README

        txbuflen                Transmit buffer length (default 32768)

        debug                   Debug output level {0-7}

        xohms                   Touchpanel sensitivity (X-plate resistance)


Name:   ov5647
Info:   Omnivision OV5647 camera module.
        Uses Unicam 1, which is the standard camera connector on most Pi
        variants.
Load:   dtoverlay=ov5647,<param>=<val>
Params: rotation                Mounting rotation of the camera sensor (0 or
                                180, default 0)


Name:   ov7251
Info:   Omnivision OV7251 camera module.
        Uses Unicam 1, which is the standard camera connector on most Pi
        variants.
Load:   dtoverlay=ov7251
Params: <None>


Name:   ov9281
Info:   Omnivision OV9281 camera module.
        Uses Unicam 1, which is the standard camera connector on most Pi
        variants.
Load:   dtoverlay=ov9281
Params: <None>


Name:   papirus
Info:   PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
Load:   dtoverlay=papirus,<param>=<val>
Params: panel                   Display panel (required):
                                1.44": e1144cs021
                                2.0":  e2200cs021
                                2.7":  e2271cs021

        speed                   Display SPI bus speed


Name:   pca953x
Info:   TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
Load:   dtoverlay=pca953x,<param>=<val>
Params: addr                    I2C address of expander. Default 0x20.
        pca6416                 Select the NXP PCA6416 (16 bit)
        pca9505                 Select the NXP PCA9505 (40 bit)
        pca9535                 Select the NXP PCA9535 (16 bit)
        pca9536                 Select the NXP PCA9536 or TI PCA9536 (4 bit)
        pca9537                 Select the NXP PCA9537 (4 bit)
        pca9538                 Select the NXP PCA9538 (8 bit)
        pca9539                 Select the NXP PCA9539 (16 bit)
        pca9554                 Select the NXP PCA9554 (8 bit)
        pca9555                 Select the NXP PCA9555 (16 bit)
        pca9556                 Select the NXP PCA9556 (8 bit)
        pca9557                 Select the NXP PCA9557 (8 bit)
        pca9574                 Select the NXP PCA9574 (8 bit)
        pca9575                 Select the NXP PCA9575 (16 bit)
        pca9698                 Select the NXP PCA9698 (40 bit)
        pca16416                Select the NXP PCA16416 (16 bit)
        pca16524                Select the NXP PCA16524 (24 bit)
        pca19555a               Select the NXP PCA19555A (16 bit)
        max7310                 Select the Maxim MAX7310 (8 bit)
        max7312                 Select the Maxim MAX7312 (16 bit)
        max7313                 Select the Maxim MAX7313 (16 bit)
        max7315                 Select the Maxim MAX7315 (8 bit)
        pca6107                 Select the TI PCA6107 (8 bit)
        tca6408                 Select the TI TCA6408 (8 bit)
        tca6416                 Select the TI TCA6416 (16 bit)
        tca6424                 Select the TI TCA6424 (24 bit)
        tca9539                 Select the TI TCA9539 (16 bit)
        tca9554                 Select the TI TCA9554 (8 bit)
        cat9554                 Select the Onnn CAT9554 (8 bit)
        pca9654                 Select the Onnn PCA9654 (8 bit)
        xra1202                 Select the Exar XRA1202 (8 bit)


[ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]


[ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]


[ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]


Name:   pi3-act-led
Info:   This overlay has been renamed act-led, keeping pi3-act-led as an alias
        for backwards compatibility.
Load:   <Deprecated>


Name:   pi3-disable-bt
Info:   This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
        alias for backwards compatibility.
Load:   <Deprecated>


Name:   pi3-disable-wifi
Info:   This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
        an alias for backwards compatibility.
Load:   <Deprecated>


Name:   pi3-miniuart-bt
Info:   This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
        an alias for backwards compatibility.
Load:   <Deprecated>


Name:   pibell
Info:   Configures the pibell audio card.
Load:   dtoverlay=pibell,<param>=<val>
Params: alsaname                Set the name as it appears in ALSA (default
                                "PiBell")


Name:   pifacedigital
Info:   Configures the PiFace Digital mcp23s17 GPIO port expander.
Load:   dtoverlay=pifacedigital,<param>=<val>
Params: spi-present-mask        8-bit integer, bitmap indicating MCP23S17 SPI0
                                CS0 address. PiFace Digital supports addresses
                                0-3, which can be configured with JP1 and JP2.


