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 LOCO DAC-AMP
734 Load: dtoverlay=dionaudio-loco
738 Name: dionaudio-loco-v2
739 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
740 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
741 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
742 Digital volume control. Enable with
743 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
744 (The default behaviour is that the Digital
745 volume control is limited to a maximum of
746 0dB. ie. it can attenuate but not provide
747 gain. For most users, this will be desired
748 as it will prevent clipping. By appending
749 the 24dB_digital_gain parameter, the Digital
750 volume control will allow up to 24dB of
751 gain. If this parameter is enabled, it is the
752 responsibility of the user to ensure that
753 the Digital volume control is set to a value
754 that does not result in clipping/distortion!)
758 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
759 UART0/ttyAMA0 over GPIOs 14 & 15.
760 N.B. To disable the systemd service that initialises the modem so it
761 doesn't use the UART, use 'sudo systemctl disable hciuart'.
762 Load: dtoverlay=disable-bt
767 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
768 Load: dtoverlay=disable-wifi
773 Info: Overlay for a generic 18-bit DPI display
774 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
775 2-3 seconds after the kernel has started.
776 Load: dtoverlay=dpi18
781 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
782 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
783 the output 3-3 seconds after the kernel has started.
784 Load: dtoverlay=dpi18cpadhi
789 Info: Overlay for a generic 24-bit DPI display
790 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
791 2-3 seconds after the kernel has started.
792 Load: dtoverlay=dpi24
797 Info: Configures the NW Digital Radio DRAWS Hat
799 The board includes an ADC to measure various board values and also
800 provides two analog user inputs on the expansion header. The ADC
801 can be configured for various sample rates and gain values to adjust
802 the input range. Tables describing the two parameters follow.
819 4 = 1600sps (default)
823 Load: dtoverlay=draws,<param>=<val>
824 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
825 input voltage sensor (default 1)
827 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
830 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
831 5V rail voltage sensor (default 1)
833 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
836 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
837 AIN2 input (default 2)
839 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
841 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
842 AIN3 input (default 2)
844 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
846 alsaname Name of the ALSA audio device (default "draws")
850 Info: Selects the dwc_otg USB controller driver which has fiq support. This
851 is the default on all except the Pi Zero which defaults to dwc2.
852 Load: dtoverlay=dwc-otg
857 Info: Selects the dwc2 USB controller driver
858 Load: dtoverlay=dwc2,<param>=<val>
859 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
861 g-rx-fifo-size Size of rx fifo size in gadget mode
863 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
867 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
871 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
872 This works with the Raspberry Pi 7" touchscreen when not being polled
874 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
875 config.txt to stop the firmware polling the touchscreen.
876 Load: dtoverlay=edt-ft5406,<param>=<val>
877 Params: sizex Touchscreen size x (default 800)
878 sizey Touchscreen size y (default 480)
879 invx Touchscreen inverted x axis
880 invy Touchscreen inverted y axis
881 swapxy Touchscreen swapped x y axis
885 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
886 Load: dtoverlay=enc28j60,<param>=<val>
887 Params: int_pin GPIO used for INT (default 25)
889 speed SPI bus speed (default 12000000)
893 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
894 Load: dtoverlay=enc28j60-spi2,<param>=<val>
895 Params: int_pin GPIO used for INT (default 39)
897 speed SPI bus speed (default 12000000)
901 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
902 GPIO 4 (pin 7 on GPIO header) for interrupt.
903 Load: dtoverlay=exc3000,<param>=<val>
904 Params: interrupt GPIO used for interrupt (default 4)
905 sizex Touchscreen size x (default 4096)
906 sizey Touchscreen size y (default 4096)
907 invx Touchscreen inverted x axis
908 invy Touchscreen inverted y axis
909 swapxy Touchscreen swapped x y axis
913 Info: Overlay for SPI-connected displays using the fbtft drivers.
915 This overlay seeks to replace the functionality provided by fbtft_device
916 which is now gone from the kernel.
918 Most displays from fbtft_device have been ported over.
920 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
922 It is also possible to specify the controller (this will use the default
923 init sequence in the driver).
925 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
927 For devices on spi1 or spi2, the interfaces should be enabled
928 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
930 The following features of fbtft_device have not been ported over:
931 - parallel bus is not supported
932 - the init property which overrides the controller initialization
933 sequence is not supported as a parameter due to memory limitations in
934 the bootloader responsible for applying the overlay.
936 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
939 Load: dtoverlay=fbtft,<param>=<val>
941 spi<n>-<m> Configure device at spi<n>, cs<m>
943 speed SPI bus speed in Hz (default 32000000)
944 cpha Shifted clock phase (CPHA) mode
945 cpol Inverse clock polarity (CPOL) mode
947 adafruit18 Adafruit 1.8
948 adafruit22 Adafruit 2.2 (old)
949 adafruit22a Adafruit 2.2
950 adafruit28 Adafruit 2.8
951 adafruit13m Adafruit 1.3 OLED
952 admatec_c-berry28 C-Berry28
954 er_tftm050_2 ER-TFTM070-2
955 er_tftm070_5 ER-TFTM070-5
957 ew24ha0_9bit EW24HA0 in 9-bit mode
958 freetronicsoled128 Freetronics OLED128
961 itdb28_spi ITDB02-2.8 with SPI interface circuit
962 mi0283qt-2 Watterott MI0283QT-2
963 mi0283qt-9a Watterott MI0283QT-9A
965 nokia3310a Nokia 3310a
968 pitft Adafruit PiTFT 2.8
970 rpi-display Watterott rpi-display
971 sainsmart18 Sainsmart 1.8
972 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
973 tinylcd35 TinyLCD 3.5
974 tm022hdh26 Tianma TM022HDH26
975 tontec35_9481 Tontect 3.5 with ILI9481 controller
976 tontec35_9486 Tontect 3.5 with ILI9486 controller
977 waveshare32b Waveshare 3.2
978 waveshare22 Waveshare 2.2
980 bd663474 BD663474 display controller
981 hx8340bn HX8340BN display controller
982 hx8347d HX8347D display controller
983 hx8353d HX8353D display controller
984 hx8357d HX8357D display controller
985 ili9163 ILI9163 display controller
986 ili9320 ILI9320 display controller
987 ili9325 ILI9325 display controller
988 ili9340 ILI9340 display controller
989 ili9341 ILI9341 display controller
990 ili9481 ILI9481 display controller
991 ili9486 ILI9486 display controller
992 pcd8544 PCD8544 display controller
993 ra8875 RA8875 display controller
994 s6d02a1 S6D02A1 display controller
995 s6d1121 S6D1121 display controller
996 seps525 SEPS525 display controller
997 sh1106 SH1106 display controller
998 ssd1289 SSD1289 display controller
999 ssd1305 SSD1305 display controller
1000 ssd1306 SSD1306 display controller
1001 ssd1325 SSD1325 display controller
1002 ssd1331 SSD1331 display controller
1003 ssd1351 SSD1351 display controller
1004 st7735r ST7735R display controller
1005 st7789v ST7789V display controller
1006 tls8204 TLS8204 display controller
1007 uc1611 UC1611 display controller
1008 uc1701 UC1701 display controller
1009 upd161704 UPD161704 display controller
1011 width Display width in pixels
1012 height Display height in pixels
1013 regwidth Display controller register width (default is
1015 buswidth Display bus interface width (default 8)
1016 debug Debug output level {0-7}
1017 rotate Display rotation {0, 90, 180, 270} (counter
1018 clockwise). Not supported by all drivers.
1019 bgr Enable BGR mode (default off). Use if Red and
1020 Blue are swapped. Not supported by all drivers.
1021 fps Frames per second (default 30). In effect this
1022 states how long the driver will wait after video
1023 memory has been changed until display update
1024 transfer is started.
1025 txbuflen Length of the FBTFT transmit buffer
1027 startbyte Sets the Start byte used by fb_ili9320,
1028 fb_ili9325 and fb_hx8347d. Common value is 0x70.
1029 gamma String representation of Gamma Curve(s). Driver
1030 specific. Not supported by all drivers.
1031 reset_pin GPIO pin for RESET
1032 dc_pin GPIO pin for D/C
1033 led_pin GPIO pin for LED backlight
1037 Info: Configures the Fe-Pi Audio Sound Card
1038 Load: dtoverlay=fe-pi-audio
1043 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1044 nicely with a "traffic-light" display of red, amber and green LEDs on
1045 GPIOs 7, 8 and 25 respectively.
1046 Load: dtoverlay=fsm-demo,<param>=<val>
1047 Params: fsm_debug Enable debug logging (default off)
1051 Info: An overlay for the Ghost amplifier.
1052 Load: dtoverlay=ghost-amp,<param>=<val>
1053 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1058 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1059 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1060 Load: dtoverlay=goodix,<param>=<val>
1061 Params: interrupt GPIO used for interrupt (default 4)
1062 reset GPIO used for reset (default 17)
1065 Name: googlevoicehat-soundcard
1066 Info: Configures the Google voiceHAT soundcard
1067 Load: dtoverlay=googlevoicehat-soundcard
1072 Info: Configure a GPIO pin to control a cooling fan.
1073 Load: dtoverlay=gpio-fan,<param>=<val>
1074 Params: gpiopin GPIO used to control the fan (default 12)
1075 temp Temperature at which the fan switches on, in
1076 millicelcius (default 55000)
1080 Info: Activate a "hog" for a GPIO - request that the kernel configures it as
1081 an output, driven low or high as indicated by the presence or absence
1082 of the active_low parameter. Note that a hogged GPIO is not available
1083 to other drivers or for gpioset/gpioget.
1084 Load: dtoverlay=gpio-hog,<param>=<val>
1085 Params: gpio GPIO pin to hog (default 26)
1086 active_low If set, the hog drives the GPIO low (defaults
1087 to off - the GPIO is driven high)
1091 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1092 based gpio_ir_recv driver maps received keys directly to a
1093 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1094 not required! The key mapping and other decoding parameters can be
1095 configured by "ir-keytable" tool.
1096 Load: dtoverlay=gpio-ir,<param>=<val>
1097 Params: gpio_pin Input pin number. Default is 18.
1099 gpio_pull Desired pull-up/down state (off, down, up)
1102 invert "1" = invert the input (active-low signalling).
1103 "0" = non-inverted input (active-high
1104 signalling). Default is "1".
1106 rc-map-name Default rc keymap (can also be changed by
1107 ir-keytable), defaults to "rc-rc6-mce"
1111 Info: Use GPIO pin as bit-banged infrared transmitter output.
1112 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1113 a PWM so it can be used together with onboard analog audio.
1114 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1115 Params: gpio_pin Output GPIO (default 18)
1117 invert "1" = invert the output (make it active-low).
1118 Default is "0" (active-high).
1122 Info: This is a generic overlay for activating GPIO keypresses using
1123 the gpio-keys library and this dtoverlay. Multiple keys can be
1124 set up using multiple calls to the overlay for configuring
1125 additional buttons or joysticks. You can see available keycodes
1126 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1127 linux/input-event-codes.h#L64
1128 Load: dtoverlay=gpio-key,<param>=<val>
1129 Params: gpio GPIO pin to trigger on (default 3)
1130 active_low When this is 1 (active low), a falling
1131 edge generates a key down event and a
1132 rising edge generates a key up event.
1133 When this is 0 (active high), this is
1134 reversed. The default is 1 (active low)
1135 gpio_pull Desired pull-up/down state (off, down, up)
1136 Default is "up". Note that the default pin
1137 (GPIO3) has an external pullup
1138 label Set a label for the key
1139 keycode Set the key code for the button
1144 Info: This is a generic overlay for activating LEDs (or any other component)
1145 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1146 overlay. While there are many existing methods to activate LEDs on the
1147 RPi, this method offers some advantages:
1148 1) Does not require any userspace programs.
1149 2) LEDs can be connected to the kernel's led-trigger framework,
1150 and drive the LED based on triggers such as cpu load, heartbeat,
1151 kernel panic, key input, timers and others.
1152 3) LED can be tied to the input state of another GPIO pin.
1153 4) The LED is setup early during the kernel boot process (useful
1154 for cpu/heartbeat/panic triggers).
1156 Typical electrical connection is:
1157 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1158 The GPIO pin number can be changed with the 'gpio=' parameter.
1160 To control an LED from userspace, write a 0 or 1 value:
1161 echo 1 > /sys/class/leds/myled1/brightness
1162 The 'myled1' name can be changed with the 'label=' parameter.
1164 To connect the LED to a kernel trigger from userspace:
1165 echo cpu > /sys/class/leds/myled1/trigger
1166 echo heartbeat > /sys/class/leds/myled1/trigger
1167 echo none > /sys/class/leds/myled1/trigger
1168 To connect the LED to GPIO.26 pin (physical pin 37):
1169 echo gpio > /sys/class/leds/myled1/trigger
1170 echo 26 > /sys/class/leds/myled1/gpio
1172 cat /sys/class/leds/myled1/trigger
1174 More information about the Linux kernel LED/Trigger system:
1175 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1176 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1177 Load: dtoverlay=gpio-led,<param>=<val>
1178 Params: gpio GPIO pin connected to the LED (default 19)
1179 label The label for this LED. It will appear under
1180 /sys/class/leds/<label> . Default 'myled1'.
