pin for CS0 (default 8)
3667 cs1_pin GPIO pin for CS1 (default 7)
3668 no_miso Don't claim and use the MISO pin (9), freeing
3673 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3674 alias for backwards compatibility.
3679 Info: This overlay has been deprecated and removed because it is no longer
3680 necessary and has been seen to prevent spi0 from working.
3685 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3686 dev node. The gpio pin number for the CS line and spidev device node
3687 creation are configurable.
3688 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3689 A+, B+, Zero and PI2 B; as well as the Compute Module.
3690 Load: dtoverlay=spi1-1cs,<param>=<val>
3691 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3692 cs0_spidev Set to 'disabled' to stop the creation of a
3693 userspace device node /dev/spidev1.0 (default
3694 is 'okay' or enabled).
3698 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3699 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3700 creation are configurable.
3701 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3702 A+, B+, Zero and PI2 B; as well as the Compute Module.
3703 Load: dtoverlay=spi1-2cs,<param>=<val>
3704 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3705 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3706 cs0_spidev Set to 'disabled' to stop the creation of a
3707 userspace device node /dev/spidev1.0 (default
3708 is 'okay' or enabled).
3709 cs1_spidev Set to 'disabled' to stop the creation of a
3710 userspace device node /dev/spidev1.1 (default
3711 is 'okay' or enabled).
3715 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3716 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3717 creation are configurable.
3718 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3719 A+, B+, Zero and PI2 B; as well as the Compute Module.
3720 Load: dtoverlay=spi1-3cs,<param>=<val>
3721 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3722 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3723 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3724 cs0_spidev Set to 'disabled' to stop the creation of a
3725 userspace device node /dev/spidev1.0 (default
3726 is 'okay' or enabled).
3727 cs1_spidev Set to 'disabled' to stop the creation of a
3728 userspace device node /dev/spidev1.1 (default
3729 is 'okay' or enabled).
3730 cs2_spidev Set to 'disabled' to stop the creation of a
3731 userspace device node /dev/spidev1.2 (default
3732 is 'okay' or enabled).
3736 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3737 dev node. The gpio pin number for the CS line and spidev device node
3738 creation are configurable.
3739 N.B.: spi2 is only accessible with the Compute Module.
3740 Load: dtoverlay=spi2-1cs,<param>=<val>
3741 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3742 cs0_spidev Set to 'disabled' to stop the creation of a
3743 userspace device node /dev/spidev2.0 (default
3744 is 'okay' or enabled).
3748 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3749 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3750 creation are configurable.
3751 N.B.: spi2 is only accessible with the Compute Module.
3752 Load: dtoverlay=spi2-2cs,<param>=<val>
3753 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3754 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3755 cs0_spidev Set to 'disabled' to stop the creation of a
3756 userspace device node /dev/spidev2.0 (default
3757 is 'okay' or enabled).
3758 cs1_spidev Set to 'disabled' to stop the creation of a
3759 userspace device node /dev/spidev2.1 (default
3760 is 'okay' or enabled).
3764 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3765 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3766 creation are configurable.
3767 N.B.: spi2 is only accessible with the Compute Module.
3768 Load: dtoverlay=spi2-3cs,<param>=<val>
3769 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3770 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3771 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3772 cs0_spidev Set to 'disabled' to stop the creation of a
3773 userspace device node /dev/spidev2.0 (default
3774 is 'okay' or enabled).
3775 cs1_spidev Set to 'disabled' to stop the creation of a
3776 userspace device node /dev/spidev2.1 (default
3777 is 'okay' or enabled).
3778 cs2_spidev Set to 'disabled' to stop the creation of a
3779 userspace device node /dev/spidev2.2 (default
3780 is 'okay' or enabled).
3784 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3785 dev node. The gpio pin number for the CS line and spidev device node
3786 creation are configurable. BCM2711 only.
3787 Load: dtoverlay=spi3-1cs,<param>=<val>
3788 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3789 cs0_spidev Set to 'off' to prevent the creation of a
3790 userspace device node /dev/spidev3.0 (default
3791 is 'on' or enabled).
3795 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3796 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3797 creation are configurable. BCM2711 only.
3798 Load: dtoverlay=spi3-2cs,<param>=<val>
3799 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3800 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3801 cs0_spidev Set to 'off' to prevent the creation of a
3802 userspace device node /dev/spidev3.0 (default
3803 is 'on' or enabled).
