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 i2c_arm Set to "on" to enable the ARM's i2c interface
196 i2c_vc Set to "on" to enable the i2c interface
197 usually reserved for the VideoCore processor
200 i2c An alias for i2c_arm
202 i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
205 i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
208 i2c_baudrate An alias for i2c_arm_baudrate
210 i2s Set to "on" to enable the i2s interface
213 krnbt Set to "on" to enable autoprobing of Bluetooth
214 driver without need of hciattach/btattach
217 krnbt_baudrate Set the baudrate of the PL011 UART when used
220 spi Set to "on" to enable the spi interfaces
223 spi_dma4 Use to enable 40-bit DMA on spi interfaces
224 (the assigned value doesn't matter)
227 random Set to "on" to enable the hardware random
228 number generator (default "on")
230 sd_overclock Clock (in MHz) to use when the MMC framework
233 sd_poll_once Looks for a card once after booting. Useful
234 for network booting scenarios to avoid the
235 overhead of continuous polling. N.B. Using
236 this option restricts the system to using a
237 single card per boot (or none at all).
240 sd_force_pio Disable DMA support for SD driver (default off)
242 sd_pio_limit Number of blocks above which to use DMA for
245 sd_debug Enable debug output from SD driver (default off)
247 sdio_overclock Clock (in MHz) to use when the MMC framework
248 requests 50MHz for the SDIO/WLAN interface.
250 tx_lpi_timer Set the delay in microseconds between going idle
251 and entering the low power state (default 600).
252 Requires EEE to be enabled - see "eee".
254 uart0 Set to "off" to disable uart0 (default "on")
256 uart1 Set to "on" or "off" to enable or disable uart1
259 watchdog Set to "on" to enable the hardware watchdog
262 act_led_trigger Choose which activity the LED tracks.
263 Use "heartbeat" for a nice load indicator.
266 act_led_activelow Set to "on" to invert the sense of the LED
268 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
271 act_led_gpio Set which GPIO to use for the activity LED
272 (in case you want to connect it to an external
274 (default "16" on a non-Plus board, "47" on a
276 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
282 As for act_led_*, but using the PWR LED.
283 Not available on Model A/B boards.
285 N.B. It is recommended to only enable those interfaces that are needed.
286 Leaving all interfaces enabled can lead to unwanted behaviour (i2c_vc
287 interfering with Pi Camera, I2S and SPI hogging GPIO pins, etc.)
288 Note also that i2c, i2c_arm and i2c_vc are aliases for the physical
289 interfaces i2c0 and i2c1. Use of the numeric variants is still possible
290 but deprecated because the ARM/VC assignments differ between board
291 revisions. The same board-specific mapping applies to i2c_baudrate,
292 and the other i2c baudrate parameters.
296 Info: Pi 3B, 3B+, 3A+ and 4B use a GPIO expander to drive the LEDs which can
297 only be accessed from the VPU. There is a special driver for this with a
298 separate DT node, which has the unfortunate consequence of breaking the
299 act_led_gpio and act_led_activelow dtparams.
300 This overlay changes the GPIO controller back to the standard one and
301 restores the dtparams.
302 Load: dtoverlay=act-led,<param>=<val>
303 Params: activelow Set to "on" to invert the sense of the LED
306 gpio Set which GPIO to use for the activity LED
307 (in case you want to connect it to an external
312 Name: adafruit-st7735r
313 Info: Overlay for the SPI-connected Adafruit 1.8" 160x128 or 128x128 displays,
314 based on the ST7735R chip.
315 This overlay uses the newer DRM/KMS "Tiny" driver.
316 Load: dtoverlay=adafruit-st7735r,<param>=<val>
317 Params: 128x128 Select the 128x128 driver (default 160x128)
318 rotate Display rotation {0,90,180,270} (default 90)
319 speed SPI bus speed in Hz (default 4000000)
320 dc_pin GPIO pin for D/C (default 24)
321 reset_pin GPIO pin for RESET (default 25)
322 led_pin GPIO used to control backlight (default 18)
326 Info: Overlay for the SPI-connected Adafruit 1.8" display (based on the
327 ST7735R chip). It includes support for the "green tab" version.
328 This overlay uses the older fbtft driver.
329 Load: dtoverlay=adafruit18,<param>=<val>
330 Params: green Use the adafruit18_green variant.
331 rotate Display rotation {0,90,180,270}
332 speed SPI bus speed in Hz (default 4000000)
333 fps Display frame rate in Hz
334 bgr Enable BGR mode (default off)
335 debug Debug output level {0-7}
336 dc_pin GPIO pin for D/C (default 24)
337 reset_pin GPIO pin for RESET (default 25)
338 led_pin GPIO used to control backlight (default 18)
342 Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
344 Load: dtoverlay=adau1977-adc
348 Name: adau7002-simple
349 Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter.
350 Load: dtoverlay=adau7002-simple,<param>=<val>
351 Params: card-name Override the default, "adau7002", card name.
355 Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
356 Load: dtoverlay=ads1015,<param>=<val>
357 Params: addr I2C bus address of device. Set based on how the
358 addr pin is wired. (default=0x48 assumes addr
360 cha_enable Enable virtual channel a. (default=true)
361 cha_cfg Set the configuration for virtual channel a.
362 (default=4 configures this channel for the
363 voltage at A0 with respect to GND)
364 cha_datarate Set the datarate (samples/sec) for this channel.
365 (default=4 sets 1600 sps)
366 cha_gain Set the gain of the Programmable Gain
367 Amplifier for this channel. (default=2 sets the
368 full scale of the channel to 2.048 Volts)
370 Channel (ch) parameters can be set for each enabled channel.
371 A maximum of 4 channels can be enabled (letters a thru d).
372 For more information refer to the device datasheet at:
373 http://www.ti.com/lit/ds/symlink/ads1015.pdf
377 Info: Texas Instruments ADS1115 ADC
378 Load: dtoverlay=ads1115,<param>[=<val>]
379 Params: addr I2C bus address of device. Set based on how the
380 addr pin is wired. (default=0x48 assumes addr
382 cha_enable Enable virtual channel a.
383 cha_cfg Set the configuration for virtual channel a.
384 (default=4 configures this channel for the
385 voltage at A0 with respect to GND)
386 cha_datarate Set the datarate (samples/sec) for this channel.
387 (default=7 sets 860 sps)
388 cha_gain Set the gain of the Programmable Gain
389 Amplifier for this channel. (Default 1 sets the
390 full scale of the channel to 4.096 Volts)
392 Channel parameters can be set for each enabled channel.
393 A maximum of 4 channels can be enabled (letters a thru d).
394 For more information refer to the device datasheet at:
395 http://www.ti.com/lit/ds/symlink/ads1115.pdf
399 Info: ADS7846 Touch controller
400 Load: dtoverlay=ads7846,<param>=<val>
401 Params: cs SPI bus Chip Select (default 1)
402 speed SPI bus speed (default 2MHz, max 3.25MHz)
403 penirq GPIO used for PENIRQ. REQUIRED
404 penirq_pull Set GPIO pull (default 0=none, 2=pullup)
405 swapxy Swap x and y axis
406 xmin Minimum value on the X axis (default 0)
407 ymin Minimum value on the Y axis (default 0)
408 xmax Maximum value on the X axis (default 4095)
409 ymax Maximum value on the Y axis (default 4095)
410 pmin Minimum reported pressure value (default 0)
411 pmax Maximum reported pressure value (default 65535)
412 xohms Touchpanel sensitivity (X-plate resistance)
415 penirq is required and usually xohms (60-100) has to be set as well.
416 Apart from that, pmax (255) and swapxy are also common.
417 The rest of the calibration can be done with xinput-calibrator.
418 See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
419 Device Tree binding document:
420 www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
424 Info: Analog Devices ADV7282M analogue video to CSI2 bridge.
425 Uses Unicam1, which is the standard camera connector on most Pi
427 Load: dtoverlay=adv7282m,<param>=<val>
428 Params: addr Overrides the I2C address (default 0x21)
429 media-controller Configure use of Media Controller API for
430 configuring the sensor (default off)
434 Info: Analog Devices ADV728[0|1|2]-M analogue video to CSI2 bridges.
435 This is a wrapper for adv7282m, and defaults to ADV7282M.
436 Load: dtoverlay=adv728x-m,<param>=<val>
437 Params: addr Overrides the I2C address (default 0x21)
438 adv7280m Select ADV7280-M.
439 adv7281m Select ADV7281-M.
440 adv7281ma Select ADV7281-MA.
441 media-controller Configure use of Media Controller API for
442 configuring the sensor (default off)
445 Name: akkordion-iqdacplus
446 Info: Configures the Digital Dreamtime Akkordion Music Player (based on the
447 OEM IQAudIO DAC+ or DAC Zero module).
448 Load: dtoverlay=akkordion-iqdacplus,<param>=<val>
449 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
450 Digital volume control. Enable with
451 dtoverlay=akkordion-iqdacplus,24db_digital_gain
452 (The default behaviour is that the Digital
453 volume control is limited to a maximum of
454 0dB. ie. it can attenuate but not provide
455 gain. For most users, this will be desired
456 as it will prevent clipping. By appending
457 the 24db_digital_gain parameter, the Digital
458 volume control will allow up to 24dB of
459 gain. If this parameter is enabled, it is the
460 responsibility of the user to ensure that
461 the Digital volume control is set to a value
462 that does not result in clipping/distortion!)
465 Name: allo-boss-dac-pcm512x-audio
466 Info: Configures the Allo Boss DAC audio cards.
467 Load: dtoverlay=allo-boss-dac-pcm512x-audio,<param>
468 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
469 Digital volume control. Enable with
470 "dtoverlay=allo-boss-dac-pcm512x-audio,
472 (The default behaviour is that the Digital
473 volume control is limited to a maximum of
474 0dB. ie. it can attenuate but not provide
475 gain. For most users, this will be desired
476 as it will prevent clipping. By appending
477 the 24db_digital_gain parameter, the Digital
478 volume control will allow up to 24dB of
479 gain. If this parameter is enabled, it is the
480 responsibility of the user to ensure that
481 the Digital volume control is set to a value
482 that does not result in clipping/distortion!)
483 slave Force Boss DAC into slave mode, using Pi a
484 master for bit clock and frame clock. Enable
485 with "dtoverlay=allo-boss-dac-pcm512x-audio,
489 Name: allo-boss2-dac-audio
490 Info: Configures the Allo Boss2 DAC audio card
491 Load: dtoverlay=allo-boss2-dac-audio
496 Info: Configures the Allo Digione audio card
497 Load: dtoverlay=allo-digione
501 Name: allo-katana-dac-audio
502 Info: Configures the Allo Katana DAC audio card
503 Load: dtoverlay=allo-katana-dac-audio
507 Name: allo-piano-dac-pcm512x-audio
508 Info: Configures the Allo Piano DAC (2.0/2.1) audio cards.
509 (NB. This initial support is for 2.0 channel audio ONLY! ie. stereo.
510 The subwoofer outputs on the Piano 2.1 are not currently supported!)
511 Load: dtoverlay=allo-piano-dac-pcm512x-audio,<param>
512 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
513 Digital volume control.
514 (The default behaviour is that the Digital
515 volume control is limited to a maximum of
516 0dB. ie. it can attenuate but not provide
517 gain. For most users, this will be desired
518 as it will prevent clipping. By appending
519 the 24db_digital_gain parameter, the Digital
520 volume control will allow up to 24dB of
521 gain. If this parameter is enabled, it is the
522 responsibility of the user to ensure that
523 the Digital volume control is set to a value
524 that does not result in clipping/distortion!)
527 Name: allo-piano-dac-plus-pcm512x-audio
528 Info: Configures the Allo Piano DAC (2.1) audio cards.
529 Load: dtoverlay=allo-piano-dac-plus-pcm512x-audio,<param>
530 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
531 Digital volume control.
532 (The default behaviour is that the Digital
533 volume control is limited to a maximum of
534 0dB. ie. it can attenuate but not provide
535 gain. For most users, this will be desired
536 as it will prevent clipping. By appending
537 the 24db_digital_gain parameter, the Digital
538 volume control will allow up to 24dB of
539 gain. If this parameter is enabled, it is the
540 responsibility of the user to ensure that
541 the Digital volume control is set to a value
542 that does not result in clipping/distortion!)
543 glb_mclk This option is only with Kali board. If enabled,
544 MCLK for Kali is used and PLL is disabled for
545 better voice quality. (default Off)
549 Info: Universal device tree overlay for SPI devices
551 Just specify the SPI address and device name ("compatible" property).
552 This overlay lacks any device-specific parameter support!
554 For devices on spi1 or spi2, the interfaces should be enabled
555 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
558 1. SPI NOR flash on spi0.1, maximum SPI clock frequency 45MHz:
559 dtoverlay=anyspi:spi0-1,dev="jedec,spi-nor",speed=45000000
560 2. MCP3204 ADC on spi1.2, maximum SPI clock frequency 500kHz:
561 dtoverlay=anyspi:spi1-2,dev="microchip,mcp3204"
562 Load: dtoverlay=anyspi,<param>=<val>
563 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
565 dev Set device name to search compatible module
567 speed Set SPI clock frequency in Hz
568 (integer, optional, default 500000)
572 Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and
574 Load: dtoverlay=apds9960,<param>=<val>
575 Params: gpiopin GPIO used for INT (default 4)
576 noints Disable the interrupt GPIO line.
