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: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
588 Load: dtoverlay=at86rf233,<param>=<val>
589 Params: interrupt GPIO used for INT (default 23)
590 reset GPIO used for Reset (default 24)
591 sleep GPIO used for Sleep (default 25)
592 speed SPI bus speed in Hz (default 3000000)
593 trim Fine tuning of the internal capacitance
594 arrays (0=+0pF, 15=+4.5pF, default 15)
597 Name: audioinjector-addons
598 Info: Configures the audioinjector.net audio add on soundcards
599 Load: dtoverlay=audioinjector-addons,<param>=<val>
600 Params: non-stop-clocks Keeps the clocks running even when the stream
601 is paused or stopped (default off)
604 Name: audioinjector-isolated-soundcard
605 Info: Configures the audioinjector.net isolated soundcard
606 Load: dtoverlay=audioinjector-isolated-soundcard
610 Name: audioinjector-ultra
611 Info: Configures the audioinjector.net ultra soundcard
612 Load: dtoverlay=audioinjector-ultra
616 Name: audioinjector-wm8731-audio
617 Info: Configures the audioinjector.net audio add on soundcard
618 Load: dtoverlay=audioinjector-wm8731-audio
623 Info: Configures the audiosense-pi add on soundcard
624 For more information refer to
625 https://gitlab.com/kakar0t/audiosense-pi
626 Load: dtoverlay=audiosense-pi
631 Info: Switches PWM sound output to GPIOs on the 40-pin header
632 Load: dtoverlay=audremap,<param>=<val>
633 Params: swap_lr Reverse the channel allocation, which will also
634 swap the audio jack outputs (default off)
635 enable_jack Don't switch off the audio jack output
637 pins_12_13 Select GPIOs 12 & 13 (default)
638 pins_18_19 Select GPIOs 18 & 19
642 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
643 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
644 Load: dtoverlay=balena-fin
648 Name: bmp085_i2c-sensor
649 Info: This overlay is now deprecated - see i2c-sensor
654 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
655 Load: dtoverlay=cap1106,<param>=<val>
656 Params: int_pin GPIO pin for interrupt signal (default 23)
660 Info: Configures Chip Dip audio cards.
661 Load: dtoverlay=chipdip-dac
666 Info: Set custom CMA sizes, only use if you know what you are doing, might
667 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
668 Load: dtoverlay=cma,<param>=<val>
669 Params: cma-512 CMA is 512MB (needs 1GB)
670 cma-448 CMA is 448MB (needs 1GB)
671 cma-384 CMA is 384MB (needs 1GB)
672 cma-320 CMA is 320MB (needs 1GB)
673 cma-256 CMA is 256MB (needs 1GB)
674 cma-192 CMA is 192MB (needs 1GB)
678 cma-size CMA size in bytes, 4MB aligned
679 cma-default Use upstream's default value
683 Info: 8" TFT LCD display and touch panel used by cutiepi.io
684 Load: dtoverlay=cutiepi-panel
689 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
690 Also sometimes found with the part number(s) AM230x.
691 Load: dtoverlay=dht11,<param>=<val>
692 Params: gpiopin GPIO connected to the sensor's DATA output.
697 Info: Configures the Dion Audio LOCO DAC-AMP
698 Load: dtoverlay=dionaudio-loco
702 Name: dionaudio-loco-v2
703 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
704 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
705 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
706 Digital volume control. Enable with
707 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
708 (The default behaviour is that the Digital
709 volume control is limited to a maximum of
710 0dB. ie. it can attenuate but not provide
711 gain. For most users, this will be desired
712 as it will prevent clipping. By appending
713 the 24dB_digital_gain parameter, the Digital
714 volume control will allow up to 24dB of
715 gain. If this parameter is enabled, it is the
716 responsibility of the user to ensure that
717 the Digital volume control is set to a value
718 that does not result in clipping/distortion!)
722 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
723 UART0/ttyAMA0 over GPIOs 14 & 15.
724 N.B. To disable the systemd service that initialises the modem so it
725 doesn't use the UART, use 'sudo systemctl disable hciuart'.
726 Load: dtoverlay=disable-bt
731 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
732 Load: dtoverlay=disable-wifi
737 Info: Overlay for a generic 18-bit DPI display
738 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
739 2-3 seconds after the kernel has started.
740 Load: dtoverlay=dpi18
745 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
746 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
747 the output 3-3 seconds after the kernel has started.
748 Load: dtoverlay=dpi18cpadhi
753 Info: Overlay for a generic 24-bit DPI display
754 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
755 2-3 seconds after the kernel has started.
756 Load: dtoverlay=dpi24
761 Info: Configures the NW Digital Radio DRAWS Hat
763 The board includes an ADC to measure various board values and also
764 provides two analog user inputs on the expansion header. The ADC
765 can be configured for various sample rates and gain values to adjust
766 the input range. Tables describing the two parameters follow.
783 4 = 1600sps (default)
787 Load: dtoverlay=draws,<param>=<val>
788 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
789 input voltage sensor (default 1)
791 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
794 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
795 5V rail voltage sensor (default 1)
797 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
800 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
801 AIN2 input (default 2)
803 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
805 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
806 AIN3 input (default 2)
808 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
810 alsaname Name of the ALSA audio device (default "draws")
814 Info: Selects the dwc_otg USB controller driver which has fiq support. This
815 is the default on all except the Pi Zero which defaults to dwc2.
816 Load: dtoverlay=dwc-otg
821 Info: Selects the dwc2 USB controller driver
822 Load: dtoverlay=dwc2,<param>=<val>
823 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
825 g-rx-fifo-size Size of rx fifo size in gadget mode
827 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
831 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
835 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
836 This works with the Raspberry Pi 7" touchscreen when not being polled
838 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
839 config.txt to stop the firmware polling the touchscreen.
840 Load: dtoverlay=edt-ft5406,<param>=<val>
841 Params: sizex Touchscreen size x (default 800)
842 sizey Touchscreen size y (default 480)
843 invx Touchscreen inverted x axis
844 invy Touchscreen inverted y axis
845 swapxy Touchscreen swapped x y axis
849 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
850 Load: dtoverlay=enc28j60,<param>=<val>
851 Params: int_pin GPIO used for INT (default 25)
853 speed SPI bus speed (default 12000000)
857 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
858 Load: dtoverlay=enc28j60-spi2,<param>=<val>
859 Params: int_pin GPIO used for INT (default 39)
861 speed SPI bus speed (default 12000000)
865 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
866 GPIO 4 (pin 7 on GPIO header) for interrupt.
867 Load: dtoverlay=exc3000,<param>=<val>
868 Params: interrupt GPIO used for interrupt (default 4)
869 sizex Touchscreen size x (default 4096)
870 sizey Touchscreen size y (default 4096)
871 invx Touchscreen inverted x axis
872 invy Touchscreen inverted y axis
873 swapxy Touchscreen swapped x y axis
877 Info: Overlay for SPI-connected displays using the fbtft drivers.
879 This overlay seeks to replace the functionality provided by fbtft_device
880 which is now gone from the kernel.
882 Most displays from fbtft_device have been ported over.
884 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
886 It is also possible to specify the controller (this will use the default
887 init sequence in the driver).
889 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
891 For devices on spi1 or spi2, the interfaces should be enabled
892 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
894 The following features of fbtft_device have not been ported over:
895 - parallel bus is not supported
896 - the init property which overrides the controller initialization
897 sequence is not supported as a parameter due to memory limitations in
898 the bootloader responsible for applying the overlay.
900 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
903 Load: dtoverlay=fbtft,<param>=<val>
905 spi<n>-<m> Configure device at spi<n>, cs<m>
907 speed SPI bus speed in Hz (default 32000000)
908 cpha Shifted clock phase (CPHA) mode
909 cpol Inverse clock polarity (CPOL) mode
911 adafruit18 Adafruit 1.8
912 adafruit22 Adafruit 2.2 (old)
913 adafruit22a Adafruit 2.2
914 adafruit28 Adafruit 2.8
915 adafruit13m Adafruit 1.3 OLED
916 admatec_c-berry28 C-Berry28
918 er_tftm050_2 ER-TFTM070-2
919 er_tftm070_5 ER-TFTM070-5
921 ew24ha0_9bit EW24HA0 in 9-bit mode
922 freetronicsoled128 Freetronics OLED128
925 itdb28_spi ITDB02-2.8 with SPI interface circuit
926 mi0283qt-2 Watterott MI0283QT-2
927 mi0283qt-9a Watterott MI0283QT-9A
929 nokia3310a Nokia 3310a
932 pitft Adafruit PiTFT 2.8
934 rpi-display Watterott rpi-display
935 sainsmart18 Sainsmart 1.8
936 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
937 tinylcd35 TinyLCD 3.5
938 tm022hdh26 Tianma TM022HDH26
939 tontec35_9481 Tontect 3.5 with ILI9481 controller
940 tontec35_9486 Tontect 3.5 with ILI9486 controller
941 waveshare32b Waveshare 3.2
942 waveshare22 Waveshare 2.2
944 bd663474 BD663474 display controller
945 hx8340bn HX8340BN display controller
946 hx8347d HX8347D display controller
947 hx8353d HX8353D display controller
948 hx8357d HX8357D display controller
949 ili9163 ILI9163 display controller
950 ili9320 ILI9320 display controller
951 ili9325 ILI9325 display controller
952 ili9340 ILI9340 display controller
953 ili9341 ILI9341 display controller
954 ili9481 ILI9481 display controller
955 ili9486 ILI9486 display controller
956 pcd8544 PCD8544 display controller
957 ra8875 RA8875 display controller
958 s6d02a1 S6D02A1 display controller
959 s6d1121 S6D1121 display controller
960 seps525 SEPS525 display controller
961 sh1106 SH1106 display controller
962 ssd1289 SSD1289 display controller
963 ssd1305 SSD1305 display controller
964 ssd1306 SSD1306 display controller
965 ssd1325 SSD1325 display controller
966 ssd1331 SSD1331 display controller
967 ssd1351 SSD1351 display controller
968 st7735r ST7735R display controller
969 st7789v ST7789V display controller
970 tls8204 TLS8204 display controller
971 uc1611 UC1611 display controller
972 uc1701 UC1701 display controller
973 upd161704 UPD161704 display controller
975 width Display width in pixels
976 height Display height in pixels
977 regwidth Display controller register width (default is
979 buswidth Display bus interface width (default 8)
980 debug Debug output level {0-7}
981 rotate Display rotation {0, 90, 180, 270} (counter
982 clockwise). Not supported by all drivers.
983 bgr Enable BGR mode (default off). Use if Red and
984 Blue are swapped. Not supported by all drivers.
985 fps Frames per second (default 30). In effect this
986 states how long the driver will wait after video
987 memory has been changed until display update
989 txbuflen Length of the FBTFT transmit buffer
991 startbyte Sets the Start byte used by fb_ili9320,
992 fb_ili9325 and fb_hx8347d. Common value is 0x70.
993 gamma String representation of Gamma Curve(s). Driver
994 specific. Not supported by all drivers.
995 reset_pin GPIO pin for RESET
996 dc_pin GPIO pin for D/C
997 led_pin GPIO pin for LED backlight
1001 Info: Configures the Fe-Pi Audio Sound Card
1002 Load: dtoverlay=fe-pi-audio
1007 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1008 nicely with a "traffic-light" display of red, amber and green LEDs on
1009 GPIOs 7, 8 and 25 respectively.
1010 Load: dtoverlay=fsm-demo,<param>=<val>
1011 Params: fsm_debug Enable debug logging (default off)
1015 Info: An overlay for the Ghost amplifier.
1016 Load: dtoverlay=ghost-amp,<param>=<val>
1017 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1022 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1023 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1024 Load: dtoverlay=goodix,<param>=<val>
1025 Params: interrupt GPIO used for interrupt (default 4)
1026 reset GPIO used for reset (default 17)
1029 Name: googlevoicehat-soundcard
1030 Info: Configures the Google voiceHAT soundcard
1031 Load: dtoverlay=googlevoicehat-soundcard
1036 Info: Configure a GPIO pin to control a cooling fan.
1037 Load: dtoverlay=gpio-fan,<param>=<val>
1038 Params: gpiopin GPIO used to control the fan (default 12)
1039 temp Temperature at which the fan switches on, in
1040 millicelcius (default 55000)
1044 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1045 based gpio_ir_recv driver maps received keys directly to a
1046 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1047 not required! The key mapping and other decoding parameters can be
1048 configured by "ir-keytable" tool.