Name:   pifi-40
Info:   Configures the PiFi 40W stereo amplifier
Load:   dtoverlay=pifi-40
Params: <None>


Name:   pifi-dac-hd
Info:   Configures the PiFi DAC HD
Load:   dtoverlay=pifi-dac-hd
Params: <None>


Name:   pifi-dac-zero
Info:   Configures the PiFi DAC Zero
Load:   dtoverlay=pifi-dac-zero
Params: <None>


Name:   pifi-mini-210
Info:   Configures the PiFi Mini stereo amplifier
Load:   dtoverlay=pifi-mini-210
Params: <None>


Name:   piglow
Info:   Configures the PiGlow by pimoroni.com
Load:   dtoverlay=piglow
Params: <None>


Name:   piscreen
Info:   PiScreen display by OzzMaker.com
Load:   dtoverlay=piscreen,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}

        xohms                   Touchpanel sensitivity (X-plate resistance)


Name:   piscreen2r
Info:   PiScreen 2 with resistive TP display by OzzMaker.com
Load:   dtoverlay=piscreen2r,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}

        xohms                   Touchpanel sensitivity (X-plate resistance)


Name:   pisound
Info:   Configures the Blokas Labs pisound card
Load:   dtoverlay=pisound
Params: <None>


Name:   pitft22
Info:   Adafruit PiTFT 2.2" screen
Load:   dtoverlay=pitft22,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}


Name:   pitft28-capacitive
Info:   Adafruit PiTFT 2.8" capacitive touch screen
Load:   dtoverlay=pitft28-capacitive,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}

        touch-sizex             Touchscreen size x (default 240)

        touch-sizey             Touchscreen size y (default 320)

        touch-invx              Touchscreen inverted x axis

        touch-invy              Touchscreen inverted y axis

        touch-swapxy            Touchscreen swapped x y axis


Name:   pitft28-resistive
Info:   Adafruit PiTFT 2.8" resistive touch screen
Load:   dtoverlay=pitft28-resistive,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}


Name:   pitft35-resistive
Info:   Adafruit PiTFT 3.5" resistive touch screen
Load:   dtoverlay=pitft35-resistive,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}


Name:   pps-gpio
Info:   Configures the pps-gpio (pulse-per-second time signal via GPIO).
Load:   dtoverlay=pps-gpio,<param>=<val>
Params: gpiopin                 Input GPIO (default "18")
        assert_falling_edge     When present, assert is indicated by a falling
                                edge, rather than by a rising edge (default
                                off)
        capture_clear           Generate clear events on the trailing edge
                                (default off)


Name:   pwm
Info:   Configures a single PWM channel
        Legal pin,function combinations for each channel:
          PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0)            52,5(Alt1)
          PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
        N.B.:
          1) Pin 18 is the only one available on all platforms, and
             it is the one used by the I2S audio interface.
             Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
          2) The onboard analogue audio output uses both PWM channels.
          3) So be careful mixing audio and PWM.
          4) Currently the clock must have been enabled and configured
             by other means.
Load:   dtoverlay=pwm,<param>=<val>
Params: pin                     Output pin (default 18) - see table
        func                    Pin function (default 2 = Alt5) - see above
        clock                   PWM clock frequency (informational)


Name:   pwm-2chan
Info:   Configures both PWM channels
        Legal pin,function combinations for each channel:
          PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0)            52,5(Alt1)
          PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
        N.B.:
          1) Pin 18 is the only one available on all platforms, and
             it is the one used by the I2S audio interface.
             Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
          2) The onboard analogue audio output uses both PWM channels.
          3) So be careful mixing audio and PWM.
          4) Currently the clock must have been enabled and configured
             by other means.
Load:   dtoverlay=pwm-2chan,<param>=<val>
Params: pin                     Output pin (default 18) - see table
        pin2                    Output pin for other channel (default 19)
        func                    Pin function (default 2 = Alt5) - see above
        func2                   Function for pin2 (default 2 = Alt5)
        clock                   PWM clock frequency (informational)