580 Info: Configures the Orchard Audio ApplePi-DAC audio card
581 Load: dtoverlay=applepi-dac
586 Info: Arducam 64MP camera module.
587 Uses Unicam 1, which is the standard camera connector on most Pi
589 Load: dtoverlay=arducam-64mp,<param>=<val>
590 Params: rotation Mounting rotation of the camera sensor (0 or
592 orientation Sensor orientation (0 = front, 1 = rear,
593 2 = external, default external)
594 media-controller Configure use of Media Controller API for
595 configuring the sensor (default on)
596 cam0 Adopt the default configuration for CAM0 on a
597 Compute Module (CSI0, i2c_vc, and cam0_reg).
600 Name: arducam-pivariety
601 Info: Arducam Pivariety camera module.
602 Uses Unicam 1, which is the standard camera connector on most Pi
604 Load: dtoverlay=arducam-pivariety,<param>=<val>
605 Params: rotation Mounting rotation of the camera sensor (0 or
607 orientation Sensor orientation (0 = front, 1 = rear,
608 2 = external, default external)
609 media-controller Configure use of Media Controller API for
610 configuring the sensor (default on)
611 cam0 Adopt the default configuration for CAM0 on a
612 Compute Module (CSI0, i2c_vc, and cam0_reg).
616 Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
618 Load: dtoverlay=at86rf233,<param>=<val>
619 Params: interrupt GPIO used for INT (default 23)
620 reset GPIO used for Reset (default 24)
621 sleep GPIO used for Sleep (default 25)
622 speed SPI bus speed in Hz (default 3000000)
623 trim Fine tuning of the internal capacitance
624 arrays (0=+0pF, 15=+4.5pF, default 15)
627 Name: audioinjector-addons
628 Info: Configures the audioinjector.net audio add on soundcards
629 Load: dtoverlay=audioinjector-addons,<param>=<val>
630 Params: non-stop-clocks Keeps the clocks running even when the stream
631 is paused or stopped (default off)
634 Name: audioinjector-bare-i2s
635 Info: Configures the audioinjector.net audio bare i2s soundcard
636 Load: dtoverlay=audioinjector-bare-i2s
640 Name: audioinjector-isolated-soundcard
641 Info: Configures the audioinjector.net isolated soundcard
642 Load: dtoverlay=audioinjector-isolated-soundcard
646 Name: audioinjector-ultra
647 Info: Configures the audioinjector.net ultra soundcard
648 Load: dtoverlay=audioinjector-ultra
652 Name: audioinjector-wm8731-audio
653 Info: Configures the audioinjector.net audio add on soundcard
654 Load: dtoverlay=audioinjector-wm8731-audio
659 Info: Configures the audiosense-pi add on soundcard
660 For more information refer to
661 https://gitlab.com/kakar0t/audiosense-pi
662 Load: dtoverlay=audiosense-pi
667 Info: Switches PWM sound output to GPIOs on the 40-pin header
668 Load: dtoverlay=audremap,<param>=<val>
669 Params: swap_lr Reverse the channel allocation, which will also
670 swap the audio jack outputs (default off)
671 enable_jack Don't switch off the audio jack output
673 pins_12_13 Select GPIOs 12 & 13 (default)
674 pins_18_19 Select GPIOs 18 & 19
678 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
679 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
680 Load: dtoverlay=balena-fin
684 Name: bmp085_i2c-sensor
685 Info: This overlay is now deprecated - see i2c-sensor
690 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
691 Load: dtoverlay=cap1106,<param>=<val>
692 Params: int_pin GPIO pin for interrupt signal (default 23)
696 Info: Configures Chip Dip audio cards.
697 Load: dtoverlay=chipdip-dac
702 Info: Set custom CMA sizes, only use if you know what you are doing, might
703 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
704 Load: dtoverlay=cma,<param>=<val>
705 Params: cma-512 CMA is 512MB (needs 1GB)
706 cma-448 CMA is 448MB (needs 1GB)
707 cma-384 CMA is 384MB (needs 1GB)
708 cma-320 CMA is 320MB (needs 1GB)
709 cma-256 CMA is 256MB (needs 1GB)
710 cma-192 CMA is 192MB (needs 1GB)
714 cma-size CMA size in bytes, 4MB aligned
715 cma-default Use upstream's default value
719 Info: 8" TFT LCD display and touch panel used by cutiepi.io
720 Load: dtoverlay=cutiepi-panel
725 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
726 Also sometimes found with the part number(s) AM230x.
727 Load: dtoverlay=dht11,<param>=<val>
728 Params: gpiopin GPIO connected to the sensor's DATA output.
733 Info: Configures the Dion Audio KIWI STREAMER
734 Load: dtoverlay=dionaudio-kiwi
739 Info: Configures the Dion Audio LOCO DAC-AMP
740 Load: dtoverlay=dionaudio-loco
744 Name: dionaudio-loco-v2
745 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
746 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
747 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
748 Digital volume control. Enable with
749 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
750 (The default behaviour is that the Digital
751 volume control is limited to a maximum of
752 0dB. ie. it can attenuate but not provide
753 gain. For most users, this will be desired
754 as it will prevent clipping. By appending
755 the 24dB_digital_gain parameter, the Digital
756 volume control will allow up to 24dB of
757 gain. If this parameter is enabled, it is the
758 responsibility of the user to ensure that
759 the Digital volume control is set to a value
760 that does not result in clipping/distortion!)
764 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
765 UART0/ttyAMA0 over GPIOs 14 & 15.
766 N.B. To disable the systemd service that initialises the modem so it
767 doesn't use the UART, use 'sudo systemctl disable hciuart'.
768 Load: dtoverlay=disable-bt
773 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
774 Load: dtoverlay=disable-wifi
779 Info: Overlay for a generic 18-bit DPI display
780 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
781 2-3 seconds after the kernel has started.
782 Load: dtoverlay=dpi18
787 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
788 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
789 the output 3-3 seconds after the kernel has started.
790 Load: dtoverlay=dpi18cpadhi
795 Info: Overlay for a generic 24-bit DPI display
796 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
797 2-3 seconds after the kernel has started.
798 Load: dtoverlay=dpi24
803 Info: Configures the NW Digital Radio DRAWS Hat
805 The board includes an ADC to measure various board values and also
806 provides two analog user inputs on the expansion header. The ADC
807 can be configured for various sample rates and gain values to adjust
808 the input range. Tables describing the two parameters follow.
825 4 = 1600sps (default)
829 Load: dtoverlay=draws,<param>=<val>
830 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
831 input voltage sensor (default 1)
833 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
836 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
837 5V rail voltage sensor (default 1)
839 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
842 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
843 AIN2 input (default 2)
845 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
847 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
848 AIN3 input (default 2)
850 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
852 alsaname Name of the ALSA audio device (default "draws")
856 Info: Selects the dwc_otg USB controller driver which has fiq support. This
857 is the default on all except the Pi Zero which defaults to dwc2.
858 Load: dtoverlay=dwc-otg
863 Info: Selects the dwc2 USB controller driver
864 Load: dtoverlay=dwc2,<param>=<val>
865 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
867 g-rx-fifo-size Size of rx fifo size in gadget mode
869 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
873 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
877 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
878 This works with the Raspberry Pi 7" touchscreen when not being polled
880 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
881 config.txt to stop the firmware polling the touchscreen.
882 Load: dtoverlay=edt-ft5406,<param>=<val>
883 Params: sizex Touchscreen size x (default 800)
884 sizey Touchscreen size y (default 480)
885 invx Touchscreen inverted x axis
886 invy Touchscreen inverted y axis
887 swapxy Touchscreen swapped x y axis
891 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
892 Load: dtoverlay=enc28j60,<param>=<val>
893 Params: int_pin GPIO used for INT (default 25)
895 speed SPI bus speed (default 12000000)
899 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
900 Load: dtoverlay=enc28j60-spi2,<param>=<val>
901 Params: int_pin GPIO used for INT (default 39)
903 speed SPI bus speed (default 12000000)
907 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
908 GPIO 4 (pin 7 on GPIO header) for interrupt.
909 Load: dtoverlay=exc3000,<param>=<val>
910 Params: interrupt GPIO used for interrupt (default 4)
911 sizex Touchscreen size x (default 4096)
912 sizey Touchscreen size y (default 4096)
913 invx Touchscreen inverted x axis
914 invy Touchscreen inverted y axis
915 swapxy Touchscreen swapped x y axis
919 Info: Overlay for SPI-connected displays using the fbtft drivers.
921 This overlay seeks to replace the functionality provided by fbtft_device
922 which is now gone from the kernel.
924 Most displays from fbtft_device have been ported over.
926 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
928 It is also possible to specify the controller (this will use the default
929 init sequence in the driver).
931 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
933 For devices on spi1 or spi2, the interfaces should be enabled
934 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
936 The following features of fbtft_device have not been ported over:
937 - parallel bus is not supported
938 - the init property which overrides the controller initialization
939 sequence is not supported as a parameter due to memory limitations in
940 the bootloader responsible for applying the overlay.
942 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
945 Load: dtoverlay=fbtft,<param>=<val>
947 spi<n>-<m> Configure device at spi<n>, cs<m>
949 speed SPI bus speed in Hz (default 32000000)
950 cpha Shifted clock phase (CPHA) mode
951 cpol Inverse clock polarity (CPOL) mode
953 adafruit18 Adafruit 1.8
954 adafruit22 Adafruit 2.2 (old)
955 adafruit22a Adafruit 2.2
956 adafruit28 Adafruit 2.8
957 adafruit13m Adafruit 1.3 OLED
958 admatec_c-berry28 C-Berry28
960 er_tftm050_2 ER-TFTM070-2
961 er_tftm070_5 ER-TFTM070-5
963 ew24ha0_9bit EW24HA0 in 9-bit mode
964 freetronicsoled128 Freetronics OLED128
967 itdb28_spi ITDB02-2.8 with SPI interface circuit
968 mi0283qt-2 Watterott MI0283QT-2
969 mi0283qt-9a Watterott MI0283QT-9A
971 nokia3310a Nokia 3310a
974 pitft Adafruit PiTFT 2.8
976 rpi-display Watterott rpi-display
977 sainsmart18 Sainsmart 1.8
978 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
979 tinylcd35 TinyLCD 3.5
980 tm022hdh26 Tianma TM022HDH26
981 tontec35_9481 Tontect 3.5 with ILI9481 controller
982 tontec35_9486 Tontect 3.5 with ILI9486 controller
983 waveshare32b Waveshare 3.2
984 waveshare22 Waveshare 2.2
986 bd663474 BD663474 display controller
987 hx8340bn HX8340BN display controller
988 hx8347d HX8347D display controller
989 hx8353d HX8353D display controller
990 hx8357d HX8357D display controller
991 ili9163 ILI9163 display controller
992 ili9320 ILI9320 display controller
993 ili9325 ILI9325 display controller
994 ili9340 ILI9340 display controller
995 ili9341 ILI9341 display controller
996 ili9481 ILI9481 display controller
997 ili9486 ILI9486 display controller
998 pcd8544 PCD8544 display controller
999 ra8875 RA8875 display controller
1000 s6d02a1 S6D02A1 display controller
1001 s6d1121 S6D1121 display controller
1002 seps525 SEPS525 display controller
1003 sh1106 SH1106 display controller
1004 ssd1289 SSD1289 display controller
1005 ssd1305 SSD1305 display controller
1006 ssd1306 SSD1306 display controller
1007 ssd1325 SSD1325 display controller
1008 ssd1331 SSD1331 display controller
1009 ssd1351 SSD1351 display controller
1010 st7735r ST7735R display controller
1011 st7789v ST7789V display controller
1012 tls8204 TLS8204 display controller
1013 uc1611 UC1611 display controller
1014 uc1701 UC1701 display controller
1015 upd161704 UPD161704 display controller
1017 width Display width in pixels
1018 height Display height in pixels
1019 regwidth Display controller register width (default is
1021 buswidth Display bus interface width (default 8)
1022 debug Debug output level {0-7}
1023 rotate Display rotation {0, 90, 180, 270} (counter
1024 clockwise). Not supported by all drivers.
1025 bgr Enable BGR mode (default off). Use if Red and
1026 Blue are swapped. Not supported by all drivers.
1027 fps Frames per second (default 30). In effect this
1028 states how long the driver will wait after video
1029 memory has been changed until display update
1030 transfer is started.
1031 txbuflen Length of the FBTFT transmit buffer
1033 startbyte Sets the Start byte used by fb_ili9320,
1034 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1035 gamma String representation of Gamma Curve(s). Driver
1036 specific. Not supported by all drivers.
1037 reset_pin GPIO pin for RESET
1038 dc_pin GPIO pin for D/C
1039 led_pin GPIO pin for LED backlight
1043 Info: Configures the Fe-Pi Audio Sound Card
1044 Load: dtoverlay=fe-pi-audio
1049 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1050 nicely with a "traffic-light" display of red, amber and green LEDs on
1051 GPIOs 7, 8 and 25 respectively.
1052 Load: dtoverlay=fsm-demo,<param>=<val>
1053 Params: fsm_debug Enable debug logging (default off)
1057 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on
1058 SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical
1059 GPIO header pins 22, 13 and 12 respectively) in addition to the
1060 SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19,
1061 23 and 24 respectively).
1062 Load: dtoverlay=gc9a01,<param>=<val>
1063 Params: speed Display SPI bus speed
1065 rotate Display rotation {0,90,180,270}
1067 width Width of the display
1069 height Height of the display
1071 fps Delay between frame updates
1073 debug Debug output level {0-7}
1077 Info: An overlay for the Ghost amplifier.
1078 Load: dtoverlay=ghost-amp,<param>=<val>
1079 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1084 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1085 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1086 Load: dtoverlay=goodix,<param>=<val>
1087 Params: interrupt GPIO used for interrupt (default 4)
1088 reset GPIO used for reset (default 17)
1091 Name: googlevoicehat-soundcard
1092 Info: Configures the Google voiceHAT soundcard
1093 Load: dtoverlay=googlevoicehat-soundcard
1098 Info: Configure a GPIO pin to control a cooling fan.
1099 Load: dtoverlay=gpio-fan,<param>=<val>
1100 Params: gpiopin GPIO used to control the fan (default 12)
1101 temp Temperature at which the fan switches on, in
1102 millicelcius (default 55000)
1106 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1107 an output, driven low or high as indicated by the presence or absence
1108 of the active_low parameter. Note that a hogged GPIO is not available
1109 to other drivers or for gpioset/gpioget.
1110 Load: dtoverlay=gpio-hog,<param>=<val>
1111 Params: gpio GPIO pin to hog (default 26)
1112 active_low If set, the hog drives the GPIO low (defaults
1113 to off - the GPIO is driven high)
1117 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1118 based gpio_ir_recv driver maps received keys directly to a
1119 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1120 not required! The key mapping and other decoding parameters can be
1121 configured by "ir-keytable" tool.
1122 Load: dtoverlay=gpio-ir,<param>=<val>
1123 Params: gpio_pin Input pin number. Default is 18.
1125 gpio_pull Desired pull-up/down state (off, down, up)
1128 invert "1" = invert the input (active-low signalling).
1129 "0" = non-inverted input (active-high
1130 signalling). Default is "1".
1132 rc-map-name Default rc keymap (can also be changed by
1133 ir-keytable), defaults to "rc-rc6-mce"
1137 Info: Use GPIO pin as bit-banged infrared transmitter output.
1138 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1139 a PWM so it can be used together with onboard analog audio.
1140 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1141 Params: gpio_pin Output GPIO (default 18)
1143 invert "1" = invert the output (make it active-low).
1144 Default is "0" (active-high).
1148 Info: This is a generic overlay for activating GPIO keypresses using
1149 the gpio-keys library and this dtoverlay. Multiple keys can be
1150 set up using multiple calls to the overlay for configuring
1151 additional buttons or joysticks. You can see available keycodes
1152 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1153 linux/input-event-codes.h#L64
1154 Load: dtoverlay=gpio-key,<param>=<val>
1155 Params: gpio GPIO pin to trigger on (default 3)
1156 active_low When this is 1 (active low), a falling
1157 edge generates a key down event and a
1158 rising edge generates a key up event.
1159 When this is 0 (active high), this is
1160 reversed. The default is 1 (active low)
1161 gpio_pull Desired pull-up/down state (off, down, up)
1162 Default is "up". Note that the default pin
1163 (GPIO3) has an external pullup
1164 label Set a label for the key
1165 keycode Set the key code for the button
1170 Info: This is a generic overlay for activating LEDs (or any other component)
1171 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1172 overlay. While there are many existing methods to activate LEDs on the
1173 RPi, this method offers some advantages:
1174 1) Does not require any userspace programs.
1175 2) LEDs can be connected to the kernel's led-trigger framework,
1176 and drive the LED based on triggers such as cpu load, heartbeat,
1177 kernel panic, key input, timers and others.
1178 3) LED can be tied to the input state of another GPIO pin.
1179 4) The LED is setup early during the kernel boot process (useful
1180 for cpu/heartbeat/panic triggers).
1182 Typical electrical connection is:
1183 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1184 The GPIO pin number can be changed with the 'gpio=' parameter.