1049 Load: dtoverlay=gpio-ir,<param>=<val>
1050 Params: gpio_pin Input pin number. Default is 18.
1052 gpio_pull Desired pull-up/down state (off, down, up)
1055 invert "1" = invert the input (active-low signalling).
1056 "0" = non-inverted input (active-high
1057 signalling). Default is "1".
1059 rc-map-name Default rc keymap (can also be changed by
1060 ir-keytable), defaults to "rc-rc6-mce"
1064 Info: Use GPIO pin as bit-banged infrared transmitter output.
1065 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1066 a PWM so it can be used together with onboard analog audio.
1067 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1068 Params: gpio_pin Output GPIO (default 18)
1070 invert "1" = invert the output (make it active-low).
1071 Default is "0" (active-high).
1075 Info: This is a generic overlay for activating GPIO keypresses using
1076 the gpio-keys library and this dtoverlay. Multiple keys can be
1077 set up using multiple calls to the overlay for configuring
1078 additional buttons or joysticks. You can see available keycodes
1079 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1080 linux/input-event-codes.h#L64
1081 Load: dtoverlay=gpio-key,<param>=<val>
1082 Params: gpio GPIO pin to trigger on (default 3)
1083 active_low When this is 1 (active low), a falling
1084 edge generates a key down event and a
1085 rising edge generates a key up event.
1086 When this is 0 (active high), this is
1087 reversed. The default is 1 (active low)
1088 gpio_pull Desired pull-up/down state (off, down, up)
1089 Default is "up". Note that the default pin
1090 (GPIO3) has an external pullup
1091 label Set a label for the key
1092 keycode Set the key code for the button
1097 Info: This is a generic overlay for activating LEDs (or any other component)
1098 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1099 overlay. While there are many existing methods to activate LEDs on the
1100 RPi, this method offers some advantages:
1101 1) Does not require any userspace programs.
1102 2) LEDs can be connected to the kernel's led-trigger framework,
1103 and drive the LED based on triggers such as cpu load, heartbeat,
1104 kernel panic, key input, timers and others.
1105 3) LED can be tied to the input state of another GPIO pin.
1106 4) The LED is setup early during the kernel boot process (useful
1107 for cpu/heartbeat/panic triggers).
1109 Typical electrical connection is:
1110 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1111 The GPIO pin number can be changed with the 'gpio=' parameter.
1113 To control an LED from userspace, write a 0 or 1 value:
1114 echo 1 > /sys/class/leds/myled1/brightness
1115 The 'myled1' name can be changed with the 'label=' parameter.
1117 To connect the LED to a kernel trigger from userspace:
1118 echo cpu > /sys/class/leds/myled1/trigger
1119 echo heartbeat > /sys/class/leds/myled1/trigger
1120 echo none > /sys/class/leds/myled1/trigger
1121 To connect the LED to GPIO.26 pin (physical pin 37):
1122 echo gpio > /sys/class/leds/myled1/trigger
1123 echo 26 > /sys/class/leds/myled1/gpio
1125 cat /sys/class/leds/myled1/trigger
1127 More information about the Linux kernel LED/Trigger system:
1128 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1129 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1130 Load: dtoverlay=gpio-led,<param>=<val>
1131 Params: gpio GPIO pin connected to the LED (default 19)
1132 label The label for this LED. It will appear under
1133 /sys/class/leds/<label> . Default 'myled1'.
1134 trigger Set the led-trigger to connect to this LED.
1135 default 'none' (LED is user-controlled).
1136 Some possible triggers:
1137 cpu - CPU load (all CPUs)
1138 cpu0 - CPU load of first CPU.
1139 mmc - disk activity (all disks)
1140 panic - turn on on kernel panic
1141 heartbeat - indicate system health
1142 gpio - connect to a GPIO input pin (note:
1143 currently the GPIO PIN can not be set
1144 using overlay parameters, must be
1145 done in userspace, see examples above.
1146 active_low Set to 1 to turn invert the LED control
1147 (writing 0 to /sys/class/leds/XXX/brightness
1148 will turn on the GPIO/LED). Default '0'.
1151 Name: gpio-no-bank0-irq
1152 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1153 which can be useful for UIO drivers.
1154 N.B. Using this overlay will trigger a kernel WARN during booting, but
1155 this can safely be ignored - the system should work as expected.
1156 Load: dtoverlay=gpio-no-bank0-irq
1161 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1162 for user-space GPIO edge detection systems.
1163 Load: dtoverlay=gpio-no-irq
1168 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1169 overlay interferes with the normal power-down sequence, preventing the
1170 kernel from resetting the SoC (a necessary step in a normal power-off
1171 or reboot). This also disables the ability to trigger a boot by driving
1174 The GPIO starts in an inactive state. At poweroff time it is driven
1175 active for 100ms, then inactive for 100ms, then active again. It is
1176 safe to remove the power at any point after the initial activation of
1179 Users of this overlay are required to provide an external mechanism to
1180 switch off the power supply when signalled - failure to do so results
1181 in a kernel BUG, increased power consumption and undefined behaviour.
1182 Load: dtoverlay=gpio-poweroff,<param>=<val>
1183 Params: gpiopin GPIO for signalling (default 26)
1185 active_low Set if the power control device requires a
1186 high->low transition to trigger a power-down.
1187 Note that this will require the support of a
1188 custom dt-blob.bin to prevent a power-down
1189 during the boot process, and that a reboot
1190 will also cause the pin to go low.
1191 input Set if the gpio pin should be configured as
1193 export Set to export the configured pin to sysfs
1194 active_delay_ms Initial GPIO active period (default 100)
1195 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1196 timeout_ms Specify (in ms) how long the kernel waits for
1197 power-down before issuing a WARN (default 3000).
1201 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1202 is configured as an input key that generates KEY_POWER events.
1204 This event is handled by systemd-logind by initiating a
1205 shutdown. Systemd versions older than 225 need an udev rule
1206 enable listening to the input device:
1208 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1209 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1210 ATTRS{keys}=="116", TAG+="power-switch"
1212 Alternatively this event can be handled also on systems without
1213 systemd, just by traditional SysV init daemon. KEY_POWER event
1214 (keycode 116) needs to be mapped to KeyboardSignal on console
1215 and then kb::kbrequest inittab action which is triggered by
1216 KeyboardSignal from console can be configured to issue system
1217 shutdown. Steps for this configuration are:
1219 Add following lines to the /etc/console-setup/remap.inc file:
1221 # Key Power as special keypress
1222 keycode 116 = KeyboardSignal
1224 Then add following lines to /etc/inittab file:
1226 # Action on special keypress (Key Power)
1227 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1229 And finally reload configuration by calling following commands:
1231 # dpkg-reconfigure console-setup
1232 # service console-setup reload
1235 This overlay only handles shutdown. After shutdown, the system
1236 can be powered up again by driving GPIO3 low. The default
1237 configuration uses GPIO3 with a pullup, so if you connect a
1238 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1239 you get a shutdown and power-up button. Please note that
1240 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1241 Load: dtoverlay=gpio-shutdown,<param>=<val>
1242 Params: gpio_pin GPIO pin to trigger on (default 3)
1243 For Raspberry Pi 1 Model B rev 1 set this
1244 explicitly to value 1, e.g.:
1246 dtoverlay=gpio-shutdown,gpio_pin=1
1248 active_low When this is 1 (active low), a falling
1249 edge generates a key down event and a
1250 rising edge generates a key up event.
1251 When this is 0 (active high), this is
1252 reversed. The default is 1 (active low).
1254 gpio_pull Desired pull-up/down state (off, down, up)
1257 Note that the default pin (GPIO3) has an
1258 external pullup. Same applies for GPIO1
1259 on Raspberry Pi 1 Model B rev 1.
1261 debounce Specify the debounce interval in milliseconds
1266 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1267 data, 2 gpio pins for enable and register select and 1 optional pin
1268 for enabling/disabling the backlight display.
1269 Load: dtoverlay=hd44780-lcd,<param>=<val>
1270 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1272 pin_d5 GPIO pin for data pin D5 (default 13)
1274 pin_d6 GPIO pin for data pin D6 (default 19)
1276 pin_d7 GPIO pin for data pin D7 (default 26)
1278 pin_en GPIO pin for "Enable" (default 21)
1280 pin_rs GPIO pin for "Register Select" (default 20)
1282 pin_bl Optional pin for enabling/disabling the
1283 display backlight. (default disabled)
1285 display_height Height of the display in characters
1287 display_width Width of the display in characters
1290 Name: hdmi-backlight-hwhack-gpio
1291 Info: Devicetree overlay for GPIO based backlight on/off capability.
1292 Use this if you have one of those HDMI displays whose backlight cannot
1293 be controlled via DPMS over HDMI and plan to do a little soldering to
1294 use an RPi gpio pin for on/off switching. See:
1295 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1296 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1297 Params: gpio_pin GPIO pin used (default 17)
1298 active_low Set this to 1 if the display backlight is
1299 switched on when the wire goes low.
1300 Leave the default (value 0) if the backlight
1301 expects a high to switch it on.
1305 Info: Configures the HifiBerry Amp and Amp+ audio cards
1306 Load: dtoverlay=hifiberry-amp
1310 Name: hifiberry-amp100
1311 Info: Configures the HifiBerry AMP100 audio card
1312 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1313 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1314 Digital volume control. Enable with
1315 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1316 (The default behaviour is that the Digital
1317 volume control is limited to a maximum of
1318 0dB. ie. it can attenuate but not provide
1319 gain. For most users, this will be desired
1320 as it will prevent clipping. By appending
1321 the 24dB_digital_gain parameter, the Digital
1322 volume control will allow up to 24dB of
1323 gain. If this parameter is enabled, it is the
1324 responsibility of the user to ensure that
1325 the Digital volume control is set to a value
1326 that does not result in clipping/distortion!)
1327 slave Force DAC+ Pro into slave mode, using Pi as
1328 master for bit clock and frame clock.
1329 leds_off If set to 'true' the onboard indicator LEDs
1330 are switched off at all times.
1331 auto_mute If set to 'true' the amplifier is automatically
1332 muted when the DAC is not playing.
1333 mute_ext_ctl The amplifier's HW mute control is enabled
1334 in ALSA mixer and set to <val>.
1335 Will be overwritten by ALSA user settings.
1339 Info: Configures the HifiBerry DAC audio cards
1340 Load: dtoverlay=hifiberry-dac
1344 Name: hifiberry-dacplus
1345 Info: Configures the HifiBerry DAC+ audio card
1346 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1347 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1348 Digital volume control. Enable with
1349 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1350 (The default behaviour is that the Digital
1351 volume control is limited to a maximum of
1352 0dB. ie. it can attenuate but not provide
1353 gain. For most users, this will be desired
1354 as it will prevent clipping. By appending
1355 the 24dB_digital_gain parameter, the Digital
1356 volume control will allow up to 24dB of
1357 gain. If this parameter is enabled, it is the
1358 responsibility of the user to ensure that
1359 the Digital volume control is set to a value
1360 that does not result in clipping/distortion!)
1361 slave Force DAC+ Pro into slave mode, using Pi as
1362 master for bit clock and frame clock.
1363 leds_off If set to 'true' the onboard indicator LEDs
1364 are switched off at all times.
1367 Name: hifiberry-dacplusadc
1368 Info: Configures the HifiBerry DAC+ADC audio card
1369 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1370 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1371 Digital volume control. Enable with
1372 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1373 (The default behaviour is that the Digital
1374 volume control is limited to a maximum of
1375 0dB. ie. it can attenuate but not provide
1376 gain. For most users, this will be desired
1377 as it will prevent clipping. By appending
1378 the 24dB_digital_gain parameter, the Digital
1379 volume control will allow up to 24dB of
1380 gain. If this parameter is enabled, it is the
1381 responsibility of the user to ensure that
1382 the Digital volume control is set to a value
1383 that does not result in clipping/distortion!)
1384 slave Force DAC+ Pro into slave mode, using Pi as
1385 master for bit clock and frame clock.
1386 leds_off If set to 'true' the onboard indicator LEDs
1387 are switched off at all times.