1181 trigger Set the led-trigger to connect to this LED.
1182 default 'none' (LED is user-controlled).
1183 Some possible triggers:
1184 cpu - CPU load (all CPUs)
1185 cpu0 - CPU load of first CPU.
1186 mmc - disk activity (all disks)
1187 panic - turn on on kernel panic
1188 heartbeat - indicate system health
1189 gpio - connect to a GPIO input pin (note:
1190 currently the GPIO PIN can not be set
1191 using overlay parameters, must be
1192 done in userspace, see examples above.
1193 active_low Set to 1 to turn invert the LED control
1194 (writing 0 to /sys/class/leds/XXX/brightness
1195 will turn on the GPIO/LED). Default '0'.
1198 Name: gpio-no-bank0-irq
1199 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1200 which can be useful for UIO drivers.
1201 N.B. Using this overlay will trigger a kernel WARN during booting, but
1202 this can safely be ignored - the system should work as expected.
1203 Load: dtoverlay=gpio-no-bank0-irq
1208 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1209 for user-space GPIO edge detection systems.
1210 Load: dtoverlay=gpio-no-irq
1215 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1216 overlay interferes with the normal power-down sequence, preventing the
1217 kernel from resetting the SoC (a necessary step in a normal power-off
1218 or reboot). This also disables the ability to trigger a boot by driving
1221 The GPIO starts in an inactive state. At poweroff time it is driven
1222 active for 100ms, then inactive for 100ms, then active again. It is
1223 safe to remove the power at any point after the initial activation of
1226 Users of this overlay are required to provide an external mechanism to
1227 switch off the power supply when signalled - failure to do so results
1228 in a kernel BUG, increased power consumption and undefined behaviour.
1229 Load: dtoverlay=gpio-poweroff,<param>=<val>
1230 Params: gpiopin GPIO for signalling (default 26)
1232 active_low Set if the power control device requires a
1233 high->low transition to trigger a power-down.
1234 Note that this will require the support of a
1235 custom dt-blob.bin to prevent a power-down
1236 during the boot process, and that a reboot
1237 will also cause the pin to go low.
1238 input Set if the gpio pin should be configured as
1240 export Set to export the configured pin to sysfs
1241 active_delay_ms Initial GPIO active period (default 100)
1242 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1243 timeout_ms Specify (in ms) how long the kernel waits for
1244 power-down before issuing a WARN (default 3000).
1248 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1249 is configured as an input key that generates KEY_POWER events.
1251 This event is handled by systemd-logind by initiating a
1252 shutdown. Systemd versions older than 225 need an udev rule
1253 enable listening to the input device:
1255 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1256 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1257 ATTRS{keys}=="116", TAG+="power-switch"
1259 Alternatively this event can be handled also on systems without
1260 systemd, just by traditional SysV init daemon. KEY_POWER event
1261 (keycode 116) needs to be mapped to KeyboardSignal on console
1262 and then kb::kbrequest inittab action which is triggered by
1263 KeyboardSignal from console can be configured to issue system
1264 shutdown. Steps for this configuration are:
1266 Add following lines to the /etc/console-setup/remap.inc file:
1268 # Key Power as special keypress
1269 keycode 116 = KeyboardSignal
1271 Then add following lines to /etc/inittab file:
1273 # Action on special keypress (Key Power)
1274 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1276 And finally reload configuration by calling following commands:
1278 # dpkg-reconfigure console-setup
1279 # service console-setup reload
1282 This overlay only handles shutdown. After shutdown, the system
1283 can be powered up again by driving GPIO3 low. The default
1284 configuration uses GPIO3 with a pullup, so if you connect a
1285 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1286 you get a shutdown and power-up button. Please note that
1287 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1288 Load: dtoverlay=gpio-shutdown,<param>=<val>
1289 Params: gpio_pin GPIO pin to trigger on (default 3)
1290 For Raspberry Pi 1 Model B rev 1 set this
1291 explicitly to value 1, e.g.:
1293 dtoverlay=gpio-shutdown,gpio_pin=1
1295 active_low When this is 1 (active low), a falling
1296 edge generates a key down event and a
1297 rising edge generates a key up event.
1298 When this is 0 (active high), this is
1299 reversed. The default is 1 (active low).
1301 gpio_pull Desired pull-up/down state (off, down, up)
1304 Note that the default pin (GPIO3) has an
1305 external pullup. Same applies for GPIO1
1306 on Raspberry Pi 1 Model B rev 1.
1308 debounce Specify the debounce interval in milliseconds
1313 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1314 data, 2 gpio pins for enable and register select and 1 optional pin
1315 for enabling/disabling the backlight display.
1316 Load: dtoverlay=hd44780-lcd,<param>=<val>
1317 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1319 pin_d5 GPIO pin for data pin D5 (default 13)
1321 pin_d6 GPIO pin for data pin D6 (default 19)
1323 pin_d7 GPIO pin for data pin D7 (default 26)
1325 pin_en GPIO pin for "Enable" (default 21)
1327 pin_rs GPIO pin for "Register Select" (default 20)
1329 pin_bl Optional pin for enabling/disabling the
1330 display backlight. (default disabled)
1332 display_height Height of the display in characters
1334 display_width Width of the display in characters
1337 Name: hdmi-backlight-hwhack-gpio
1338 Info: Devicetree overlay for GPIO based backlight on/off capability.
1339 Use this if you have one of those HDMI displays whose backlight cannot
1340 be controlled via DPMS over HDMI and plan to do a little soldering to
1341 use an RPi gpio pin for on/off switching. See:
1342 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1343 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1344 Params: gpio_pin GPIO pin used (default 17)
1345 active_low Set this to 1 if the display backlight is
1346 switched on when the wire goes low.
1347 Leave the default (value 0) if the backlight
1348 expects a high to switch it on.
1352 Info: Configures the HifiBerry Amp and Amp+ audio cards
1353 Load: dtoverlay=hifiberry-amp
1357 Name: hifiberry-amp100
1358 Info: Configures the HifiBerry AMP100 audio card
1359 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1360 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1361 Digital volume control. Enable with
1362 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1363 (The default behaviour is that the Digital
1364 volume control is limited to a maximum of
1365 0dB. ie. it can attenuate but not provide
1366 gain. For most users, this will be desired
1367 as it will prevent clipping. By appending
1368 the 24dB_digital_gain parameter, the Digital
1369 volume control will allow up to 24dB of
1370 gain. If this parameter is enabled, it is the
1371 responsibility of the user to ensure that
1372 the Digital volume control is set to a value
1373 that does not result in clipping/distortion!)
1374 slave Force DAC+ Pro into slave mode, using Pi as
1375 master for bit clock and frame clock.
1376 leds_off If set to 'true' the onboard indicator LEDs
1377 are switched off at all times.
1378 auto_mute If set to 'true' the amplifier is automatically
1379 muted when the DAC is not playing.
1380 mute_ext_ctl The amplifier's HW mute control is enabled
1381 in ALSA mixer and set to <val>.
1382 Will be overwritten by ALSA user settings.
1386 Info: Configures the HifiBerry DAC audio cards
1387 Load: dtoverlay=hifiberry-dac
1391 Name: hifiberry-dacplus
1392 Info: Configures the HifiBerry DAC+ audio card
1393 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1394 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1395 Digital volume control. Enable with
1396 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1397 (The default behaviour is that the Digital
1398 volume control is limited to a maximum of
1399 0dB. ie. it can attenuate but not provide
1400 gain. For most users, this will be desired
1401 as it will prevent clipping. By appending
1402 the 24dB_digital_gain parameter, the Digital
1403 volume control will allow up to 24dB of
1404 gain. If this parameter is enabled, it is the
1405 responsibility of the user to ensure that
1406 the Digital volume control is set to a value
1407 that does not result in clipping/distortion!)
1408 slave Force DAC+ Pro into slave mode, using Pi as
1409 master for bit clock and frame clock.
1410 leds_off If set to 'true' the onboard indicator LEDs
1411 are switched off at all times.
1414 Name: hifiberry-dacplusadc
1415 Info: Configures the HifiBerry DAC+ADC audio card
1416 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1417 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1418 Digital volume control. Enable with
1419 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1420 (The default behaviour is that the Digital
1421 volume control is limited to a maximum of
1422 0dB. ie. it can attenuate but not provide
1423 gain. For most users, this will be desired
1424 as it will prevent clipping. By appending
1425 the 24dB_digital_gain parameter, the Digital
1426 volume control will allow up to 24dB of
1427 gain. If this parameter is enabled, it is the
1428 responsibility of the user to ensure that
1429 the Digital volume control is set to a value
1430 that does not result in clipping/distortion!)
1431 slave Force DAC+ Pro into slave mode, using Pi as
1432 master for bit clock and frame clock.
1433 leds_off If set to 'true' the onboard indicator LEDs
1434 are switched off at all times.
1437 Name: hifiberry-dacplusadcpro
1438 Info: Configures the HifiBerry DAC+ADC PRO audio card
1439 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1440 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1441 Digital volume control. Enable with
1442 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1443 (The default behaviour is that the Digital
1444 volume control is limited to a maximum of
1445 0dB. ie. it can attenuate but not provide
1446 gain. For most users, this will be desired
1447 as it will prevent clipping. By appending
1448 the 24dB_digital_gain parameter, the Digital
1449 volume control will allow up to 24dB of
1450 gain. If this parameter is enabled, it is the
1451 responsibility of the user to ensure that
1452 the Digital volume control is set to a value
1453 that does not result in clipping/distortion!)
1454 slave Force DAC+ADC Pro into slave mode, using Pi as
1455 master for bit clock and frame clock.
1456 leds_off If set to 'true' the onboard indicator LEDs
1457 are switched off at all times.
1460 Name: hifiberry-dacplusdsp
1461 Info: Configures the HifiBerry DAC+DSP audio card
1462 Load: dtoverlay=hifiberry-dacplusdsp
1466 Name: hifiberry-dacplushd
1467 Info: Configures the HifiBerry DAC+ HD audio card
1468 Load: dtoverlay=hifiberry-dacplushd
1472 Name: hifiberry-digi
1473 Info: Configures the HifiBerry Digi and Digi+ audio card
1474 Load: dtoverlay=hifiberry-digi
1478 Name: hifiberry-digi-pro
1479 Info: Configures the HifiBerry Digi+ Pro audio card
1480 Load: dtoverlay=hifiberry-digi-pro
1485 Info: Enables "High Peripheral" mode
1486 Load: dtoverlay=highperi
1491 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1492 Default values match Texy's display shield
1493 Load: dtoverlay=hy28a,<param>=<val>
1494 Params: speed Display SPI bus speed
1496 rotate Display rotation {0,90,180,270}
1498 fps Delay between frame updates
1500 debug Debug output level {0-7}
1502 xohms Touchpanel sensitivity (X-plate resistance)
1504 resetgpio GPIO used to reset controller
1506 ledgpio GPIO used to control backlight
1510 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1511 Default values match Texy's display shield
1512 Load: dtoverlay=hy28b,<param>=<val>
1513 Params: speed Display SPI bus speed
1515 rotate Display rotation {0,90,180,270}
1517 fps Delay between frame updates
1519 debug Debug output level {0-7}
1521 xohms Touchpanel sensitivity (X-plate resistance)
1523 resetgpio GPIO used to reset controller
1525 ledgpio GPIO used to control backlight
1529 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1530 Default values match Texy's display shield
1531 Load: dtoverlay=hy28b-2017,<param>=<val>
1532 Params: speed Display SPI bus speed
1534 rotate Display rotation {0,90,180,270}
1536 fps Delay between frame updates
1538 debug Debug output level {0-7}
1540 xohms Touchpanel sensitivity (X-plate resistance)
1542 resetgpio GPIO used to reset controller
1544 ledgpio GPIO used to control backlight
1548 Info: Configures the Audiophonics I-SABRE Q2M DAC
1549 Load: dtoverlay=i-sabre-q2m
1554 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1555 Load: dtoverlay=i2c-bcm2708
1560 Info: Adds support for a number of I2C fan controllers
1561 Load: dtoverlay=i2c-fan,<param>=<val>
1562 Params: addr Sets the address for the fan controller. Note
1563 that the device must be configured to use the
1566 i2c0 Choose the I2C0 bus on GPIOs 0&1
1568 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1570 i2c3 Choose the I2C3 bus (configure with the i2c3
1571 overlay - BCM2711 only)
1573 i2c4 Choose the I2C3 bus (configure with the i2c3
1574 overlay - BCM2711 only)
1576 i2c5 Choose the I2C5 bus (configure with the i2c4
1577 overlay - BCM2711 only)
1579 i2c6 Choose the I2C6 bus (configure with the i2c6
1580 overlay - BCM2711 only)
1582 minpwm PWM setting for the fan when the SoC is below
1583 mintemp (range 0-255. default 0)
1584 maxpwm PWM setting for the fan when the SoC is above
1585 maxtemp (range 0-255. default 255)
1586 midtemp Temperature (in millicelcius) at which the fan
1587 begins to speed up (default 50000)
1589 midtemp_hyst Temperature delta (in millicelcius) below
1590 mintemp at which the fan will drop to minrpm
1593 maxtemp Temperature (in millicelcius) at which the fan
1594 will be held at maxrpm (default 70000)
1596 maxtemp_hyst Temperature delta (in millicelcius) below
1597 maxtemp at which the fan begins to slow down
1600 emc2301 Select the Microchip EMC230x controller family
1601 - EMC2301, EMC2302, EMC2303, EMC2305.