1186 To control an LED from userspace, write a 0 or 1 value:
1187 echo 1 > /sys/class/leds/myled1/brightness
1188 The 'myled1' name can be changed with the 'label=' parameter.
1190 To connect the LED to a kernel trigger from userspace:
1191 echo cpu > /sys/class/leds/myled1/trigger
1192 echo heartbeat > /sys/class/leds/myled1/trigger
1193 echo none > /sys/class/leds/myled1/trigger
1194 To connect the LED to GPIO.26 pin (physical pin 37):
1195 echo gpio > /sys/class/leds/myled1/trigger
1196 echo 26 > /sys/class/leds/myled1/gpio
1198 cat /sys/class/leds/myled1/trigger
1200 More information about the Linux kernel LED/Trigger system:
1201 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1202 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1203 Load: dtoverlay=gpio-led,<param>=<val>
1204 Params: gpio GPIO pin connected to the LED (default 19)
1205 label The label for this LED. It will appear under
1206 /sys/class/leds/<label> . Default 'myled1'.
1207 trigger Set the led-trigger to connect to this LED.
1208 default 'none' (LED is user-controlled).
1209 Some possible triggers:
1210 cpu - CPU load (all CPUs)
1211 cpu0 - CPU load of first CPU.
1212 mmc - disk activity (all disks)
1213 panic - turn on on kernel panic
1214 heartbeat - indicate system health
1215 gpio - connect to a GPIO input pin (note:
1216 currently the GPIO PIN can not be set
1217 using overlay parameters, must be
1218 done in userspace, see examples above.
1219 active_low Set to 1 to turn invert the LED control
1220 (writing 0 to /sys/class/leds/XXX/brightness
1221 will turn on the GPIO/LED). Default '0'.
1224 Name: gpio-no-bank0-irq
1225 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1226 which can be useful for UIO drivers.
1227 N.B. Using this overlay will trigger a kernel WARN during booting, but
1228 this can safely be ignored - the system should work as expected.
1229 Load: dtoverlay=gpio-no-bank0-irq
1234 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1235 for user-space GPIO edge detection systems.
1236 Load: dtoverlay=gpio-no-irq
1241 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1242 overlay interferes with the normal power-down sequence, preventing the
1243 kernel from resetting the SoC (a necessary step in a normal power-off
1244 or reboot). This also disables the ability to trigger a boot by driving
1247 The GPIO starts in an inactive state. At poweroff time it is driven
1248 active for 100ms, then inactive for 100ms, then active again. It is
1249 safe to remove the power at any point after the initial activation of
1252 Users of this overlay are required to provide an external mechanism to
1253 switch off the power supply when signalled - failure to do so results
1254 in a kernel BUG, increased power consumption and undefined behaviour.
1255 Load: dtoverlay=gpio-poweroff,<param>=<val>
1256 Params: gpiopin GPIO for signalling (default 26)
1258 active_low Set if the power control device requires a
1259 high->low transition to trigger a power-down.
1260 Note that this will require the support of a
1261 custom dt-blob.bin to prevent a power-down
1262 during the boot process, and that a reboot
1263 will also cause the pin to go low.
1264 input Set if the gpio pin should be configured as
1266 export Set to export the configured pin to sysfs
1267 active_delay_ms Initial GPIO active period (default 100)
1268 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1269 timeout_ms Specify (in ms) how long the kernel waits for
1270 power-down before issuing a WARN (default 3000).
1274 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1275 is configured as an input key that generates KEY_POWER events.
1277 This event is handled by systemd-logind by initiating a
1278 shutdown. Systemd versions older than 225 need an udev rule
1279 enable listening to the input device:
1281 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1282 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1283 ATTRS{keys}=="116", TAG+="power-switch"
1285 Alternatively this event can be handled also on systems without
1286 systemd, just by traditional SysV init daemon. KEY_POWER event
1287 (keycode 116) needs to be mapped to KeyboardSignal on console
1288 and then kb::kbrequest inittab action which is triggered by
1289 KeyboardSignal from console can be configured to issue system
1290 shutdown. Steps for this configuration are:
1292 Add following lines to the /etc/console-setup/remap.inc file:
1294 # Key Power as special keypress
1295 keycode 116 = KeyboardSignal
1297 Then add following lines to /etc/inittab file:
1299 # Action on special keypress (Key Power)
1300 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1302 And finally reload configuration by calling following commands:
1304 # dpkg-reconfigure console-setup
1305 # service console-setup reload
1308 This overlay only handles shutdown. After shutdown, the system
1309 can be powered up again by driving GPIO3 low. The default
1310 configuration uses GPIO3 with a pullup, so if you connect a
1311 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1312 you get a shutdown and power-up button. Please note that
1313 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1314 Load: dtoverlay=gpio-shutdown,<param>=<val>
1315 Params: gpio_pin GPIO pin to trigger on (default 3)
1316 For Raspberry Pi 1 Model B rev 1 set this
1317 explicitly to value 1, e.g.:
1319 dtoverlay=gpio-shutdown,gpio_pin=1
1321 active_low When this is 1 (active low), a falling
1322 edge generates a key down event and a
1323 rising edge generates a key up event.
1324 When this is 0 (active high), this is
1325 reversed. The default is 1 (active low).
1327 gpio_pull Desired pull-up/down state (off, down, up)
1330 Note that the default pin (GPIO3) has an
1331 external pullup. Same applies for GPIO1
1332 on Raspberry Pi 1 Model B rev 1.
1334 debounce Specify the debounce interval in milliseconds
1339 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1340 data, 2 gpio pins for enable and register select and 1 optional pin
1341 for enabling/disabling the backlight display.
1342 Load: dtoverlay=hd44780-lcd,<param>=<val>
1343 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1345 pin_d5 GPIO pin for data pin D5 (default 13)
1347 pin_d6 GPIO pin for data pin D6 (default 19)
1349 pin_d7 GPIO pin for data pin D7 (default 26)
1351 pin_en GPIO pin for "Enable" (default 21)
1353 pin_rs GPIO pin for "Register Select" (default 20)
1355 pin_bl Optional pin for enabling/disabling the
1356 display backlight. (default disabled)
1358 display_height Height of the display in characters
1360 display_width Width of the display in characters
1363 Name: hdmi-backlight-hwhack-gpio
1364 Info: Devicetree overlay for GPIO based backlight on/off capability.
1365 Use this if you have one of those HDMI displays whose backlight cannot
1366 be controlled via DPMS over HDMI and plan to do a little soldering to
1367 use an RPi gpio pin for on/off switching. See:
1368 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1369 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1370 Params: gpio_pin GPIO pin used (default 17)
1371 active_low Set this to 1 if the display backlight is
1372 switched on when the wire goes low.
1373 Leave the default (value 0) if the backlight
1374 expects a high to switch it on.
1378 Info: Configures the HifiBerry Amp and Amp+ audio cards
1379 Load: dtoverlay=hifiberry-amp
1383 Name: hifiberry-amp100
1384 Info: Configures the HifiBerry AMP100 audio card
1385 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1386 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1387 Digital volume control. Enable with
1388 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1389 (The default behaviour is that the Digital
1390 volume control is limited to a maximum of
1391 0dB. ie. it can attenuate but not provide
1392 gain. For most users, this will be desired
1393 as it will prevent clipping. By appending
1394 the 24dB_digital_gain parameter, the Digital
1395 volume control will allow up to 24dB of
1396 gain. If this parameter is enabled, it is the
1397 responsibility of the user to ensure that
1398 the Digital volume control is set to a value
1399 that does not result in clipping/distortion!)
1400 slave Force DAC+ Pro into slave mode, using Pi as
1401 master for bit clock and frame clock.
1402 leds_off If set to 'true' the onboard indicator LEDs
1403 are switched off at all times.
1404 auto_mute If set to 'true' the amplifier is automatically
1405 muted when the DAC is not playing.
1406 mute_ext_ctl The amplifier's HW mute control is enabled
1407 in ALSA mixer and set to <val>.
1408 Will be overwritten by ALSA user settings.
1412 Info: Configures the HifiBerry DAC audio cards
1413 Load: dtoverlay=hifiberry-dac
1417 Name: hifiberry-dacplus
1418 Info: Configures the HifiBerry DAC+ audio card
1419 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1420 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1421 Digital volume control. Enable with
1422 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1423 (The default behaviour is that the Digital
1424 volume control is limited to a maximum of
1425 0dB. ie. it can attenuate but not provide
1426 gain. For most users, this will be desired
1427 as it will prevent clipping. By appending
1428 the 24dB_digital_gain parameter, the Digital
1429 volume control will allow up to 24dB of
1430 gain. If this parameter is enabled, it is the
1431 responsibility of the user to ensure that
1432 the Digital volume control is set to a value
1433 that does not result in clipping/distortion!)
1434 slave Force DAC+ Pro into slave mode, using Pi as
1435 master for bit clock and frame clock.
1436 leds_off If set to 'true' the onboard indicator LEDs
1437 are switched off at all times.
1440 Name: hifiberry-dacplusadc
1441 Info: Configures the HifiBerry DAC+ADC audio card
1442 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1443 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1444 Digital volume control. Enable with
1445 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1446 (The default behaviour is that the Digital
1447 volume control is limited to a maximum of
1448 0dB. ie. it can attenuate but not provide
1449 gain. For most users, this will be desired
1450 as it will prevent clipping. By appending
1451 the 24dB_digital_gain parameter, the Digital
1452 volume control will allow up to 24dB of
1453 gain. If this parameter is enabled, it is the
1454 responsibility of the user to ensure that
1455 the Digital volume control is set to a value
1456 that does not result in clipping/distortion!)
1457 slave Force DAC+ Pro into slave mode, using Pi as
1458 master for bit clock and frame clock.
1459 leds_off If set to 'true' the onboard indicator LEDs
1460 are switched off at all times.
1463 Name: hifiberry-dacplusadcpro
1464 Info: Configures the HifiBerry DAC+ADC PRO audio card
1465 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1466 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1467 Digital volume control. Enable with
1468 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1469 (The default behaviour is that the Digital
1470 volume control is limited to a maximum of
1471 0dB. ie. it can attenuate but not provide
1472 gain. For most users, this will be desired
1473 as it will prevent clipping. By appending
1474 the 24dB_digital_gain parameter, the Digital
1475 volume control will allow up to 24dB of
1476 gain. If this parameter is enabled, it is the
1477 responsibility of the user to ensure that
1478 the Digital volume control is set to a value
1479 that does not result in clipping/distortion!)
1480 slave Force DAC+ADC Pro into slave mode, using Pi as
1481 master for bit clock and frame clock.
1482 leds_off If set to 'true' the onboard indicator LEDs
1483 are switched off at all times.
1486 Name: hifiberry-dacplusdsp
1487 Info: Configures the HifiBerry DAC+DSP audio card
1488 Load: dtoverlay=hifiberry-dacplusdsp
1492 Name: hifiberry-dacplushd
1493 Info: Configures the HifiBerry DAC+ HD audio card
1494 Load: dtoverlay=hifiberry-dacplushd
1498 Name: hifiberry-digi
1499 Info: Configures the HifiBerry Digi and Digi+ audio card
1500 Load: dtoverlay=hifiberry-digi
1504 Name: hifiberry-digi-pro
1505 Info: Configures the HifiBerry Digi+ Pro audio card
1506 Load: dtoverlay=hifiberry-digi-pro
1511 Info: Enables "High Peripheral" mode
1512 Load: dtoverlay=highperi
1517 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1518 Default values match Texy's display shield
1519 Load: dtoverlay=hy28a,<param>=<val>
1520 Params: speed Display SPI bus speed
1522 rotate Display rotation {0,90,180,270}
1524 fps Delay between frame updates
1526 debug Debug output level {0-7}
1528 xohms Touchpanel sensitivity (X-plate resistance)
1530 resetgpio GPIO used to reset controller
1532 ledgpio GPIO used to control backlight
1536 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1537 Default values match Texy's display shield
1538 Load: dtoverlay=hy28b,<param>=<val>
1539 Params: speed Display SPI bus speed
1541 rotate Display rotation {0,90,180,270}
1543 fps Delay between frame updates
1545 debug Debug output level {0-7}
1547 xohms Touchpanel sensitivity (X-plate resistance)
1549 resetgpio GPIO used to reset controller
1551 ledgpio GPIO used to control backlight
1555 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1556 Default values match Texy's display shield
1557 Load: dtoverlay=hy28b-2017,<param>=<val>
1558 Params: speed Display SPI bus speed
1560 rotate Display rotation {0,90,180,270}
1562 fps Delay between frame updates
1564 debug Debug output level {0-7}
1566 xohms Touchpanel sensitivity (X-plate resistance)
1568 resetgpio GPIO used to reset controller
1570 ledgpio GPIO used to control backlight
1574 Info: Configures the Audiophonics I-SABRE Q2M DAC
1575 Load: dtoverlay=i-sabre-q2m
1580 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1581 Load: dtoverlay=i2c-bcm2708
1586 Info: Adds support for a number of I2C fan controllers
1587 Load: dtoverlay=i2c-fan,<param>=<val>
1588 Params: addr Sets the address for the fan controller. Note
1589 that the device must be configured to use the
1592 i2c0 Choose the I2C0 bus on GPIOs 0&1
1594 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1596 i2c3 Choose the I2C3 bus (configure with the i2c3
1597 overlay - BCM2711 only)
1599 i2c4 Choose the I2C3 bus (configure with the i2c3
1600 overlay - BCM2711 only)
1602 i2c5 Choose the I2C5 bus (configure with the i2c4
1603 overlay - BCM2711 only)
1605 i2c6 Choose the I2C6 bus (configure with the i2c6
1606 overlay - BCM2711 only)
1608 minpwm PWM setting for the fan when the SoC is below
1609 mintemp (range 0-255. default 0)
1610 maxpwm PWM setting for the fan when the SoC is above
1611 maxtemp (range 0-255. default 255)
1612 midtemp Temperature (in millicelcius) at which the fan
1613 begins to speed up (default 50000)
1615 midtemp_hyst Temperature delta (in millicelcius) below
1616 mintemp at which the fan will drop to minrpm
1619 maxtemp Temperature (in millicelcius) at which the fan
1620 will be held at maxrpm (default 70000)
1622 maxtemp_hyst Temperature delta (in millicelcius) below
1623 maxtemp at which the fan begins to slow down
1626 emc2301 Select the Microchip EMC230x controller family
1627 - EMC2301, EMC2302, EMC2303, EMC2305.