3804 cs1_spidev Set to 'off' to prevent the creation of a
3805 userspace device node /dev/spidev3.1 (default
3806 is 'on' or enabled).
3810 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3811 dev node. The gpio pin number for the CS line and spidev device node
3812 creation are configurable. BCM2711 only.
3813 Load: dtoverlay=spi4-1cs,<param>=<val>
3814 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3815 cs0_spidev Set to 'off' to prevent the creation of a
3816 userspace device node /dev/spidev4.0 (default
3817 is 'on' or enabled).
3821 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3822 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3823 creation are configurable. BCM2711 only.
3824 Load: dtoverlay=spi4-2cs,<param>=<val>
3825 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3826 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3827 cs0_spidev Set to 'off' to prevent the creation of a
3828 userspace device node /dev/spidev4.0 (default
3829 is 'on' or enabled).
3830 cs1_spidev Set to 'off' to prevent the creation of a
3831 userspace device node /dev/spidev4.1 (default
3832 is 'on' or enabled).
3836 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3837 dev node. The gpio pin numbers for the CS lines and spidev device node
3838 creation are configurable. BCM2711 only.
3839 Load: dtoverlay=spi5-1cs,<param>=<val>
3840 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3841 cs0_spidev Set to 'off' to prevent the creation of a
3842 userspace device node /dev/spidev5.0 (default
3843 is 'on' or enabled).
3847 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3848 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3849 creation are configurable. BCM2711 only.
3850 Load: dtoverlay=spi5-2cs,<param>=<val>
3851 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3852 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3853 cs0_spidev Set to 'off' to prevent the creation of a
3854 userspace device node /dev/spidev5.0 (default
3855 is 'on' or enabled).
3856 cs1_spidev Set to 'off' to prevent the creation of a
3857 userspace device node /dev/spidev5.1 (default
3858 is 'on' or enabled).
3862 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3863 dev node. The gpio pin number for the CS line and spidev device node
3864 creation are configurable. BCM2711 only.
3865 Load: dtoverlay=spi6-1cs,<param>=<val>
3866 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3867 cs0_spidev Set to 'off' to prevent the creation of a
3868 userspace device node /dev/spidev6.0 (default
3869 is 'on' or enabled).
3873 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3874 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3875 creation are configurable. BCM2711 only.
3876 Load: dtoverlay=spi6-2cs,<param>=<val>
3877 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3878 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3879 cs0_spidev Set to 'off' to prevent the creation of a
3880 userspace device node /dev/spidev6.0 (default
3881 is 'on' or enabled).
3882 cs1_spidev Set to 'off' to prevent the creation of a
3883 userspace device node /dev/spidev6.1 (default
3884 is 'on' or enabled).
3888 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3889 Load: dtoverlay=ssd1306,<param>=<val>
3890 Params: address Location in display memory of first character.
3892 width Width of display. (default=128)
3893 height Height of display. (default=64)
3894 offset virtual channel a. (default=0)
3895 normal Has no effect on displays tested. (default=not
3897 sequential Set this if every other scan line is missing.
3899 remapped Set this if display is garbled. (default=not
3901 inverted Set this if display is inverted and mirrored.
3905 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3907 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3909 i2c_baudrate=400000 will speed up the display.
3911 i2c_baudrate=1000000 seems to work even though it's not officially
3912 supported by the hardware, and is faster still.
3914 For more information refer to the device datasheet at:
3915 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3919 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3920 Load: dtoverlay=ssd1306-spi,<param>=<val>
3921 Params: speed SPI bus speed (default 10000000)
3922 rotate Display rotation (0, 90, 180 or 270; default 0)
3923 fps Delay between frame updates (default 25)
3924 debug Debug output level (0-7; default 0)
3925 dc_pin GPIO pin for D/C (default 24)
3926 reset_pin GPIO pin for RESET (default 25)
3927 height Display height (32 or 64; default 64)
3931 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3932 Load: dtoverlay=ssd1331-spi,<param>=<val>
3933 Params: speed SPI bus speed (default 4500000)
3934 rotate Display rotation (0, 90, 180 or 270; default 0)
3935 fps Delay between frame updates (default 25)
3936 debug Debug output level (0-7; default 0)
3937 dc_pin GPIO pin for D/C (default 24)
3938 reset_pin GPIO pin for RESET (default 25)
3942 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3943 Load: dtoverlay=ssd1351-spi,<param>=<val>
3944 Params: speed SPI bus speed (default 4500000)
3945 rotate Display rotation (0, 90, 180 or 270; default 0)
3946 fps Delay between frame updates (default 25)
3947 debug Debug output level (0-7; default 0)
3948 dc_pin GPIO pin for D/C (default 24)
3949 reset_pin GPIO pin for RESET (default 25)