Name:   pwm-ir-tx
Info:   Use GPIO pin as pwm-assisted infrared transmitter output.
        This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
        of PWM0 to reduce the CPU load during transmission compared to
        gpio-ir-tx which uses bit-banging.
        Legal pin,function combinations are:
          12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
Load:   dtoverlay=pwm-ir-tx,<param>=<val>
Params: gpio_pin                Output GPIO (default 18)

        func                    Pin function (default 2 = Alt5)


Name:   qca7000
Info:   I2SE's Evaluation Board for PLC Stamp micro
Load:   dtoverlay=qca7000,<param>=<val>
Params: int_pin                 GPIO pin for interrupt signal (default 23)

        speed                   SPI bus speed (default 12 MHz)


Name:   rotary-encoder
Info:   Overlay for GPIO connected rotary encoder.
Load:   dtoverlay=rotary-encoder,<param>=<val>
Params: pin_a                   GPIO connected to rotary encoder channel A
                                (default 4).
        pin_b                   GPIO connected to rotary encoder channel B
                                (default 17).
        relative_axis           register a relative axis rather than an
                                absolute one. Relative axis will only
                                generate +1/-1 events on the input device,
                                hence no steps need to be passed.
        linux_axis              the input subsystem axis to map to this
                                rotary encoder. Defaults to 0 (ABS_X / REL_X)
        rollover                Automatic rollover when the rotary value
                                becomes greater than the specified steps or
                                smaller than 0. For absolute axis only.
        steps-per-period        Number of steps (stable states) per period.
                                The values have the following meaning:
                                1: Full-period mode (default)
                                2: Half-period mode
                                4: Quarter-period mode
        steps                   Number of steps in a full turnaround of the
                                encoder. Only relevant for absolute axis.
                                Defaults to 24 which is a typical value for
                                such devices.
        wakeup                  Boolean, rotary encoder can wake up the
                                system.
        encoding                String, the method used to encode steps.
                                Supported are "gray" (the default and more
                                common) and "binary".


Name:   rpi-backlight
Info:   Raspberry Pi official display backlight driver
Load:   dtoverlay=rpi-backlight
Params: <None>


Name:   rpi-cirrus-wm5102
Info:   Configures the Cirrus Logic Audio Card
Load:   dtoverlay=rpi-cirrus-wm5102
Params: <None>


Name:   rpi-dac
Info:   Configures the RPi DAC audio card
Load:   dtoverlay=rpi-dac
Params: <None>


Name:   rpi-display
Info:   RPi-Display - 2.8" Touch Display by Watterott
Load:   dtoverlay=rpi-display,<param>=<val>
Params: speed                   Display SPI bus speed
        rotate                  Display rotation {0,90,180,270}
        fps                     Delay between frame updates
        debug                   Debug output level {0-7}
        xohms                   Touchpanel sensitivity (X-plate resistance)
        swapxy                  Swap x and y axis
        backlight               Change backlight GPIO pin {e.g. 12, 18}


Name:   rpi-ft5406
Info:   Official Raspberry Pi display touchscreen
Load:   dtoverlay=rpi-ft5406,<param>=<val>
Params: touchscreen-size-x      Touchscreen X resolution (default 800)
        touchscreen-size-y      Touchscreen Y resolution (default 600);
        touchscreen-inverted-x  Invert touchscreen X coordinates (default 0);
        touchscreen-inverted-y  Invert touchscreen Y coordinates (default 0);
        touchscreen-swapped-x-y Swap X and Y cordinates (default 0);


Name:   rpi-poe
Info:   Raspberry Pi PoE HAT fan
Load:   dtoverlay=rpi-poe,<param>[=<val>]
Params: poe_fan_temp0           Temperature (in millicelcius) at which the fan
                                turns on (default 40000)
        poe_fan_temp0_hyst      Temperature delta (in millicelcius) at which
                                the fan turns off (default 2000)
        poe_fan_temp1           Temperature (in millicelcius) at which the fan
                                speeds up (default 45000)
        poe_fan_temp1_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 2000)
        poe_fan_temp2           Temperature (in millicelcius) at which the fan
                                speeds up (default 50000)
        poe_fan_temp2_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 2000)
        poe_fan_temp3           Temperature (in millicelcius) at which the fan
                                speeds up (default 55000)
        poe_fan_temp3_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 5000)


