On Fri, Oct 01, 2021 at 01:37:57PM +0200, Hannes Schmelzer wrote:

> This commit adds support for the MAX7320 (and clones) gpio expander.
> 
> Signed-off-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
> ---
> 
>  doc/device-tree-bindings/gpio/gpio-max7320.txt |  36 ++++++++
>  drivers/gpio/Kconfig                           |   8 ++
>  drivers/gpio/Makefile                          |   1 +
>  drivers/gpio/max7320_gpio.c                    | 113 +++++++++++++++++++++++++
>  4 files changed, 158 insertions(+)
>  create mode 100644 doc/device-tree-bindings/gpio/gpio-max7320.txt
>  create mode 100644 drivers/gpio/max7320_gpio.c
> 
> diff --git a/doc/device-tree-bindings/gpio/gpio-max7320.txt b/doc/device-tree-bindings/gpio/gpio-max7320.txt
> new file mode 100644
> index 0000000..87b703b
> --- /dev/null
> +++ b/doc/device-tree-bindings/gpio/gpio-max7320.txt
> @@ -0,0 +1,36 @@
> +* MAX7320 I/O expanders
> +
> +The original maxim 7320 i/o expander offers 8 bit push/pull outputs.
> +There exists some clones which offers 16 bit.
> +
> +Required Properties:
> +
> +  - compatible: should be one of the following.
> +    - "maxim,max7320"
> +
> +  - reg: I2C slave address.
> +
> +  - gpio-controller: Marks the device node as a gpio controller.
> +  - #gpio-cells: Should be 2. The first cell is the GPIO number and the second
> +    cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the
> +    GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported.
> +
> +Optional Properties:
> +
> +   - ngpios: tell the driver how many gpios the device offers.
> +     if the property is omitted, 8bit (original maxim) is assumed.
> +
> +Please refer to gpio.txt in this directory for details of the common GPIO
> +bindings used by client devices.
> +
> +Example: MAX7320 I/O expander node
> +
> +	ledgpio: max7320@5d {
> +		status = "okay";
> +		compatible = "maxim,max7320";
> +		reg = <0x5d>;
> +		#gpio-cells = <2>;
> +		gpio-controller;
> +		ngpios = <16>;
> +	};
> +

Where does this binding come from?  Thanks!

-- 
Tom