1631 Info: Adds support for software i2c controller on gpio pins
1632 Load: dtoverlay=i2c-gpio,<param>=<val>
1633 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1635 i2c_gpio_scl GPIO used for I2C clock (default "24")
1637 i2c_gpio_delay_us Clock delay in microseconds
1638 (default "2" = ~100kHz)
1640 bus Set to a unique, non-zero value if wanting
1641 multiple i2c-gpio busses. If set, will be used
1642 as the preferred bus number (/dev/i2c-<n>). If
1643 not set, the default value is 0, but the bus
1644 number will be dynamically assigned - probably
1649 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1650 Load: dtoverlay=i2c-mux,<param>=<val>
1651 Params: pca9542 Select the NXP PCA9542 device
1653 pca9545 Select the NXP PCA9545 device
1655 pca9548 Select the NXP PCA9548 device
1657 addr Change I2C address of the device (default 0x70)
1660 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1663 Name: i2c-pwm-pca9685a
1664 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1665 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1666 Params: addr I2C address of PCA9685A (default 0x40)
1670 Info: Adds support for a number of I2C Real Time Clock devices
1671 Load: dtoverlay=i2c-rtc,<param>=<val>
1672 Params: abx80x Select one of the ABx80x family:
1673 AB0801, AB0803, AB0804, AB0805,
1674 AB1801, AB1803, AB1804, AB1805
1676 bq32000 Select the TI BQ32000 device
1678 ds1307 Select the DS1307 device
1680 ds1339 Select the DS1339 device
1682 ds1340 Select the DS1340 device
1684 ds3231 Select the DS3231 device
1686 m41t62 Select the M41T62 device
1688 mcp7940x Select the MCP7940x device
1690 mcp7941x Select the MCP7941x device
1692 pcf2127 Select the PCF2127 device
1694 pcf2129 Select the PCF2129 device
1696 pcf85063 Select the PCF85063 device
1698 pcf85063a Select the PCF85063A device
1700 pcf8523 Select the PCF8523 device
1702 pcf85363 Select the PCF85363 device
1704 pcf8563 Select the PCF8563 device
1706 rv1805 Select the Micro Crystal RV1805 device
1708 rv3028 Select the Micro Crystal RV3028 device
1710 rv8803 Select the Micro Crystal RV8803 device
1712 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1714 s35390a Select the ABLIC S35390A device
1716 i2c0 Choose the I2C0 bus on GPIOs 0&1
1718 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1720 i2c3 Choose the I2C3 bus (configure with the i2c3
1721 overlay - BCM2711 only)
1723 i2c4 Choose the I2C3 bus (configure with the i2c3
1724 overlay - BCM2711 only)
1726 i2c5 Choose the I2C5 bus (configure with the i2c4
1727 overlay - BCM2711 only)
1729 i2c6 Choose the I2C6 bus (configure with the i2c6
1730 overlay - BCM2711 only)
1732 addr Sets the address for the RTC. Note that the
1733 device must be configured to use the specified
1736 trickle-diode-disable Do not use the internal trickle charger diode
1739 trickle-diode-type Diode type for trickle charge - "standard" or
1740 "schottky" (ABx80x and RV1805 only)
1742 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1743 ABx80x, RV1805, RV3028)
1745 wakeup-source Specify that the RTC can be used as a wakeup
1748 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1749 off or 1 for Vdd < VBackup (RV3028 only)
1753 Info: Adds support for a number of I2C Real Time Clock devices
1754 using the software i2c controller
1755 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1756 Params: abx80x Select one of the ABx80x family:
1757 AB0801, AB0803, AB0804, AB0805,
1758 AB1801, AB1803, AB1804, AB1805
1760 bq32000 Select the TI BQ32000 device
1762 ds1307 Select the DS1307 device
1764 ds1339 Select the DS1339 device
1766 ds1340 Select the DS1340 device
1768 ds3231 Select the DS3231 device
1770 m41t62 Select the M41T62 device
1772 mcp7940x Select the MCP7940x device
1774 mcp7941x Select the MCP7941x device
1776 pcf2127 Select the PCF2127 device
1778 pcf2129 Select the PCF2129 device
1780 pcf85063 Select the PCF85063 device
1782 pcf85063a Select the PCF85063A device
1784 pcf8523 Select the PCF8523 device
1786 pcf85363 Select the PCF85363 device
1788 pcf8563 Select the PCF8563 device
1790 rv1805 Select the Micro Crystal RV1805 device
1792 rv3028 Select the Micro Crystal RV3028 device
1794 rv8803 Select the Micro Crystal RV8803 device
1796 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1798 s35390a Select the ABLIC S35390A device
1800 addr Sets the address for the RTC. Note that the
1801 device must be configured to use the specified
1804 trickle-diode-disable Do not use the internal trickle charger diode
1807 trickle-diode-type Diode type for trickle charge - "standard" or
1808 "schottky" (ABx80x and RV1805 only)
1810 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1811 ABx80x, RV1805, RV3028)
1813 wakeup-source Specify that the RTC can be used as a wakeup
1816 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1817 off or 1 for Vdd < VBackup (RV3028 only)
1819 i2c_gpio_sda GPIO used for I2C data (default "23")
1821 i2c_gpio_scl GPIO used for I2C clock (default "24")
1823 i2c_gpio_delay_us Clock delay in microseconds
1824 (default "2" = ~100kHz)
1828 Info: Adds support for a number of I2C barometric pressure, temperature,
1829 light level and chemical sensors on i2c_arm
1830 Load: dtoverlay=i2c-sensor,<param>=<val>
1831 Params: addr Set the address for the BH1750, BME280, BME680,
1832 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1835 bh1750 Select the Rohm BH1750 ambient light sensor
1836 Valid addresses 0x23 or 0x5c, default 0x23
1838 bme280 Select the Bosch Sensortronic BME280
1839 Valid addresses 0x76-0x77, default 0x76
1841 bme680 Select the Bosch Sensortronic BME680
1842 Valid addresses 0x76-0x77, default 0x76
1844 bmp085 Select the Bosch Sensortronic BMP085
1846 bmp180 Select the Bosch Sensortronic BMP180
1848 bmp280 Select the Bosch Sensortronic BMP280
1849 Valid addresses 0x76-0x77, default 0x76
1851 ccs811 Select the AMS CCS811 digital gas sensor
1852 Valid addresses 0x5a-0x5b, default 0x5b
1854 ds1621 Select the Dallas Semiconductors DS1621 temp
1855 sensor. Valid addresses 0x48-0x4f, default 0x48
1857 hdc100x Select the Texas Instruments HDC100x temp sensor
1858 Valid addresses 0x40-0x43, default 0x40
1860 htu21 Select the HTU21 temperature and humidity sensor
1862 int_pin Set the GPIO to use for interrupts (max30102
1865 lm75 Select the Maxim LM75 temperature sensor
1866 Valid addresses 0x48-0x4f, default 0x4f
1868 lm75addr Deprecated - use addr parameter instead
1870 max17040 Select the Maxim Integrated MAX17040 battery
1873 max30102 Select the Maxim Integrated MAX30102 heart-rate
1874 and blood-oxygen sensor
1876 sht3x Select the Sensiron SHT3x temperature and
1877 humidity sensor. Valid addresses 0x44-0x45,
1880 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1883 sps30 Select the Sensirion SPS30 particulate matter
1884 sensor. Fixed address 0x69.
1886 sgp30 Select the Sensirion SGP30 VOC sensor.
1889 tmp102 Select the Texas Instruments TMP102 temp sensor
1890 Valid addresses 0x48-0x4b, default 0x48
1892 tsl4531 Select the AMS TSL4531 digital ambient light
1895 veml6070 Select the Vishay VEML6070 ultraviolet light
1898 i2c0 Choose the I2C0 bus on GPIOs 0&1
1900 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1902 i2c3 Choose the I2C3 bus (configure with the i2c3
1903 overlay - BCM2711 only)
1905 i2c4 Choose the I2C3 bus (configure with the i2c3
1906 overlay - BCM2711 only)
1908 i2c5 Choose the I2C5 bus (configure with the i2c4
1909 overlay - BCM2711 only)
1911 i2c6 Choose the I2C6 bus (configure with the i2c6
1912 overlay - BCM2711 only)
1916 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
1917 platforms - platforms other then Compute Modules can only use this
1918 to disable transaction combining.
1919 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
1920 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
1921 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
1922 camera and display connectors. This overlay disables that mux and
1923 configures /dev/i2c0 to point at whichever set of pins is requested.
1924 dtparam=i2c_vc=on will try and enable the mux, so combining the two
1925 will cause conflicts.
1926 Load: dtoverlay=i2c0,<param>=<val>
1927 Params: pins_0_1 Use pins 0 and 1 (default)
1928 pins_28_29 Use pins 28 and 29
1929 pins_44_45 Use pins 44 and 45
1930 pins_46_47 Use pins 46 and 47
1931 combine Allow transactions to be combined (default
1936 Info: Deprecated, legacy version of i2c0.
1941 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
1942 platforms - platforms other then Compute Modules can only use this
1943 to disable transaction combining.
1944 Load: dtoverlay=i2c1,<param>=<val>
1945 Params: pins_2_3 Use pins 2 and 3 (default)
1946 pins_44_45 Use pins 44 and 45
1947 combine Allow transactions to be combined (default
1952 Info: Deprecated, legacy version of i2c1.
1957 Info: Enable the i2c3 bus. BCM2711 only.
1958 Load: dtoverlay=i2c3,<param>
1959 Params: pins_2_3 Use GPIOs 2 and 3
1960 pins_4_5 Use GPIOs 4 and 5 (default)
1961 baudrate Set the baudrate for the interface (default
1966 Info: Enable the i2c4 bus. BCM2711 only.
1967 Load: dtoverlay=i2c4,<param>
1968 Params: pins_6_7 Use GPIOs 6 and 7
1969 pins_8_9 Use GPIOs 8 and 9 (default)
1970 baudrate Set the baudrate for the interface (default
1975 Info: Enable the i2c5 bus. BCM2711 only.
1976 Load: dtoverlay=i2c5,<param>
1977 Params: pins_10_11 Use GPIOs 10 and 11
1978 pins_12_13 Use GPIOs 12 and 13 (default)
1979 baudrate Set the baudrate for the interface (default
1984 Info: Enable the i2c6 bus. BCM2711 only.
1985 Load: dtoverlay=i2c6,<param>
1986 Params: pins_0_1 Use GPIOs 0 and 1
1987 pins_22_23 Use GPIOs 22 and 23 (default)
1988 baudrate Set the baudrate for the interface (default
1993 Info: move I2S function block to GPIO 28 to 31
1994 Load: dtoverlay=i2s-gpio28-31
1999 Info: Enables I2C connected Ilitek 251x multiple touch controller using
2000 GPIO 4 (pin 7 on GPIO header) for interrupt.
2001 Load: dtoverlay=ilitek251x,<param>=<val>
2002 Params: interrupt GPIO used for interrupt (default 4)
2003 sizex Touchscreen size x, horizontal resolution of
2004 touchscreen (in pixels)
2005 sizey Touchscreen size y, vertical resolution of
2006 touchscreen (in pixels)
2010 Info: Sony IMX219 camera module.
2011 Uses Unicam 1, which is the standard camera connector on most Pi
2013 Load: dtoverlay=imx219,<param>=<val>
2014 Params: rotation Mounting rotation of the camera sensor (0 or
2016 orientation Sensor orientation (0 = front, 1 = rear,
2017 2 = external, default external)
2018 media-controller Configure use of Media Controller API for
2019 configuring the sensor (default on)
2020 cam0 Adopt the default configuration for CAM0 on a
2021 Compute Module (CSI0, i2c_vc, and cam0_reg).
2022 vcm Configure a VCM focus drive on the sensor.
2026 Info: Sony IMX258 camera module.
2027 Uses Unicam 1, which is the standard camera connector on most Pi
2029 Load: dtoverlay=imx258,<param>=<val>
2030 Params: rotation Mounting rotation of the camera sensor (0 or
2032 orientation Sensor orientation (0 = front, 1 = rear,
2033 2 = external, default external)
2034 media-controller Configure use of Media Controller API for
2035 configuring the sensor (default on)
2036 cam0 Adopt the default configuration for CAM0 on a
2037 Compute Module (CSI0, i2c_vc, and cam0_reg).
2038 vcm Configure a VCM focus drive on the sensor.
2039 4lane Enable 4 CSI2 lanes. This requires a Compute
2040 Module (1, 3, or 4).
2044 Info: Sony IMX290 camera module.
2045 Uses Unicam 1, which is the standard camera connector on most Pi
2046 variants. NB This currently uses 4 CSI2 data lanes and therefore will
2048 Load: dtoverlay=imx290,<param>
2049 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2050 Module (1, 3, or 4).
2051 clock-frequency Sets the clock frequency to match that used on
2053 Modules from Vision Components use 37.125MHz
2054 (the default), whilst those from Innomaker use
2056 mono Denote that the module is a mono sensor.
2057 orientation Sensor orientation (0 = front, 1 = rear,
2058 2 = external, default external)
2059 rotation Mounting rotation of the camera sensor (0 or
2061 media-controller Configure use of Media Controller API for
2062 configuring the sensor (default on)
2063 cam0 Adopt the default configuration for CAM0 on a
2064 Compute Module (CSI0, i2c_vc, and cam0_reg).
2068 Info: Sony IMX296 camera module.
2069 Uses Unicam 1, which is the standard camera connector on most Pi
2071 Load: dtoverlay=imx296,<param>=<val>
2072 Params: rotation Mounting rotation of the camera sensor (0 or
2074 orientation Sensor orientation (0 = front, 1 = rear,
2075 2 = external, default external)
2076 media-controller Configure use of Media Controller API for
2077 configuring the sensor (default on)
2078 cam0 Adopt the default configuration for CAM0 on a
2079 Compute Module (CSI0, i2c_vc, and cam0_reg).
2083 Info: Sony IMX378 camera module.
2084 Uses Unicam 1, which is the standard camera connector on most Pi
2086 Load: dtoverlay=imx378,<param>=<val>
2087 Params: rotation Mounting rotation of the camera sensor (0 or
2089 orientation Sensor orientation (0 = front, 1 = rear,
2090 2 = external, default external)
2091 media-controller Configure use of Media Controller API for
2092 configuring the sensor (default on)
2093 cam0 Adopt the default configuration for CAM0 on a
2094 Compute Module (CSI0, i2c_vc, and cam0_reg).
2098 Info: Sony IMX477 camera module.
2099 Uses Unicam 1, which is the standard camera connector on most Pi
2101 Load: dtoverlay=imx477,<param>=<val>
2102 Params: rotation Mounting rotation of the camera sensor (0 or
2104 orientation Sensor orientation (0 = front, 1 = rear,
2105 2 = external, default external)
2106 media-controller Configure use of Media Controller API for
2107 configuring the sensor (default on)
2108 cam0 Adopt the default configuration for CAM0 on a
2109 Compute Module (CSI0, i2c_vc, and cam0_reg).
2113 Info: Sony IMX519 camera module.
2114 Uses Unicam 1, which is the standard camera connector on most Pi
2116 Load: dtoverlay=imx519,<param>=<val>
2117 Params: rotation Mounting rotation of the camera sensor (0 or
2119 orientation Sensor orientation (0 = front, 1 = rear,
2120 2 = external, default external)
2121 media-controller Configure use of Media Controller API for
2122 configuring the sensor (default on)
2123 cam0 Adopt the default configuration for CAM0 on a
2124 Compute Module (CSI0, i2c_vc, and cam0_reg).
2128 Info: Configures the IQaudio Codec audio card
2129 Load: dtoverlay=iqaudio-codec
2134 Info: Configures the IQaudio DAC audio card
2135 Load: dtoverlay=iqaudio-dac,<param>
2136 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2137 Digital volume control. Enable with
2138 "dtoverlay=iqaudio-dac,24db_digital_gain"
2139 (The default behaviour is that the Digital
2140 volume control is limited to a maximum of
2141 0dB. ie. it can attenuate but not provide
2142 gain. For most users, this will be desired
2143 as it will prevent clipping. By appending
2144 the 24db_digital_gain parameter, the Digital
2145 volume control will allow up to 24dB of
2146 gain. If this parameter is enabled, it is the
2147 responsibility of the user to ensure that
2148 the Digital volume control is set to a value
2149 that does not result in clipping/distortion!)