3952 Name: superaudioboard
3953 Info: Configures the SuperAudioBoard sound card
3954 Load: dtoverlay=superaudioboard,<param>=<val>
3955 Params: gpiopin GPIO pin for codec reset
3959 Info: Configures the Semtech SX150X I2C GPIO expanders.
3960 Load: dtoverlay=sx150x,<param>=<val>
3961 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3962 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3963 Permissible values of <m> (which is denoted in
3964 hex) depend on the device variant. For SX1501,
3965 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3966 For SX1503 and SX1506, <m> may be 20. For
3967 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3968 For SX1508, <m> may be 20, 21, 22 or 23.
3970 sx150<x>-<n>-<m>-int-gpio
3971 Integer, enables interrupts on SX150X device on
3972 I2C#<n> with slave address <m>, specifies
3973 the GPIO pin to which NINT output of SX150X is
3978 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3979 Uses Unicam 1, which is the standard camera connector on most Pi
3981 Load: dtoverlay=tc358743,<param>=<val>
3982 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3985 link-frequency Set the link frequency. Only values of 297000000
3986 (574Mbit/s) and 486000000 (972Mbit/s - default)
3987 are supported by the driver.
3988 media-controller Configure use of Media Controller API for
3989 configuring the sensor (default off)
3990 cam0 Adopt the default configuration for CAM0 on a
3991 Compute Module (CSI0, i2c_vc, and cam0_reg).
3994 Name: tc358743-audio
3995 Info: Used in combination with the tc358743-fast overlay to route the audio
3996 from the TC358743 over I2S to the Pi.
3997 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3999 Load: dtoverlay=tc358743-audio,<param>=<val>
4000 Params: card-name Override the default, "tc358743", card name.
4004 Info: 3.5" Color TFT Display by www.tinylcd.com
4005 Options: Touch, RTC, keypad
4006 Load: dtoverlay=tinylcd35,<param>=<val>
4007 Params: speed Display SPI bus speed
4009 rotate Display rotation {0,90,180,270}
4011 fps Delay between frame updates
4013 debug Debug output level {0-7}
4015 touch Enable touch panel
4017 touchgpio Touch controller IRQ GPIO
4019 xohms Touchpanel: Resistance of X-plate in ohms
4021 rtc-pcf PCF8563 Real Time Clock
4023 rtc-ds DS1307 Real Time Clock
4025 keypad Enable keypad
4028 Display with touchpanel, PCF8563 RTC and keypad:
4029 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
4031 dtoverlay=tinylcd35,touch,touchgpio=3
4035 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
4036 boards, which can be used as a secure key storage and hwrng,
4037 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
4038 Load: dtoverlay=tpm-slb9670
4043 Info: Change the pin usage of uart0
4044 Load: dtoverlay=uart0,<param>=<val>
4045 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
4047 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
4049 pin_func Alternative pin function - 4(Alt0) for 14&15,
4050 7(Alt3) for 32&33, 6(Alt2) for 36&37
4054 Info: Change the pin usage of uart1
4055 Load: dtoverlay=uart1,<param>=<val>
4056 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
4058 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
4062 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
4063 Load: dtoverlay=uart2,<param>
4064 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
4068 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
4069 Load: dtoverlay=uart3,<param>
4070 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
4074 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
4075 Load: dtoverlay=uart4,<param>
4076 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
4080 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
4081 Load: dtoverlay=uart5,<param>
4082 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
4086 Info: Configures the NW Digital Radio UDRC Hat
4087 Load: dtoverlay=udrc,<param>=<val>
4088 Params: alsaname Name of the ALSA audio device (default "udrc")
4091 Name: ugreen-dabboard
4092 Info: Configures the ugreen-dabboard I2S overlay
4093 This is a simple overlay based on the simple-audio-card and the dmic
4094 codec. It has the speciality that it is configured to use the codec
4095 as a master I2S device. It works for example with the Si468x DAB
4096 receiver on the uGreen DABBoard.
4097 Load: dtoverlay=ugreen-dabboard,<param>=<val>
4098 Params: card-name Override the default, "dabboard", card name.
4102 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
4103 vc4-kms-v3d and dwc2 overlays.