1605 Info: Adds support for software i2c controller on gpio pins
1606 Load: dtoverlay=i2c-gpio,<param>=<val>
1607 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1609 i2c_gpio_scl GPIO used for I2C clock (default "24")
1611 i2c_gpio_delay_us Clock delay in microseconds
1612 (default "2" = ~100kHz)
1614 bus Set to a unique, non-zero value if wanting
1615 multiple i2c-gpio busses. If set, will be used
1616 as the preferred bus number (/dev/i2c-<n>). If
1617 not set, the default value is 0, but the bus
1618 number will be dynamically assigned - probably
1623 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1624 Load: dtoverlay=i2c-mux,<param>=<val>
1625 Params: pca9542 Select the NXP PCA9542 device
1627 pca9545 Select the NXP PCA9545 device
1629 pca9548 Select the NXP PCA9548 device
1631 addr Change I2C address of the device (default 0x70)
1634 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1637 Name: i2c-pwm-pca9685a
1638 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1639 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1640 Params: addr I2C address of PCA9685A (default 0x40)
1644 Info: Adds support for a number of I2C Real Time Clock devices
1645 Load: dtoverlay=i2c-rtc,<param>=<val>
1646 Params: abx80x Select one of the ABx80x family:
1647 AB0801, AB0803, AB0804, AB0805,
1648 AB1801, AB1803, AB1804, AB1805
1650 bq32000 Select the TI BQ32000 device
1652 ds1307 Select the DS1307 device
1654 ds1339 Select the DS1339 device
1656 ds1340 Select the DS1340 device
1658 ds3231 Select the DS3231 device
1660 m41t62 Select the M41T62 device
1662 mcp7940x Select the MCP7940x device
1664 mcp7941x Select the MCP7941x device
1666 pcf2127 Select the PCF2127 device
1668 pcf2129 Select the PCF2129 device
1670 pcf85063 Select the PCF85063 device
1672 pcf85063a Select the PCF85063A device
1674 pcf8523 Select the PCF8523 device
1676 pcf85363 Select the PCF85363 device
1678 pcf8563 Select the PCF8563 device
1680 rv1805 Select the Micro Crystal RV1805 device
1682 rv3028 Select the Micro Crystal RV3028 device
1684 rv8803 Select the Micro Crystal RV8803 device
1686 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1688 s35390a Select the ABLIC S35390A device
1690 i2c0 Choose the I2C0 bus on GPIOs 0&1
1692 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1694 i2c3 Choose the I2C3 bus (configure with the i2c3
1695 overlay - BCM2711 only)
1697 i2c4 Choose the I2C3 bus (configure with the i2c3
1698 overlay - BCM2711 only)
1700 i2c5 Choose the I2C5 bus (configure with the i2c4
1701 overlay - BCM2711 only)
1703 i2c6 Choose the I2C6 bus (configure with the i2c6
1704 overlay - BCM2711 only)
1706 addr Sets the address for the RTC. Note that the
1707 device must be configured to use the specified
1710 trickle-diode-disable Do not use the internal trickle charger diode
1713 trickle-diode-type Diode type for trickle charge - "standard" or
1714 "schottky" (ABx80x and RV1805 only)
1716 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1717 ABx80x, RV1805, RV3028)
1719 wakeup-source Specify that the RTC can be used as a wakeup
1722 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1723 off or 1 for Vdd < VBackup (RV3028 only)
1727 Info: Adds support for a number of I2C Real Time Clock devices
1728 using the software i2c controller
1729 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1730 Params: abx80x Select one of the ABx80x family:
1731 AB0801, AB0803, AB0804, AB0805,
1732 AB1801, AB1803, AB1804, AB1805
1734 bq32000 Select the TI BQ32000 device
1736 ds1307 Select the DS1307 device
1738 ds1339 Select the DS1339 device
1740 ds1340 Select the DS1340 device
1742 ds3231 Select the DS3231 device
1744 m41t62 Select the M41T62 device
1746 mcp7940x Select the MCP7940x device
1748 mcp7941x Select the MCP7941x device
1750 pcf2127 Select the PCF2127 device
1752 pcf2129 Select the PCF2129 device
1754 pcf85063 Select the PCF85063 device
1756 pcf85063a Select the PCF85063A device
1758 pcf8523 Select the PCF8523 device
1760 pcf85363 Select the PCF85363 device
1762 pcf8563 Select the PCF8563 device
1764 rv1805 Select the Micro Crystal RV1805 device
1766 rv3028 Select the Micro Crystal RV3028 device
1768 rv8803 Select the Micro Crystal RV8803 device
1770 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1772 s35390a Select the ABLIC S35390A device
1774 addr Sets the address for the RTC. Note that the
1775 device must be configured to use the specified
1778 trickle-diode-disable Do not use the internal trickle charger diode
1781 trickle-diode-type Diode type for trickle charge - "standard" or
1782 "schottky" (ABx80x and RV1805 only)
1784 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1785 ABx80x, RV1805, RV3028)
1787 wakeup-source Specify that the RTC can be used as a wakeup
1790 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1791 off or 1 for Vdd < VBackup (RV3028 only)
1793 i2c_gpio_sda GPIO used for I2C data (default "23")
1795 i2c_gpio_scl GPIO used for I2C clock (default "24")
1797 i2c_gpio_delay_us Clock delay in microseconds
1798 (default "2" = ~100kHz)
1802 Info: Adds support for a number of I2C barometric pressure, temperature,
1803 light level and chemical sensors on i2c_arm
1804 Load: dtoverlay=i2c-sensor,<param>=<val>
1805 Params: addr Set the address for the BH1750, BME280, BME680,
1806 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1809 bh1750 Select the Rohm BH1750 ambient light sensor
1810 Valid addresses 0x23 or 0x5c, default 0x23
1812 bme280 Select the Bosch Sensortronic BME280
1813 Valid addresses 0x76-0x77, default 0x76
1815 bme680 Select the Bosch Sensortronic BME680
1816 Valid addresses 0x76-0x77, default 0x76
1818 bmp085 Select the Bosch Sensortronic BMP085
1820 bmp180 Select the Bosch Sensortronic BMP180
1822 bmp280 Select the Bosch Sensortronic BMP280
1823 Valid addresses 0x76-0x77, default 0x76
1825 ccs811 Select the AMS CCS811 digital gas sensor
1826 Valid addresses 0x5a-0x5b, default 0x5b
1828 ds1621 Select the Dallas Semiconductors DS1621 temp
1829 sensor. Valid addresses 0x48-0x4f, default 0x48
1831 hdc100x Select the Texas Instruments HDC100x temp sensor
1832 Valid addresses 0x40-0x43, default 0x40
1834 htu21 Select the HTU21 temperature and humidity sensor
1836 int_pin Set the GPIO to use for interrupts (max30102
1839 lm75 Select the Maxim LM75 temperature sensor
1840 Valid addresses 0x48-0x4f, default 0x4f
1842 lm75addr Deprecated - use addr parameter instead
1844 max17040 Select the Maxim Integrated MAX17040 battery
1847 max30102 Select the Maxim Integrated MAX30102 heart-rate
1848 and blood-oxygen sensor
1850 sht3x Select the Sensiron SHT3x temperature and
1851 humidity sensor. Valid addresses 0x44-0x45,
1854 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1857 sps30 Select the Sensirion SPS30 particulate matter
1858 sensor. Fixed address 0x69.
1860 sgp30 Select the Sensirion SGP30 VOC sensor.
1863 tmp102 Select the Texas Instruments TMP102 temp sensor
1864 Valid addresses 0x48-0x4b, default 0x48
1866 tsl4531 Select the AMS TSL4531 digital ambient light
1869 veml6070 Select the Vishay VEML6070 ultraviolet light
1872 i2c0 Choose the I2C0 bus on GPIOs 0&1
1874 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1876 i2c3 Choose the I2C3 bus (configure with the i2c3
1877 overlay - BCM2711 only)
1879 i2c4 Choose the I2C3 bus (configure with the i2c3
1880 overlay - BCM2711 only)
1882 i2c5 Choose the I2C5 bus (configure with the i2c4
1883 overlay - BCM2711 only)
1885 i2c6 Choose the I2C6 bus (configure with the i2c6
1886 overlay - BCM2711 only)
1890 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
1891 platforms - platforms other then Compute Modules can only use this
1892 to disable transaction combining.
1893 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
1894 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
1895 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
1896 camera and display connectors. This overlay disables that mux and
1897 configures /dev/i2c0 to point at whichever set of pins is requested.
1898 dtparam=i2c_vc=on will try and enable the mux, so combining the two
1899 will cause conflicts.
1900 Load: dtoverlay=i2c0,<param>=<val>
1901 Params: pins_0_1 Use pins 0 and 1 (default)
1902 pins_28_29 Use pins 28 and 29
1903 pins_44_45 Use pins 44 and 45
1904 pins_46_47 Use pins 46 and 47
1905 combine Allow transactions to be combined (default
1910 Info: Deprecated, legacy version of i2c0.
1915 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
1916 platforms - platforms other then Compute Modules can only use this
1917 to disable transaction combining.
1918 Load: dtoverlay=i2c1,<param>=<val>
1919 Params: pins_2_3 Use pins 2 and 3 (default)
1920 pins_44_45 Use pins 44 and 45
1921 combine Allow transactions to be combined (default
1926 Info: Deprecated, legacy version of i2c1.
1931 Info: Enable the i2c3 bus. BCM2711 only.
1932 Load: dtoverlay=i2c3,<param>
1933 Params: pins_2_3 Use GPIOs 2 and 3
1934 pins_4_5 Use GPIOs 4 and 5 (default)
1935 baudrate Set the baudrate for the interface (default
1940 Info: Enable the i2c4 bus. BCM2711 only.
1941 Load: dtoverlay=i2c4,<param>
1942 Params: pins_6_7 Use GPIOs 6 and 7
1943 pins_8_9 Use GPIOs 8 and 9 (default)
1944 baudrate Set the baudrate for the interface (default
1949 Info: Enable the i2c5 bus. BCM2711 only.
1950 Load: dtoverlay=i2c5,<param>
1951 Params: pins_10_11 Use GPIOs 10 and 11
1952 pins_12_13 Use GPIOs 12 and 13 (default)
1953 baudrate Set the baudrate for the interface (default
1958 Info: Enable the i2c6 bus. BCM2711 only.
1959 Load: dtoverlay=i2c6,<param>
1960 Params: pins_0_1 Use GPIOs 0 and 1
1961 pins_22_23 Use GPIOs 22 and 23 (default)
1962 baudrate Set the baudrate for the interface (default
1967 Info: move I2S function block to GPIO 28 to 31
1968 Load: dtoverlay=i2s-gpio28-31
1973 Info: Enables I2C connected Ilitek 251x multiple touch controller using
1974 GPIO 4 (pin 7 on GPIO header) for interrupt.
1975 Load: dtoverlay=ilitek251x,<param>=<val>
1976 Params: interrupt GPIO used for interrupt (default 4)
1977 sizex Touchscreen size x, horizontal resolution of
1978 touchscreen (in pixels)
1979 sizey Touchscreen size y, vertical resolution of
1980 touchscreen (in pixels)
1984 Info: Sony IMX219 camera module.
1985 Uses Unicam 1, which is the standard camera connector on most Pi
1987 Load: dtoverlay=imx219,<param>=<val>
1988 Params: rotation Mounting rotation of the camera sensor (0 or
1990 orientation Sensor orientation (0 = front, 1 = rear,
1991 2 = external, default external)
1992 media-controller Configure use of Media Controller API for
1993 configuring the sensor (default on)
1994 cam0 Adopt the default configuration for CAM0 on a
1995 Compute Module (CSI0, i2c_vc, and cam0_reg).
1996 vcm Configure a VCM focus drive on the sensor.
2000 Info: Sony IMX258 camera module.
2001 Uses Unicam 1, which is the standard camera connector on most Pi
2003 Load: dtoverlay=imx258,<param>=<val>
2004 Params: rotation Mounting rotation of the camera sensor (0 or
2006 orientation Sensor orientation (0 = front, 1 = rear,
2007 2 = external, default external)
2008 media-controller Configure use of Media Controller API for
2009 configuring the sensor (default on)
2010 cam0 Adopt the default configuration for CAM0 on a
2011 Compute Module (CSI0, i2c_vc, and cam0_reg).
2012 vcm Configure a VCM focus drive on the sensor.