2152 Name: iqaudio-dacplus
2153 Info: Configures the IQaudio DAC+ audio card
2154 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2155 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2156 Digital volume control. Enable with
2157 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2158 (The default behaviour is that the Digital
2159 volume control is limited to a maximum of
2160 0dB. ie. it can attenuate but not provide
2161 gain. For most users, this will be desired
2162 as it will prevent clipping. By appending
2163 the 24db_digital_gain parameter, the Digital
2164 volume control will allow up to 24dB of
2165 gain. If this parameter is enabled, it is the
2166 responsibility of the user to ensure that
2167 the Digital volume control is set to a value
2168 that does not result in clipping/distortion!)
2169 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2170 starting/stopping audio playback.
2171 unmute_amp If specified, unmute the IQaudIO amp once when
2172 the DAC driver module loads.
2175 Name: iqaudio-digi-wm8804-audio
2176 Info: Configures the IQAudIO Digi WM8804 audio card
2177 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2178 Params: card_name Override the default, "IQAudIODigi", card name.
2179 dai_name Override the default, "IQAudIO Digi", dai name.
2180 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2185 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2186 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2187 Load: dtoverlay=iqs550,<param>=<val>
2188 Params: interrupt GPIO used for interrupt (default 4)
2189 reset GPIO used for reset (optional)
2190 sizex Touchscreen size x (default 800)
2191 sizey Touchscreen size y (default 480)
2192 invx Touchscreen inverted x axis
2193 invy Touchscreen inverted y axis
2194 swapxy Touchscreen swapped x y axis
2198 Info: Infineon irs1125 TOF camera module.
2199 Uses Unicam 1, which is the standard camera connector on most Pi
2201 Load: dtoverlay=irs1125,<param>=<val>
2202 Params: media-controller Configure use of Media Controller API for
2203 configuring the sensor (default off)
2204 cam0 Adopt the default configuration for CAM0 on a
2205 Compute Module (CSI0, i2c_vc, and cam0_reg).
2209 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2210 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2211 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2212 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2213 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2218 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2220 Load: dtoverlay=justboom-both,<param>=<val>
2221 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2222 Digital volume control. Enable with
2223 "dtoverlay=justboom-dac,24db_digital_gain"
2224 (The default behaviour is that the Digital
2225 volume control is limited to a maximum of
2226 0dB. ie. it can attenuate but not provide
2227 gain. For most users, this will be desired
2228 as it will prevent clipping. By appending
2229 the 24dB_digital_gain parameter, the Digital
2230 volume control will allow up to 24dB of
2231 gain. If this parameter is enabled, it is the
2232 responsibility of the user to ensure that
2233 the Digital volume control is set to a value
2234 that does not result in clipping/distortion!)
2238 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2240 Load: dtoverlay=justboom-dac,<param>=<val>
2241 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2242 Digital volume control. Enable with
2243 "dtoverlay=justboom-dac,24db_digital_gain"
2244 (The default behaviour is that the Digital
2245 volume control is limited to a maximum of
2246 0dB. ie. it can attenuate but not provide
2247 gain. For most users, this will be desired
2248 as it will prevent clipping. By appending
2249 the 24dB_digital_gain parameter, the Digital
2250 volume control will allow up to 24dB of
2251 gain. If this parameter is enabled, it is the
2252 responsibility of the user to ensure that
2253 the Digital volume control is set to a value
2254 that does not result in clipping/distortion!)
2258 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2259 Load: dtoverlay=justboom-digi
2264 Info: This overlay has been deprecated and removed - see gpio-ir
2269 Info: Adds support for the ltc294x family of battery gauges
2270 Load: dtoverlay=ltc294x,<param>=<val>
2271 Params: ltc2941 Select the ltc2941 device
2273 ltc2942 Select the ltc2942 device
2275 ltc2943 Select the ltc2943 device
2277 ltc2944 Select the ltc2944 device
2279 resistor-sense The sense resistor value in milli-ohms.
2280 Can be a 32-bit negative value when the battery
2281 has been connected to the wrong end of the
2284 prescaler-exponent Range and accuracy of the gauge. The value is
2285 programmed into the chip only if it differs
2286 from the current setting.
2288 - Default value is 128
2289 - the exponent is in the range 0-7 (default 7)
2290 See the datasheet for more information.
2294 Info: Configures the Maxim MAX98357A I2S DAC
2295 Load: dtoverlay=max98357a,<param>=<val>
2296 Params: no-sdmode Driver does not manage the state of the DAC's
2297 SD_MODE pin (i.e. chip is always on).
2298 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2299 of the DAC (default GPIO4 if parameter omitted).
2303 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2305 For devices on spi1 or spi2, the interfaces should be enabled
2306 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2307 The overlay expects to disable the relevant spidev node, so also using
2308 e.g. cs0_spidev=off is unnecessary.
2311 MAX31855 on /dev/spidev0.0
2312 dtoverlay=maxtherm,spi0-0,max31855
2313 MAX31856 using a type J thermocouple on /dev/spidev2.1
2315 dtoverlay=maxtherm,spi2-1,max31856,type_j
2317 Load: dtoverlay=maxtherm,<param>=<val>
2318 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2320 max6675 Enable support for the MAX6675 (default)
2321 max31855 Enable support for the MAX31855
2322 max31855e Enable support for the MAX31855E
2323 max31855j Enable support for the MAX31855J
2324 max31855k Enable support for the MAX31855K
2325 max31855n Enable support for the MAX31855N
2326 max31855r Enable support for the MAX31855R
2327 max31855s Enable support for the MAX31855S
2328 max31855t Enable support for the MAX31855T
2329 max31856 Enable support for the MAX31856 (with type K)
2330 type_b Select a type B sensor for max31856
2331 type_e Select a type E sensor for max31856
2332 type_j Select a type J sensor for max31856
2333 type_k Select a type K sensor for max31856
2334 type_n Select a type N sensor for max31856
2335 type_r Select a type R sensor for max31856
2336 type_s Select a type S sensor for max31856
2337 type_t Select a type T sensor for max31856
2341 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2342 Load: dtoverlay=mbed-dac
2347 Info: Configures the MCP23017 I2C GPIO expander
2348 Load: dtoverlay=mcp23017,<param>=<val>
2349 Params: gpiopin Gpio pin connected to the INTA output of the
2350 MCP23017 (default: 4)
2352 addr I2C address of the MCP23017 (default: 0x20)
2354 mcp23008 Configure an MCP23008 instead.
2355 noints Disable the interrupt GPIO line.
2359 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2360 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2361 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2362 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2363 device must be the only one present on that SPI bus/CS#.
2364 Load: dtoverlay=mcp23s17,<param>=<val>
2365 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2366 devices present on SPI<n>, CS#<m>
2368 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2369 devices present on SPI<n>, CS#<m>
2371 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2372 MCP23S08 device on SPI<n>, CS#<m>, specifies
2373 the GPIO pin to which INT output of MCP23S08
2376 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2377 single MCP23S17 device on SPI<n>, CS#<m>,
2378 specifies the GPIO pin to which either INTA
2379 or INTB output of MCP23S17 is connected.
2383 Info: Configures the MCP2515 CAN controller on spi0/1/2
2384 For devices on spi1 or spi2, the interfaces should be enabled
2385 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2386 Load: dtoverlay=mcp2515,<param>=<val>
2387 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2390 oscillator Clock frequency for the CAN controller (Hz)
2392 speed Maximum SPI frequence (Hz)
2394 interrupt GPIO for interrupt signal
2398 Info: Configures the MCP2515 CAN controller on spi0.0
2399 Load: dtoverlay=mcp2515-can0,<param>=<val>
2400 Params: oscillator Clock frequency for the CAN controller (Hz)
2402 spimaxfrequency Maximum SPI frequence (Hz)
2404 interrupt GPIO for interrupt signal
2408 Info: Configures the MCP2515 CAN controller on spi0.1
2409 Load: dtoverlay=mcp2515-can1,<param>=<val>
2410 Params: oscillator Clock frequency for the CAN controller (Hz)
2412 spimaxfrequency Maximum SPI frequence (Hz)
2414 interrupt GPIO for interrupt signal
2418 Info: Configures the MCP251XFD CAN controller family
2419 For devices on spi1 or spi2, the interfaces should be enabled
2420 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2421 Load: dtoverlay=mcp251xfd,<param>=<val>
2422 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2425 oscillator Clock frequency for the CAN controller (Hz)
2427 speed Maximum SPI frequence (Hz)
2429 interrupt GPIO for interrupt signal
2431 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2433 xceiver_enable GPIO for CAN transceiver enable (optional)
2435 xceiver_active_high specifiy if CAN transceiver enable pin is
2436 active high (optional, default: active low)
2440 Info: Configures MCP3008 A/D converters
2441 For devices on spi1 or spi2, the interfaces should be enabled
2442 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2443 Load: dtoverlay=mcp3008,<param>[=<val>]
2444 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2445 spi<n>-<m>-speed integer, set the spi bus speed for this device
2449 Info: Configures MCP3202 A/D converters
2450 For devices on spi1 or spi2, the interfaces should be enabled
2451 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2452 Load: dtoverlay=mcp3202,<param>[=<val>]
2453 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2454 spi<n>-<m>-speed integer, set the spi bus speed for this device
2458 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2459 Load: dtoverlay=mcp342x,<param>=<val>
2460 Params: addr I2C bus address of device, for devices with
2461 addresses that are configurable, e.g. by
2462 hardware links (default=0x68)
2463 mcp3421 The device is an MCP3421
2464 mcp3422 The device is an MCP3422
2465 mcp3423 The device is an MCP3423
2466 mcp3424 The device is an MCP3424
2467 mcp3425 The device is an MCP3425
2468 mcp3426 The device is an MCP3426
2469 mcp3427 The device is an MCP3427
2470 mcp3428 The device is an MCP3428
2474 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2475 Load: dtoverlay=media-center,<param>=<val>
2476 Params: speed Display SPI bus speed
2477 rotate Display rotation {0,90,180,270}
2478 fps Delay between frame updates
2479 xohms Touchpanel sensitivity (X-plate resistance)
2480 swapxy Swap x and y axis
2481 backlight Change backlight GPIO pin {e.g. 12, 18}
2482 gpio_out_pin GPIO for output (default "17")
2483 gpio_in_pin GPIO for input (default "18")
2484 gpio_in_pull Pull up/down/off on the input pin
2486 sense Override the IR receive auto-detection logic:
2487 "0" = force active-high
2488 "1" = force active-low
2489 "-1" = use auto-detection
2491 softcarrier Turn the software carrier "on" or "off"
2493 invert "on" = invert the output pin (default "off")
2494 debug "on" = enable additional debug messages
2499 Info: Configures the merus-amp audio card
2500 Load: dtoverlay=merus-amp
2505 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2506 31.25kbaud, the frequency required for MIDI
2507 Load: dtoverlay=midi-uart0
2512 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2513 31.25kbaud, the frequency required for MIDI
2514 Load: dtoverlay=midi-uart1
2519 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2520 31.25kbaud, the frequency required for MIDI
2521 Load: dtoverlay=midi-uart2
2526 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2527 31.25kbaud, the frequency required for MIDI
2528 Load: dtoverlay=midi-uart3
2533 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2534 31.25kbaud, the frequency required for MIDI
2535 Load: dtoverlay=midi-uart4
2540 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2541 31.25kbaud, the frequency required for MIDI
2542 Load: dtoverlay=midi-uart5
2547 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2548 Load: dtoverlay=minipitft13,<param>=<val>
2549 Params: speed SPI bus speed (default 32000000)
2550 rotate Display rotation (0, 90, 180 or 270; default 0)
2551 width Display width (default 240)
2552 height Display height (default 240)
2553 fps Delay between frame updates (default 25)
2554 debug Debug output level (0-7; default 0)
2558 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2559 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2560 15. Note that this may reduce the maximum usable baudrate.
2561 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2562 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2563 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2564 in which case use /dev/serial1 instead because it will always be
2565 correct. Furthermore, you must also set core_freq and core_freq_min to
2566 the same value in config.txt or the miniuart will not work.
2567 Load: dtoverlay=miniuart-bt,<param>=<val>
2568 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2569 driver without need of hciattach/btattach
2573 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2574 driver. The driver will load a file /lib/firmware/panel.bin containing
2575 the initialisation commands.
2578 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2579 dtparam=width=320,height=240
2580 dtparam=reset-gpio=23,dc-gpio=24
2581 dtparam=backlight-gpio=18
2583 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2584 and init commands at 10MHz. This makes it possible to push the envelope
2585 without messing up the controller configuration due to command
2586 transmission errors.
2588 For devices on spi1 or spi2, the interfaces should be enabled
2589 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2591 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2593 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2595 compatible Set the compatible string to load a different
2596 firmware file. Both the panel compatible value
2597 used to load the firmware file and the value
2598 used to load the driver has to be set having a
2599 NUL (\0) separator between them.
2601 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2602 spi<n>-<m> Configure device at spi<n>, cs<m>
2604 speed SPI bus speed in Hz (default 32000000)
2605 cpha Shifted SPI clock phase (CPHA) mode
2606 cpol Inverse SPI clock polarity (CPOL) mode
2607 write-only Controller is not readable
2608 (ie. MISO is not wired up).
2610 width Panel width in pixels (required)
2611 height Panel height in pixels (required)
2612 width-mm Panel width in mm
2613 height-mm Panel height in mm
2614 x-offset Panel x-offset in controller RAM
2615 y-offset Panel y-offset in controller RAM
2617 clock-frequency Panel clock frequency in Hz
2618 (optional, just informational).
2620 reset-gpio GPIO pin to be used for RESET
2621 dc-gpio GPIO pin to be used for D/C
2623 backlight-gpio GPIO pin to be used for backlight control
2625 backlight-pwm PWM channel to be used for backlight control
2626 (default of none). NB Disables audio headphone
2627 output as that also uses PWM.
2628 backlight-pwm-chan Choose channel on &pwm node for backlight
2629 control (default 0).
2630 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2631 pwm-2chan for valid options (default 18).
2632 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2633 See pwm-2chan for valid options (default 2).
2634 backlight-def-brightness
2635 Set the default brightness. Normal range 1-16.
2640 Info: Overlay for i2c connected mlx90640 thermal camera
2641 Load: dtoverlay=mlx90640
2646 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2647 Load: dtoverlay=mmc,<param>=<val>
2648 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2653 Info: Overlay for i2c connected mpu6050 imu
2654 Load: dtoverlay=mpu6050,<param>=<val>
2655 Params: interrupt GPIO pin for interrupt (default 4)
2656 addr I2C address of the device (default 0x68)
2660 Info: MZ61581 display by Tontec
2661 Load: dtoverlay=mz61581,<param>=<val>
2662 Params: speed Display SPI bus speed
2664 rotate Display rotation {0,90,180,270}
2666 fps Delay between frame updates
2668 txbuflen Transmit buffer length (default 32768)
2670 debug Debug output level {0-7}
2672 xohms Touchpanel sensitivity (X-plate resistance)
2676 Info: Omnivision OV2311 camera module.
2677 Uses Unicam 1, which is the standard camera connector on most Pi
2679 Load: dtoverlay=ov2311,<param>=<val>
2680 Params: rotation Mounting rotation of the camera sensor (0 or
2682 orientation Sensor orientation (0 = front, 1 = rear,
2683 2 = external, default external)
2684 media-controller Configure use of Media Controller API for
2685 configuring the sensor (default on)
2686 cam0 Adopt the default configuration for CAM0 on a
2687 Compute Module (CSI0, i2c_vc, and cam0_reg).
2691 Info: Omnivision OV5647 camera module.
2692 Uses Unicam 1, which is the standard camera connector on most Pi
2694 Load: dtoverlay=ov5647,<param>=<val>
2695 Params: rotation Mounting rotation of the camera sensor (0 or
2697 orientation Sensor orientation (0 = front, 1 = rear,
2698 2 = external, default external)
2699 media-controller Configure use of Media Controller API for
2700 configuring the sensor (default on)
2701 cam0 Adopt the default configuration for CAM0 on a
2702 Compute Module (CSI0, i2c_vc, and cam0_reg).
2703 vcm Configure a VCM focus drive on the sensor.