1390 Name: hifiberry-dacplusadcpro
1391 Info: Configures the HifiBerry DAC+ADC PRO audio card
1392 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1393 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1394 Digital volume control. Enable with
1395 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1396 (The default behaviour is that the Digital
1397 volume control is limited to a maximum of
1398 0dB. ie. it can attenuate but not provide
1399 gain. For most users, this will be desired
1400 as it will prevent clipping. By appending
1401 the 24dB_digital_gain parameter, the Digital
1402 volume control will allow up to 24dB of
1403 gain. If this parameter is enabled, it is the
1404 responsibility of the user to ensure that
1405 the Digital volume control is set to a value
1406 that does not result in clipping/distortion!)
1407 slave Force DAC+ADC Pro into slave mode, using Pi as
1408 master for bit clock and frame clock.
1409 leds_off If set to 'true' the onboard indicator LEDs
1410 are switched off at all times.
1413 Name: hifiberry-dacplusdsp
1414 Info: Configures the HifiBerry DAC+DSP audio card
1415 Load: dtoverlay=hifiberry-dacplusdsp
1419 Name: hifiberry-dacplushd
1420 Info: Configures the HifiBerry DAC+ HD audio card
1421 Load: dtoverlay=hifiberry-dacplushd
1425 Name: hifiberry-digi
1426 Info: Configures the HifiBerry Digi and Digi+ audio card
1427 Load: dtoverlay=hifiberry-digi
1431 Name: hifiberry-digi-pro
1432 Info: Configures the HifiBerry Digi+ Pro audio card
1433 Load: dtoverlay=hifiberry-digi-pro
1438 Info: Enables "High Peripheral" mode
1439 Load: dtoverlay=highperi
1444 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1445 Default values match Texy's display shield
1446 Load: dtoverlay=hy28a,<param>=<val>
1447 Params: speed Display SPI bus speed
1449 rotate Display rotation {0,90,180,270}
1451 fps Delay between frame updates
1453 debug Debug output level {0-7}
1455 xohms Touchpanel sensitivity (X-plate resistance)
1457 resetgpio GPIO used to reset controller
1459 ledgpio GPIO used to control backlight
1463 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1464 Default values match Texy's display shield
1465 Load: dtoverlay=hy28b,<param>=<val>
1466 Params: speed Display SPI bus speed
1468 rotate Display rotation {0,90,180,270}
1470 fps Delay between frame updates
1472 debug Debug output level {0-7}
1474 xohms Touchpanel sensitivity (X-plate resistance)
1476 resetgpio GPIO used to reset controller
1478 ledgpio GPIO used to control backlight
1482 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1483 Default values match Texy's display shield
1484 Load: dtoverlay=hy28b-2017,<param>=<val>
1485 Params: speed Display SPI bus speed
1487 rotate Display rotation {0,90,180,270}
1489 fps Delay between frame updates
1491 debug Debug output level {0-7}
1493 xohms Touchpanel sensitivity (X-plate resistance)
1495 resetgpio GPIO used to reset controller
1497 ledgpio GPIO used to control backlight
1501 Info: Configures the Audiophonics I-SABRE Q2M DAC
1502 Load: dtoverlay=i-sabre-q2m
1507 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1508 Load: dtoverlay=i2c-bcm2708
1513 Info: Adds support for software i2c controller on gpio pins
1514 Load: dtoverlay=i2c-gpio,<param>=<val>
1515 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1517 i2c_gpio_scl GPIO used for I2C clock (default "24")
1519 i2c_gpio_delay_us Clock delay in microseconds
1520 (default "2" = ~100kHz)
1522 bus Set to a unique, non-zero value if wanting
1523 multiple i2c-gpio busses. If set, will be used
1524 as the preferred bus number (/dev/i2c-<n>). If
1525 not set, the default value is 0, but the bus
1526 number will be dynamically assigned - probably
1531 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1532 Load: dtoverlay=i2c-mux,<param>=<val>
1533 Params: pca9542 Select the NXP PCA9542 device
1535 pca9545 Select the NXP PCA9545 device
1537 pca9548 Select the NXP PCA9548 device
1539 addr Change I2C address of the device (default 0x70)
1542 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1545 Name: i2c-pwm-pca9685a
1546 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1547 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1548 Params: addr I2C address of PCA9685A (default 0x40)
1552 Info: Adds support for a number of I2C Real Time Clock devices
1553 Load: dtoverlay=i2c-rtc,<param>=<val>
1554 Params: abx80x Select one of the ABx80x family:
1555 AB0801, AB0803, AB0804, AB0805,
1556 AB1801, AB1803, AB1804, AB1805
1558 bq32000 Select the TI BQ32000 device
1560 ds1307 Select the DS1307 device
1562 ds1339 Select the DS1339 device
1564 ds1340 Select the DS1340 device
1566 ds3231 Select the DS3231 device
1568 m41t62 Select the M41T62 device
1570 mcp7940x Select the MCP7940x device
1572 mcp7941x Select the MCP7941x device
1574 pcf2127 Select the PCF2127 device
1576 pcf2129 Select the PCF2129 device
1578 pcf85063 Select the PCF85063 device
1580 pcf85063a Select the PCF85063A device
1582 pcf8523 Select the PCF8523 device
1584 pcf85363 Select the PCF85363 device
1586 pcf8563 Select the PCF8563 device
1588 rv1805 Select the Micro Crystal RV1805 device
1590 rv3028 Select the Micro Crystal RV3028 device
1592 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1594 s35390a Select the ABLIC S35390A device
1596 i2c0 Choose the I2C0 bus on GPIOs 0&1
1598 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1600 addr Sets the address for the RTC. Note that the
1601 device must be configured to use the specified
1604 trickle-diode-disable Do not use the internal trickle charger diode
1607 trickle-diode-type Diode type for trickle charge - "standard" or
1608 "schottky" (ABx80x and RV1805 only)
1610 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1611 ABx80x, RV1805, RV3028)
1613 wakeup-source Specify that the RTC can be used as a wakeup
1616 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1617 off or 1 for Vdd < VBackup (RV3028 only)
1621 Info: Adds support for a number of I2C Real Time Clock devices
1622 using the software i2c controller
1623 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1624 Params: abx80x Select one of the ABx80x family:
1625 AB0801, AB0803, AB0804, AB0805,
1626 AB1801, AB1803, AB1804, AB1805
1628 bq32000 Select the TI BQ32000 device
1630 ds1307 Select the DS1307 device
1632 ds1339 Select the DS1339 device
1634 ds1340 Select the DS1340 device
1636 ds3231 Select the DS3231 device
1638 m41t62 Select the M41T62 device
1640 mcp7940x Select the MCP7940x device
1642 mcp7941x Select the MCP7941x device
1644 pcf2127 Select the PCF2127 device
1646 pcf2129 Select the PCF2129 device
1648 pcf85063 Select the PCF85063 device
1650 pcf85063a Select the PCF85063A device
1652 pcf8523 Select the PCF8523 device
1654 pcf85363 Select the PCF85363 device
1656 pcf8563 Select the PCF8563 device
1658 rv1805 Select the Micro Crystal RV1805 device
1660 rv3028 Select the Micro Crystal RV3028 device
1662 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1664 s35390a Select the ABLIC S35390A device
1666 addr Sets the address for the RTC. Note that the
1667 device must be configured to use the specified
1670 trickle-diode-disable Do not use the internal trickle charger diode
1673 trickle-diode-type Diode type for trickle charge - "standard" or
1674 "schottky" (ABx80x and RV1805 only)
1676 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1677 ABx80x, RV1805, RV3028)
1679 wakeup-source Specify that the RTC can be used as a wakeup
1682 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1683 off or 1 for Vdd < VBackup (RV3028 only)
1685 i2c_gpio_sda GPIO used for I2C data (default "23")
1687 i2c_gpio_scl GPIO used for I2C clock (default "24")
1689 i2c_gpio_delay_us Clock delay in microseconds
1690 (default "2" = ~100kHz)
1694 Info: Adds support for a number of I2C barometric pressure, temperature,
1695 light level and chemical sensors on i2c_arm
1696 Load: dtoverlay=i2c-sensor,<param>=<val>
1697 Params: addr Set the address for the BH1750, BME280, BME680,
1698 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1701 bh1750 Select the Rohm BH1750 ambient light sensor
1702 Valid addresses 0x23 or 0x5c, default 0x23
1704 bme280 Select the Bosch Sensortronic BME280
1705 Valid addresses 0x76-0x77, default 0x76
1707 bme680 Select the Bosch Sensortronic BME680
1708 Valid addresses 0x76-0x77, default 0x76
1710 bmp085 Select the Bosch Sensortronic BMP085
1712 bmp180 Select the Bosch Sensortronic BMP180
1714 bmp280 Select the Bosch Sensortronic BMP280
1715 Valid addresses 0x76-0x77, default 0x76
1717 ccs811 Select the AMS CCS811 digital gas sensor
1718 Valid addresses 0x5a-0x5b, default 0x5b
1720 ds1621 Select the Dallas Semiconductors DS1621 temp
1721 sensor. Valid addresses 0x48-0x4f, default 0x48
1723 hdc100x Select the Texas Instruments HDC100x temp sensor
1724 Valid addresses 0x40-0x43, default 0x40
1726 htu21 Select the HTU21 temperature and humidity sensor
1728 int_pin Set the GPIO to use for interrupts (max30102
1731 lm75 Select the Maxim LM75 temperature sensor
1732 Valid addresses 0x48-0x4f, default 0x4f
1734 lm75addr Deprecated - use addr parameter instead
1736 max17040 Select the Maxim Integrated MAX17040 battery
1739 max30102 Select the Maxim Integrated MAX30102 heart-rate
1740 and blood-oxygen sensor
1742 sht3x Select the Sensiron SHT3x temperature and
1743 humidity sensor. Valid addresses 0x44-0x45,
1746 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1749 sps30 Select the Sensirion SPS30 particulate matter
1750 sensor. Fixed address 0x69.
1752 sgp30 Select the Sensirion SGP30 VOC sensor.
1755 tmp102 Select the Texas Instruments TMP102 temp sensor
1756 Valid addresses 0x48-0x4b, default 0x48
1758 tsl4531 Select the AMS TSL4531 digital ambient light
1761 veml6070 Select the Vishay VEML6070 ultraviolet light
1766 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
1767 platforms - platforms other then Compute Modules can only use this
1768 to disable transaction combining.
1769 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
1770 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
1771 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
1772 camera and display connectors. This overlay disables that mux and
1773 configures /dev/i2c0 to point at whichever set of pins is requested.
1774 dtparam=i2c_vc=on will try and enable the mux, so combining the two
1775 will cause conflicts.
1776 Load: dtoverlay=i2c0,<param>=<val>
1777 Params: pins_0_1 Use pins 0 and 1 (default)
1778 pins_28_29 Use pins 28 and 29
1779 pins_44_45 Use pins 44 and 45
1780 pins_46_47 Use pins 46 and 47
1781 combine Allow transactions to be combined (default
1786 Info: Deprecated, legacy version of i2c0.
1791 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
1792 platforms - platforms other then Compute Modules can only use this
1793 to disable transaction combining.
1794 Load: dtoverlay=i2c1,<param>=<val>
1795 Params: pins_2_3 Use pins 2 and 3 (default)
1796 pins_44_45 Use pins 44 and 45
1797 combine Allow transactions to be combined (default
1802 Info: Deprecated, legacy version of i2c1.
1807 Info: Enable the i2c3 bus. BCM2711 only.
1808 Load: dtoverlay=i2c3,<param>
1809 Params: pins_2_3 Use GPIOs 2 and 3
1810 pins_4_5 Use GPIOs 4 and 5 (default)
1811 baudrate Set the baudrate for the interface (default
1816 Info: Enable the i2c4 bus. BCM2711 only.
1817 Load: dtoverlay=i2c4,<param>
1818 Params: pins_6_7 Use GPIOs 6 and 7
1819 pins_8_9 Use GPIOs 8 and 9 (default)
1820 baudrate Set the baudrate for the interface (default
1825 Info: Enable the i2c5 bus. BCM2711 only.
1826 Load: dtoverlay=i2c5,<param>
1827 Params: pins_10_11 Use GPIOs 10 and 11
1828 pins_12_13 Use GPIOs 12 and 13 (default)
1829 baudrate Set the baudrate for the interface (default
1834 Info: Enable the i2c6 bus. BCM2711 only.
1835 Load: dtoverlay=i2c6,<param>
1836 Params: pins_0_1 Use GPIOs 0 and 1
1837 pins_22_23 Use GPIOs 22 and 23 (default)
1838 baudrate Set the baudrate for the interface (default
1843 Info: move I2S function block to GPIO 28 to 31
1844 Load: dtoverlay=i2s-gpio28-31
1849 Info: Enables I2C connected Ilitek 251x multiple touch controller using
1850 GPIO 4 (pin 7 on GPIO header) for interrupt.
1851 Load: dtoverlay=ilitek251x,<param>=<val>
1852 Params: interrupt GPIO used for interrupt (default 4)
1853 sizex Touchscreen size x, horizontal resolution of
1854 touchscreen (in pixels)
1855 sizey Touchscreen size y, vertical resolution of
1856 touchscreen (in pixels)
1860 Info: Sony IMX219 camera module.
1861 Uses Unicam 1, which is the standard camera connector on most Pi
1863 Load: dtoverlay=imx219,<param>=<val>
1864 Params: rotation Mounting rotation of the camera sensor (0 or
1866 orientation Sensor orientation (0 = front, 1 = rear,
1867 2 = external, default external)
1868 media-controller Configure use of Media Controller API for
1869 configuring the sensor (default on)
1870 cam0 Adopt the default configuration for CAM0 on a
1871 Compute Module (CSI0, i2c_vc, and cam0_reg).
1875 Info: Sony IMX290 camera module.
1876 Uses Unicam 1, which is the standard camera connector on most Pi
1877 variants. NB This currently uses 4 CSI2 data lanes and therefore will
1879 Load: dtoverlay=imx290,<param>
1880 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
1881 Module (1, 3, or 4).
1882 clock-frequency Sets the clock frequency to match that used on
1884 Modules from Vision Components use 37.125MHz
1885 (the default), whilst those from Innomaker use
1887 mono Denote that the module is a mono sensor.
1888 orientation Sensor orientation (0 = front, 1 = rear,
1889 2 = external, default external)
1890 rotation Mounting rotation of the camera sensor (0 or
1892 media-controller Configure use of Media Controller API for
1893 configuring the sensor (default on)
1894 cam0 Adopt the default configuration for CAM0 on a
1895 Compute Module (CSI0, i2c_vc, and cam0_reg).
1899 Info: Sony IMX378 camera module.
1900 Uses Unicam 1, which is the standard camera connector on most Pi
1902 Load: dtoverlay=imx378,<param>=<val>
1903 Params: rotation Mounting rotation of the camera sensor (0 or
1905 orientation Sensor orientation (0 = front, 1 = rear,
1906 2 = external, default external)
1907 media-controller Configure use of Media Controller API for
1908 configuring the sensor (default on)
1909 cam0 Adopt the default configuration for CAM0 on a
1910 Compute Module (CSI0, i2c_vc, and cam0_reg).
1914 Info: Sony IMX477 camera module.
1915 Uses Unicam 1, which is the standard camera connector on most Pi
1917 Load: dtoverlay=imx477,<param>=<val>
1918 Params: rotation Mounting rotation of the camera sensor (0 or
1920 orientation Sensor orientation (0 = front, 1 = rear,
1921 2 = external, default external)
1922 media-controller Configure use of Media Controller API for
1923 configuring the sensor (default on)
1924 cam0 Adopt the default configuration for CAM0 on a
1925 Compute Module (CSI0, i2c_vc, and cam0_reg).
1929 Info: Sony IMX519 camera module.
1930 Uses Unicam 1, which is the standard camera connector on most Pi
1932 Load: dtoverlay=imx519,<param>=<val>
1933 Params: rotation Mounting rotation of the camera sensor (0 or
1935 orientation Sensor orientation (0 = front, 1 = rear,
1936 2 = external, default external)
1937 media-controller Configure use of Media Controller API for
1938 configuring the sensor (default on)
1939 cam0 Adopt the default configuration for CAM0 on a
1940 Compute Module (CSI0, i2c_vc, and cam0_reg).
1944 Info: Configures the IQaudio Codec audio card
1945 Load: dtoverlay=iqaudio-codec
1950 Info: Configures the IQaudio DAC audio card
1951 Load: dtoverlay=iqaudio-dac,<param>
1952 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1953 Digital volume control. Enable with
1954 "dtoverlay=iqaudio-dac,24db_digital_gain"
1955 (The default behaviour is that the Digital
1956 volume control is limited to a maximum of
1957 0dB. ie. it can attenuate but not provide
1958 gain. For most users, this will be desired
1959 as it will prevent clipping. By appending
1960 the 24db_digital_gain parameter, the Digital
1961 volume control will allow up to 24dB of
1962 gain. If this parameter is enabled, it is the
1963 responsibility of the user to ensure that
1964 the Digital volume control is set to a value
1965 that does not result in clipping/distortion!)
1968 Name: iqaudio-dacplus
1969 Info: Configures the IQaudio DAC+ audio card
1970 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
1971 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1972 Digital volume control. Enable with
1973 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
1974 (The default behaviour is that the Digital
1975 volume control is limited to a maximum of
1976 0dB. ie. it can attenuate but not provide
1977 gain. For most users, this will be desired
1978 as it will prevent clipping. By appending
1979 the 24db_digital_gain parameter, the Digital
1980 volume control will allow up to 24dB of
1981 gain. If this parameter is enabled, it is the
1982 responsibility of the user to ensure that
1983 the Digital volume control is set to a value
1984 that does not result in clipping/distortion!)
1985 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
1986 starting/stopping audio playback.
1987 unmute_amp If specified, unmute the IQaudIO amp once when
1988 the DAC driver module loads.
1991 Name: iqaudio-digi-wm8804-audio
1992 Info: Configures the IQAudIO Digi WM8804 audio card
1993 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
1994 Params: card_name Override the default, "IQAudIODigi", card name.
1995 dai_name Override the default, "IQAudIO Digi", dai name.
1996 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2001 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2002 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2003 Load: dtoverlay=iqs550,<param>=<val>
2004 Params: interrupt GPIO used for interrupt (default 4)
2005 reset GPIO used for reset (optional)
2006 sizex Touchscreen size x (default 800)
2007 sizey Touchscreen size y (default 480)
2008 invx Touchscreen inverted x axis
2009 invy Touchscreen inverted y axis
2010 swapxy Touchscreen swapped x y axis
2014 Info: Infineon irs1125 TOF camera module.
2015 Uses Unicam 1, which is the standard camera connector on most Pi
2017 Load: dtoverlay=irs1125,<param>=<val>
2018 Params: media-controller Configure use of Media Controller API for
2019 configuring the sensor (default off)
2020 cam0 Adopt the default configuration for CAM0 on a
2021 Compute Module (CSI0, i2c_vc, and cam0_reg).
2025 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2026 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2027 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2028 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2029 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2034 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2036 Load: dtoverlay=justboom-both,<param>=<val>
2037 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2038 Digital volume control. Enable with
2039 "dtoverlay=justboom-dac,24db_digital_gain"
2040 (The default behaviour is that the Digital
2041 volume control is limited to a maximum of
2042 0dB. ie. it can attenuate but not provide
2043 gain. For most users, this will be desired
2044 as it will prevent clipping. By appending
2045 the 24dB_digital_gain parameter, the Digital
2046 volume control will allow up to 24dB of
2047 gain. If this parameter is enabled, it is the
2048 responsibility of the user to ensure that
2049 the Digital volume control is set to a value
2050 that does not result in clipping/distortion!)
2054 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2056 Load: dtoverlay=justboom-dac,<param>=<val>
2057 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2058 Digital volume control. Enable with
2059 "dtoverlay=justboom-dac,24db_digital_gain"
2060 (The default behaviour is that the Digital
2061 volume control is limited to a maximum of
2062 0dB. ie. it can attenuate but not provide
2063 gain. For most users, this will be desired
2064 as it will prevent clipping. By appending
2065 the 24dB_digital_gain parameter, the Digital
2066 volume control will allow up to 24dB of
2067 gain. If this parameter is enabled, it is the
2068 responsibility of the user to ensure that
2069 the Digital volume control is set to a value
2070 that does not result in clipping/distortion!)
2074 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2075 Load: dtoverlay=justboom-digi
2080 Info: This overlay has been deprecated and removed - see gpio-ir
2085 Info: Adds support for the ltc294x family of battery gauges
2086 Load: dtoverlay=ltc294x,<param>=<val>
2087 Params: ltc2941 Select the ltc2941 device
2089 ltc2942 Select the ltc2942 device
2091 ltc2943 Select the ltc2943 device
2093 ltc2944 Select the ltc2944 device
2095 resistor-sense The sense resistor value in milli-ohms.
2096 Can be a 32-bit negative value when the battery
2097 has been connected to the wrong end of the
2100 prescaler-exponent Range and accuracy of the gauge. The value is
2101 programmed into the chip only if it differs
2102 from the current setting.
2104 - Default value is 128
2105 - the exponent is in the range 0-7 (default 7)
2106 See the datasheet for more information.
2110 Info: Configures the Maxim MAX98357A I2S DAC
2111 Load: dtoverlay=max98357a,<param>=<val>
2112 Params: no-sdmode Driver does not manage the state of the DAC's
2113 SD_MODE pin (i.e. chip is always on).
2114 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2115 of the DAC (default GPIO4 if parameter omitted).
2119 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2121 For devices on spi1 or spi2, the interfaces should be enabled
2122 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2123 The overlay expects to disable the relevant spidev node, so also using
2124 e.g. cs0_spidev=off is unnecessary.
2127 MAX31855 on /dev/spidev0.0
2128 dtoverlay=maxtherm,spi0-0,max31855
2129 MAX31856 using a type J thermocouple on /dev/spidev2.1
2131 dtoverlay=maxtherm,spi2-1,max31856,type_j
2133 Load: dtoverlay=maxtherm,<param>=<val>
2134 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2136 max6675 Enable support for the MAX6675 (default)
2137 max31855 Enable support for the MAX31855
2138 max31855e Enable support for the MAX31855E
2139 max31855j Enable support for the MAX31855J
2140 max31855k Enable support for the MAX31855K
2141 max31855n Enable support for the MAX31855N
2142 max31855r Enable support for the MAX31855R
2143 max31855s Enable support for the MAX31855S
2144 max31855t Enable support for the MAX31855T
2145 max31856 Enable support for the MAX31856 (with type K)
2146 type_b Select a type B sensor for max31856
2147 type_e Select a type E sensor for max31856
2148 type_j Select a type J sensor for max31856
2149 type_k Select a type K sensor for max31856
2150 type_n Select a type N sensor for max31856
2151 type_r Select a type R sensor for max31856
2152 type_s Select a type S sensor for max31856
2153 type_t Select a type T sensor for max31856
2157 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2158 Load: dtoverlay=mbed-dac
2163 Info: Configures the MCP23017 I2C GPIO expander
2164 Load: dtoverlay=mcp23017,<param>=<val>
2165 Params: gpiopin Gpio pin connected to the INTA output of the
2166 MCP23017 (default: 4)
2168 addr I2C address of the MCP23017 (default: 0x20)
2170 mcp23008 Configure an MCP23008 instead.
2171 noints Disable the interrupt GPIO line.
2175 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2176 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2177 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2178 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2179 device must be the only one present on that SPI bus/CS#.
2180 Load: dtoverlay=mcp23s17,<param>=<val>
2181 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2182 devices present on SPI<n>, CS#<m>
2184 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2185 devices present on SPI<n>, CS#<m>
2187 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2188 MCP23S08 device on SPI<n>, CS#<m>, specifies
2189 the GPIO pin to which INT output of MCP23S08
2192 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2193 single MCP23S17 device on SPI<n>, CS#<m>,
2194 specifies the GPIO pin to which either INTA
2195 or INTB output of MCP23S17 is connected.