2013 4lane Enable 4 CSI2 lanes. This requires a Compute
2014 Module (1, 3, or 4).
2018 Info: Sony IMX290 camera module.
2019 Uses Unicam 1, which is the standard camera connector on most Pi
2020 variants. NB This currently uses 4 CSI2 data lanes and therefore will
2022 Load: dtoverlay=imx290,<param>
2023 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
2024 Module (1, 3, or 4).
2025 clock-frequency Sets the clock frequency to match that used on
2027 Modules from Vision Components use 37.125MHz
2028 (the default), whilst those from Innomaker use
2030 mono Denote that the module is a mono sensor.
2031 orientation Sensor orientation (0 = front, 1 = rear,
2032 2 = external, default external)
2033 rotation Mounting rotation of the camera sensor (0 or
2035 media-controller Configure use of Media Controller API for
2036 configuring the sensor (default on)
2037 cam0 Adopt the default configuration for CAM0 on a
2038 Compute Module (CSI0, i2c_vc, and cam0_reg).
2042 Info: Sony IMX296 camera module.
2043 Uses Unicam 1, which is the standard camera connector on most Pi
2045 Load: dtoverlay=imx296,<param>=<val>
2046 Params: rotation Mounting rotation of the camera sensor (0 or
2048 orientation Sensor orientation (0 = front, 1 = rear,
2049 2 = external, default external)
2050 media-controller Configure use of Media Controller API for
2051 configuring the sensor (default on)
2052 cam0 Adopt the default configuration for CAM0 on a
2053 Compute Module (CSI0, i2c_vc, and cam0_reg).
2057 Info: Sony IMX378 camera module.
2058 Uses Unicam 1, which is the standard camera connector on most Pi
2060 Load: dtoverlay=imx378,<param>=<val>
2061 Params: rotation Mounting rotation of the camera sensor (0 or
2063 orientation Sensor orientation (0 = front, 1 = rear,
2064 2 = external, default external)
2065 media-controller Configure use of Media Controller API for
2066 configuring the sensor (default on)
2067 cam0 Adopt the default configuration for CAM0 on a
2068 Compute Module (CSI0, i2c_vc, and cam0_reg).
2072 Info: Sony IMX477 camera module.
2073 Uses Unicam 1, which is the standard camera connector on most Pi
2075 Load: dtoverlay=imx477,<param>=<val>
2076 Params: rotation Mounting rotation of the camera sensor (0 or
2078 orientation Sensor orientation (0 = front, 1 = rear,
2079 2 = external, default external)
2080 media-controller Configure use of Media Controller API for
2081 configuring the sensor (default on)
2082 cam0 Adopt the default configuration for CAM0 on a
2083 Compute Module (CSI0, i2c_vc, and cam0_reg).
2087 Info: Sony IMX519 camera module.
2088 Uses Unicam 1, which is the standard camera connector on most Pi
2090 Load: dtoverlay=imx519,<param>=<val>
2091 Params: rotation Mounting rotation of the camera sensor (0 or
2093 orientation Sensor orientation (0 = front, 1 = rear,
2094 2 = external, default external)
2095 media-controller Configure use of Media Controller API for
2096 configuring the sensor (default on)
2097 cam0 Adopt the default configuration for CAM0 on a
2098 Compute Module (CSI0, i2c_vc, and cam0_reg).
2102 Info: Configures the IQaudio Codec audio card
2103 Load: dtoverlay=iqaudio-codec
2108 Info: Configures the IQaudio DAC audio card
2109 Load: dtoverlay=iqaudio-dac,<param>
2110 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2111 Digital volume control. Enable with
2112 "dtoverlay=iqaudio-dac,24db_digital_gain"
2113 (The default behaviour is that the Digital
2114 volume control is limited to a maximum of
2115 0dB. ie. it can attenuate but not provide
2116 gain. For most users, this will be desired
2117 as it will prevent clipping. By appending
2118 the 24db_digital_gain parameter, the Digital
2119 volume control will allow up to 24dB of
2120 gain. If this parameter is enabled, it is the
2121 responsibility of the user to ensure that
2122 the Digital volume control is set to a value
2123 that does not result in clipping/distortion!)
2126 Name: iqaudio-dacplus
2127 Info: Configures the IQaudio DAC+ audio card
2128 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
2129 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2130 Digital volume control. Enable with
2131 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
2132 (The default behaviour is that the Digital
2133 volume control is limited to a maximum of
2134 0dB. ie. it can attenuate but not provide
2135 gain. For most users, this will be desired
2136 as it will prevent clipping. By appending
2137 the 24db_digital_gain parameter, the Digital
2138 volume control will allow up to 24dB of
2139 gain. If this parameter is enabled, it is the
2140 responsibility of the user to ensure that
2141 the Digital volume control is set to a value
2142 that does not result in clipping/distortion!)
2143 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2144 starting/stopping audio playback.
2145 unmute_amp If specified, unmute the IQaudIO amp once when
2146 the DAC driver module loads.
2149 Name: iqaudio-digi-wm8804-audio
2150 Info: Configures the IQAudIO Digi WM8804 audio card
2151 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2152 Params: card_name Override the default, "IQAudIODigi", card name.
2153 dai_name Override the default, "IQAudIO Digi", dai name.
2154 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2159 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2160 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2161 Load: dtoverlay=iqs550,<param>=<val>
2162 Params: interrupt GPIO used for interrupt (default 4)
2163 reset GPIO used for reset (optional)
2164 sizex Touchscreen size x (default 800)
2165 sizey Touchscreen size y (default 480)
2166 invx Touchscreen inverted x axis
2167 invy Touchscreen inverted y axis
2168 swapxy Touchscreen swapped x y axis
2172 Info: Infineon irs1125 TOF camera module.
2173 Uses Unicam 1, which is the standard camera connector on most Pi
2175 Load: dtoverlay=irs1125,<param>=<val>
2176 Params: media-controller Configure use of Media Controller API for
2177 configuring the sensor (default off)
2178 cam0 Adopt the default configuration for CAM0 on a
2179 Compute Module (CSI0, i2c_vc, and cam0_reg).
2183 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2184 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2185 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2186 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2187 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2192 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2194 Load: dtoverlay=justboom-both,<param>=<val>
2195 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2196 Digital volume control. Enable with
2197 "dtoverlay=justboom-dac,24db_digital_gain"
2198 (The default behaviour is that the Digital
2199 volume control is limited to a maximum of
2200 0dB. ie. it can attenuate but not provide
2201 gain. For most users, this will be desired
2202 as it will prevent clipping. By appending
2203 the 24dB_digital_gain parameter, the Digital
2204 volume control will allow up to 24dB of
2205 gain. If this parameter is enabled, it is the
2206 responsibility of the user to ensure that
2207 the Digital volume control is set to a value
2208 that does not result in clipping/distortion!)
2212 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2214 Load: dtoverlay=justboom-dac,<param>=<val>
2215 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2216 Digital volume control. Enable with
2217 "dtoverlay=justboom-dac,24db_digital_gain"
2218 (The default behaviour is that the Digital
2219 volume control is limited to a maximum of
2220 0dB. ie. it can attenuate but not provide
2221 gain. For most users, this will be desired
2222 as it will prevent clipping. By appending
2223 the 24dB_digital_gain parameter, the Digital
2224 volume control will allow up to 24dB of
2225 gain. If this parameter is enabled, it is the
2226 responsibility of the user to ensure that
2227 the Digital volume control is set to a value
2228 that does not result in clipping/distortion!)
2232 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2233 Load: dtoverlay=justboom-digi
2238 Info: This overlay has been deprecated and removed - see gpio-ir
2243 Info: Adds support for the ltc294x family of battery gauges
2244 Load: dtoverlay=ltc294x,<param>=<val>
2245 Params: ltc2941 Select the ltc2941 device
2247 ltc2942 Select the ltc2942 device
2249 ltc2943 Select the ltc2943 device
2251 ltc2944 Select the ltc2944 device
2253 resistor-sense The sense resistor value in milli-ohms.
2254 Can be a 32-bit negative value when the battery
2255 has been connected to the wrong end of the
2258 prescaler-exponent Range and accuracy of the gauge. The value is
2259 programmed into the chip only if it differs
2260 from the current setting.
2262 - Default value is 128
2263 - the exponent is in the range 0-7 (default 7)
2264 See the datasheet for more information.
2268 Info: Configures the Maxim MAX98357A I2S DAC
2269 Load: dtoverlay=max98357a,<param>=<val>
2270 Params: no-sdmode Driver does not manage the state of the DAC's
2271 SD_MODE pin (i.e. chip is always on).
2272 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2273 of the DAC (default GPIO4 if parameter omitted).
2277 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2279 For devices on spi1 or spi2, the interfaces should be enabled
2280 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2281 The overlay expects to disable the relevant spidev node, so also using
2282 e.g. cs0_spidev=off is unnecessary.
2285 MAX31855 on /dev/spidev0.0
2286 dtoverlay=maxtherm,spi0-0,max31855
2287 MAX31856 using a type J thermocouple on /dev/spidev2.1
2289 dtoverlay=maxtherm,spi2-1,max31856,type_j
2291 Load: dtoverlay=maxtherm,<param>=<val>
2292 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2294 max6675 Enable support for the MAX6675 (default)
2295 max31855 Enable support for the MAX31855
2296 max31855e Enable support for the MAX31855E
2297 max31855j Enable support for the MAX31855J
2298 max31855k Enable support for the MAX31855K
2299 max31855n Enable support for the MAX31855N
2300 max31855r Enable support for the MAX31855R
2301 max31855s Enable support for the MAX31855S
2302 max31855t Enable support for the MAX31855T
2303 max31856 Enable support for the MAX31856 (with type K)
2304 type_b Select a type B sensor for max31856
2305 type_e Select a type E sensor for max31856
2306 type_j Select a type J sensor for max31856
2307 type_k Select a type K sensor for max31856
2308 type_n Select a type N sensor for max31856
2309 type_r Select a type R sensor for max31856
2310 type_s Select a type S sensor for max31856
2311 type_t Select a type T sensor for max31856
2315 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2316 Load: dtoverlay=mbed-dac
2321 Info: Configures the MCP23017 I2C GPIO expander
2322 Load: dtoverlay=mcp23017,<param>=<val>
2323 Params: gpiopin Gpio pin connected to the INTA output of the
2324 MCP23017 (default: 4)
2326 addr I2C address of the MCP23017 (default: 0x20)
2328 mcp23008 Configure an MCP23008 instead.
2329 noints Disable the interrupt GPIO line.
2333 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2334 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2335 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2336 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2337 device must be the only one present on that SPI bus/CS#.
2338 Load: dtoverlay=mcp23s17,<param>=<val>
2339 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2340 devices present on SPI<n>, CS#<m>
2342 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2343 devices present on SPI<n>, CS#<m>
2345 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2346 MCP23S08 device on SPI<n>, CS#<m>, specifies
2347 the GPIO pin to which INT output of MCP23S08
2350 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2351 single MCP23S17 device on SPI<n>, CS#<m>,
2352 specifies the GPIO pin to which either INTA
2353 or INTB output of MCP23S17 is connected.
2357 Info: Configures the MCP2515 CAN controller on spi0/1/2
2358 For devices on spi1 or spi2, the interfaces should be enabled
2359 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2360 Load: dtoverlay=mcp2515,<param>=<val>
2361 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2364 oscillator Clock frequency for the CAN controller (Hz)
2366 speed Maximum SPI frequence (Hz)
2368 interrupt GPIO for interrupt signal
2372 Info: Configures the MCP2515 CAN controller on spi0.0
2373 Load: dtoverlay=mcp2515-can0,<param>=<val>
2374 Params: oscillator Clock frequency for the CAN controller (Hz)
2376 spimaxfrequency Maximum SPI frequence (Hz)
2378 interrupt GPIO for interrupt signal
2382 Info: Configures the MCP2515 CAN controller on spi0.1
2383 Load: dtoverlay=mcp2515-can1,<param>=<val>
2384 Params: oscillator Clock frequency for the CAN controller (Hz)
2386 spimaxfrequency Maximum SPI frequence (Hz)
2388 interrupt GPIO for interrupt signal
2392 Info: Configures the MCP251XFD CAN controller family
2393 For devices on spi1 or spi2, the interfaces should be enabled
2394 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2395 Load: dtoverlay=mcp251xfd,<param>=<val>
2396 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2399 oscillator Clock frequency for the CAN controller (Hz)
2401 speed Maximum SPI frequence (Hz)
2403 interrupt GPIO for interrupt signal
2405 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2407 xceiver_enable GPIO for CAN transceiver enable (optional)
2409 xceiver_active_high specifiy if CAN transceiver enable pin is
2410 active high (optional, default: active low)
2414 Info: Configures MCP3008 A/D converters
2415 For devices on spi1 or spi2, the interfaces should be enabled
2416 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2417 Load: dtoverlay=mcp3008,<param>[=<val>]
2418 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2419 spi<n>-<m>-speed integer, set the spi bus speed for this device
2423 Info: Configures MCP3202 A/D converters
2424 For devices on spi1 or spi2, the interfaces should be enabled
2425 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2426 Load: dtoverlay=mcp3202,<param>[=<val>]
2427 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2428 spi<n>-<m>-speed integer, set the spi bus speed for this device
2432 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2433 Load: dtoverlay=mcp342x,<param>=<val>
2434 Params: addr I2C bus address of device, for devices with
2435 addresses that are configurable, e.g. by
2436 hardware links (default=0x68)
2437 mcp3421 The device is an MCP3421
2438 mcp3422 The device is an MCP3422
2439 mcp3423 The device is an MCP3423
2440 mcp3424 The device is an MCP3424
2441 mcp3425 The device is an MCP3425
2442 mcp3426 The device is an MCP3426
2443 mcp3427 The device is an MCP3427
2444 mcp3428 The device is an MCP3428
2448 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2449 Load: dtoverlay=media-center,<param>=<val>
2450 Params: speed Display SPI bus speed
2451 rotate Display rotation {0,90,180,270}
2452 fps Delay between frame updates
2453 xohms Touchpanel sensitivity (X-plate resistance)
2454 swapxy Swap x and y axis
2455 backlight Change backlight GPIO pin {e.g. 12, 18}
2456 gpio_out_pin GPIO for output (default "17")
2457 gpio_in_pin GPIO for input (default "18")
2458 gpio_in_pull Pull up/down/off on the input pin
2460 sense Override the IR receive auto-detection logic:
2461 "0" = force active-high
2462 "1" = force active-low
2463 "-1" = use auto-detection
2465 softcarrier Turn the software carrier "on" or "off"
2467 invert "on" = invert the output pin (default "off")
2468 debug "on" = enable additional debug messages
2473 Info: Configures the merus-amp audio card
2474 Load: dtoverlay=merus-amp
2479 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2480 31.25kbaud, the frequency required for MIDI
2481 Load: dtoverlay=midi-uart0
2486 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2487 31.25kbaud, the frequency required for MIDI
2488 Load: dtoverlay=midi-uart1
2493 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2494 31.25kbaud, the frequency required for MIDI
2495 Load: dtoverlay=midi-uart2
2500 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2501 31.25kbaud, the frequency required for MIDI
2502 Load: dtoverlay=midi-uart3
2507 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2508 31.25kbaud, the frequency required for MIDI
2509 Load: dtoverlay=midi-uart4
2514 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2515 31.25kbaud, the frequency required for MIDI
2516 Load: dtoverlay=midi-uart5
2521 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2522 Load: dtoverlay=minipitft13,<param>=<val>
2523 Params: speed SPI bus speed (default 32000000)
2524 rotate Display rotation (0, 90, 180 or 270; default 0)
2525 width Display width (default 240)
2526 height Display height (default 240)
2527 fps Delay between frame updates (default 25)
2528 debug Debug output level (0-7; default 0)
2532 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2533 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2534 15. Note that this may reduce the maximum usable baudrate.
2535 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2536 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2537 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2538 in which case use /dev/serial1 instead because it will always be
2539 correct. Furthermore, you must also set core_freq and core_freq_min to
2540 the same value in config.txt or the miniuart will not work.
2541 Load: dtoverlay=miniuart-bt,<param>=<val>
2542 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2543 driver without need of hciattach/btattach
2547 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2548 driver. The driver will load a file /lib/firmware/panel.bin containing
2549 the initialisation commands.
2552 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2553 dtparam=width=320,height=240
2554 dtparam=reset-gpio=23,dc-gpio=24
2555 dtparam=backlight-gpio=18
2557 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2558 and init commands at 10MHz. This makes it possible to push the envelope
2559 without messing up the controller configuration due to command
2560 transmission errors.
2562 For devices on spi1 or spi2, the interfaces should be enabled
2563 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2565 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2567 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2569 compatible Set the compatible string to load a different
2570 firmware file. Both the panel compatible value
2571 used to load the firmware file and the value
2572 used to load the driver has to be set having a
2573 NUL (\0) separator between them.
2575 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2576 spi<n>-<m> Configure device at spi<n>, cs<m>
2578 speed SPI bus speed in Hz (default 32000000)
2579 cpha Shifted SPI clock phase (CPHA) mode
2580 cpol Inverse SPI clock polarity (CPOL) mode
2581 write-only Controller is not readable
2582 (ie. MISO is not wired up).
2584 width Panel width in pixels (required)
2585 height Panel height in pixels (required)
2586 width-mm Panel width in mm
2587 height-mm Panel height in mm
2588 x-offset Panel x-offset in controller RAM
2589 y-offset Panel y-offset in controller RAM
2591 clock-frequency Panel clock frequency in Hz
2592 (optional, just informational).
2594 reset-gpio GPIO pin to be used for RESET
2595 dc-gpio GPIO pin to be used for D/C
2597 backlight-gpio GPIO pin to be used for backlight control
2599 backlight-pwm PWM channel to be used for backlight control
2600 (default of none). NB Disables audio headphone
2601 output as that also uses PWM.
2602 backlight-pwm-chan Choose channel on &pwm node for backlight
2603 control (default 0).
2604 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2605 pwm-2chan for valid options (default 18).
2606 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2607 See pwm-2chan for valid options (default 2).
2608 backlight-def-brightness
2609 Set the default brightness. Normal range 1-16.
2614 Info: Overlay for i2c connected mlx90640 thermal camera
2615 Load: dtoverlay=mlx90640
2620 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2621 Load: dtoverlay=mmc,<param>=<val>
2622 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2627 Info: Overlay for i2c connected mpu6050 imu
2628 Load: dtoverlay=mpu6050,<param>=<val>
2629 Params: interrupt GPIO pin for interrupt (default 4)
2630 addr I2C address of the device (default 0x68)
2634 Info: MZ61581 display by Tontec
2635 Load: dtoverlay=mz61581,<param>=<val>
2636 Params: speed Display SPI bus speed
2638 rotate Display rotation {0,90,180,270}
2640 fps Delay between frame updates
2642 txbuflen Transmit buffer length (default 32768)
2644 debug Debug output level {0-7}
2646 xohms Touchpanel sensitivity (X-plate resistance)
2650 Info: Omnivision OV2311 camera module.
2651 Uses Unicam 1, which is the standard camera connector on most Pi
2653 Load: dtoverlay=ov2311,<param>=<val>
2654 Params: rotation Mounting rotation of the camera sensor (0 or
2656 orientation Sensor orientation (0 = front, 1 = rear,
2657 2 = external, default external)
2658 media-controller Configure use of Media Controller API for
2659 configuring the sensor (default on)
2660 cam0 Adopt the default configuration for CAM0 on a
2661 Compute Module (CSI0, i2c_vc, and cam0_reg).
2665 Info: Omnivision OV5647 camera module.
2666 Uses Unicam 1, which is the standard camera connector on most Pi
2668 Load: dtoverlay=ov5647,<param>=<val>
2669 Params: rotation Mounting rotation of the camera sensor (0 or
2671 orientation Sensor orientation (0 = front, 1 = rear,
2672 2 = external, default external)
2673 media-controller Configure use of Media Controller API for
2674 configuring the sensor (default on)
2675 cam0 Adopt the default configuration for CAM0 on a
2676 Compute Module (CSI0, i2c_vc, and cam0_reg).
2677 vcm Configure a VCM focus drive on the sensor.
2681 Info: Omnivision OV7251 camera module.
2682 Uses Unicam 1, which is the standard camera connector on most Pi
2684 Load: dtoverlay=ov7251,<param>=<val>
2685 Params: rotation Mounting rotation of the camera sensor (0 or
2687 orientation Sensor orientation (0 = front, 1 = rear,
2688 2 = external, default external)
2689 media-controller Configure use of Media Controller API for
2690 configuring the sensor (default off)
2691 cam0 Adopt the default configuration for CAM0 on a
2692 Compute Module (CSI0, i2c_vc, and cam0_reg).
2696 Info: Omnivision OV9281 camera module.
2697 Uses Unicam 1, which is the standard camera connector on most Pi
2699 Load: dtoverlay=ov9281,<param>=<val>
2700 Params: rotation Mounting rotation of the camera sensor (0 or
2702 orientation Sensor orientation (0 = front, 1 = rear,
2703 2 = external, default external)
2704 media-controller Configure use of Media Controller API for
2705 configuring the sensor (default on)
2706 cam0 Adopt the default configuration for CAM0 on a
2707 Compute Module (CSI0, i2c_vc, and cam0_reg).
2711 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2712 Load: dtoverlay=papirus,<param>=<val>
2713 Params: panel Display panel (required):
2718 speed Display SPI bus speed
2722 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2723 Load: dtoverlay=pca953x,<param>=<val>
2724 Params: addr I2C address of expander. Default 0x20.
2725 pca6416 Select the NXP PCA6416 (16 bit)
2726 pca9505 Select the NXP PCA9505 (40 bit)
2727 pca9535 Select the NXP PCA9535 (16 bit)
2728 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2729 pca9537 Select the NXP PCA9537 (4 bit)
2730 pca9538 Select the NXP PCA9538 (8 bit)
2731 pca9539 Select the NXP PCA9539 (16 bit)
2732 pca9554 Select the NXP PCA9554 (8 bit)
2733 pca9555 Select the NXP PCA9555 (16 bit)
2734 pca9556 Select the NXP PCA9556 (8 bit)
2735 pca9557 Select the NXP PCA9557 (8 bit)
2736 pca9574 Select the NXP PCA9574 (8 bit)
2737 pca9575 Select the NXP PCA9575 (16 bit)
2738 pca9698 Select the NXP PCA9698 (40 bit)
2739 pca16416 Select the NXP PCA16416 (16 bit)
2740 pca16524 Select the NXP PCA16524 (24 bit)
2741 pca19555a Select the NXP PCA19555A (16 bit)
2742 max7310 Select the Maxim MAX7310 (8 bit)
2743 max7312 Select the Maxim MAX7312 (16 bit)
2744 max7313 Select the Maxim MAX7313 (16 bit)
2745 max7315 Select the Maxim MAX7315 (8 bit)
2746 pca6107 Select the TI PCA6107 (8 bit)
2747 tca6408 Select the TI TCA6408 (8 bit)
2748 tca6416 Select the TI TCA6416 (16 bit)
2749 tca6424 Select the TI TCA6424 (24 bit)
2750 tca9539 Select the TI TCA9539 (16 bit)
2751 tca9554 Select the TI TCA9554 (8 bit)
2752 cat9554 Select the Onnn CAT9554 (8 bit)
2753 pca9654 Select the Onnn PCA9654 (8 bit)
2754 xra1202 Select the Exar XRA1202 (8 bit)
2757 Name: pcie-32bit-dma
2758 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2759 having to bounce buffers.
2760 Load: dtoverlay=pcie-32bit-dma
2764 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2767 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2770 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2774 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2775 for backwards compatibility.
2779 Name: pi3-disable-bt
2780 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2781 alias for backwards compatibility.
2785 Name: pi3-disable-wifi
2786 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2787 an alias for backwards compatibility.
2791 Name: pi3-miniuart-bt
2792 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2793 an alias for backwards compatibility.
2798 Info: Configures the pibell audio card.
2799 Load: dtoverlay=pibell,<param>=<val>
2800 Params: alsaname Set the name as it appears in ALSA (default
2805 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2806 Load: dtoverlay=pifacedigital,<param>=<val>
2807 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2808 CS0 address. PiFace Digital supports addresses
2809 0-3, which can be configured with JP1 and JP2.
2813 Info: Configures the PiFi 40W stereo amplifier
2814 Load: dtoverlay=pifi-40
2819 Info: Configures the PiFi DAC HD
2820 Load: dtoverlay=pifi-dac-hd
2825 Info: Configures the PiFi DAC Zero
2826 Load: dtoverlay=pifi-dac-zero
2831 Info: Configures the PiFi Mini stereo amplifier
2832 Load: dtoverlay=pifi-mini-210
2837 Info: Configures the PiGlow by pimoroni.com
2838 Load: dtoverlay=piglow
2843 Info: PiScreen display by OzzMaker.com
2844 Load: dtoverlay=piscreen,<param>=<val>
2845 Params: speed Display SPI bus speed
2847 rotate Display rotation {0,90,180,270}
2849 fps Delay between frame updates
2851 debug Debug output level {0-7}
2853 xohms Touchpanel sensitivity (X-plate resistance)
2857 Info: PiScreen 2 with resistive TP display by OzzMaker.com
2858 Load: dtoverlay=piscreen2r,<param>=<val>
2859 Params: speed Display SPI bus speed
2861 rotate Display rotation {0,90,180,270}
2863 fps Delay between frame updates
2865 debug Debug output level {0-7}
2867 xohms Touchpanel sensitivity (X-plate resistance)
2871 Info: Configures the Blokas Labs pisound card
2872 Load: dtoverlay=pisound
2877 Info: Adafruit PiTFT 2.2" screen
2878 Load: dtoverlay=pitft22,<param>=<val>
2879 Params: speed Display SPI bus speed
2881 rotate Display rotation {0,90,180,270}
2883 fps Delay between frame updates
2885 debug Debug output level {0-7}
2888 Name: pitft28-capacitive
2889 Info: Adafruit PiTFT 2.8" capacitive touch screen
2890 Load: dtoverlay=pitft28-capacitive,<param>=<val>
2891 Params: speed Display SPI bus speed
2893 rotate Display rotation {0,90,180,270}
2895 fps Delay between frame updates
2897 debug Debug output level {0-7}
2899 touch-sizex Touchscreen size x (default 240)
2901 touch-sizey Touchscreen size y (default 320)
2903 touch-invx Touchscreen inverted x axis
2905 touch-invy Touchscreen inverted y axis
2907 touch-swapxy Touchscreen swapped x y axis
2910 Name: pitft28-resistive
2911 Info: Adafruit PiTFT 2.8" resistive touch screen
2912 Load: dtoverlay=pitft28-resistive,<param>=<val>
2913 Params: speed Display SPI bus speed
2915 rotate Display rotation {0,90,180,270}
2917 fps Delay between frame updates
2919 debug Debug output level {0-7}
2921 drm Force the use of the mi0283qt DRM driver (by
2922 default the ili9340 framebuffer driver will
2923 be used in preference if available)
2926 Name: pitft35-resistive
2927 Info: Adafruit PiTFT 3.5" resistive touch screen
2928 Load: dtoverlay=pitft35-resistive,<param>=<val>
2929 Params: speed Display SPI bus speed
2931 rotate Display rotation {0,90,180,270}
2933 fps Delay between frame updates
2935 debug Debug output level {0-7}
2937 drm Force the use of the hx8357d DRM driver (by
2938 default the fb_hx8357d framebuffer driver will
2939 be used in preference if available)
2943 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
2944 Load: dtoverlay=pps-gpio,<param>=<val>
2945 Params: gpiopin Input GPIO (default "18")
2946 assert_falling_edge When present, assert is indicated by a falling
2947 edge, rather than by a rising edge (default
2949 capture_clear Generate clear events on the trailing edge
2954 Info: Configures a single PWM channel
2955 Legal pin,function combinations for each channel:
2956 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2957 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2959 1) Pin 18 is the only one available on all platforms, and
2960 it is the one used by the I2S audio interface.
2961 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2962 2) The onboard analogue audio output uses both PWM channels.
2963 3) So be careful mixing audio and PWM.
2964 4) Currently the clock must have been enabled and configured
2966 Load: dtoverlay=pwm,<param>=<val>
2967 Params: pin Output pin (default 18) - see table
2968 func Pin function (default 2 = Alt5) - see above
2969 clock PWM clock frequency (informational)
2973 Info: Configures both PWM channels
2974 Legal pin,function combinations for each channel:
2975 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2976 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2978 1) Pin 18 is the only one available on all platforms, and
2979 it is the one used by the I2S audio interface.
2980 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2981 2) The onboard analogue audio output uses both PWM channels.
2982 3) So be careful mixing audio and PWM.
2983 4) Currently the clock must have been enabled and configured
2985 Load: dtoverlay=pwm-2chan,<param>=<val>
2986 Params: pin Output pin (default 18) - see table
2987 pin2 Output pin for other channel (default 19)
2988 func Pin function (default 2 = Alt5) - see above
2989 func2 Function for pin2 (default 2 = Alt5)
2990 clock PWM clock frequency (informational)
2994 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
2995 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
2996 of PWM0 to reduce the CPU load during transmission compared to
2997 gpio-ir-tx which uses bit-banging.
2998 Legal pin,function combinations are:
2999 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
3000 Load: dtoverlay=pwm-ir-tx,<param>=<val>
3001 Params: gpio_pin Output GPIO (default 18)
3003 func Pin function (default 2 = Alt5)
3007 Info: in-tech's Evaluation Board for PLC Stamp micro
3008 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
3009 Load: dtoverlay=qca7000,<param>=<val>
3010 Params: int_pin GPIO pin for interrupt signal (default 23)
3012 speed SPI bus speed (default 12 MHz)
3016 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
3017 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
3018 But it requires disabling of onboard Bluetooth on
3019 Pi 3B, 3B+, 3A+, 4B and Zero W.
3020 Load: dtoverlay=qca7000-uart0,<param>=<val>
3021 Params: baudrate Set the baudrate for the UART (default
3026 Info: Enable the preservation of crash logs across a reboot. With
3027 systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs
3028 are moved to /var/lib/systemd/pstore/ on reboot.
3029 Load: dtoverlay=ramoops,<param>=<val>
3030 Params: base-addr Where to place the capture buffer (default
3032 total-size How much memory to allocate altogether (in
3033 bytes - default 64kB)
3034 record-size How much space to use for each capture, i.e.
3035 total-size / record-size = number of captures
3037 console-size Size of non-panic dmesg captures (default 0)
3041 Info: The version of the ramoops overlay for the Pi 4 family. It should be
3042 loaded automatically if dtoverlay=ramoops is specified on a Pi 4.
3043 Load: dtoverlay=ramoops-pi4,<param>=<val>
3044 Params: base-addr Where to place the capture buffer (default
3046 total-size How much memory to allocate altogether (in
3047 bytes - default 64kB)
3048 record-size How much space to use for each capture, i.e.
3049 total-size / record-size = number of captures
3051 console-size Size of non-panic dmesg captures (default 0)
3054 Name: rotary-encoder
3055 Info: Overlay for GPIO connected rotary encoder.
3056 Load: dtoverlay=rotary-encoder,<param>=<val>
3057 Params: pin_a GPIO connected to rotary encoder channel A
3059 pin_b GPIO connected to rotary encoder channel B
3061 relative_axis register a relative axis rather than an
3062 absolute one. Relative axis will only
3063 generate +1/-1 events on the input device,
3064 hence no steps need to be passed.
3065 linux_axis the input subsystem axis to map to this
3066 rotary encoder. Defaults to 0 (ABS_X / REL_X)
3067 rollover Automatic rollover when the rotary value
3068 becomes greater than the specified steps or
3069 smaller than 0. For absolute axis only.
3070 steps-per-period Number of steps (stable states) per period.
3071 The values have the following meaning:
3072 1: Full-period mode (default)
3074 4: Quarter-period mode
3075 steps Number of steps in a full turnaround of the
3076 encoder. Only relevant for absolute axis.
3077 Defaults to 24 which is a typical value for
3079 wakeup Boolean, rotary encoder can wake up the
3081 encoding String, the method used to encode steps.
3082 Supported are "gray" (the default and more
3083 common) and "binary".
3087 Info: Raspberry Pi official display backlight driver
3088 Load: dtoverlay=rpi-backlight
3092 Name: rpi-cirrus-wm5102
3093 Info: Configures the Cirrus Logic Audio Card
3094 Load: dtoverlay=rpi-cirrus-wm5102
3099 Info: Configures the RPi DAC audio card
3100 Load: dtoverlay=rpi-dac
3105 Info: RPi-Display - 2.8" Touch Display by Watterott
3106 Linux has 2 drivers that support this display and this overlay supports
3110 fbtft/fb_ili9341: dtoverlay=rpi-display
3111 drm/mi0283qt: dtoverlay=rpi-display,drm,backlight-pwm,rotate=180
3113 Some notable differences with the DRM driver compared to fbtft:
3114 - The display is turned on when it's first used and not on driver load
3115 as with fbtft. So if nothing uses the display it stays off.
3116 - Can run with a higher SPI clock increasing framerate. This is possible
3117 since the driver avoids messing up the controller configuration due to
3118 transmission errors by running config commands at 10MHz and only pixel
3119 data at full speed (occasional pixel glitch might occur).
3120 - PWM backlight is supported.
3122 Load: dtoverlay=rpi-display,<param>=<val>
3123 Params: speed Display SPI bus speed
3124 rotate Display rotation {0,90,180,270}
3125 fps Delay between frame updates (fbtft only)
3126 debug Debug output level {0-7} (fbtft only)
3127 xohms Touchpanel sensitivity (X-plate resistance)
3128 swapxy Swap x and y axis
3129 backlight Change backlight GPIO pin {e.g. 12, 18}
3131 drm Use DRM/KMS driver mi0283qt instead of fbtft.
3132 Set the SPI clock to 70MHz.
3133 This has to be the first parameter.
3134 backlight-pwm Use pwm for backlight (drm only). NB: Disables
3135 audio headphone output as that also uses PWM.
3139 Info: Official Raspberry Pi display touchscreen
3140 Load: dtoverlay=rpi-ft5406,<param>=<val>
3141 Params: touchscreen-size-x Touchscreen X resolution (default 800)
3142 touchscreen-size-y Touchscreen Y resolution (default 600);
3143 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
3144 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
3145 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
3149 Info: Raspberry Pi PoE HAT fan
3150 Load: dtoverlay=rpi-poe,<param>[=<val>]
3151 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3152 turns on (default 40000)
3153 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3154 the fan turns off (default 2000)
3155 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3156 speeds up (default 45000)
3157 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3158 the fan slows down (default 2000)
3159 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3160 speeds up (default 50000)
3161 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3162 the fan slows down (default 2000)
3163 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3164 speeds up (default 55000)
3165 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3166 the fan slows down (default 5000)
3167 i2c Control the fan via Linux I2C drivers instead of
3172 Info: Raspberry Pi PoE+ HAT fan
3173 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3174 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3175 turns on (default 40000)
3176 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3177 the fan turns off (default 2000)
3178 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3179 speeds up (default 45000)
3180 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3181 the fan slows down (default 2000)
3182 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3183 speeds up (default 50000)
3184 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3185 the fan slows down (default 2000)
3186 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3187 speeds up (default 55000)
3188 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3189 the fan slows down (default 5000)
3190 i2c Control the fan via Linux I2C drivers instead of
3195 Info: Configures the RPi Proto audio card
3196 Load: dtoverlay=rpi-proto
3201 Info: Raspberry Pi Sense HAT
3202 Load: dtoverlay=rpi-sense
3207 Info: Raspberry Pi TV HAT
3208 Load: dtoverlay=rpi-tv
3213 Info: This overlay has been deprecated and deleted as the V4L2 stateless
3214 video decoder driver is enabled by default.
3218 Name: rra-digidac1-wm8741-audio
3219 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3220 Load: dtoverlay=rra-digidac1-wm8741-audio
3225 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3227 Load: dtoverlay=sainsmart18,<param>=<val>
3228 Params: rotate Display rotation {0,90,180,270}
3229 speed SPI bus speed in Hz (default 4000000)
3230 fps Display frame rate in Hz
3231 bgr Enable BGR mode (default off)
3232 debug Debug output level {0-7}
3233 dc_pin GPIO pin for D/C (default 24)
3234 reset_pin GPIO pin for RESET (default 25)
3238 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3239 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3240 select another address, please refer to table 10 in reference manual.
3241 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3242 Params: int_pin GPIO used for IRQ (default 24)
3243 addr Address (default 0x48)
3244 xtal On-board crystal frequency (default 14745600)
3248 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3249 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3250 select another address, please refer to table 10 in reference manual.
3251 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3252 Params: int_pin GPIO used for IRQ (default 24)
3253 addr Address (default 0x48)
3254 xtal On-board crystal frequency (default 14745600)
3257 Name: sc16is752-spi0
3258 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3259 Enables the chip on SPI0.
3260 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3261 Params: int_pin GPIO used for IRQ (default 24)
3262 xtal On-board crystal frequency (default 14745600)
3265 Name: sc16is752-spi1
3266 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3267 Enables the chip on SPI1.
3268 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3269 A+, B+, Zero and PI2 B; as well as the Compute Module.
3271 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3272 Params: int_pin GPIO used for IRQ (default 24)
3273 xtal On-board crystal frequency (default 14745600)
3277 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3278 N.B. This overlay is designed for situations where the mmc driver is
3279 the default, so it disables the other (mmc) interface - this will kill
3280 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3281 overlay or the new sd_* dtparams of the base DTBs.
3282 Load: dtoverlay=sdhost,<param>=<val>
3283 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3286 force_pio Disable DMA support (default off)
3288 pio_limit Number of blocks above which to use DMA
3291 debug Enable debug output (default off)
3295 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3296 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3297 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3298 Load: dtoverlay=sdio,<param>=<val>
3299 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3300 framework requests 50MHz
3302 poll_once Disable SDIO-device polling every second
3303 (default on: polling once at boot-time)
3305 bus_width Set the SDIO host bus width (default 4 bits)
3307 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3308 with bus_width=1. This replaces the sdio-1bit
3309 overlay, which is now deprecated.
3311 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3314 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3315 with bus_width=4 (the default).
3319 Info: This overlay is now deprecated. Use
3320 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3325 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3326 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3327 "dtparam=sd_poll_once".