Name:   rpi-poe-plus
Info:   Raspberry Pi PoE+ HAT fan
Load:   dtoverlay=rpi-poe-plus,<param>[=<val>]
Params: poe_fan_temp0           Temperature (in millicelcius) at which the fan
                                turns on (default 40000)
        poe_fan_temp0_hyst      Temperature delta (in millicelcius) at which
                                the fan turns off (default 2000)
        poe_fan_temp1           Temperature (in millicelcius) at which the fan
                                speeds up (default 45000)
        poe_fan_temp1_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 2000)
        poe_fan_temp2           Temperature (in millicelcius) at which the fan
                                speeds up (default 50000)
        poe_fan_temp2_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 2000)
        poe_fan_temp3           Temperature (in millicelcius) at which the fan
                                speeds up (default 55000)
        poe_fan_temp3_hyst      Temperature delta (in millicelcius) at which
                                the fan slows down (default 5000)


Name:   rpi-proto
Info:   Configures the RPi Proto audio card
Load:   dtoverlay=rpi-proto
Params: <None>


Name:   rpi-sense
Info:   Raspberry Pi Sense HAT
Load:   dtoverlay=rpi-sense
Params: <None>


Name:   rpi-tv
Info:   Raspberry Pi TV HAT
Load:   dtoverlay=rpi-tv
Params: <None>


Name:   rpivid-v4l2
Info:   Load the V4L2 stateless video decoder driver for the HEVC block,
        disabling the memory mapped devices in the process.
Load:   dtoverlay=rpivid-v4l2
Params: <None>


Name:   rra-digidac1-wm8741-audio
Info:   Configures the Red Rocks Audio DigiDAC1 soundcard
Load:   dtoverlay=rra-digidac1-wm8741-audio
Params: <None>


Name:   sainsmart18
Info:   Overlay for the SPI-connected Sainsmart 1.8" display (based on the
        ST7735R chip).
Load:   dtoverlay=sainsmart18,<param>=<val>
Params: rotate                  Display rotation {0,90,180,270}
        speed                   SPI bus speed in Hz (default 4000000)
        fps                     Display frame rate in Hz
        bgr                     Enable BGR mode (default off)
        debug                   Debug output level {0-7}
        dc_pin                  GPIO pin for D/C (default 24)
        reset_pin               GPIO pin for RESET (default 25)


Name:   sc16is750-i2c
Info:   Overlay for the NXP SC16IS750 UART with I2C Interface
        Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
        select another address, please refer to table 10 in reference manual.
Load:   dtoverlay=sc16is750-i2c,<param>=<val>
Params: int_pin                 GPIO used for IRQ (default 24)
        addr                    Address (default 0x48)
        xtal                    On-board crystal frequency (default 14745600)


Name:   sc16is752-i2c
Info:   Overlay for the NXP SC16IS752 dual UART with I2C Interface
        Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
        select another address, please refer to table 10 in reference manual.
Load:   dtoverlay=sc16is752-i2c,<param>=<val>
Params: int_pin                 GPIO used for IRQ (default 24)
        addr                    Address (default 0x48)
        xtal                    On-board crystal frequency (default 14745600)


Name:   sc16is752-spi0
Info:   Overlay for the NXP SC16IS752 Dual UART with SPI Interface
        Enables the chip on SPI0.
Load:   dtoverlay=sc16is752-spi0,<param>=<val>
Params: int_pin                 GPIO used for IRQ (default 24)
        xtal                    On-board crystal frequency (default 14745600)


Name:   sc16is752-spi1
Info:   Overlay for the NXP SC16IS752 Dual UART with SPI Interface
        Enables the chip on SPI1.
        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
              A+, B+, Zero and PI2 B; as well as the Compute Module.

Load:   dtoverlay=sc16is752-spi1,<param>=<val>
Params: int_pin                 GPIO used for IRQ (default 24)
        xtal                    On-board crystal frequency (default 14745600)


Name:   sdhost
Info:   Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
        N.B. This overlay is designed for situations where the mmc driver is
        the default, so it disables the other (mmc) interface - this will kill
        WiFi on a Pi3. If this isn't what you want, either use the sdtweak
        overlay or the new sd_* dtparams of the base DTBs.
Load:   dtoverlay=sdhost,<param>=<val>
Params: overclock_50            Clock (in MHz) to use when the MMC framework
                                requests 50MHz

        force_pio               Disable DMA support (default off)

        pio_limit               Number of blocks above which to use DMA
                                (default 1)

        debug                   Enable debug output (default off)