4104 Load: dtoverlay=upstream
4108 Name: upstream-aux-interrupt
4109 Info: This overlay has been deprecated and removed because it is no longer
4115 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
4116 the vc4-kms-v3d-pi4 and dwc2 overlays.
4117 Load: dtoverlay=upstream-pi4
4122 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4124 Load: dtoverlay=vc4-fkms-v3d,<param>
4125 Params: cma-512 CMA is 512MB (needs 1GB)
4126 cma-448 CMA is 448MB (needs 1GB)
4127 cma-384 CMA is 384MB (needs 1GB)
4128 cma-320 CMA is 320MB (needs 1GB)
4129 cma-256 CMA is 256MB (needs 1GB)
4130 cma-192 CMA is 192MB (needs 1GB)
4131 cma-128 CMA is 128MB
4134 cma-size CMA size in bytes, 4MB aligned
4135 cma-default Use upstream's default value
4138 Name: vc4-fkms-v3d-pi4
4139 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
4141 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
4142 Params: cma-512 CMA is 512MB (needs 1GB)
4143 cma-448 CMA is 448MB (needs 1GB)
4144 cma-384 CMA is 384MB (needs 1GB)
4145 cma-320 CMA is 320MB (needs 1GB)
4146 cma-256 CMA is 256MB (needs 1GB)
4147 cma-192 CMA is 192MB (needs 1GB)
4148 cma-128 CMA is 128MB
4151 cma-size CMA size in bytes, 4MB aligned
4152 cma-default Use upstream's default value
4155 Name: vc4-kms-dpi-at056tn53v1
4156 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
4160 Name: vc4-kms-dpi-generic
4161 Info: Enable a generic DPI display under KMS. Default timings are for the
4162 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
4163 Requires vc4-kms-v3d to be loaded.
4164 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
4165 Params: clock-frequency Display clock frequency (Hz)
4166 hactive Horizontal active pixels
4167 hfp Horizontal front porch
4168 hsync Horizontal sync pulse width
4169 hbp Horizontal back porch
4170 vactive Vertical active lines
4171 vfp Vertical front porch
4172 vsync Vertical sync pulse width
4173 vbp Vertical back porch
4174 hsync-invert Horizontal sync active low
4175 vsync-invert Vertical sync active low
4176 de-invert Data Enable active low
4177 pixclk-invert Negative edge pixel clock
4178 width-mm Define the screen width in mm
4179 height-mm Define the screen height in mm
4180 rgb565 Change to RGB565 output on GPIOs 0-19
4181 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
4183 bgr666 Change to BGR666 output on GPIOs 0-21.
4184 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
4186 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
4188 bgr888 Change to BGR888 output on GPIOs 0-27
4189 rgb888 Change to RGB888 output on GPIOs 0-27
4190 bus-format Override the bus format for a MEDIA_BUS_FMT_*
4191 value. NB also overridden by rgbXXX overrides.
4192 backlight-gpio Defines a GPIO to be used for backlight control
4194 backlight-pwm Defines a PWM channel to be used for backlight
4195 control (default of none). NB Disables audio
4196 headphone output as that also uses PWM.
4197 backlight-pwm-chan Choose channel on &pwm node for backlight
4200 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4201 pwm-2chan for valid options.
4202 (default 18 - note this can only work with
4204 backlight-pwm-func Pin function of GPIO used for the PWM
4206 See pwm-2chan for valid options.
4208 backlight-def-brightness
4209 Set the default brightness. Normal range 1-16.
4211 rotate Display rotation {0,90,180,270} (default 0)
4214 Name: vc4-kms-dpi-hyperpixel2r
4215 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
4216 Requires vc4-kms-v3d to be loaded.
4217 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
4218 Params: disable-touch Disables the touch controller
4219 touchscreen-inverted-x Inverts X direction of touch controller
4220 touchscreen-inverted-y Inverts Y direction of touch controller
4221 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4222 rotate Display rotation {0,90,180,270} (default 0)
4225 Name: vc4-kms-dpi-hyperpixel4
4226 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
4227 Requires vc4-kms-v3d to be loaded.
4228 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
4229 Params: disable-touch Disables the touch controller
4230 touchscreen-inverted-x Inverts X direction of touch controller
4231 touchscreen-inverted-y Inverts Y direction of touch controller
4232 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4233 rotate Display rotation {0,90,180,270} (default 0)
4236 Name: vc4-kms-dpi-hyperpixel4sq
4237 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4238 Requires vc4-kms-v3d to be loaded.
4239 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4240 Params: disable-touch Disables the touch controller
4241 touchscreen-inverted-x Inverts X direction of touch controller
4242 touchscreen-inverted-y Inverts Y direction of touch controller
4243 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4244 rotate Display rotation {0,90,180,270} (default 0)
4247 Name: vc4-kms-dpi-panel
4248 Info: Enable a preconfigured KMS DPI panel.
4249 Requires vc4-kms-v3d to be loaded.
4250 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4251 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4252 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4253 mzp280 Enable a Geekworm MZP280 panel.
4254 backlight-gpio Defines a GPIO to be used for backlight control
4256 backlight-pwm Defines a PWM channel to be used for backlight
4257 control (default of none). NB Disables audio
4258 headphone output as that also uses PWM.
4259 backlight-pwm-chan Choose channel on &pwm node for backlight
4262 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4263 pwm-2chan for valid options.
4264 (default 18 - note this can only work with
4266 backlight-pwm-func Pin function of GPIO used for the PWM
4268 See pwm-2chan for valid options.
4270 backlight-def-brightness
4271 Set the default brightness. Normal range 1-16.
4273 rotate Display rotation {0,90,180,270} (default 0)
4276 Name: vc4-kms-dsi-7inch
4277 Info: Enable the Raspberry Pi DSI 7" screen.
4278 Includes the edt-ft5406 for the touchscreen element.
4279 Requires vc4-kms-v3d to be loaded.
4280 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4281 Params: sizex Touchscreen size x (default 800)
4282 sizey Touchscreen size y (default 480)
4283 invx Touchscreen inverted x axis
4284 invy Touchscreen inverted y axis
4285 swapxy Touchscreen swapped x y axis
4286 disable_touch Disables the touch screen overlay driver
4289 Name: vc4-kms-dsi-lt070me05000
4290 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4291 Note that this is a 4 lane DSI device, so it will only work on a Compute
4293 Requires vc4-kms-v3d to be loaded.
4294 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4295 Params: reset GPIO for the reset signal (default 17)
4296 enable GPIO for the enable signal (default 4)
4297 dcdc-en GPIO for the DC-DC converter enable (default 5)
4300 Name: vc4-kms-dsi-lt070me05000-v2
4301 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4303 Note that this is a 4 lane DSI device, so it will only work on a Compute
4305 Requires vc4-kms-v3d to be loaded.
4306 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4310 Name: vc4-kms-kippah-7inch
4311 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4316 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4317 Load: dtoverlay=vc4-kms-v3d,<param>
4318 Params: cma-512 CMA is 512MB (needs 1GB)
4319 cma-448 CMA is 448MB (needs 1GB)
4320 cma-384 CMA is 384MB (needs 1GB)
4321 cma-320 CMA is 320MB (needs 1GB)
4322 cma-256 CMA is 256MB (needs 1GB)
4323 cma-192 CMA is 192MB (needs 1GB)
4324 cma-128 CMA is 128MB
4327 cma-size CMA size in bytes, 4MB aligned
4328 cma-default Use upstream's default value
4329 audio Enable or disable audio over HDMI (default "on")
4330 noaudio Disable all HDMI audio (default "off")
4331 composite Enable the composite output (default "off")
4332 N.B. Disables all other outputs on a Pi 4.
4333 nohdmi Disable HDMI output
4336 Name: vc4-kms-v3d-pi4
4337 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4338 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4339 Params: cma-512 CMA is 512MB
4340 cma-448 CMA is 448MB
4341 cma-384 CMA is 384MB
4342 cma-320 CMA is 320MB
4343 cma-256 CMA is 256MB
4344 cma-192 CMA is 192MB
4345 cma-128 CMA is 128MB
4348 cma-size CMA size in bytes, 4MB aligned
4349 cma-default Use upstream's default value
4350 audio Enable or disable audio over HDMI0 (default
4352 audio1 Enable or disable audio over HDMI1 (default
4354 noaudio Disable all HDMI audio (default "off")
4355 composite Enable the composite output (disables all other
4357 nohdmi Disable both HDMI 0 & 1 outputs
4358 nohdmi0 Disable HDMI 0 output
4359 nohdmi1 Disable HDMI 1 output
4363 Name: vc4-kms-vga666
4364 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4365 Requires vc4-kms-v3d to be loaded.