2199 Info: Configures the MCP2515 CAN controller on spi0/1/2
2200 For devices on spi1 or spi2, the interfaces should be enabled
2201 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2202 Load: dtoverlay=mcp2515,<param>=<val>
2203 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2206 oscillator Clock frequency for the CAN controller (Hz)
2208 speed Maximum SPI frequence (Hz)
2210 interrupt GPIO for interrupt signal
2214 Info: Configures the MCP2515 CAN controller on spi0.0
2215 Load: dtoverlay=mcp2515-can0,<param>=<val>
2216 Params: oscillator Clock frequency for the CAN controller (Hz)
2218 spimaxfrequency Maximum SPI frequence (Hz)
2220 interrupt GPIO for interrupt signal
2224 Info: Configures the MCP2515 CAN controller on spi0.1
2225 Load: dtoverlay=mcp2515-can1,<param>=<val>
2226 Params: oscillator Clock frequency for the CAN controller (Hz)
2228 spimaxfrequency Maximum SPI frequence (Hz)
2230 interrupt GPIO for interrupt signal
2234 Info: Configures the MCP251XFD CAN controller family
2235 For devices on spi1 or spi2, the interfaces should be enabled
2236 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2237 Load: dtoverlay=mcp251xfd,<param>=<val>
2238 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2241 oscillator Clock frequency for the CAN controller (Hz)
2243 speed Maximum SPI frequence (Hz)
2245 interrupt GPIO for interrupt signal
2247 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2249 xceiver_enable GPIO for CAN transceiver enable (optional)
2251 xceiver_active_high specifiy if CAN transceiver enable pin is
2252 active high (optional, default: active low)
2256 Info: Configures MCP3008 A/D converters
2257 For devices on spi1 or spi2, the interfaces should be enabled
2258 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2259 Load: dtoverlay=mcp3008,<param>[=<val>]
2260 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2261 spi<n>-<m>-speed integer, set the spi bus speed for this device
2265 Info: Configures MCP3202 A/D converters
2266 For devices on spi1 or spi2, the interfaces should be enabled
2267 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2268 Load: dtoverlay=mcp3202,<param>[=<val>]
2269 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2270 spi<n>-<m>-speed integer, set the spi bus speed for this device
2274 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2275 Load: dtoverlay=mcp342x,<param>=<val>
2276 Params: addr I2C bus address of device, for devices with
2277 addresses that are configurable, e.g. by
2278 hardware links (default=0x68)
2279 mcp3421 The device is an MCP3421
2280 mcp3422 The device is an MCP3422
2281 mcp3423 The device is an MCP3423
2282 mcp3424 The device is an MCP3424
2283 mcp3425 The device is an MCP3425
2284 mcp3426 The device is an MCP3426
2285 mcp3427 The device is an MCP3427
2286 mcp3428 The device is an MCP3428
2290 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2291 Load: dtoverlay=media-center,<param>=<val>
2292 Params: speed Display SPI bus speed
2293 rotate Display rotation {0,90,180,270}
2294 fps Delay between frame updates
2295 xohms Touchpanel sensitivity (X-plate resistance)
2296 swapxy Swap x and y axis
2297 backlight Change backlight GPIO pin {e.g. 12, 18}
2298 gpio_out_pin GPIO for output (default "17")
2299 gpio_in_pin GPIO for input (default "18")
2300 gpio_in_pull Pull up/down/off on the input pin
2302 sense Override the IR receive auto-detection logic:
2303 "0" = force active-high
2304 "1" = force active-low
2305 "-1" = use auto-detection
2307 softcarrier Turn the software carrier "on" or "off"
2309 invert "on" = invert the output pin (default "off")
2310 debug "on" = enable additional debug messages
2315 Info: Configures the merus-amp audio card
2316 Load: dtoverlay=merus-amp
2321 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2322 31.25kbaud, the frequency required for MIDI
2323 Load: dtoverlay=midi-uart0
2328 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2329 31.25kbaud, the frequency required for MIDI
2330 Load: dtoverlay=midi-uart1
2335 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2336 31.25kbaud, the frequency required for MIDI
2337 Load: dtoverlay=midi-uart2
2342 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2343 31.25kbaud, the frequency required for MIDI
2344 Load: dtoverlay=midi-uart3
2349 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2350 31.25kbaud, the frequency required for MIDI
2351 Load: dtoverlay=midi-uart4
2356 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2357 31.25kbaud, the frequency required for MIDI
2358 Load: dtoverlay=midi-uart5
2363 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2364 Load: dtoverlay=minipitft13,<param>=<val>
2365 Params: speed SPI bus speed (default 32000000)
2366 rotate Display rotation (0, 90, 180 or 270; default 0)
2367 width Display width (default 240)
2368 height Display height (default 240)
2369 fps Delay between frame updates (default 25)
2370 debug Debug output level (0-7; default 0)
2374 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2375 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2376 15. Note that this may reduce the maximum usable baudrate.
2377 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2378 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2379 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2380 in which case use /dev/serial1 instead because it will always be
2381 correct. Furthermore, you must also set core_freq and core_freq_min to
2382 the same value in config.txt or the miniuart will not work.
2383 Load: dtoverlay=miniuart-bt,<param>=<val>
2384 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2385 driver without need of hciattach/btattach
2389 Info: Overlay for i2c connected mlx90640 thermal camera
2390 Load: dtoverlay=mlx90640
2395 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2396 Load: dtoverlay=mmc,<param>=<val>
2397 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2402 Info: Overlay for i2c connected mpu6050 imu
2403 Load: dtoverlay=mpu6050,<param>=<val>
2404 Params: interrupt GPIO pin for interrupt (default 4)
2405 addr I2C address of the device (default 0x68)
2409 Info: MZ61581 display by Tontec
2410 Load: dtoverlay=mz61581,<param>=<val>
2411 Params: speed Display SPI bus speed
2413 rotate Display rotation {0,90,180,270}
2415 fps Delay between frame updates
2417 txbuflen Transmit buffer length (default 32768)
2419 debug Debug output level {0-7}
2421 xohms Touchpanel sensitivity (X-plate resistance)
2425 Info: Omnivision OV5647 camera module.
2426 Uses Unicam 1, which is the standard camera connector on most Pi
2428 Load: dtoverlay=ov5647,<param>=<val>
2429 Params: rotation Mounting rotation of the camera sensor (0 or
2431 orientation Sensor orientation (0 = front, 1 = rear,
2432 2 = external, default external)
2433 media-controller Configure use of Media Controller API for
2434 configuring the sensor (default on)
2435 cam0 Adopt the default configuration for CAM0 on a
2436 Compute Module (CSI0, i2c_vc, and cam0_reg).
2440 Info: Omnivision OV7251 camera module.
2441 Uses Unicam 1, which is the standard camera connector on most Pi
2443 Load: dtoverlay=ov7251,<param>=<val>
2444 Params: rotation Mounting rotation of the camera sensor (0 or
2446 orientation Sensor orientation (0 = front, 1 = rear,
2447 2 = external, default external)
2448 media-controller Configure use of Media Controller API for
2449 configuring the sensor (default off)
2450 cam0 Adopt the default configuration for CAM0 on a
2451 Compute Module (CSI0, i2c_vc, and cam0_reg).
2455 Info: Omnivision OV9281 camera module.
2456 Uses Unicam 1, which is the standard camera connector on most Pi
2458 Load: dtoverlay=ov9281,<param>=<val>
2459 Params: rotation Mounting rotation of the camera sensor (0 or
2461 orientation Sensor orientation (0 = front, 1 = rear,
2462 2 = external, default external)
2463 media-controller Configure use of Media Controller API for
2464 configuring the sensor (default on)
2465 cam0 Adopt the default configuration for CAM0 on a
2466 Compute Module (CSI0, i2c_vc, and cam0_reg).
2470 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2471 Load: dtoverlay=papirus,<param>=<val>
2472 Params: panel Display panel (required):
2477 speed Display SPI bus speed
2481 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2482 Load: dtoverlay=pca953x,<param>=<val>
2483 Params: addr I2C address of expander. Default 0x20.
2484 pca6416 Select the NXP PCA6416 (16 bit)
2485 pca9505 Select the NXP PCA9505 (40 bit)
2486 pca9535 Select the NXP PCA9535 (16 bit)
2487 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2488 pca9537 Select the NXP PCA9537 (4 bit)
2489 pca9538 Select the NXP PCA9538 (8 bit)
2490 pca9539 Select the NXP PCA9539 (16 bit)
2491 pca9554 Select the NXP PCA9554 (8 bit)
2492 pca9555 Select the NXP PCA9555 (16 bit)
2493 pca9556 Select the NXP PCA9556 (8 bit)
2494 pca9557 Select the NXP PCA9557 (8 bit)
2495 pca9574 Select the NXP PCA9574 (8 bit)
2496 pca9575 Select the NXP PCA9575 (16 bit)
2497 pca9698 Select the NXP PCA9698 (40 bit)
2498 pca16416 Select the NXP PCA16416 (16 bit)
2499 pca16524 Select the NXP PCA16524 (24 bit)
2500 pca19555a Select the NXP PCA19555A (16 bit)
2501 max7310 Select the Maxim MAX7310 (8 bit)
2502 max7312 Select the Maxim MAX7312 (16 bit)
2503 max7313 Select the Maxim MAX7313 (16 bit)
2504 max7315 Select the Maxim MAX7315 (8 bit)
2505 pca6107 Select the TI PCA6107 (8 bit)
2506 tca6408 Select the TI TCA6408 (8 bit)
2507 tca6416 Select the TI TCA6416 (16 bit)
2508 tca6424 Select the TI TCA6424 (24 bit)
2509 tca9539 Select the TI TCA9539 (16 bit)
2510 tca9554 Select the TI TCA9554 (8 bit)
2511 cat9554 Select the Onnn CAT9554 (8 bit)
2512 pca9654 Select the Onnn PCA9654 (8 bit)
2513 xra1202 Select the Exar XRA1202 (8 bit)
2516 Name: pcie-32bit-dma
2517 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2518 having to bounce buffers.
2519 Load: dtoverlay=pcie-32bit-dma
2523 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2526 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2529 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2533 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2534 for backwards compatibility.
2538 Name: pi3-disable-bt
2539 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2540 alias for backwards compatibility.
2544 Name: pi3-disable-wifi
2545 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2546 an alias for backwards compatibility.
2550 Name: pi3-miniuart-bt
2551 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2552 an alias for backwards compatibility.
2557 Info: Configures the pibell audio card.
2558 Load: dtoverlay=pibell,<param>=<val>
2559 Params: alsaname Set the name as it appears in ALSA (default
2564 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2565 Load: dtoverlay=pifacedigital,<param>=<val>
2566 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2567 CS0 address. PiFace Digital supports addresses
2568 0-3, which can be configured with JP1 and JP2.
2572 Info: Configures the PiFi 40W stereo amplifier
2573 Load: dtoverlay=pifi-40
2578 Info: Configures the PiFi DAC HD
2579 Load: dtoverlay=pifi-dac-hd
2584 Info: Configures the PiFi DAC Zero
2585 Load: dtoverlay=pifi-dac-zero
2590 Info: Configures the PiFi Mini stereo amplifier
2591 Load: dtoverlay=pifi-mini-210
2596 Info: Configures the PiGlow by pimoroni.com
2597 Load: dtoverlay=piglow
2602 Info: PiScreen display by OzzMaker.com
2603 Load: dtoverlay=piscreen,<param>=<val>
2604 Params: speed Display SPI bus speed
2606 rotate Display rotation {0,90,180,270}
2608 fps Delay between frame updates
2610 debug Debug output level {0-7}
2612 xohms Touchpanel sensitivity (X-plate resistance)
2616 Info: PiScreen 2 with resistive TP display by OzzMaker.com
2617 Load: dtoverlay=piscreen2r,<param>=<val>
2618 Params: speed Display SPI bus speed
2620 rotate Display rotation {0,90,180,270}
2622 fps Delay between frame updates
2624 debug Debug output level {0-7}
2626 xohms Touchpanel sensitivity (X-plate resistance)
2630 Info: Configures the Blokas Labs pisound card
2631 Load: dtoverlay=pisound
2636 Info: Adafruit PiTFT 2.2" screen
2637 Load: dtoverlay=pitft22,<param>=<val>
2638 Params: speed Display SPI bus speed
2640 rotate Display rotation {0,90,180,270}
2642 fps Delay between frame updates
2644 debug Debug output level {0-7}
2647 Name: pitft28-capacitive
2648 Info: Adafruit PiTFT 2.8" capacitive touch screen
2649 Load: dtoverlay=pitft28-capacitive,<param>=<val>
2650 Params: speed Display SPI bus speed
2652 rotate Display rotation {0,90,180,270}
2654 fps Delay between frame updates
2656 debug Debug output level {0-7}
2658 touch-sizex Touchscreen size x (default 240)
2660 touch-sizey Touchscreen size y (default 320)
2662 touch-invx Touchscreen inverted x axis
2664 touch-invy Touchscreen inverted y axis
2666 touch-swapxy Touchscreen swapped x y axis
2669 Name: pitft28-resistive
2670 Info: Adafruit PiTFT 2.8" resistive touch screen
2671 Load: dtoverlay=pitft28-resistive,<param>=<val>
2672 Params: speed Display SPI bus speed
2674 rotate Display rotation {0,90,180,270}
2676 fps Delay between frame updates
2678 debug Debug output level {0-7}
2681 Name: pitft35-resistive
2682 Info: Adafruit PiTFT 3.5" resistive touch screen
2683 Load: dtoverlay=pitft35-resistive,<param>=<val>
2684 Params: speed Display SPI bus speed
2686 rotate Display rotation {0,90,180,270}
2688 fps Delay between frame updates
2690 debug Debug output level {0-7}
2694 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
2695 Load: dtoverlay=pps-gpio,<param>=<val>
2696 Params: gpiopin Input GPIO (default "18")
2697 assert_falling_edge When present, assert is indicated by a falling
2698 edge, rather than by a rising edge (default
2700 capture_clear Generate clear events on the trailing edge
2705 Info: Configures a single PWM channel
2706 Legal pin,function combinations for each channel:
2707 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2708 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2710 1) Pin 18 is the only one available on all platforms, and
2711 it is the one used by the I2S audio interface.