3331 Name: seeed-can-fd-hat-v1
3332 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3333 channels without RTC. Use this overlay if your HAT has no
3335 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3336 Load: dtoverlay=seeed-can-fd-hat-v1
3340 Name: seeed-can-fd-hat-v2
3341 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3342 channels and an RTC. Use this overlay if your HAT has a
3344 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3345 Load: dtoverlay=seeed-can-fd-hat-v2
3350 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3351 Load: dtoverlay=sh1106-spi,<param>=<val>
3352 Params: speed SPI bus speed (default 4000000)
3353 rotate Display rotation (0, 90, 180 or 270; default 0)
3354 fps Delay between frame updates (default 25)
3355 debug Debug output level (0-7; default 0)
3356 dc_pin GPIO pin for D/C (default 24)
3357 reset_pin GPIO pin for RESET (default 25)
3358 height Display height (32 or 64; default 64)
3362 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3363 The driver is currently out-of-tree at
3364 https://github.com/sunipkmukherjee/silabs.git
3365 Load: dtoverlay=si446x-spi0,<param>=<val>
3366 Params: speed SPI bus speed (default 4000000)
3367 int_pin GPIO pin for interrupts (default 17)
3368 reset_pin GPIO pin for RESET (default 27)
3372 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3378 Info: Enables the userspace interface for the SMI driver
3379 Load: dtoverlay=smi-dev
3384 Info: Enables access to NAND flash via the SMI interface
3385 Load: dtoverlay=smi-nand
3390 Info: Move SPI function block to GPIO 35 to 39
3391 Load: dtoverlay=spi-gpio35-39
3396 Info: Move SPI function block to GPIOs 40 to 45
3397 Load: dtoverlay=spi-gpio40-45
3402 Info: Adds support for a number of SPI Real Time Clock devices
3403 Load: dtoverlay=spi-rtc,<param>=<val>
3404 Params: ds3232 Select the DS3232 device
3405 ds3234 Select the DS3234 device
3406 pcf2123 Select the PCF2123 device
3408 spi0_0 Use spi0.0 (default)
3414 cs_high This device requires an active-high CS
3418 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3419 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3420 Load: dtoverlay=spi0-0cs,<param>=<val>
3421 Params: no_miso Don't claim and use the MISO pin (9), freeing
3426 Info: Only use one CS pin for SPI0
3427 Load: dtoverlay=spi0-1cs,<param>=<val>
3428 Params: cs0_pin GPIO pin for CS0 (default 8)
3429 no_miso Don't claim and use the MISO pin (9), freeing
3434 Info: Change the CS pins for SPI0
3435 Load: dtoverlay=spi0-2cs,<param>=<val>
3436 Params: cs0_pin GPIO pin for CS0 (default 8)
3437 cs1_pin GPIO pin for CS1 (default 7)
3438 no_miso Don't claim and use the MISO pin (9), freeing
3443 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3444 alias for backwards compatibility.
3449 Info: This overlay has been deprecated and removed because it is no longer
3450 necessary and has been seen to prevent spi0 from working.
3455 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3456 dev node. The gpio pin number for the CS line and spidev device node
3457 creation are configurable.
3458 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3459 A+, B+, Zero and PI2 B; as well as the Compute Module.
3460 Load: dtoverlay=spi1-1cs,<param>=<val>
3461 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3462 cs0_spidev Set to 'disabled' to stop the creation of a
3463 userspace device node /dev/spidev1.0 (default
3464 is 'okay' or enabled).
3468 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3469 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3470 creation are configurable.
3471 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3472 A+, B+, Zero and PI2 B; as well as the Compute Module.
3473 Load: dtoverlay=spi1-2cs,<param>=<val>
3474 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3475 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3476 cs0_spidev Set to 'disabled' to stop the creation of a
3477 userspace device node /dev/spidev1.0 (default
3478 is 'okay' or enabled).
3479 cs1_spidev Set to 'disabled' to stop the creation of a
3480 userspace device node /dev/spidev1.1 (default
3481 is 'okay' or enabled).
3485 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3486 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3487 creation are configurable.
3488 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3489 A+, B+, Zero and PI2 B; as well as the Compute Module.
3490 Load: dtoverlay=spi1-3cs,<param>=<val>
3491 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3492 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3493 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3494 cs0_spidev Set to 'disabled' to stop the creation of a
3495 userspace device node /dev/spidev1.0 (default
3496 is 'okay' or enabled).
3497 cs1_spidev Set to 'disabled' to stop the creation of a
3498 userspace device node /dev/spidev1.1 (default
3499 is 'okay' or enabled).
3500 cs2_spidev Set to 'disabled' to stop the creation of a
3501 userspace device node /dev/spidev1.2 (default
3502 is 'okay' or enabled).
3506 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3507 dev node. The gpio pin number for the CS line and spidev device node
3508 creation are configurable.
3509 N.B.: spi2 is only accessible with the Compute Module.
3510 Load: dtoverlay=spi2-1cs,<param>=<val>
3511 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3512 cs0_spidev Set to 'disabled' to stop the creation of a
3513 userspace device node /dev/spidev2.0 (default
3514 is 'okay' or enabled).
3518 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3519 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3520 creation are configurable.
3521 N.B.: spi2 is only accessible with the Compute Module.
3522 Load: dtoverlay=spi2-2cs,<param>=<val>
3523 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3524 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3525 cs0_spidev Set to 'disabled' to stop the creation of a
3526 userspace device node /dev/spidev2.0 (default
3527 is 'okay' or enabled).
3528 cs1_spidev Set to 'disabled' to stop the creation of a
3529 userspace device node /dev/spidev2.1 (default
3530 is 'okay' or enabled).
3534 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3535 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3536 creation are configurable.
3537 N.B.: spi2 is only accessible with the Compute Module.
3538 Load: dtoverlay=spi2-3cs,<param>=<val>
3539 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3540 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3541 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3542 cs0_spidev Set to 'disabled' to stop the creation of a
3543 userspace device node /dev/spidev2.0 (default
3544 is 'okay' or enabled).
3545 cs1_spidev Set to 'disabled' to stop the creation of a
3546 userspace device node /dev/spidev2.1 (default
3547 is 'okay' or enabled).
3548 cs2_spidev Set to 'disabled' to stop the creation of a
3549 userspace device node /dev/spidev2.2 (default
3550 is 'okay' or enabled).
3554 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3555 dev node. The gpio pin number for the CS line and spidev device node
3556 creation are configurable. BCM2711 only.
3557 Load: dtoverlay=spi3-1cs,<param>=<val>
3558 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3559 cs0_spidev Set to 'off' to prevent the creation of a
3560 userspace device node /dev/spidev3.0 (default
3561 is 'on' or enabled).
3565 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3566 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3567 creation are configurable. BCM2711 only.
3568 Load: dtoverlay=spi3-2cs,<param>=<val>
3569 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3570 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3571 cs0_spidev Set to 'off' to prevent the creation of a
3572 userspace device node /dev/spidev3.0 (default
3573 is 'on' or enabled).
3574 cs1_spidev Set to 'off' to prevent the creation of a
3575 userspace device node /dev/spidev3.1 (default
3576 is 'on' or enabled).
3580 Info: Enables spi4 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=spi4-1cs,<param>=<val>
3584 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3585 cs0_spidev Set to 'off' to prevent the creation of a
3586 userspace device node /dev/spidev4.0 (default
3587 is 'on' or enabled).
3591 Info: Enables spi4 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=spi4-2cs,<param>=<val>
3595 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3596 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3597 cs0_spidev Set to 'off' to prevent the creation of a
3598 userspace device node /dev/spidev4.0 (default
3599 is 'on' or enabled).
3600 cs1_spidev Set to 'off' to prevent the creation of a
3601 userspace device node /dev/spidev4.1 (default
3602 is 'on' or enabled).
3606 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3607 dev node. The gpio pin numbers for the CS lines and spidev device node
3608 creation are configurable. BCM2711 only.
3609 Load: dtoverlay=spi5-1cs,<param>=<val>
3610 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3611 cs0_spidev Set to 'off' to prevent the creation of a
3612 userspace device node /dev/spidev5.0 (default
3613 is 'on' or enabled).
3617 Info: Enables spi5 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=spi5-2cs,<param>=<val>
3621 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3622 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3623 cs0_spidev Set to 'off' to prevent the creation of a
3624 userspace device node /dev/spidev5.0 (default
3625 is 'on' or enabled).
3626 cs1_spidev Set to 'off' to prevent the creation of a
3627 userspace device node /dev/spidev5.1 (default
3628 is 'on' or enabled).
3632 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3633 dev node. The gpio pin number for the CS line and spidev device node
3634 creation are configurable. BCM2711 only.
3635 Load: dtoverlay=spi6-1cs,<param>=<val>
3636 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3637 cs0_spidev Set to 'off' to prevent the creation of a
3638 userspace device node /dev/spidev6.0 (default
3639 is 'on' or enabled).
3643 Info: Enables spi6 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=spi6-2cs,<param>=<val>
3647 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3648 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3649 cs0_spidev Set to 'off' to prevent the creation of a
3650 userspace device node /dev/spidev6.0 (default
3651 is 'on' or enabled).
3652 cs1_spidev Set to 'off' to prevent the creation of a
3653 userspace device node /dev/spidev6.1 (default
3654 is 'on' or enabled).
3658 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3659 Load: dtoverlay=ssd1306,<param>=<val>
3660 Params: address Location in display memory of first character.
3662 width Width of display. (default=128)
3663 height Height of display. (default=64)
3664 offset virtual channel a. (default=0)
3665 normal Has no effect on displays tested. (default=not
3667 sequential Set this if every other scan line is missing.
3669 remapped Set this if display is garbled. (default=not
3671 inverted Set this if display is inverted and mirrored.
3675 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3677 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3679 i2c_baudrate=400000 will speed up the display.
3681 i2c_baudrate=1000000 seems to work even though it's not officially
3682 supported by the hardware, and is faster still.
3684 For more information refer to the device datasheet at:
3685 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3689 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3690 Load: dtoverlay=ssd1306-spi,<param>=<val>
3691 Params: speed SPI bus speed (default 10000000)
3692 rotate Display rotation (0, 90, 180 or 270; default 0)
3693 fps Delay between frame updates (default 25)
3694 debug Debug output level (0-7; default 0)
3695 dc_pin GPIO pin for D/C (default 24)
3696 reset_pin GPIO pin for RESET (default 25)
3697 height Display height (32 or 64; default 64)
3701 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3702 Load: dtoverlay=ssd1331-spi,<param>=<val>
3703 Params: speed SPI bus speed (default 4500000)
3704 rotate Display rotation (0, 90, 180 or 270; default 0)
3705 fps Delay between frame updates (default 25)
3706 debug Debug output level (0-7; default 0)
3707 dc_pin GPIO pin for D/C (default 24)
3708 reset_pin GPIO pin for RESET (default 25)
3712 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3713 Load: dtoverlay=ssd1351-spi,<param>=<val>
3714 Params: speed SPI bus speed (default 4500000)
3715 rotate Display rotation (0, 90, 180 or 270; default 0)
3716 fps Delay between frame updates (default 25)
3717 debug Debug output level (0-7; default 0)
3718 dc_pin GPIO pin for D/C (default 24)
3719 reset_pin GPIO pin for RESET (default 25)
3722 Name: superaudioboard
3723 Info: Configures the SuperAudioBoard sound card
3724 Load: dtoverlay=superaudioboard,<param>=<val>
3725 Params: gpiopin GPIO pin for codec reset
3729 Info: Configures the Semtech SX150X I2C GPIO expanders.
3730 Load: dtoverlay=sx150x,<param>=<val>
3731 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3732 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3733 Permissible values of <m> (which is denoted in
3734 hex) depend on the device variant. For SX1501,
3735 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3736 For SX1503 and SX1506, <m> may be 20. For
3737 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3738 For SX1508, <m> may be 20, 21, 22 or 23.
3740 sx150<x>-<n>-<m>-int-gpio
3741 Integer, enables interrupts on SX150X device on
3742 I2C#<n> with slave address <m>, specifies
3743 the GPIO pin to which NINT output of SX150X is
3748 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3749 Uses Unicam 1, which is the standard camera connector on most Pi
3751 Load: dtoverlay=tc358743,<param>=<val>
3752 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3755 link-frequency Set the link frequency. Only values of 297000000
3756 (574Mbit/s) and 486000000 (972Mbit/s - default)
3757 are supported by the driver.
3758 media-controller Configure use of Media Controller API for
3759 configuring the sensor (default off)
3760 cam0 Adopt the default configuration for CAM0 on a
3761 Compute Module (CSI0, i2c_vc, and cam0_reg).
3764 Name: tc358743-audio
3765 Info: Used in combination with the tc358743-fast overlay to route the audio
3766 from the TC358743 over I2S to the Pi.