2707 Info: Omnivision OV7251 camera module.
2708 Uses Unicam 1, which is the standard camera connector on most Pi
2710 Load: dtoverlay=ov7251,<param>=<val>
2711 Params: rotation Mounting rotation of the camera sensor (0 or
2713 orientation Sensor orientation (0 = front, 1 = rear,
2714 2 = external, default external)
2715 media-controller Configure use of Media Controller API for
2716 configuring the sensor (default off)
2717 cam0 Adopt the default configuration for CAM0 on a
2718 Compute Module (CSI0, i2c_vc, and cam0_reg).
2722 Info: Omnivision OV9281 camera module.
2723 Uses Unicam 1, which is the standard camera connector on most Pi
2725 Load: dtoverlay=ov9281,<param>=<val>
2726 Params: rotation Mounting rotation of the camera sensor (0 or
2728 orientation Sensor orientation (0 = front, 1 = rear,
2729 2 = external, default external)
2730 media-controller Configure use of Media Controller API for
2731 configuring the sensor (default on)
2732 cam0 Adopt the default configuration for CAM0 on a
2733 Compute Module (CSI0, i2c_vc, and cam0_reg).
2737 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2738 Load: dtoverlay=papirus,<param>=<val>
2739 Params: panel Display panel (required):
2744 speed Display SPI bus speed
2748 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2749 Load: dtoverlay=pca953x,<param>=<val>
2750 Params: addr I2C address of expander. Default 0x20.
2751 pca6416 Select the NXP PCA6416 (16 bit)
2752 pca9505 Select the NXP PCA9505 (40 bit)
2753 pca9535 Select the NXP PCA9535 (16 bit)
2754 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2755 pca9537 Select the NXP PCA9537 (4 bit)
2756 pca9538 Select the NXP PCA9538 (8 bit)
2757 pca9539 Select the NXP PCA9539 (16 bit)
2758 pca9554 Select the NXP PCA9554 (8 bit)
2759 pca9555 Select the NXP PCA9555 (16 bit)
2760 pca9556 Select the NXP PCA9556 (8 bit)
2761 pca9557 Select the NXP PCA9557 (8 bit)
2762 pca9574 Select the NXP PCA9574 (8 bit)
2763 pca9575 Select the NXP PCA9575 (16 bit)
2764 pca9698 Select the NXP PCA9698 (40 bit)
2765 pca16416 Select the NXP PCA16416 (16 bit)
2766 pca16524 Select the NXP PCA16524 (24 bit)
2767 pca19555a Select the NXP PCA19555A (16 bit)
2768 max7310 Select the Maxim MAX7310 (8 bit)
2769 max7312 Select the Maxim MAX7312 (16 bit)
2770 max7313 Select the Maxim MAX7313 (16 bit)
2771 max7315 Select the Maxim MAX7315 (8 bit)
2772 pca6107 Select the TI PCA6107 (8 bit)
2773 tca6408 Select the TI TCA6408 (8 bit)
2774 tca6416 Select the TI TCA6416 (16 bit)
2775 tca6424 Select the TI TCA6424 (24 bit)
2776 tca9539 Select the TI TCA9539 (16 bit)
2777 tca9554 Select the TI TCA9554 (8 bit)
2778 cat9554 Select the Onnn CAT9554 (8 bit)
2779 pca9654 Select the Onnn PCA9654 (8 bit)
2780 xra1202 Select the Exar XRA1202 (8 bit)
2783 Name: pcie-32bit-dma
2784 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2785 having to bounce buffers.
2786 Load: dtoverlay=pcie-32bit-dma
2790 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2793 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2796 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2800 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2801 for backwards compatibility.
2805 Name: pi3-disable-bt
2806 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2807 alias for backwards compatibility.
2811 Name: pi3-disable-wifi
2812 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2813 an alias for backwards compatibility.
2817 Name: pi3-miniuart-bt
2818 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2819 an alias for backwards compatibility.
2824 Info: Configures the pibell audio card.
2825 Load: dtoverlay=pibell,<param>=<val>
2826 Params: alsaname Set the name as it appears in ALSA (default
2831 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2832 Load: dtoverlay=pifacedigital,<param>=<val>
2833 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2834 CS0 address. PiFace Digital supports addresses
2835 0-3, which can be configured with JP1 and JP2.
2839 Info: Configures the PiFi 40W stereo amplifier
2840 Load: dtoverlay=pifi-40
2845 Info: Configures the PiFi DAC HD
2846 Load: dtoverlay=pifi-dac-hd
2851 Info: Configures the PiFi DAC Zero
2852 Load: dtoverlay=pifi-dac-zero
2857 Info: Configures the PiFi Mini stereo amplifier
2858 Load: dtoverlay=pifi-mini-210
2863 Info: Configures the PiGlow by pimoroni.com
2864 Load: dtoverlay=piglow
2869 Info: PiScreen display by OzzMaker.com
2870 Load: dtoverlay=piscreen,<param>=<val>
2871 Params: speed Display SPI bus speed
2873 rotate Display rotation {0,90,180,270}
2875 fps Delay between frame updates
2877 debug Debug output level {0-7}
2879 xohms Touchpanel sensitivity (X-plate resistance)
2883 Info: PiScreen 2 with resistive TP display by OzzMaker.com
2884 Load: dtoverlay=piscreen2r,<param>=<val>
2885 Params: speed Display SPI bus speed
2887 rotate Display rotation {0,90,180,270}
2889 fps Delay between frame updates
2891 debug Debug output level {0-7}
2893 xohms Touchpanel sensitivity (X-plate resistance)
2897 Info: Configures the Blokas Labs pisound card
2898 Load: dtoverlay=pisound
2903 Info: Adafruit PiTFT 2.2" screen
2904 Load: dtoverlay=pitft22,<param>=<val>
2905 Params: speed Display SPI bus speed
2907 rotate Display rotation {0,90,180,270}
2909 fps Delay between frame updates
2911 debug Debug output level {0-7}
2914 Name: pitft28-capacitive
2915 Info: Adafruit PiTFT 2.8" capacitive touch screen
2916 Load: dtoverlay=pitft28-capacitive,<param>=<val>
2917 Params: speed Display SPI bus speed
2919 rotate Display rotation {0,90,180,270}
2921 fps Delay between frame updates
2923 debug Debug output level {0-7}
2925 touch-sizex Touchscreen size x (default 240)
2927 touch-sizey Touchscreen size y (default 320)
2929 touch-invx Touchscreen inverted x axis
2931 touch-invy Touchscreen inverted y axis
2933 touch-swapxy Touchscreen swapped x y axis
2936 Name: pitft28-resistive
2937 Info: Adafruit PiTFT 2.8" resistive touch screen
2938 Load: dtoverlay=pitft28-resistive,<param>=<val>
2939 Params: speed Display SPI bus speed
2941 rotate Display rotation {0,90,180,270}
2943 fps Delay between frame updates
2945 debug Debug output level {0-7}
2947 drm Force the use of the mi0283qt DRM driver (by
2948 default the ili9340 framebuffer driver will
2949 be used in preference if available)
2952 Name: pitft35-resistive
2953 Info: Adafruit PiTFT 3.5" resistive touch screen
2954 Load: dtoverlay=pitft35-resistive,<param>=<val>
2955 Params: speed Display SPI bus speed
2957 rotate Display rotation {0,90,180,270}
2959 fps Delay between frame updates
2961 debug Debug output level {0-7}
2963 drm Force the use of the hx8357d DRM driver (by
2964 default the fb_hx8357d framebuffer driver will
2965 be used in preference if available)
2969 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
2970 Load: dtoverlay=pps-gpio,<param>=<val>
2971 Params: gpiopin Input GPIO (default "18")
2972 assert_falling_edge When present, assert is indicated by a falling
2973 edge, rather than by a rising edge (default
2975 capture_clear Generate clear events on the trailing edge
2980 Info: Configures a single PWM channel
2981 Legal pin,function combinations for each channel:
2982 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2983 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2985 1) Pin 18 is the only one available on all platforms, and
2986 it is the one used by the I2S audio interface.
2987 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2988 2) The onboard analogue audio output uses both PWM channels.
2989 3) So be careful mixing audio and PWM.
2990 4) Currently the clock must have been enabled and configured
2992 Load: dtoverlay=pwm,<param>=<val>
2993 Params: pin Output pin (default 18) - see table
2994 func Pin function (default 2 = Alt5) - see above
2995 clock PWM clock frequency (informational)
2999 Info: Configures both PWM channels
3000 Legal pin,function combinations for each channel:
3001 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3002 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
3004 1) Pin 18 is the only one available on all platforms, and
3005 it is the one used by the I2S audio interface.
3006 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
3007 2) The onboard analogue audio output uses both PWM channels.
3008 3) So be careful mixing audio and PWM.
3009 4) Currently the clock must have been enabled and configured
3011 Load: dtoverlay=pwm-2chan,<param>=<val>
3012 Params: pin Output pin (default 18) - see table
3013 pin2 Output pin for other channel (default 19)
3014 func Pin function (default 2 = Alt5) - see above
3015 func2 Function for pin2 (default 2 = Alt5)
3016 clock PWM clock frequency (informational)
3020 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
3021 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
3022 of PWM0 to reduce the CPU load during transmission compared to
3023 gpio-ir-tx which uses bit-banging.
3024 Legal pin,function combinations are:
3025 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3026 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3027 Params: gpio_pin Output GPIO (default 18)
3029 func Pin function (default 2 = Alt5)
3033 Info: in-tech's Evaluation Board for PLC Stamp micro
3034 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3035 Load: dtoverlay=qca7000,<param>=<val>
3036 Params: int_pin GPIO pin for interrupt signal (default 23)
3038 speed SPI bus speed (default 12 MHz)
3042 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3043 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3044 But it requires disabling of onboard Bluetooth on
3045 Pi 3B, 3B+, 3A+, 4B and Zero W.
3046 Load: dtoverlay=qca7000-uart0,<param>=<val>
3047 Params: baudrate Set the baudrate for the UART (default
3052 Info: Enable the preservation of crash logs across a reboot. With
3053 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3054 are moved to /var/lib/systemd/pstore/ on reboot.
3055 Load: dtoverlay=ramoops,<param>=<val>
3056 Params: base-addr Where to place the capture buffer (default
3058 total-size How much memory to allocate altogether (in
3059 bytes - default 64kB)
3060 record-size How much space to use for each capture, i.e.
3061 total-size / record-size = number of captures
3063 console-size Size of non-panic dmesg captures (default 0)
3067 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3068 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3069 Load: dtoverlay=ramoops-pi4,<param>=<val>
3070 Params: base-addr Where to place the capture buffer (default
3072 total-size How much memory to allocate altogether (in
3073 bytes - default 64kB)
3074 record-size How much space to use for each capture, i.e.
3075 total-size / record-size = number of captures
3077 console-size Size of non-panic dmesg captures (default 0)
3080 Name: rotary-encoder
3081 Info: Overlay for GPIO connected rotary encoder.
3082 Load: dtoverlay=rotary-encoder,<param>=<val>
3083 Params: pin_a GPIO connected to rotary encoder channel A
3085 pin_b GPIO connected to rotary encoder channel B
3087 relative_axis register a relative axis rather than an
3088 absolute one. Relative axis will only
3089 generate +1/-1 events on the input device,
3090 hence no steps need to be passed.
3091 linux_axis the input subsystem axis to map to this
3092 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3093 rollover Automatic rollover when the rotary value
3094 becomes greater than the specified steps or
3095 smaller than 0. For absolute axis only.
3096 steps-per-period Number of steps (stable states) per period.
3097 The values have the following meaning:
3098 1: Full-period mode (default)
3100 4: Quarter-period mode
3101 steps Number of steps in a full turnaround of the
3102 encoder. Only relevant for absolute axis.
3103 Defaults to 24 which is a typical value for
3105 wakeup Boolean, rotary encoder can wake up the
3107 encoding String, the method used to encode steps.
3108 Supported are "gray" (the default and more
3109 common) and "binary".
3113 Info: Raspberry Pi official display backlight driver
3114 Load: dtoverlay=rpi-backlight
3118 Name: rpi-cirrus-wm5102
3119 Info: Configures the Cirrus Logic Audio Card
3120 Load: dtoverlay=rpi-cirrus-wm5102
3125 Info: Configures the RPi DAC audio card
3126 Load: dtoverlay=rpi-dac
3131 Info: RPi-Display - 2.8" Touch Display by Watterott
3132 Linux has 2 drivers that support this display and this overlay supports
3136 fbtft/fb_ili9341: dtoverlay=rpi-display
3137 drm/mi0283qt: dtoverlay=rpi-display,drm,backlight-pwm,rotate=180
3139 Some notable differences with the DRM driver compared to fbtft:
3140 - The display is turned on when it's first used and not on driver load
3141 as with fbtft. So if nothing uses the display it stays off.
3142 - Can run with a higher SPI clock increasing framerate. This is possible
3143 since the driver avoids messing up the controller configuration due to
3144 transmission errors by running config commands at 10MHz and only pixel
3145 data at full speed (occasional pixel glitch might occur).
3146 - PWM backlight is supported.
3148 Load: dtoverlay=rpi-display,<param>=<val>
3149 Params: speed Display SPI bus speed
3150 rotate Display rotation {0,90,180,270}
3151 fps Delay between frame updates (fbtft only)
3152 debug Debug output level {0-7} (fbtft only)
3153 xohms Touchpanel sensitivity (X-plate resistance)
3154 swapxy Swap x and y axis
3155 backlight Change backlight GPIO pin {e.g. 12, 18}
3157 drm Use DRM/KMS driver mi0283qt instead of fbtft.
3158 Set the SPI clock to 70MHz.
3159 This has to be the first parameter.
3160 backlight-pwm Use pwm for backlight (drm only). NB: Disables
3161 audio headphone output as that also uses PWM.