4366 Load: dtoverlay=vc4-kms-vga666,<param>
4367 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4368 from the display. NB These are NOT 5V tolerant
4369 GPIOs, therefore level shifters are required.
4373 Info: Overlay for the Fen Logic VGA666 board
4374 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4375 after the kernel has started.
4376 NOT for use with vc4-kms-v3d.
4377 Load: dtoverlay=vga666
4382 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4383 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4384 set in the EEPROM config.
4385 Load: dtoverlay=vl805
4390 Info: Configures the w1-gpio Onewire interface module.
4391 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4392 Load: dtoverlay=w1-gpio,<param>=<val>
4393 Params: gpiopin GPIO for I/O (default "4")
4394 pullup Now enabled by default (ignored)
4397 Name: w1-gpio-pullup
4398 Info: Configures the w1-gpio Onewire interface module.
4399 Use this overlay if you *do* need a GPIO to drive an external pullup.
4400 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4401 Params: gpiopin GPIO for I/O (default "4")
4402 extpullup GPIO for external pullup (default "5")
4403 pullup Now enabled by default (ignored)
4407 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4408 Load: dtoverlay=w5500,<param>=<val>
4409 Params: int_pin GPIO used for INT (default 25)
4411 speed SPI bus speed (default 30000000)
4413 cs SPI bus Chip Select (default 0)
4416 Name: watterott-display
4417 Info: Watterott RPi-Display - 2.8" Touch Display
4418 Linux has 2 drivers that support this display and this overlay supports
4422 fbtft/fb_ili9341: dtoverlay=watterott-display
4423 drm/mi0283qt: dtoverlay=watterott-display,drm,backlight-pwm,rotate=180
4425 Some notable differences with the DRM driver compared to fbtft:
4426 - The display is turned on when it's first used and not on driver load
4427 as with fbtft. So if nothing uses the display it stays off.
4428 - Can run with a higher SPI clock increasing framerate. This is possible
4429 since the driver avoids messing up the controller configuration due to
4430 transmission errors by running config commands at 10MHz and only pixel
4431 data at full speed (occasional pixel glitch might occur).
4432 - PWM backlight is supported.
4434 Load: dtoverlay=watterott-display,<param>=<val>
4435 Params: speed Display SPI bus speed
4436 rotate Display rotation {0,90,180,270}
4437 fps Delay between frame updates (fbtft only)
4438 debug Debug output level {0-7} (fbtft only)
4439 xohms Touchpanel sensitivity (X-plate resistance)
4440 swapxy Swap x and y axis
4441 backlight Change backlight GPIO pin {e.g. 12, 18}
4443 drm Use DRM/KMS driver mi0283qt instead of fbtft.
4444 Set the SPI clock to 70MHz.
4445 This has to be the first parameter.
4446 backlight-pwm Use pwm for backlight (drm only). NB: Disables
4447 audio headphone output as that also uses PWM.
4450 Name: waveshare-can-fd-hat-mode-a
4451 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4452 for Raspberry Pi, Multi Protections. Use this overlay when the
4453 HAT is configured in Mode A (Default), with can0 on spi0.0
4455 https://www.waveshare.com/2-ch-can-fd-hat.htm
4456 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4460 Name: waveshare-can-fd-hat-mode-b
4461 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4462 for Raspberry Pi, Multi Protections. Use this overlay when the
4463 HAT is configured in Mode B (requires hardware modification), with
4464 can0 on spi0.0 and can1 on spi0.1.
4465 https://www.waveshare.com/2-ch-can-fd-hat.htm
4466 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4471 Info: Configures the wittypi RTC module.
4472 Load: dtoverlay=wittypi,<param>=<val>
4473 Params: led_gpio GPIO for LED (default "17")
4474 led_trigger Choose which activity the LED tracks (default
4478 Name: wm8960-soundcard
4479 Info: Overlay for the Waveshare wm8960 soundcard
4480 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4481 Params: alsaname Changes the card name in ALSA
4482 compatible Changes the codec compatibility
4488 If you are experiencing problems that you think are DT-related, enable DT
4489 diagnostic output by adding this to /boot/config.txt:
4493 and rebooting. Then run:
4497 and look for relevant messages.
4502 This is only meant to be a quick introduction to the subject of Device Tree on
4503 Raspberry Pi. There is a more complete explanation here:
4505 http://www.raspberrypi.org/documentation/configuration/device-tree.md