2712 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2713 2) The onboard analogue audio output uses both PWM channels.
2714 3) So be careful mixing audio and PWM.
2715 4) Currently the clock must have been enabled and configured
2717 Load: dtoverlay=pwm,<param>=<val>
2718 Params: pin Output pin (default 18) - see table
2719 func Pin function (default 2 = Alt5) - see above
2720 clock PWM clock frequency (informational)
2724 Info: Configures both PWM channels
2725 Legal pin,function combinations for each channel:
2726 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2727 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2729 1) Pin 18 is the only one available on all platforms, and
2730 it is the one used by the I2S audio interface.
2731 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2732 2) The onboard analogue audio output uses both PWM channels.
2733 3) So be careful mixing audio and PWM.
2734 4) Currently the clock must have been enabled and configured
2736 Load: dtoverlay=pwm-2chan,<param>=<val>
2737 Params: pin Output pin (default 18) - see table
2738 pin2 Output pin for other channel (default 19)
2739 func Pin function (default 2 = Alt5) - see above
2740 func2 Function for pin2 (default 2 = Alt5)
2741 clock PWM clock frequency (informational)
2745 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
2746 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
2747 of PWM0 to reduce the CPU load during transmission compared to
2748 gpio-ir-tx which uses bit-banging.
2749 Legal pin,function combinations are:
2750 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2751 Load: dtoverlay=pwm-ir-tx,<param>=<val>
2752 Params: gpio_pin Output GPIO (default 18)
2754 func Pin function (default 2 = Alt5)
2758 Info: in-tech's Evaluation Board for PLC Stamp micro
2759 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
2760 Load: dtoverlay=qca7000,<param>=<val>
2761 Params: int_pin GPIO pin for interrupt signal (default 23)
2763 speed SPI bus speed (default 12 MHz)
2767 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
2768 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
2769 But it requires disabling of onboard Bluetooth on
2770 Pi 3B, 3B+, 3A+, 4B and Zero W.
2771 Load: dtoverlay=qca7000-uart0,<param>=<val>
2772 Params: baudrate Set the baudrate for the UART (default
2776 Name: rotary-encoder
2777 Info: Overlay for GPIO connected rotary encoder.
2778 Load: dtoverlay=rotary-encoder,<param>=<val>
2779 Params: pin_a GPIO connected to rotary encoder channel A
2781 pin_b GPIO connected to rotary encoder channel B
2783 relative_axis register a relative axis rather than an
2784 absolute one. Relative axis will only
2785 generate +1/-1 events on the input device,
2786 hence no steps need to be passed.
2787 linux_axis the input subsystem axis to map to this
2788 rotary encoder. Defaults to 0 (ABS_X / REL_X)
2789 rollover Automatic rollover when the rotary value
2790 becomes greater than the specified steps or
2791 smaller than 0. For absolute axis only.
2792 steps-per-period Number of steps (stable states) per period.
2793 The values have the following meaning:
2794 1: Full-period mode (default)
2796 4: Quarter-period mode
2797 steps Number of steps in a full turnaround of the
2798 encoder. Only relevant for absolute axis.
2799 Defaults to 24 which is a typical value for
2801 wakeup Boolean, rotary encoder can wake up the
2803 encoding String, the method used to encode steps.
2804 Supported are "gray" (the default and more
2805 common) and "binary".
2809 Info: Raspberry Pi official display backlight driver
2810 Load: dtoverlay=rpi-backlight
2814 Name: rpi-cirrus-wm5102
2815 Info: Configures the Cirrus Logic Audio Card
2816 Load: dtoverlay=rpi-cirrus-wm5102
2821 Info: Configures the RPi DAC audio card
2822 Load: dtoverlay=rpi-dac
2827 Info: RPi-Display - 2.8" Touch Display by Watterott
2828 Load: dtoverlay=rpi-display,<param>=<val>
2829 Params: speed Display SPI bus speed
2830 rotate Display rotation {0,90,180,270}
2831 fps Delay between frame updates
2832 debug Debug output level {0-7}
2833 xohms Touchpanel sensitivity (X-plate resistance)
2834 swapxy Swap x and y axis
2835 backlight Change backlight GPIO pin {e.g. 12, 18}
2839 Info: Official Raspberry Pi display touchscreen
2840 Load: dtoverlay=rpi-ft5406,<param>=<val>
2841 Params: touchscreen-size-x Touchscreen X resolution (default 800)
2842 touchscreen-size-y Touchscreen Y resolution (default 600);
2843 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
2844 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
2845 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
2849 Info: Raspberry Pi PoE HAT fan
2850 Load: dtoverlay=rpi-poe,<param>[=<val>]
2851 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
2852 turns on (default 40000)
2853 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
2854 the fan turns off (default 2000)
2855 poe_fan_temp1 Temperature (in millicelcius) at which the fan
2856 speeds up (default 45000)
2857 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
2858 the fan slows down (default 2000)
2859 poe_fan_temp2 Temperature (in millicelcius) at which the fan
2860 speeds up (default 50000)
2861 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
2862 the fan slows down (default 2000)
2863 poe_fan_temp3 Temperature (in millicelcius) at which the fan
2864 speeds up (default 55000)
2865 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
2866 the fan slows down (default 5000)
2867 i2c Control the fan via Linux I2C drivers instead of
2872 Info: Raspberry Pi PoE+ HAT fan
2873 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
2874 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
2875 turns on (default 40000)
2876 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
2877 the fan turns off (default 2000)
2878 poe_fan_temp1 Temperature (in millicelcius) at which the fan
2879 speeds up (default 45000)
2880 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
2881 the fan slows down (default 2000)
2882 poe_fan_temp2 Temperature (in millicelcius) at which the fan
2883 speeds up (default 50000)
2884 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
2885 the fan slows down (default 2000)
2886 poe_fan_temp3 Temperature (in millicelcius) at which the fan
2887 speeds up (default 55000)
2888 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
2889 the fan slows down (default 5000)
2890 i2c Control the fan via Linux I2C drivers instead of
2895 Info: Configures the RPi Proto audio card
2896 Load: dtoverlay=rpi-proto
2901 Info: Raspberry Pi Sense HAT
2902 Load: dtoverlay=rpi-sense
2907 Info: Raspberry Pi TV HAT
2908 Load: dtoverlay=rpi-tv
2913 Info: Load the V4L2 stateless video decoder driver for the HEVC block,
2914 disabling the memory mapped devices in the process.
2915 Load: dtoverlay=rpivid-v4l2
2919 Name: rra-digidac1-wm8741-audio
2920 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
2921 Load: dtoverlay=rra-digidac1-wm8741-audio
2926 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
2928 Load: dtoverlay=sainsmart18,<param>=<val>
2929 Params: rotate Display rotation {0,90,180,270}
2930 speed SPI bus speed in Hz (default 4000000)
2931 fps Display frame rate in Hz
2932 bgr Enable BGR mode (default off)
2933 debug Debug output level {0-7}
2934 dc_pin GPIO pin for D/C (default 24)
2935 reset_pin GPIO pin for RESET (default 25)
2939 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
2940 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
2941 select another address, please refer to table 10 in reference manual.
2942 Load: dtoverlay=sc16is750-i2c,<param>=<val>
2943 Params: int_pin GPIO used for IRQ (default 24)
2944 addr Address (default 0x48)
2945 xtal On-board crystal frequency (default 14745600)
2949 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
2950 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
2951 select another address, please refer to table 10 in reference manual.
2952 Load: dtoverlay=sc16is752-i2c,<param>=<val>
2953 Params: int_pin GPIO used for IRQ (default 24)
2954 addr Address (default 0x48)
2955 xtal On-board crystal frequency (default 14745600)
2958 Name: sc16is752-spi0
2959 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
2960 Enables the chip on SPI0.
2961 Load: dtoverlay=sc16is752-spi0,<param>=<val>
2962 Params: int_pin GPIO used for IRQ (default 24)
2963 xtal On-board crystal frequency (default 14745600)
2966 Name: sc16is752-spi1
2967 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
2968 Enables the chip on SPI1.
2969 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
2970 A+, B+, Zero and PI2 B; as well as the Compute Module.
2972 Load: dtoverlay=sc16is752-spi1,<param>=<val>
2973 Params: int_pin GPIO used for IRQ (default 24)
2974 xtal On-board crystal frequency (default 14745600)
2978 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
2979 N.B. This overlay is designed for situations where the mmc driver is
2980 the default, so it disables the other (mmc) interface - this will kill
2981 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
2982 overlay or the new sd_* dtparams of the base DTBs.
2983 Load: dtoverlay=sdhost,<param>=<val>
2984 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2987 force_pio Disable DMA support (default off)
2989 pio_limit Number of blocks above which to use DMA
2992 debug Enable debug output (default off)
2996 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
2997 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
2998 "dtoverlay=sdio,bus_width=1,gpios_22_25"
2999 Load: dtoverlay=sdio,<param>=<val>
3000 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3001 framework requests 50MHz
3003 poll_once Disable SDIO-device polling every second
3004 (default on: polling once at boot-time)
3006 bus_width Set the SDIO host bus width (default 4 bits)
3008 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3009 with bus_width=1. This replaces the sdio-1bit
3010 overlay, which is now deprecated.
3012 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3015 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3016 with bus_width=4 (the default).
3020 Info: This overlay is now deprecated. Use
3021 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3026 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3027 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3028 "dtparam=sd_poll_once".
3032 Name: seeed-can-fd-hat-v1
3033 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3034 channels without RTC. Use this overlay if your HAT has no
3036 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3037 Load: dtoverlay=seeed-can-fd-hat-v1
3041 Name: seeed-can-fd-hat-v2
3042 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3043 channels and an RTC. Use this overlay if your HAT has a
3045 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3046 Load: dtoverlay=seeed-can-fd-hat-v2
3051 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3052 Load: dtoverlay=sh1106-spi,<param>=<val>
3053 Params: speed SPI bus speed (default 4000000)
3054 rotate Display rotation (0, 90, 180 or 270; default 0)
3055 fps Delay between frame updates (default 25)
3056 debug Debug output level (0-7; default 0)
3057 dc_pin GPIO pin for D/C (default 24)
3058 reset_pin GPIO pin for RESET (default 25)
3059 height Display height (32 or 64; default 64)
3063 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3064 The driver is currently out-of-tree at
3065 https://github.com/sunipkmukherjee/silabs.git
3066 Load: dtoverlay=si446x-spi0,<param>=<val>
3067 Params: speed SPI bus speed (default 4000000)
3068 int_pin GPIO pin for interrupts (default 17)
3069 reset_pin GPIO pin for RESET (default 27)
3073 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3079 Info: Enables the userspace interface for the SMI driver
3080 Load: dtoverlay=smi-dev
3085 Info: Enables access to NAND flash via the SMI interface
3086 Load: dtoverlay=smi-nand
3091 Info: Move SPI function block to GPIO 35 to 39
3092 Load: dtoverlay=spi-gpio35-39
3097 Info: Move SPI function block to GPIOs 40 to 45
3098 Load: dtoverlay=spi-gpio40-45
3103 Info: Adds support for a number of SPI Real Time Clock devices
3104 Load: dtoverlay=spi-rtc,<param>=<val>
3105 Params: ds3232 Select the DS3232 device
3106 ds3234 Select the DS3234 device
3107 pcf2123 Select the PCF2123 device
3109 spi0_0 Use spi0.0 (default)
3115 cs_high This device requires an active-high CS
3119 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3120 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3121 Load: dtoverlay=spi0-0cs,<param>=<val>
3122 Params: no_miso Don't claim and use the MISO pin (9), freeing
3127 Info: Only use one CS pin for SPI0
3128 Load: dtoverlay=spi0-1cs,<param>=<val>
3129 Params: cs0_pin GPIO pin for CS0 (default 8)
3130 no_miso Don't claim and use the MISO pin (9), freeing
3135 Info: Change the CS pins for SPI0
3136 Load: dtoverlay=spi0-2cs,<param>=<val>
3137 Params: cs0_pin GPIO pin for CS0 (default 8)
3138 cs1_pin GPIO pin for CS1 (default 7)
3139 no_miso Don't claim and use the MISO pin (9), freeing
3144 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3145 alias for backwards compatibility.