3165 Info: Official Raspberry Pi display touchscreen
3166 Load: dtoverlay=rpi-ft5406,<param>=<val>
3167 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3168 touchscreen-size-y Touchscreen Y resolution (default 600);
3169 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3170 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3171 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3175 Info: Raspberry Pi PoE HAT fan
3176 Load: dtoverlay=rpi-poe,<param>[=<val>]
3177 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3178 turns on (default 40000)
3179 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3180 the fan turns off (default 2000)
3181 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3182 speeds up (default 45000)
3183 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3184 the fan slows down (default 2000)
3185 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3186 speeds up (default 50000)
3187 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3188 the fan slows down (default 2000)
3189 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3190 speeds up (default 55000)
3191 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3192 the fan slows down (default 5000)
3193 i2c Control the fan via Linux I2C drivers instead of
3198 Info: Raspberry Pi PoE+ HAT fan
3199 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3200 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3201 turns on (default 40000)
3202 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3203 the fan turns off (default 2000)
3204 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3205 speeds up (default 45000)
3206 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3207 the fan slows down (default 2000)
3208 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3209 speeds up (default 50000)
3210 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3211 the fan slows down (default 2000)
3212 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3213 speeds up (default 55000)
3214 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3215 the fan slows down (default 5000)
3216 i2c Control the fan via Linux I2C drivers instead of
3221 Info: Configures the RPi Proto audio card
3222 Load: dtoverlay=rpi-proto
3227 Info: Raspberry Pi Sense HAT
3228 Load: dtoverlay=rpi-sense
3233 Info: Raspberry Pi TV HAT
3234 Load: dtoverlay=rpi-tv
3239 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3240 video decoder driver is enabled by default.
3244 Name: rra-digidac1-wm8741-audio
3245 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3246 Load: dtoverlay=rra-digidac1-wm8741-audio
3251 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3253 Load: dtoverlay=sainsmart18,<param>=<val>
3254 Params: rotate Display rotation {0,90,180,270}
3255 speed SPI bus speed in Hz (default 4000000)
3256 fps Display frame rate in Hz
3257 bgr Enable BGR mode (default off)
3258 debug Debug output level {0-7}
3259 dc_pin GPIO pin for D/C (default 24)
3260 reset_pin GPIO pin for RESET (default 25)
3264 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3265 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3266 select another address, please refer to table 10 in reference manual.
3267 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3268 Params: int_pin GPIO used for IRQ (default 24)
3269 addr Address (default 0x48)
3270 xtal On-board crystal frequency (default 14745600)
3274 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3275 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3276 select another address, please refer to table 10 in reference manual.
3277 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3278 Params: int_pin GPIO used for IRQ (default 24)
3279 addr Address (default 0x48)
3280 xtal On-board crystal frequency (default 14745600)
3283 Name: sc16is752-spi0
3284 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3285 Enables the chip on SPI0.
3286 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3287 Params: int_pin GPIO used for IRQ (default 24)
3288 xtal On-board crystal frequency (default 14745600)
3291 Name: sc16is752-spi1
3292 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3293 Enables the chip on SPI1.
3294 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3295 A+, B+, Zero and PI2 B; as well as the Compute Module.
3297 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3298 Params: int_pin GPIO used for IRQ (default 24)
3299 xtal On-board crystal frequency (default 14745600)
3303 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3304 N.B. This overlay is designed for situations where the mmc driver is
3305 the default, so it disables the other (mmc) interface - this will kill
3306 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3307 overlay or the new sd_* dtparams of the base DTBs.
3308 Load: dtoverlay=sdhost,<param>=<val>
3309 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3312 force_pio Disable DMA support (default off)
3314 pio_limit Number of blocks above which to use DMA
3317 debug Enable debug output (default off)
3321 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3322 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3323 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3324 Load: dtoverlay=sdio,<param>=<val>
3325 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3326 framework requests 50MHz
3328 poll_once Disable SDIO-device polling every second
3329 (default on: polling once at boot-time)
3331 bus_width Set the SDIO host bus width (default 4 bits)
3333 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3334 with bus_width=1. This replaces the sdio-1bit
3335 overlay, which is now deprecated.
3337 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3340 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3341 with bus_width=4 (the default).
3345 Info: This overlay is now deprecated. Use
3346 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3351 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3352 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3353 "dtparam=sd_poll_once".
3357 Name: seeed-can-fd-hat-v1
3358 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3359 channels without RTC. Use this overlay if your HAT has no
3361 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3362 Load: dtoverlay=seeed-can-fd-hat-v1
3366 Name: seeed-can-fd-hat-v2
3367 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3368 channels and an RTC. Use this overlay if your HAT has a
3370 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3371 Load: dtoverlay=seeed-can-fd-hat-v2
3376 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3377 Load: dtoverlay=sh1106-spi,<param>=<val>
3378 Params: speed SPI bus speed (default 4000000)
3379 rotate Display rotation (0, 90, 180 or 270; default 0)
3380 fps Delay between frame updates (default 25)
3381 debug Debug output level (0-7; default 0)
3382 dc_pin GPIO pin for D/C (default 24)
3383 reset_pin GPIO pin for RESET (default 25)
3384 height Display height (32 or 64; default 64)
3388 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3389 The driver is currently out-of-tree at
3390 https://github.com/sunipkmukherjee/silabs.git
3391 Load: dtoverlay=si446x-spi0,<param>=<val>
3392 Params: speed SPI bus speed (default 4000000)
3393 int_pin GPIO pin for interrupts (default 17)
3394 reset_pin GPIO pin for RESET (default 27)
3398 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3404 Info: Enables the userspace interface for the SMI driver
3405 Load: dtoverlay=smi-dev
3410 Info: Enables access to NAND flash via the SMI interface
3411 Load: dtoverlay=smi-nand
3416 Info: Move SPI function block to GPIO 35 to 39
3417 Load: dtoverlay=spi-gpio35-39
3422 Info: Move SPI function block to GPIOs 40 to 45
3423 Load: dtoverlay=spi-gpio40-45
3428 Info: Adds support for a number of SPI Real Time Clock devices
3429 Load: dtoverlay=spi-rtc,<param>=<val>
3430 Params: ds3232 Select the DS3232 device
3431 ds3234 Select the DS3234 device
3432 pcf2123 Select the PCF2123 device
3434 spi0_0 Use spi0.0 (default)
3440 cs_high This device requires an active-high CS
3444 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3445 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3446 Load: dtoverlay=spi0-0cs,<param>=<val>
3447 Params: no_miso Don't claim and use the MISO pin (9), freeing
3452 Info: Only use one CS pin for SPI0
3453 Load: dtoverlay=spi0-1cs,<param>=<val>
3454 Params: cs0_pin GPIO pin for CS0 (default 8)
3455 no_miso Don't claim and use the MISO pin (9), freeing
3460 Info: Change the CS pins for SPI0
3461 Load: dtoverlay=spi0-2cs,<param>=<val>
3462 Params: cs0_pin GPIO pin for CS0 (default 8)
3463 cs1_pin GPIO pin for CS1 (default 7)
3464 no_miso Don't claim and use the MISO pin (9), freeing
3469 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3470 alias for backwards compatibility.
3475 Info: This overlay has been deprecated and removed because it is no longer
3476 necessary and has been seen to prevent spi0 from working.
3481 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3482 dev node. The gpio pin number for the CS line and spidev device node
3483 creation are configurable.
3484 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3485 A+, B+, Zero and PI2 B; as well as the Compute Module.
3486 Load: dtoverlay=spi1-1cs,<param>=<val>
3487 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3488 cs0_spidev Set to 'disabled' to stop the creation of a
3489 userspace device node /dev/spidev1.0 (default
3490 is 'okay' or enabled).
3494 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3495 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3496 creation are configurable.
3497 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3498 A+, B+, Zero and PI2 B; as well as the Compute Module.
3499 Load: dtoverlay=spi1-2cs,<param>=<val>
3500 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3501 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3502 cs0_spidev Set to 'disabled' to stop the creation of a
3503 userspace device node /dev/spidev1.0 (default
3504 is 'okay' or enabled).
3505 cs1_spidev Set to 'disabled' to stop the creation of a
3506 userspace device node /dev/spidev1.1 (default
3507 is 'okay' or enabled).
3511 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3512 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3513 creation are configurable.
3514 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3515 A+, B+, Zero and PI2 B; as well as the Compute Module.
3516 Load: dtoverlay=spi1-3cs,<param>=<val>
3517 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3518 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3519 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3520 cs0_spidev Set to 'disabled' to stop the creation of a
3521 userspace device node /dev/spidev1.0 (default
3522 is 'okay' or enabled).
3523 cs1_spidev Set to 'disabled' to stop the creation of a
3524 userspace device node /dev/spidev1.1 (default
3525 is 'okay' or enabled).
3526 cs2_spidev Set to 'disabled' to stop the creation of a
3527 userspace device node /dev/spidev1.2 (default
3528 is 'okay' or enabled).
3532 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3533 dev node. The gpio pin number for the CS line and spidev device node
3534 creation are configurable.
3535 N.B.: spi2 is only accessible with the Compute Module.
3536 Load: dtoverlay=spi2-1cs,<param>=<val>
3537 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3538 cs0_spidev Set to 'disabled' to stop the creation of a
3539 userspace device node /dev/spidev2.0 (default
3540 is 'okay' or enabled).
3544 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3545 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3546 creation are configurable.
3547 N.B.: spi2 is only accessible with the Compute Module.
3548 Load: dtoverlay=spi2-2cs,<param>=<val>
3549 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3550 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3551 cs0_spidev Set to 'disabled' to stop the creation of a
3552 userspace device node /dev/spidev2.0 (default
3553 is 'okay' or enabled).
3554 cs1_spidev Set to 'disabled' to stop the creation of a
3555 userspace device node /dev/spidev2.1 (default
3556 is 'okay' or enabled).
3560 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3561 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3562 creation are configurable.
3563 N.B.: spi2 is only accessible with the Compute Module.
3564 Load: dtoverlay=spi2-3cs,<param>=<val>
3565 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3566 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3567 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3568 cs0_spidev Set to 'disabled' to stop the creation of a
3569 userspace device node /dev/spidev2.0 (default
3570 is 'okay' or enabled).
3571 cs1_spidev Set to 'disabled' to stop the creation of a
3572 userspace device node /dev/spidev2.1 (default
3573 is 'okay' or enabled).
3574 cs2_spidev Set to 'disabled' to stop the creation of a
3575 userspace device node /dev/spidev2.2 (default
3576 is 'okay' or enabled).
3580 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3581 dev node. The gpio pin number for the CS line and spidev device node
3582 creation are configurable. BCM2711 only.
3583 Load: dtoverlay=spi3-1cs,<param>=<val>
3584 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3585 cs0_spidev Set to 'off' to prevent the creation of a
3586 userspace device node /dev/spidev3.0 (default
3587 is 'on' or enabled).
3591 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3592 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3593 creation are configurable. BCM2711 only.
3594 Load: dtoverlay=spi3-2cs,<param>=<val>
3595 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3596 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3597 cs0_spidev Set to 'off' to prevent the creation of a
3598 userspace device node /dev/spidev3.0 (default
3599 is 'on' or enabled).
3600 cs1_spidev Set to 'off' to prevent the creation of a
3601 userspace device node /dev/spidev3.1 (default
3602 is 'on' or enabled).
3606 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3607 dev node. The gpio pin number for the CS line and spidev device node
3608 creation are configurable. BCM2711 only.
3609 Load: dtoverlay=spi4-1cs,<param>=<val>
3610 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3611 cs0_spidev Set to 'off' to prevent the creation of a
3612 userspace device node /dev/spidev4.0 (default
3613 is 'on' or enabled).
3617 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3618 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3619 creation are configurable. BCM2711 only.
3620 Load: dtoverlay=spi4-2cs,<param>=<val>
3621 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3622 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3623 cs0_spidev Set to 'off' to prevent the creation of a
3624 userspace device node /dev/spidev4.0 (default
3625 is 'on' or enabled).
3626 cs1_spidev Set to 'off' to prevent the creation of a
3627 userspace device node /dev/spidev4.1 (default
3628 is 'on' or enabled).
3632 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3633 dev node. The gpio pin numbers for the CS lines and spidev device node
3634 creation are configurable. BCM2711 only.
3635 Load: dtoverlay=spi5-1cs,<param>=<val>
3636 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3637 cs0_spidev Set to 'off' to prevent the creation of a
3638 userspace device node /dev/spidev5.0 (default
3639 is 'on' or enabled).
3643 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3644 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3645 creation are configurable. BCM2711 only.
3646 Load: dtoverlay=spi5-2cs,<param>=<val>
3647 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3648 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3649 cs0_spidev Set to 'off' to prevent the creation of a
3650 userspace device node /dev/spidev5.0 (default
3651 is 'on' or enabled).
3652 cs1_spidev Set to 'off' to prevent the creation of a
3653 userspace device node /dev/spidev5.1 (default
3654 is 'on' or enabled).
3658 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3659 dev node. The gpio pin number for the CS line and spidev device node
3660 creation are configurable. BCM2711 only.
3661 Load: dtoverlay=spi6-1cs,<param>=<val>
3662 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3663 cs0_spidev Set to 'off' to prevent the creation of a
3664 userspace device node /dev/spidev6.0 (default
3665 is 'on' or enabled).
3669 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3670 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3671 creation are configurable. BCM2711 only.
3672 Load: dtoverlay=spi6-2cs,<param>=<val>
3673 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3674 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3675 cs0_spidev Set to 'off' to prevent the creation of a
3676 userspace device node /dev/spidev6.0 (default
3677 is 'on' or enabled).
3678 cs1_spidev Set to 'off' to prevent the creation of a
3679 userspace device node /dev/spidev6.1 (default
3680 is 'on' or enabled).
3684 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3685 Load: dtoverlay=ssd1306,<param>=<val>
3686 Params: address Location in display memory of first character.
3688 width Width of display. (default=128)
3689 height Height of display. (default=64)
3690 offset virtual channel a. (default=0)
3691 normal Has no effect on displays tested. (default=not
3693 sequential Set this if every other scan line is missing.
3695 remapped Set this if display is garbled. (default=not
3697 inverted Set this if display is inverted and mirrored.
3701 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3703 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3705 i2c_baudrate=400000 will speed up the display.
3707 i2c_baudrate=1000000 seems to work even though it's not officially
3708 supported by the hardware, and is faster still.
3710 For more information refer to the device datasheet at:
3711 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3715 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3716 Load: dtoverlay=ssd1306-spi,<param>=<val>
3717 Params: speed SPI bus speed (default 10000000)
3718 rotate Display rotation (0, 90, 180 or 270; default 0)
3719 fps Delay between frame updates (default 25)
3720 debug Debug output level (0-7; default 0)
3721 dc_pin GPIO pin for D/C (default 24)
3722 reset_pin GPIO pin for RESET (default 25)
3723 height Display height (32 or 64; default 64)
3727 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3728 Load: dtoverlay=ssd1331-spi,<param>=<val>
3729 Params: speed SPI bus speed (default 4500000)
3730 rotate Display rotation (0, 90, 180 or 270; default 0)
3731 fps Delay between frame updates (default 25)
3732 debug Debug output level (0-7; default 0)
3733 dc_pin GPIO pin for D/C (default 24)
3734 reset_pin GPIO pin for RESET (default 25)
3738 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3739 Load: dtoverlay=ssd1351-spi,<param>=<val>
3740 Params: speed SPI bus speed (default 4500000)
3741 rotate Display rotation (0, 90, 180 or 270; default 0)
3742 fps Delay between frame updates (default 25)
3743 debug Debug output level (0-7; default 0)
3744 dc_pin GPIO pin for D/C (default 24)
3745 reset_pin GPIO pin for RESET (default 25)
3748 Name: superaudioboard
3749 Info: Configures the SuperAudioBoard sound card
3750 Load: dtoverlay=superaudioboard,<param>=<val>
3751 Params: gpiopin GPIO pin for codec reset
3755 Info: Configures the Semtech SX150X I2C GPIO expanders.
3756 Load: dtoverlay=sx150x,<param>=<val>
3757 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3758 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3759 Permissible values of <m> (which is denoted in
3760 hex) depend on the device variant. For SX1501,
3761 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3762 For SX1503 and SX1506, <m> may be 20. For
3763 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3764 For SX1508, <m> may be 20, 21, 22 or 23.