Name:   sdio
Info:   Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
        and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
        "dtoverlay=sdio,bus_width=1,gpios_22_25"
Load:   dtoverlay=sdio,<param>=<val>
Params: sdio_overclock          SDIO Clock (in MHz) to use when the MMC
                                framework requests 50MHz

        poll_once               Disable SDIO-device polling every second
                                (default on: polling once at boot-time)

        bus_width               Set the SDIO host bus width (default 4 bits)

        gpios_22_25             Select GPIOs 22-25 for 1-bit mode. Must be used
                                with bus_width=1. This replaces the sdio-1bit
                                overlay, which is now deprecated.

        gpios_34_37             Select GPIOs 34-37 for 1-bit mode. Must be used
                                with bus_width=1.

        gpios_34_39             Select GPIOs 34-39 for 4-bit mode. Must be used
                                with bus_width=4 (the default).


Name:   sdio-1bit
Info:   This overlay is now deprecated. Use
        "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
Load:   <Deprecated>


Name:   sdtweak
Info:   This overlay is now deprecated. Use the sd_* dtparams in the
        base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
        "dtparam=sd_poll_once".
Load:   <Deprecated>


Name:   seeed-can-fd-hat-v1
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
        channels without RTC. Use this overlay if your HAT has no
        battery holder.
        https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
Load:   dtoverlay=seeed-can-fd-hat-v1
Params: <None>


Name:   seeed-can-fd-hat-v2
Info:   Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
        channels and an RTC. Use this overlay if your HAT has a
        battery holder.
        https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
Load:   dtoverlay=seeed-can-fd-hat-v2
Params: <None>


Name:   sh1106-spi
Info:   Overlay for SH1106 OLED via SPI using fbtft staging driver.
Load:   dtoverlay=sh1106-spi,<param>=<val>
Params: speed                   SPI bus speed (default 4000000)
        rotate                  Display rotation (0, 90, 180 or 270; default 0)
        fps                     Delay between frame updates (default 25)
        debug                   Debug output level (0-7; default 0)
        dc_pin                  GPIO pin for D/C (default 24)
        reset_pin               GPIO pin for RESET (default 25)
        height                  Display height (32 or 64; default 64)


Name:   smi
Info:   Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
Load:   dtoverlay=smi
Params: <None>


Name:   smi-dev
Info:   Enables the userspace interface for the SMI driver
Load:   dtoverlay=smi-dev
Params: <None>


Name:   smi-nand
Info:   Enables access to NAND flash via the SMI interface
Load:   dtoverlay=smi-nand
Params: <None>


Name:   spi-gpio35-39
Info:   Move SPI function block to GPIO 35 to 39
Load:   dtoverlay=spi-gpio35-39
Params: <None>


Name:   spi-gpio40-45
Info:   Move SPI function block to GPIOs 40 to 45
Load:   dtoverlay=spi-gpio40-45
Params: <None>


Name:   spi-rtc
Info:   Adds support for a number of SPI Real Time Clock devices
Load:   dtoverlay=spi-rtc,<param>=<val>
Params: pcf2123                 Select the PCF2123 device


Name:   spi0-1cs
Info:   Only use one CS pin for SPI0
Load:   dtoverlay=spi0-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 8)
        no_miso                 Don't claim and use the MISO pin (9), freeing
                                it for other uses.


Name:   spi0-2cs
Info:   Change the CS pins for SPI0
Load:   dtoverlay=spi0-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 8)
        cs1_pin                 GPIO pin for CS1 (default 7)
        no_miso                 Don't claim and use the MISO pin (9), freeing
                                it for other uses.


Name:   spi0-cs
Info:   This overlay has been renamed spi0-2cs, keeping spi0-cs as an
        alias for backwards compatibility.
Load:   <Deprecated>


Name:   spi0-hw-cs
Info:   This overlay has been deprecated and removed because it is no longer
        necessary and has been seen to prevent spi0 from working.
Load:   <Deprecated>


Name:   spi1-1cs
Info:   Enables spi1 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin number for the CS line and spidev device node
        creation are configurable.
        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
              A+, B+, Zero and PI2 B; as well as the Compute Module.
Load:   dtoverlay=spi1-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.0 (default
                                is 'okay' or enabled).