3150 Info: This overlay has been deprecated and removed because it is no longer
3151 necessary and has been seen to prevent spi0 from working.
3156 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3157 dev node. The gpio pin number for the CS line and spidev device node
3158 creation are configurable.
3159 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3160 A+, B+, Zero and PI2 B; as well as the Compute Module.
3161 Load: dtoverlay=spi1-1cs,<param>=<val>
3162 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3163 cs0_spidev Set to 'disabled' to stop the creation of a
3164 userspace device node /dev/spidev1.0 (default
3165 is 'okay' or enabled).
3169 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3170 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3171 creation are configurable.
3172 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3173 A+, B+, Zero and PI2 B; as well as the Compute Module.
3174 Load: dtoverlay=spi1-2cs,<param>=<val>
3175 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3176 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3177 cs0_spidev Set to 'disabled' to stop the creation of a
3178 userspace device node /dev/spidev1.0 (default
3179 is 'okay' or enabled).
3180 cs1_spidev Set to 'disabled' to stop the creation of a
3181 userspace device node /dev/spidev1.1 (default
3182 is 'okay' or enabled).
3186 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3187 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3188 creation are configurable.
3189 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3190 A+, B+, Zero and PI2 B; as well as the Compute Module.
3191 Load: dtoverlay=spi1-3cs,<param>=<val>
3192 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3193 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3194 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3195 cs0_spidev Set to 'disabled' to stop the creation of a
3196 userspace device node /dev/spidev1.0 (default
3197 is 'okay' or enabled).
3198 cs1_spidev Set to 'disabled' to stop the creation of a
3199 userspace device node /dev/spidev1.1 (default
3200 is 'okay' or enabled).
3201 cs2_spidev Set to 'disabled' to stop the creation of a
3202 userspace device node /dev/spidev1.2 (default
3203 is 'okay' or enabled).
3207 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3208 dev node. The gpio pin number for the CS line and spidev device node
3209 creation are configurable.
3210 N.B.: spi2 is only accessible with the Compute Module.
3211 Load: dtoverlay=spi2-1cs,<param>=<val>
3212 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3213 cs0_spidev Set to 'disabled' to stop the creation of a
3214 userspace device node /dev/spidev2.0 (default
3215 is 'okay' or enabled).
3219 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3220 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3221 creation are configurable.
3222 N.B.: spi2 is only accessible with the Compute Module.
3223 Load: dtoverlay=spi2-2cs,<param>=<val>
3224 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3225 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3226 cs0_spidev Set to 'disabled' to stop the creation of a
3227 userspace device node /dev/spidev2.0 (default
3228 is 'okay' or enabled).
3229 cs1_spidev Set to 'disabled' to stop the creation of a
3230 userspace device node /dev/spidev2.1 (default
3231 is 'okay' or enabled).
3235 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3236 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3237 creation are configurable.
3238 N.B.: spi2 is only accessible with the Compute Module.
3239 Load: dtoverlay=spi2-3cs,<param>=<val>
3240 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3241 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3242 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3243 cs0_spidev Set to 'disabled' to stop the creation of a
3244 userspace device node /dev/spidev2.0 (default
3245 is 'okay' or enabled).
3246 cs1_spidev Set to 'disabled' to stop the creation of a
3247 userspace device node /dev/spidev2.1 (default
3248 is 'okay' or enabled).
3249 cs2_spidev Set to 'disabled' to stop the creation of a
3250 userspace device node /dev/spidev2.2 (default
3251 is 'okay' or enabled).
3255 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3256 dev node. The gpio pin number for the CS line and spidev device node
3257 creation are configurable. BCM2711 only.
3258 Load: dtoverlay=spi3-1cs,<param>=<val>
3259 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3260 cs0_spidev Set to 'off' to prevent the creation of a
3261 userspace device node /dev/spidev3.0 (default
3262 is 'on' or enabled).
3266 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3267 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3268 creation are configurable. BCM2711 only.
3269 Load: dtoverlay=spi3-2cs,<param>=<val>
3270 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3271 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3272 cs0_spidev Set to 'off' to prevent the creation of a
3273 userspace device node /dev/spidev3.0 (default
3274 is 'on' or enabled).
3275 cs1_spidev Set to 'off' to prevent the creation of a
3276 userspace device node /dev/spidev3.1 (default
3277 is 'on' or enabled).
3281 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3282 dev node. The gpio pin number for the CS line and spidev device node
3283 creation are configurable. BCM2711 only.
3284 Load: dtoverlay=spi4-1cs,<param>=<val>
3285 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3286 cs0_spidev Set to 'off' to prevent the creation of a
3287 userspace device node /dev/spidev4.0 (default
3288 is 'on' or enabled).
3292 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3293 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3294 creation are configurable. BCM2711 only.
3295 Load: dtoverlay=spi4-2cs,<param>=<val>
3296 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3297 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3298 cs0_spidev Set to 'off' to prevent the creation of a
3299 userspace device node /dev/spidev4.0 (default
3300 is 'on' or enabled).
3301 cs1_spidev Set to 'off' to prevent the creation of a
3302 userspace device node /dev/spidev4.1 (default
3303 is 'on' or enabled).
3307 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3308 dev node. The gpio pin numbers for the CS lines and spidev device node
3309 creation are configurable. BCM2711 only.
3310 Load: dtoverlay=spi5-1cs,<param>=<val>
3311 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3312 cs0_spidev Set to 'off' to prevent the creation of a
3313 userspace device node /dev/spidev5.0 (default
3314 is 'on' or enabled).
3318 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3319 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3320 creation are configurable. BCM2711 only.
3321 Load: dtoverlay=spi5-2cs,<param>=<val>
3322 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3323 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3324 cs0_spidev Set to 'off' to prevent the creation of a
3325 userspace device node /dev/spidev5.0 (default
3326 is 'on' or enabled).
3327 cs1_spidev Set to 'off' to prevent the creation of a
3328 userspace device node /dev/spidev5.1 (default
3329 is 'on' or enabled).
3333 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3334 dev node. The gpio pin number for the CS line and spidev device node
3335 creation are configurable. BCM2711 only.
3336 Load: dtoverlay=spi6-1cs,<param>=<val>
3337 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3338 cs0_spidev Set to 'off' to prevent the creation of a
3339 userspace device node /dev/spidev6.0 (default
3340 is 'on' or enabled).
3344 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3345 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3346 creation are configurable. BCM2711 only.
3347 Load: dtoverlay=spi6-2cs,<param>=<val>
3348 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3349 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3350 cs0_spidev Set to 'off' to prevent the creation of a
3351 userspace device node /dev/spidev6.0 (default
3352 is 'on' or enabled).
3353 cs1_spidev Set to 'off' to prevent the creation of a
3354 userspace device node /dev/spidev6.1 (default
3355 is 'on' or enabled).
3359 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3360 Load: dtoverlay=ssd1306,<param>=<val>
3361 Params: address Location in display memory of first character.
3363 width Width of display. (default=128)
3364 height Height of display. (default=64)
3365 offset virtual channel a. (default=0)
3366 normal Has no effect on displays tested. (default=not
3368 sequential Set this if every other scan line is missing.
3370 remapped Set this if display is garbled. (default=not
3372 inverted Set this if display is inverted and mirrored.
3376 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3378 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3380 i2c_baudrate=400000 will speed up the display.
3382 i2c_baudrate=1000000 seems to work even though it's not officially
3383 supported by the hardware, and is faster still.
3385 For more information refer to the device datasheet at:
3386 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3390 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3391 Load: dtoverlay=ssd1306-spi,<param>=<val>
3392 Params: speed SPI bus speed (default 10000000)
3393 rotate Display rotation (0, 90, 180 or 270; default 0)
3394 fps Delay between frame updates (default 25)
3395 debug Debug output level (0-7; default 0)
3396 dc_pin GPIO pin for D/C (default 24)
3397 reset_pin GPIO pin for RESET (default 25)
3398 height Display height (32 or 64; default 64)
3402 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3403 Load: dtoverlay=ssd1331-spi,<param>=<val>
3404 Params: speed SPI bus speed (default 4500000)
3405 rotate Display rotation (0, 90, 180 or 270; default 0)
3406 fps Delay between frame updates (default 25)
3407 debug Debug output level (0-7; default 0)
3408 dc_pin GPIO pin for D/C (default 24)
3409 reset_pin GPIO pin for RESET (default 25)
3413 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3414 Load: dtoverlay=ssd1351-spi,<param>=<val>
3415 Params: speed SPI bus speed (default 4500000)
3416 rotate Display rotation (0, 90, 180 or 270; default 0)
3417 fps Delay between frame updates (default 25)
3418 debug Debug output level (0-7; default 0)
3419 dc_pin GPIO pin for D/C (default 24)
3420 reset_pin GPIO pin for RESET (default 25)
3423 Name: superaudioboard
3424 Info: Configures the SuperAudioBoard sound card
3425 Load: dtoverlay=superaudioboard,<param>=<val>
3426 Params: gpiopin GPIO pin for codec reset
3430 Info: Configures the Semtech SX150X I2C GPIO expanders.
3431 Load: dtoverlay=sx150x,<param>=<val>
3432 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3433 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3434 Permissible values of <m> (which is denoted in
3435 hex) depend on the device variant. For SX1501,
3436 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3437 For SX1503 and SX1506, <m> may be 20. For
3438 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3439 For SX1508, <m> may be 20, 21, 22 or 23.
3441 sx150<x>-<n>-<m>-int-gpio
3442 Integer, enables interrupts on SX150X device on
3443 I2C#<n> with slave address <m>, specifies
3444 the GPIO pin to which NINT output of SX150X is
3449 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3450 Uses Unicam 1, which is the standard camera connector on most Pi
3452 Load: dtoverlay=tc358743,<param>=<val>
3453 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3456 link-frequency Set the link frequency. Only values of 297000000
3457 (574Mbit/s) and 486000000 (972Mbit/s - default)
3458 are supported by the driver.
3459 media-controller Configure use of Media Controller API for
3460 configuring the sensor (default off)
3461 cam0 Adopt the default configuration for CAM0 on a
3462 Compute Module (CSI0, i2c_vc, and cam0_reg).
3465 Name: tc358743-audio
3466 Info: Used in combination with the tc358743-fast overlay to route the audio
3467 from the TC358743 over I2S to the Pi.