3766 sx150<x>-<n>-<m>-int-gpio
3767 Integer, enables interrupts on SX150X device on
3768 I2C#<n> with slave address <m>, specifies
3769 the GPIO pin to which NINT output of SX150X is
3774 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3775 Uses Unicam 1, which is the standard camera connector on most Pi
3777 Load: dtoverlay=tc358743,<param>=<val>
3778 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3781 link-frequency Set the link frequency. Only values of 297000000
3782 (574Mbit/s) and 486000000 (972Mbit/s - default)
3783 are supported by the driver.
3784 media-controller Configure use of Media Controller API for
3785 configuring the sensor (default off)
3786 cam0 Adopt the default configuration for CAM0 on a
3787 Compute Module (CSI0, i2c_vc, and cam0_reg).
3790 Name: tc358743-audio
3791 Info: Used in combination with the tc358743-fast overlay to route the audio
3792 from the TC358743 over I2S to the Pi.
3793 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3795 Load: dtoverlay=tc358743-audio,<param>=<val>
3796 Params: card-name Override the default, "tc358743", card name.
3800 Info: 3.5" Color TFT Display by www.tinylcd.com
3801 Options: Touch, RTC, keypad
3802 Load: dtoverlay=tinylcd35,<param>=<val>
3803 Params: speed Display SPI bus speed
3805 rotate Display rotation {0,90,180,270}
3807 fps Delay between frame updates
3809 debug Debug output level {0-7}
3811 touch Enable touch panel
3813 touchgpio Touch controller IRQ GPIO
3815 xohms Touchpanel: Resistance of X-plate in ohms
3817 rtc-pcf PCF8563 Real Time Clock
3819 rtc-ds DS1307 Real Time Clock
3821 keypad Enable keypad
3824 Display with touchpanel, PCF8563 RTC and keypad:
3825 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
3827 dtoverlay=tinylcd35,touch,touchgpio=3
3831 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
3832 boards, which can be used as a secure key storage and hwrng,
3833 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
3834 Load: dtoverlay=tpm-slb9670
3839 Info: Change the pin usage of uart0
3840 Load: dtoverlay=uart0,<param>=<val>
3841 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
3843 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
3845 pin_func Alternative pin function - 4(Alt0) for 14&15,
3846 7(Alt3) for 32&33, 6(Alt2) for 36&37
3850 Info: Change the pin usage of uart1
3851 Load: dtoverlay=uart1,<param>=<val>
3852 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
3854 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
3858 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
3859 Load: dtoverlay=uart2,<param>
3860 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
3864 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
3865 Load: dtoverlay=uart3,<param>
3866 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
3870 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
3871 Load: dtoverlay=uart4,<param>
3872 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
3876 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
3877 Load: dtoverlay=uart5,<param>
3878 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
3882 Info: Configures the NW Digital Radio UDRC Hat
3883 Load: dtoverlay=udrc,<param>=<val>
3884 Params: alsaname Name of the ALSA audio device (default "udrc")
3887 Name: ugreen-dabboard
3888 Info: Configures the ugreen-dabboard I2S overlay
3889 This is a simple overlay based on the simple-audio-card and the dmic
3890 codec. It has the speciality that it is configured to use the codec
3891 as a master I2S device. It works for example with the Si468x DAB
3892 receiver on the uGreen DABBoard.
3893 Load: dtoverlay=ugreen-dabboard,<param>=<val>
3894 Params: card-name Override the default, "dabboard", card name.
3898 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
3899 vc4-kms-v3d and dwc2 overlays.
3900 Load: dtoverlay=upstream
3904 Name: upstream-aux-interrupt
3905 Info: This overlay has been deprecated and removed because it is no longer
3911 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
3912 the vc4-kms-v3d-pi4 and dwc2 overlays.
3913 Load: dtoverlay=upstream-pi4
3918 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3920 Load: dtoverlay=vc4-fkms-v3d,<param>
3921 Params: cma-512 CMA is 512MB (needs 1GB)
3922 cma-448 CMA is 448MB (needs 1GB)
3923 cma-384 CMA is 384MB (needs 1GB)
3924 cma-320 CMA is 320MB (needs 1GB)
3925 cma-256 CMA is 256MB (needs 1GB)
3926 cma-192 CMA is 192MB (needs 1GB)
3927 cma-128 CMA is 128MB
3930 cma-size CMA size in bytes, 4MB aligned
3931 cma-default Use upstream's default value
3934 Name: vc4-fkms-v3d-pi4
3935 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3937 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
3938 Params: cma-512 CMA is 512MB (needs 1GB)
3939 cma-448 CMA is 448MB (needs 1GB)
3940 cma-384 CMA is 384MB (needs 1GB)
3941 cma-320 CMA is 320MB (needs 1GB)
3942 cma-256 CMA is 256MB (needs 1GB)
3943 cma-192 CMA is 192MB (needs 1GB)
3944 cma-128 CMA is 128MB
3947 cma-size CMA size in bytes, 4MB aligned
3948 cma-default Use upstream's default value
3951 Name: vc4-kms-dpi-at056tn53v1
3952 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
3956 Name: vc4-kms-dpi-generic
3957 Info: Enable a generic DPI display under KMS. Default timings are for the
3958 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
3959 Requires vc4-kms-v3d to be loaded.
3960 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
3961 Params: clock-frequency Display clock frequency (Hz)
3962 hactive Horizontal active pixels
3963 hfp Horizontal front porch
3964 hsync Horizontal sync pulse width
3965 hbp Horizontal back porch
3966 vactive Vertical active lines
3967 vfp Vertical front porch
3968 vsync Vertical sync pulse width
3969 vbp Vertical back porch
3970 hsync-invert Horizontal sync active low
3971 vsync-invert Vertical sync active low
3972 de-invert Data Enable active low
3973 pixclk-invert Negative edge pixel clock
3974 width-mm Define the screen width in mm
3975 height-mm Define the screen height in mm
3976 rgb565 Change to RGB565 output on GPIOs 0-19
3977 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
3979 bgr666 Change to BGR666 output on GPIOs 0-21.
3980 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
3982 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
3984 bgr888 Change to BGR888 output on GPIOs 0-27
3985 rgb888 Change to RGB888 output on GPIOs 0-27
3986 bus-format Override the bus format for a MEDIA_BUS_FMT_*
3987 value. NB also overridden by rgbXXX overrides.
3988 backlight-gpio Defines a GPIO to be used for backlight control
3990 backlight-pwm Defines a PWM channel to be used for backlight
3991 control (default of none). NB Disables audio
3992 headphone output as that also uses PWM.
3993 backlight-pwm-chan Choose channel on &pwm node for backlight
3996 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3997 pwm-2chan for valid options.
3998 (default 18 - note this can only work with
4000 backlight-pwm-func Pin function of GPIO used for the PWM
4002 See pwm-2chan for valid options.
4004 backlight-def-brightness
4005 Set the default brightness. Normal range 1-16.
4007 rotate Display rotation {0,90,180,270} (default 0)
4010 Name: vc4-kms-dpi-hyperpixel2r
4011 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
4012 Requires vc4-kms-v3d to be loaded.
4013 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
4014 Params: disable-touch Disables the touch controller
4015 touchscreen-inverted-x Inverts X direction of touch controller
4016 touchscreen-inverted-y Inverts Y direction of touch controller
4017 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4018 rotate Display rotation {0,90,180,270} (default 0)
4021 Name: vc4-kms-dpi-hyperpixel4
4022 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
4023 Requires vc4-kms-v3d to be loaded.
4024 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
4025 Params: disable-touch Disables the touch controller
4026 touchscreen-inverted-x Inverts X direction of touch controller
4027 touchscreen-inverted-y Inverts Y direction of touch controller
4028 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4029 rotate Display rotation {0,90,180,270} (default 0)
4032 Name: vc4-kms-dpi-hyperpixel4sq
4033 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4034 Requires vc4-kms-v3d to be loaded.
4035 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4036 Params: disable-touch Disables the touch controller
4037 touchscreen-inverted-x Inverts X direction of touch controller
4038 touchscreen-inverted-y Inverts Y direction of touch controller
4039 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4040 rotate Display rotation {0,90,180,270} (default 0)
4043 Name: vc4-kms-dpi-panel
4044 Info: Enable a preconfigured KMS DPI panel.
4045 Requires vc4-kms-v3d to be loaded.
4046 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4047 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4048 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4049 mzp280 Enable a Geekworm MZP280 panel.
4050 backlight-gpio Defines a GPIO to be used for backlight control
4052 backlight-pwm Defines a PWM channel to be used for backlight
4053 control (default of none). NB Disables audio
4054 headphone output as that also uses PWM.
4055 backlight-pwm-chan Choose channel on &pwm node for backlight
4058 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4059 pwm-2chan for valid options.
4060 (default 18 - note this can only work with
4062 backlight-pwm-func Pin function of GPIO used for the PWM
4064 See pwm-2chan for valid options.
4066 backlight-def-brightness
4067 Set the default brightness. Normal range 1-16.
4069 rotate Display rotation {0,90,180,270} (default 0)
4072 Name: vc4-kms-dsi-7inch
4073 Info: Enable the Raspberry Pi DSI 7" screen.
4074 Includes the edt-ft5406 for the touchscreen element.
4075 Requires vc4-kms-v3d to be loaded.
4076 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4077 Params: sizex Touchscreen size x (default 800)
4078 sizey Touchscreen size y (default 480)
4079 invx Touchscreen inverted x axis
4080 invy Touchscreen inverted y axis
4081 swapxy Touchscreen swapped x y axis
4082 disable_touch Disables the touch screen overlay driver
4085 Name: vc4-kms-dsi-lt070me05000
4086 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4087 Note that this is a 4 lane DSI device, so it will only work on a Compute
4089 Requires vc4-kms-v3d to be loaded.
4090 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4091 Params: reset GPIO for the reset signal (default 17)
4092 enable GPIO for the enable signal (default 4)
4093 dcdc-en GPIO for the DC-DC converter enable (default 5)
4096 Name: vc4-kms-dsi-lt070me05000-v2
4097 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4099 Note that this is a 4 lane DSI device, so it will only work on a Compute
4101 Requires vc4-kms-v3d to be loaded.
4102 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4106 Name: vc4-kms-kippah-7inch
4107 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4112 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4113 Load: dtoverlay=vc4-kms-v3d,<param>
4114 Params: cma-512 CMA is 512MB (needs 1GB)
4115 cma-448 CMA is 448MB (needs 1GB)
4116 cma-384 CMA is 384MB (needs 1GB)
4117 cma-320 CMA is 320MB (needs 1GB)
4118 cma-256 CMA is 256MB (needs 1GB)
4119 cma-192 CMA is 192MB (needs 1GB)
4120 cma-128 CMA is 128MB
4123 cma-size CMA size in bytes, 4MB aligned
4124 cma-default Use upstream's default value
4125 audio Enable or disable audio over HDMI (default "on")
4126 noaudio Disable all HDMI audio (default "off")
4127 composite Enable the composite output (default "off")
4128 N.B. Disables all other outputs on a Pi 4.
4129 nohdmi Disable HDMI output
4132 Name: vc4-kms-v3d-pi4
4133 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4134 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4135 Params: cma-512 CMA is 512MB
4136 cma-448 CMA is 448MB
4137 cma-384 CMA is 384MB
4138 cma-320 CMA is 320MB
4139 cma-256 CMA is 256MB
4140 cma-192 CMA is 192MB
4141 cma-128 CMA is 128MB
4144 cma-size CMA size in bytes, 4MB aligned
4145 cma-default Use upstream's default value
4146 audio Enable or disable audio over HDMI0 (default
4148 audio1 Enable or disable audio over HDMI1 (default
4150 noaudio Disable all HDMI audio (default "off")
4151 composite Enable the composite output (disables all other
4153 nohdmi Disable both HDMI 0 & 1 outputs
4154 nohdmi0 Disable HDMI 0 output
4155 nohdmi1 Disable HDMI 1 output
4159 Name: vc4-kms-vga666
4160 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4161 Requires vc4-kms-v3d to be loaded.
4162 Load: dtoverlay=vc4-kms-vga666,<param>
4163 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4164 from the display. NB These are NOT 5V tolerant
4165 GPIOs, therefore level shifters are required.
4169 Info: Overlay for the Fen Logic VGA666 board
4170 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4171 after the kernel has started.
4172 NOT for use with vc4-kms-v3d.
4173 Load: dtoverlay=vga666
4178 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4179 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4180 set in the EEPROM config.
4181 Load: dtoverlay=vl805
4186 Info: Configures the w1-gpio Onewire interface module.
4187 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4188 Load: dtoverlay=w1-gpio,<param>=<val>
4189 Params: gpiopin GPIO for I/O (default "4")
4190 pullup Now enabled by default (ignored)
4193 Name: w1-gpio-pullup
4194 Info: Configures the w1-gpio Onewire interface module.
4195 Use this overlay if you *do* need a GPIO to drive an external pullup.
4196 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4197 Params: gpiopin GPIO for I/O (default "4")
4198 extpullup GPIO for external pullup (default "5")
4199 pullup Now enabled by default (ignored)
4203 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4204 Load: dtoverlay=w5500,<param>=<val>
4205 Params: int_pin GPIO used for INT (default 25)
4207 speed SPI bus speed (default 30000000)
4209 cs SPI bus Chip Select (default 0)
4212 Name: waveshare-can-fd-hat-mode-a
4213 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4214 for Raspberry Pi, Multi Protections. Use this overlay when the
4215 HAT is configured in Mode A (Default), with can0 on spi0.0
4217 https://www.waveshare.com/2-ch-can-fd-hat.htm
4218 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4222 Name: waveshare-can-fd-hat-mode-b
4223 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4224 for Raspberry Pi, Multi Protections. Use this overlay when the
4225 HAT is configured in Mode B (requires hardware modification), with
4226 can0 on spi0.0 and can1 on spi0.1.
4227 https://www.waveshare.com/2-ch-can-fd-hat.htm
4228 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4233 Info: Configures the wittypi RTC module.
4234 Load: dtoverlay=wittypi,<param>=<val>
4235 Params: led_gpio GPIO for LED (default "17")
4236 led_trigger Choose which activity the LED tracks (default
4240 Name: wm8960-soundcard
4241 Info: Overlay for the Waveshare wm8960 soundcard
4242 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4243 Params: alsaname Changes the card name in ALSA
4244 compatible Changes the codec compatibility
4250 If you are experiencing problems that you think are DT-related, enable DT
4251 diagnostic output by adding this to /boot/config.txt:
4255 and rebooting. Then run:
4259 and look for relevant messages.
4264 This is only meant to be a quick introduction to the subject of Device Tree on
4265 Raspberry Pi. There is a more complete explanation here:
4267 http://www.raspberrypi.org/documentation/configuration/device-tree.md