Name:   spi1-2cs
Info:   Enables spi1 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable.
        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
              A+, B+, Zero and PI2 B; as well as the Compute Module.
Load:   dtoverlay=spi1-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
        cs1_pin                 GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.0 (default
                                is 'okay' or enabled).
        cs1_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.1 (default
                                is 'okay' or enabled).


Name:   spi1-3cs
Info:   Enables spi1 with three chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable.
        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
              A+, B+, Zero and PI2 B; as well as the Compute Module.
Load:   dtoverlay=spi1-3cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
        cs1_pin                 GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
        cs2_pin                 GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.0 (default
                                is 'okay' or enabled).
        cs1_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.1 (default
                                is 'okay' or enabled).
        cs2_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev1.2 (default
                                is 'okay' or enabled).


Name:   spi2-1cs
Info:   Enables spi2 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin number for the CS line and spidev device node
        creation are configurable.
        N.B.: spi2 is only accessible with the Compute Module.
Load:   dtoverlay=spi2-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.0 (default
                                is 'okay' or enabled).


Name:   spi2-2cs
Info:   Enables spi2 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable.
        N.B.: spi2 is only accessible with the Compute Module.
Load:   dtoverlay=spi2-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
        cs1_pin                 GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.0 (default
                                is 'okay' or enabled).
        cs1_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.1 (default
                                is 'okay' or enabled).


Name:   spi2-3cs
Info:   Enables spi2 with three chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable.
        N.B.: spi2 is only accessible with the Compute Module.
Load:   dtoverlay=spi2-3cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
        cs1_pin                 GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
        cs2_pin                 GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
        cs0_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.0 (default
                                is 'okay' or enabled).
        cs1_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.1 (default
                                is 'okay' or enabled).
        cs2_spidev              Set to 'disabled' to stop the creation of a
                                userspace device node /dev/spidev2.2 (default
                                is 'okay' or enabled).


Name:   spi3-1cs
Info:   Enables spi3 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin number for the CS line and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi3-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev3.0 (default
                                is 'on' or enabled).


Name:   spi3-2cs
Info:   Enables spi3 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi3-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
        cs1_pin                 GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev3.0 (default
                                is 'on' or enabled).
        cs1_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev3.1 (default
                                is 'on' or enabled).


Name:   spi4-1cs
Info:   Enables spi4 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin number for the CS line and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi4-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev4.0 (default
                                is 'on' or enabled).


Name:   spi4-2cs
Info:   Enables spi4 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi4-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
        cs1_pin                 GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev4.0 (default
                                is 'on' or enabled).
        cs1_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev4.1 (default
                                is 'on' or enabled).


Name:   spi5-1cs
Info:   Enables spi5 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi5-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev5.0 (default
                                is 'on' or enabled).


Name:   spi5-2cs
Info:   Enables spi5 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi5-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
        cs1_pin                 GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev5.0 (default
                                is 'on' or enabled).
        cs1_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev5.1 (default
                                is 'on' or enabled).


Name:   spi6-1cs
Info:   Enables spi6 with a single chip select (CS) line and associated spidev
        dev node. The gpio pin number for the CS line and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi6-1cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev6.0 (default
                                is 'on' or enabled).


Name:   spi6-2cs
Info:   Enables spi6 with two chip select (CS) lines and associated spidev
        dev nodes. The gpio pin numbers for the CS lines and spidev device node
        creation are configurable. BCM2711 only.
Load:   dtoverlay=spi6-2cs,<param>=<val>
Params: cs0_pin                 GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
        cs1_pin                 GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
        cs0_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev6.0 (default
                                is 'on' or enabled).
        cs1_spidev              Set to 'off' to prevent the creation of a
                                userspace device node /dev/spidev6.1 (default
                                is 'on' or enabled).


Name:   ssd1306
Info:   Overlay for activation of SSD1306 over I2C OLED display framebuffer.
Load:   dtoverlay=ssd1306,<param>=<val>
Params: address                 Location in display memory of first character.
                                (default=0)
        width                   Width of display. (default=128)
        height                  Height of display. (default=64)
        offset                  virtual channel a. (default=0)
        normal                  Has no effect on displays tested. (default=not
                                set)
        sequential              Set this if every other scan line is missing.
                                (default=not set)
        remapped                Set this if display is garbled. (default=not
                                set)
        inverted                Set this if display is inverted and mirrored.
                                (default=not set)

        Examples:
        Typical usage for 128x64 display: dtoverlay=ssd1306,inverted

        Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential

        i2c_baudrate=400000 will speed up the display.

        i2c_baudrate=1000000 seems to work even though it's not officially
        supported by the hardware, and is faster still.