3767 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3769 Load: dtoverlay=tc358743-audio,<param>=<val>
3770 Params: card-name Override the default, "tc358743", card name.
3774 Info: 3.5" Color TFT Display by www.tinylcd.com
3775 Options: Touch, RTC, keypad
3776 Load: dtoverlay=tinylcd35,<param>=<val>
3777 Params: speed Display SPI bus speed
3779 rotate Display rotation {0,90,180,270}
3781 fps Delay between frame updates
3783 debug Debug output level {0-7}
3785 touch Enable touch panel
3787 touchgpio Touch controller IRQ GPIO
3789 xohms Touchpanel: Resistance of X-plate in ohms
3791 rtc-pcf PCF8563 Real Time Clock
3793 rtc-ds DS1307 Real Time Clock
3795 keypad Enable keypad
3798 Display with touchpanel, PCF8563 RTC and keypad:
3799 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
3801 dtoverlay=tinylcd35,touch,touchgpio=3
3805 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
3806 boards, which can be used as a secure key storage and hwrng,
3807 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
3808 Load: dtoverlay=tpm-slb9670
3813 Info: Change the pin usage of uart0
3814 Load: dtoverlay=uart0,<param>=<val>
3815 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
3817 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
3819 pin_func Alternative pin function - 4(Alt0) for 14&15,
3820 7(Alt3) for 32&33, 6(Alt2) for 36&37
3824 Info: Change the pin usage of uart1
3825 Load: dtoverlay=uart1,<param>=<val>
3826 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
3828 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
3832 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
3833 Load: dtoverlay=uart2,<param>
3834 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
3838 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
3839 Load: dtoverlay=uart3,<param>
3840 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
3844 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
3845 Load: dtoverlay=uart4,<param>
3846 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
3850 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
3851 Load: dtoverlay=uart5,<param>
3852 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
3856 Info: Configures the NW Digital Radio UDRC Hat
3857 Load: dtoverlay=udrc,<param>=<val>
3858 Params: alsaname Name of the ALSA audio device (default "udrc")
3861 Name: ugreen-dabboard
3862 Info: Configures the ugreen-dabboard I2S overlay
3863 This is a simple overlay based on the simple-audio-card and the dmic
3864 codec. It has the speciality that it is configured to use the codec
3865 as a master I2S device. It works for example with the Si468x DAB
3866 receiver on the uGreen DABBoard.
3867 Load: dtoverlay=ugreen-dabboard,<param>=<val>
3868 Params: card-name Override the default, "dabboard", card name.
3872 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
3873 vc4-kms-v3d and dwc2 overlays.
3874 Load: dtoverlay=upstream
3878 Name: upstream-aux-interrupt
3879 Info: This overlay has been deprecated and removed because it is no longer
3885 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
3886 the vc4-kms-v3d-pi4 and dwc2 overlays.
3887 Load: dtoverlay=upstream-pi4
3892 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3894 Load: dtoverlay=vc4-fkms-v3d,<param>
3895 Params: cma-512 CMA is 512MB (needs 1GB)
3896 cma-448 CMA is 448MB (needs 1GB)
3897 cma-384 CMA is 384MB (needs 1GB)
3898 cma-320 CMA is 320MB (needs 1GB)
3899 cma-256 CMA is 256MB (needs 1GB)
3900 cma-192 CMA is 192MB (needs 1GB)
3901 cma-128 CMA is 128MB
3904 cma-size CMA size in bytes, 4MB aligned
3905 cma-default Use upstream's default value
3908 Name: vc4-fkms-v3d-pi4
3909 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3911 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
3912 Params: cma-512 CMA is 512MB (needs 1GB)
3913 cma-448 CMA is 448MB (needs 1GB)
3914 cma-384 CMA is 384MB (needs 1GB)
3915 cma-320 CMA is 320MB (needs 1GB)
3916 cma-256 CMA is 256MB (needs 1GB)
3917 cma-192 CMA is 192MB (needs 1GB)
3918 cma-128 CMA is 128MB
3921 cma-size CMA size in bytes, 4MB aligned
3922 cma-default Use upstream's default value
3925 Name: vc4-kms-dpi-at056tn53v1
3926 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
3930 Name: vc4-kms-dpi-generic
3931 Info: Enable a generic DPI display under KMS. Default timings are for the
3932 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
3933 Requires vc4-kms-v3d to be loaded.
3934 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
3935 Params: clock-frequency Display clock frequency (Hz)
3936 hactive Horizontal active pixels
3937 hfp Horizontal front porch
3938 hsync Horizontal sync pulse width
3939 hbp Horizontal back porch
3940 vactive Vertical active lines
3941 vfp Vertical front porch
3942 vsync Vertical sync pulse width
3943 vbp Vertical back porch
3944 hsync-invert Horizontal sync active low
3945 vsync-invert Vertical sync active low
3946 de-invert Data Enable active low
3947 pixclk-invert Negative edge pixel clock
3948 width-mm Define the screen width in mm
3949 height-mm Define the screen height in mm
3950 rgb565 Change to RGB565 output on GPIOs 0-19
3951 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
3953 bgr666 Change to BGR666 output on GPIOs 0-21.
3954 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
3956 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
3958 bgr888 Change to BGR888 output on GPIOs 0-27
3959 rgb888 Change to RGB888 output on GPIOs 0-27
3960 bus-format Override the bus format for a MEDIA_BUS_FMT_*
3961 value. NB also overridden by rgbXXX overrides.
3962 backlight-gpio Defines a GPIO to be used for backlight control
3964 backlight-pwm Defines a PWM channel to be used for backlight
3965 control (default of none). NB Disables audio
3966 headphone output as that also uses PWM.
3967 backlight-pwm-chan Choose channel on &pwm node for backlight
3970 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3971 pwm-2chan for valid options.
3972 (default 18 - note this can only work with
3974 backlight-pwm-func Pin function of GPIO used for the PWM
3976 See pwm-2chan for valid options.
3978 backlight-def-brightness
3979 Set the default brightness. Normal range 1-16.
3981 rotate Display rotation {0,90,180,270} (default 0)
3984 Name: vc4-kms-dpi-hyperpixel2r
3985 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
3986 Requires vc4-kms-v3d to be loaded.
3987 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
3988 Params: disable-touch Disables the touch controller
3989 touchscreen-inverted-x Inverts X direction of touch controller
3990 touchscreen-inverted-y Inverts Y direction of touch controller
3991 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3992 rotate Display rotation {0,90,180,270} (default 0)
3995 Name: vc4-kms-dpi-hyperpixel4
3996 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
3997 Requires vc4-kms-v3d to be loaded.
3998 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
3999 Params: disable-touch Disables the touch controller
4000 touchscreen-inverted-x Inverts X direction of touch controller
4001 touchscreen-inverted-y Inverts Y direction of touch controller
4002 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4003 rotate Display rotation {0,90,180,270} (default 0)
4006 Name: vc4-kms-dpi-hyperpixel4sq
4007 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
4008 Requires vc4-kms-v3d to be loaded.
4009 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
4010 Params: disable-touch Disables the touch controller
4011 touchscreen-inverted-x Inverts X direction of touch controller
4012 touchscreen-inverted-y Inverts Y direction of touch controller
4013 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
4014 rotate Display rotation {0,90,180,270} (default 0)
4017 Name: vc4-kms-dpi-panel
4018 Info: Enable a preconfigured KMS DPI panel.
4019 Requires vc4-kms-v3d to be loaded.
4020 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
4021 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
4022 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
4023 mzp280 Enable a Geekworm MZP280 panel.
4024 backlight-gpio Defines a GPIO to be used for backlight control
4026 backlight-pwm Defines a PWM channel to be used for backlight
4027 control (default of none). NB Disables audio
4028 headphone output as that also uses PWM.
4029 backlight-pwm-chan Choose channel on &pwm node for backlight
4032 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
4033 pwm-2chan for valid options.
4034 (default 18 - note this can only work with
4036 backlight-pwm-func Pin function of GPIO used for the PWM
4038 See pwm-2chan for valid options.
4040 backlight-def-brightness
4041 Set the default brightness. Normal range 1-16.
4043 rotate Display rotation {0,90,180,270} (default 0)
4046 Name: vc4-kms-dsi-7inch
4047 Info: Enable the Raspberry Pi DSI 7" screen.
4048 Includes the edt-ft5406 for the touchscreen element.
4049 Requires vc4-kms-v3d to be loaded.
4050 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
4051 Params: sizex Touchscreen size x (default 800)
4052 sizey Touchscreen size y (default 480)
4053 invx Touchscreen inverted x axis
4054 invy Touchscreen inverted y axis
4055 swapxy Touchscreen swapped x y axis
4056 disable_touch Disables the touch screen overlay driver
4059 Name: vc4-kms-dsi-lt070me05000
4060 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
4061 Note that this is a 4 lane DSI device, so it will only work on a Compute
4063 Requires vc4-kms-v3d to be loaded.
4064 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
4065 Params: reset GPIO for the reset signal (default 17)
4066 enable GPIO for the enable signal (default 4)
4067 dcdc-en GPIO for the DC-DC converter enable (default 5)
4070 Name: vc4-kms-dsi-lt070me05000-v2
4071 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
4073 Note that this is a 4 lane DSI device, so it will only work on a Compute
4075 Requires vc4-kms-v3d to be loaded.
4076 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
4080 Name: vc4-kms-kippah-7inch
4081 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
4086 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
4087 Load: dtoverlay=vc4-kms-v3d,<param>
4088 Params: cma-512 CMA is 512MB (needs 1GB)
4089 cma-448 CMA is 448MB (needs 1GB)
4090 cma-384 CMA is 384MB (needs 1GB)
4091 cma-320 CMA is 320MB (needs 1GB)
4092 cma-256 CMA is 256MB (needs 1GB)
4093 cma-192 CMA is 192MB (needs 1GB)
4094 cma-128 CMA is 128MB
4097 cma-size CMA size in bytes, 4MB aligned
4098 cma-default Use upstream's default value
4099 audio Enable or disable audio over HDMI (default "on")
4100 noaudio Disable all HDMI audio (default "off")
4101 composite Enable the composite output (default "off")
4102 N.B. Disables all other outputs on a Pi 4.
4105 Name: vc4-kms-v3d-pi4
4106 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
4107 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
4108 Params: cma-512 CMA is 512MB
4109 cma-448 CMA is 448MB
4110 cma-384 CMA is 384MB
4111 cma-320 CMA is 320MB
4112 cma-256 CMA is 256MB
4113 cma-192 CMA is 192MB
4114 cma-128 CMA is 128MB
4117 cma-size CMA size in bytes, 4MB aligned
4118 cma-default Use upstream's default value
4119 audio Enable or disable audio over HDMI0 (default
4121 audio1 Enable or disable audio over HDMI1 (default
4123 noaudio Disable all HDMI audio (default "off")
4124 composite Enable the composite output (disables all other
4128 Name: vc4-kms-vga666
4129 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
4130 Requires vc4-kms-v3d to be loaded.
4131 Load: dtoverlay=vc4-kms-vga666,<param>
4132 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
4133 from the display. NB These are NOT 5V tolerant
4134 GPIOs, therefore level shifters are required.
4138 Info: Overlay for the Fen Logic VGA666 board
4139 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
4140 after the kernel has started.
4141 NOT for use with vc4-kms-v3d.
4142 Load: dtoverlay=vga666
4147 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
4148 Will be loaded automatically by up-to-date firmware if "VL805=1" is
4149 set in the EEPROM config.
4150 Load: dtoverlay=vl805
4155 Info: Configures the w1-gpio Onewire interface module.
4156 Use this overlay if you *don't* need a GPIO to drive an external pullup.
4157 Load: dtoverlay=w1-gpio,<param>=<val>
4158 Params: gpiopin GPIO for I/O (default "4")
4159 pullup Now enabled by default (ignored)
4162 Name: w1-gpio-pullup
4163 Info: Configures the w1-gpio Onewire interface module.
4164 Use this overlay if you *do* need a GPIO to drive an external pullup.
4165 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4166 Params: gpiopin GPIO for I/O (default "4")
4167 extpullup GPIO for external pullup (default "5")
4168 pullup Now enabled by default (ignored)
4172 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4173 Load: dtoverlay=w5500,<param>=<val>
4174 Params: int_pin GPIO used for INT (default 25)
4176 speed SPI bus speed (default 30000000)
4178 cs SPI bus Chip Select (default 0)
4181 Name: waveshare-can-fd-hat-mode-a
4182 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4183 for Raspberry Pi, Multi Protections. Use this overlay when the
4184 HAT is configured in Mode A (Default), with can0 on spi0.0
4186 https://www.waveshare.com/2-ch-can-fd-hat.htm
4187 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4191 Name: waveshare-can-fd-hat-mode-b
4192 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4193 for Raspberry Pi, Multi Protections. Use this overlay when the
4194 HAT is configured in Mode B (requires hardware modification), with
4195 can0 on spi0.0 and can1 on spi0.1.
4196 https://www.waveshare.com/2-ch-can-fd-hat.htm
4197 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4202 Info: Configures the wittypi RTC module.
4203 Load: dtoverlay=wittypi,<param>=<val>
4204 Params: led_gpio GPIO for LED (default "17")
4205 led_trigger Choose which activity the LED tracks (default
4209 Name: wm8960-soundcard
4210 Info: Overlay for the Waveshare wm8960 soundcard
4211 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4212 Params: alsaname Changes the card name in ALSA
4213 compatible Changes the codec compatibility
4219 If you are experiencing problems that you think are DT-related, enable DT
4220 diagnostic output by adding this to /boot/config.txt:
4224 and rebooting. Then run:
4228 and look for relevant messages.
4233 This is only meant to be a quick introduction to the subject of Device Tree on
4234 Raspberry Pi. There is a more complete explanation here:
4236 http://www.raspberrypi.org/documentation/configuration/device-tree.md