3468 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3470 Load: dtoverlay=tc358743-audio,<param>=<val>
3471 Params: card-name Override the default, "tc358743", card name.
3475 Info: 3.5" Color TFT Display by www.tinylcd.com
3476 Options: Touch, RTC, keypad
3477 Load: dtoverlay=tinylcd35,<param>=<val>
3478 Params: speed Display SPI bus speed
3480 rotate Display rotation {0,90,180,270}
3482 fps Delay between frame updates
3484 debug Debug output level {0-7}
3486 touch Enable touch panel
3488 touchgpio Touch controller IRQ GPIO
3490 xohms Touchpanel: Resistance of X-plate in ohms
3492 rtc-pcf PCF8563 Real Time Clock
3494 rtc-ds DS1307 Real Time Clock
3496 keypad Enable keypad
3499 Display with touchpanel, PCF8563 RTC and keypad:
3500 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
3502 dtoverlay=tinylcd35,touch,touchgpio=3
3506 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
3507 boards, which can be used as a secure key storage and hwrng,
3508 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
3509 Load: dtoverlay=tpm-slb9670
3514 Info: Change the pin usage of uart0
3515 Load: dtoverlay=uart0,<param>=<val>
3516 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
3518 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
3520 pin_func Alternative pin function - 4(Alt0) for 14&15,
3521 7(Alt3) for 32&33, 6(Alt2) for 36&37
3525 Info: Change the pin usage of uart1
3526 Load: dtoverlay=uart1,<param>=<val>
3527 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
3529 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
3533 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
3534 Load: dtoverlay=uart2,<param>
3535 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
3539 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
3540 Load: dtoverlay=uart3,<param>
3541 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
3545 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
3546 Load: dtoverlay=uart4,<param>
3547 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
3551 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
3552 Load: dtoverlay=uart5,<param>
3553 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
3557 Info: Configures the NW Digital Radio UDRC Hat
3558 Load: dtoverlay=udrc,<param>=<val>
3559 Params: alsaname Name of the ALSA audio device (default "udrc")
3562 Name: ugreen-dabboard
3563 Info: Configures the ugreen-dabboard I2S overlay
3564 This is a simple overlay based on the simple-audio-card and the dmic
3565 codec. It has the speciality that it is configured to use the codec
3566 as a master I2S device. It works for example with the Si468x DAB
3567 receiver on the uGreen DABBoard.
3568 Load: dtoverlay=ugreen-dabboard,<param>=<val>
3569 Params: card-name Override the default, "dabboard", card name.
3573 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
3574 vc4-kms-v3d and dwc2 overlays.
3575 Load: dtoverlay=upstream
3579 Name: upstream-aux-interrupt
3580 Info: This overlay has been deprecated and removed because it is no longer
3586 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
3587 the vc4-kms-v3d-pi4 and dwc2 overlays.
3588 Load: dtoverlay=upstream-pi4
3593 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3595 Load: dtoverlay=vc4-fkms-v3d,<param>
3596 Params: cma-512 CMA is 512MB (needs 1GB)
3597 cma-448 CMA is 448MB (needs 1GB)
3598 cma-384 CMA is 384MB (needs 1GB)
3599 cma-320 CMA is 320MB (needs 1GB)
3600 cma-256 CMA is 256MB (needs 1GB)
3601 cma-192 CMA is 192MB (needs 1GB)
3602 cma-128 CMA is 128MB
3605 cma-size CMA size in bytes, 4MB aligned
3606 cma-default Use upstream's default value
3609 Name: vc4-fkms-v3d-pi4
3610 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3612 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
3613 Params: cma-512 CMA is 512MB (needs 1GB)
3614 cma-448 CMA is 448MB (needs 1GB)
3615 cma-384 CMA is 384MB (needs 1GB)
3616 cma-320 CMA is 320MB (needs 1GB)
3617 cma-256 CMA is 256MB (needs 1GB)
3618 cma-192 CMA is 192MB (needs 1GB)
3619 cma-128 CMA is 128MB
3622 cma-size CMA size in bytes, 4MB aligned
3623 cma-default Use upstream's default value
3626 Name: vc4-kms-dpi-at056tn53v1
3627 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
3631 Name: vc4-kms-dpi-generic
3632 Info: Enable a generic DPI display under KMS. Default timings are for the
3633 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
3634 Requires vc4-kms-v3d to be loaded.
3635 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
3636 Params: clock-frequency Display clock frequency (Hz)
3637 hactive Horizontal active pixels
3638 hfp Horizontal front porch
3639 hsync Horizontal sync pulse width
3640 hbp Horizontal back porch
3641 vactive Vertical active lines
3642 vfp Vertical front porch
3643 vsync Vertical sync pulse width
3644 vbp Vertical back porch
3645 hsync-invert Horizontal sync active low
3646 vsync-invert Vertical sync active low
3647 de-invert Data Enable active low
3648 pixclk-invert Negative edge pixel clock
3649 width-mm Define the screen width in mm
3650 height-mm Define the screen height in mm
3651 rgb565 Change to RGB565 output on GPIOs 0-19
3652 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
3654 bgr666 Change to BGR666 output on GPIOs 0-21.
3655 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
3657 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
3659 bgr888 Change to BGR888 output on GPIOs 0-27
3660 rgb888 Change to RGB888 output on GPIOs 0-27
3661 bus-format Override the bus format for a MEDIA_BUS_FMT_*
3662 value. NB also overridden by rgbXXX overrides.
3663 backlight-gpio Defines a GPIO to be used for backlight control
3665 backlight-pwm Defines a PWM channel to be used for backlight
3666 control (default of none). NB Disables audio
3667 headphone output as that also uses PWM.
3668 backlight-pwm-chan Choose channel on &pwm node for backlight
3671 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3672 pwm-2chan for valid options.
3673 (default 18 - note this can only work with
3675 backlight-pwm-func Pin function of GPIO used for the PWM
3677 See pwm-2chan for valid options.
3679 backlight-def-brightness
3680 Set the default brightness. Normal range 1-16.
3682 rotate Display rotation {0,90,180,270} (default 0)
3685 Name: vc4-kms-dpi-hyperpixel2r
3686 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
3687 Requires vc4-kms-v3d to be loaded.
3688 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
3689 Params: disable-touch Disables the touch controller
3690 touchscreen-inverted-x Inverts X direction of touch controller
3691 touchscreen-inverted-y Inverts Y direction of touch controller
3692 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3693 rotate Display rotation {0,90,180,270} (default 0)
3696 Name: vc4-kms-dpi-hyperpixel4
3697 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
3698 Requires vc4-kms-v3d to be loaded.
3699 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
3700 Params: disable-touch Disables the touch controller
3701 touchscreen-inverted-x Inverts X direction of touch controller
3702 touchscreen-inverted-y Inverts Y direction of touch controller
3703 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3704 rotate Display rotation {0,90,180,270} (default 0)
3707 Name: vc4-kms-dpi-hyperpixel4sq
3708 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
3709 Requires vc4-kms-v3d to be loaded.
3710 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
3711 Params: disable-touch Disables the touch controller
3712 touchscreen-inverted-x Inverts X direction of touch controller
3713 touchscreen-inverted-y Inverts Y direction of touch controller
3714 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3715 rotate Display rotation {0,90,180,270} (default 0)
3718 Name: vc4-kms-dpi-panel
3719 Info: Enable a preconfigured KMS DPI panel.
3720 Requires vc4-kms-v3d to be loaded.
3721 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
3722 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
3723 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
3724 mzp280 Enable a Geekworm MZP280 panel.
3725 backlight-gpio Defines a GPIO to be used for backlight control
3727 backlight-pwm Defines a PWM channel to be used for backlight
3728 control (default of none). NB Disables audio
3729 headphone output as that also uses PWM.
3730 backlight-pwm-chan Choose channel on &pwm node for backlight
3733 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3734 pwm-2chan for valid options.
3735 (default 18 - note this can only work with
3737 backlight-pwm-func Pin function of GPIO used for the PWM
3739 See pwm-2chan for valid options.
3741 backlight-def-brightness
3742 Set the default brightness. Normal range 1-16.
3744 rotate Display rotation {0,90,180,270} (default 0)
3747 Name: vc4-kms-dsi-7inch
3748 Info: Enable the Raspberry Pi DSI 7" screen.
3749 Includes the edt-ft5406 for the touchscreen element.
3750 Requires vc4-kms-v3d to be loaded.
3751 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
3752 Params: sizex Touchscreen size x (default 800)
3753 sizey Touchscreen size y (default 480)
3754 invx Touchscreen inverted x axis
3755 invy Touchscreen inverted y axis
3756 swapxy Touchscreen swapped x y axis
3757 disable_touch Disables the touch screen overlay driver
3760 Name: vc4-kms-dsi-lt070me05000
3761 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
3762 Note that this is a 4 lane DSI device, so it will only work on a Compute
3764 Requires vc4-kms-v3d to be loaded.
3765 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
3766 Params: reset GPIO for the reset signal (default 17)
3767 enable GPIO for the enable signal (default 4)
3768 dcdc-en GPIO for the DC-DC converter enable (default 5)
3771 Name: vc4-kms-dsi-lt070me05000-v2
3772 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
3774 Note that this is a 4 lane DSI device, so it will only work on a Compute
3776 Requires vc4-kms-v3d to be loaded.
3777 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
3781 Name: vc4-kms-kippah-7inch
3782 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
3787 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
3788 Load: dtoverlay=vc4-kms-v3d,<param>
3789 Params: cma-512 CMA is 512MB (needs 1GB)
3790 cma-448 CMA is 448MB (needs 1GB)
3791 cma-384 CMA is 384MB (needs 1GB)
3792 cma-320 CMA is 320MB (needs 1GB)
3793 cma-256 CMA is 256MB (needs 1GB)
3794 cma-192 CMA is 192MB (needs 1GB)
3795 cma-128 CMA is 128MB
3798 cma-size CMA size in bytes, 4MB aligned
3799 cma-default Use upstream's default value
3800 audio Enable or disable audio over HDMI (default "on")
3801 noaudio Disable all HDMI audio (default "off")
3802 composite Enable the composite output (default "off")
3803 N.B. Disables all other outputs on a Pi 4.
3806 Name: vc4-kms-v3d-pi4
3807 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
3808 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
3809 Params: cma-512 CMA is 512MB
3810 cma-448 CMA is 448MB
3811 cma-384 CMA is 384MB
3812 cma-320 CMA is 320MB
3813 cma-256 CMA is 256MB
3814 cma-192 CMA is 192MB
3815 cma-128 CMA is 128MB
3818 cma-size CMA size in bytes, 4MB aligned
3819 cma-default Use upstream's default value
3820 audio Enable or disable audio over HDMI0 (default
3822 audio1 Enable or disable audio over HDMI1 (default
3824 noaudio Disable all HDMI audio (default "off")
3825 composite Enable the composite output (disables all other
3829 Name: vc4-kms-vga666
3830 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
3831 Requires vc4-kms-v3d to be loaded.
3832 Load: dtoverlay=vc4-kms-vga666,<param>
3833 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
3834 from the display. NB These are NOT 5V tolerant
3835 GPIOs, therefore level shifters are required.
3839 Info: Overlay for the Fen Logic VGA666 board
3840 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
3841 after the kernel has started.
3842 NOT for use with vc4-kms-v3d.
3843 Load: dtoverlay=vga666
3848 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
3849 Will be loaded automatically by up-to-date firmware if "VL805=1" is
3850 set in the EEPROM config.
3851 Load: dtoverlay=vl805
3856 Info: Configures the w1-gpio Onewire interface module.
3857 Use this overlay if you *don't* need a GPIO to drive an external pullup.
3858 Load: dtoverlay=w1-gpio,<param>=<val>
3859 Params: gpiopin GPIO for I/O (default "4")
3860 pullup Now enabled by default (ignored)
3863 Name: w1-gpio-pullup
3864 Info: Configures the w1-gpio Onewire interface module.
3865 Use this overlay if you *do* need a GPIO to drive an external pullup.
3866 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
3867 Params: gpiopin GPIO for I/O (default "4")
3868 extpullup GPIO for external pullup (default "5")
3869 pullup Now enabled by default (ignored)
3873 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
3874 Load: dtoverlay=w5500,<param>=<val>
3875 Params: int_pin GPIO used for INT (default 25)
3877 speed SPI bus speed (default 30000000)
3879 cs SPI bus Chip Select (default 0)
3883 Info: Configures the wittypi RTC module.
3884 Load: dtoverlay=wittypi,<param>=<val>
3885 Params: led_gpio GPIO for LED (default "17")
3886 led_trigger Choose which activity the LED tracks (default
3890 Name: wm8960-soundcard
3891 Info: Overlay for the Waveshare wm8960 soundcard
3892 Load: dtoverlay=wm8960-soundcard,<param>=<val>
3893 Params: alsaname Changes the card name in ALSA
3894 compatible Changes the codec compatibility
3900 If you are experiencing problems that you think are DT-related, enable DT
3901 diagnostic output by adding this to /boot/config.txt:
3905 and rebooting. Then run:
3909 and look for relevant messages.
3914 This is only meant to be a quick introduction to the subject of Device Tree on
3915 Raspberry Pi. There is a more complete explanation here:
3917 http://www.raspberrypi.org/documentation/configuration/device-tree.md