        For more information refer to the device datasheet at:
        https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf


Name:   ssd1306-spi
Info:   Overlay for SSD1306 OLED via SPI using fbtft staging driver.
Load:   dtoverlay=ssd1306-spi,<param>=<val>
Params: speed                   SPI bus speed (default 10000000)
        rotate                  Display rotation (0, 90, 180 or 270; default 0)
        fps                     Delay between frame updates (default 25)
        debug                   Debug output level (0-7; default 0)
        dc_pin                  GPIO pin for D/C (default 24)
        reset_pin               GPIO pin for RESET (default 25)
        height                  Display height (32 or 64; default 64)


Name:   ssd1351-spi
Info:   Overlay for SSD1351 OLED via SPI using fbtft staging driver.
Load:   dtoverlay=ssd1351-spi,<param>=<val>
Params: speed                   SPI bus speed (default 4500000)
        rotate                  Display rotation (0, 90, 180 or 270; default 0)
        fps                     Delay between frame updates (default 25)
        debug                   Debug output level (0-7; default 0)
        dc_pin                  GPIO pin for D/C (default 24)
        reset_pin               GPIO pin for RESET (default 25)


Name:   superaudioboard
Info:   Configures the SuperAudioBoard sound card
Load:   dtoverlay=superaudioboard,<param>=<val>
Params: gpiopin                 GPIO pin for codec reset


Name:   sx150x
Info:   Configures the Semtech SX150X I2C GPIO expanders.
Load:   dtoverlay=sx150x,<param>=<val>
Params: sx150<x>-<n>-<m>        Enables SX150X device on I2C#<n> with slave
                                address <m>. <x> may be 1-9. <n> may be 0 or 1.
                                Permissible values of <m> (which is denoted in
                                hex) depend on the device variant. For SX1501,
                                SX1502, SX1504 and SX1505, <m> may be 20 or 21.
                                For SX1503 and SX1506, <m> may be 20. For
                                SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
                                For SX1508, <m> may be 20, 21, 22 or 23.

        sx150<x>-<n>-<m>-int-gpio
                                Integer, enables interrupts on SX150X device on
                                I2C#<n> with slave address <m>, specifies
                                the GPIO pin to which NINT output of SX150X is
                                connected.


Name:   tc358743
Info:   Toshiba TC358743 HDMI to CSI-2 bridge chip.
        Uses Unicam 1, which is the standard camera connector on most Pi
        variants.
Load:   dtoverlay=tc358743,<param>=<val>
Params: 4lane                   Use 4 lanes (only applicable to Compute Modules
                                CAM1 connector).

        link-frequency          Set the link frequency. Only values of 297000000
                                (574Mbit/s) and 486000000 (972Mbit/s - default)
                                are supported by the driver.


Name:   tc358743-audio
Info:   Used in combination with the tc358743-fast overlay to route the audio
        from the TC358743 over I2S to the Pi.
        Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
        20.
Load:   dtoverlay=tc358743-audio,<param>=<val>
Params: card-name               Override the default, "tc358743", card name.


Name:   tinylcd35
Info:   3.5" Color TFT Display by www.tinylcd.com
        Options: Touch, RTC, keypad
Load:   dtoverlay=tinylcd35,<param>=<val>
Params: speed                   Display SPI bus speed

        rotate                  Display rotation {0,90,180,270}

        fps                     Delay between frame updates

        debug                   Debug output level {0-7}

        touch                   Enable touch panel

        touchgpio               Touch controller IRQ GPIO

        xohms                   Touchpanel: Resistance of X-plate in ohms

        rtc-pcf                 PCF8563 Real Time Clock

        rtc-ds                  DS1307 Real Time Clock

        keypad                  Enable keypad

        Examples:
            Display with touchpanel, PCF8563 RTC and keypad:
                dtoverlay=tinylcd35,touch,rtc-pcf,keypad
            Old touch display: