[v6,1/2] mfd: devicetree: add bindings for Atmel Flexcom

This patch documents the DT bindings for the Atmel Flexcom which will be
introduced by sama5d2x SoCs. These bindings will be used by the actual
Flexcom driver to be sent in another patch.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
---
 .../devicetree/bindings/mfd/atmel-flexcom.txt      | 67 ++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt

On Wed, 22 Jul 2015, Cyrille Pitchen wrote:

> This patch documents the DT bindings for the Atmel Flexcom which will be
> introduced by sama5d2x SoCs. These bindings will be used by the actual
> Flexcom driver to be sent in another patch.
> 
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> ---
>  .../devicetree/bindings/mfd/atmel-flexcom.txt      | 67 ++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> 
> diff --git a/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> new file mode 100644
> index 000000000000..87a366b95ecf
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> @@ -0,0 +1,67 @@
> +* Device tree bindings for Atmel Flexcom (Flexible Serial Communication Unit)
> +
> +The Atmel Flexcom is just a wrapper which embeds a SPI controller, an I2C
> +controller and an USART. Only one function can be used at a time and is chosen
> +at boot time according to the device tree.
> +
> +Required properties:
> +- compatible:		"atmel,sama5d2-flexcom"
> +- reg:			shall be the offset/length value for Flexcom dedicated
> +			I/O registers (without USART, TWI or SPI registers).
> +- clocks:		shall be the Flexcom peripheral clock from PMC.
> +- #address-cells:	should be <1>
> +- #size-cells:		should be <1>
> +- ranges:		one range for the full I/O register region (including
> +			USART, TWI and SPI registers).
> +
> +Required child:
> +a single available child for the serial controller to enable.

Not a fan of uppercase characters I see.

Nevertheless, documentation looks fine and doesn't introduce any new
properties, which we like.

Acked-by: Lee Jones <lee.jones@linaro.org>

> +One of the following substrings must be found inside the compatible property of
> +this child to enable the right serial controller:
> +- "-usart"
> +- "-spi"
> +- "-i2c"
> +
> +The reg property of this child should be:
> +- <0x200 0x200> for USART
> +- <0x400 0x200> for SPI
> +- <0x600 0x200> for I2C
> +
> +The phandle provided by the clocks property of the child is the same as one for
> +the Flexcom parent.
> +
> +Other properties remain unchanged. See documentation of the respective device:
> +- ../serial/atmel-usart.txt
> +- ../spi/spi_atmel.txt
> +- ../i2c/i2c-at91.txt
> +
> +Example:
> +
> +flexcom@f8034000 {
> +	compatible = "atmel,sama5d2-flexcom";
> +	reg = <0xf8034000 0x200>;
> +	clocks = <&flx0_clk>;
> +	#address-cells = <1>;
> +	#size-cells = <1>;
> +	ranges = <0x0 0xf8034000 0x800>;
> +
> +	spi@f8034400 {
> +		compatible = "atmel,at91rm9200-spi";
> +		reg = <0x400 0x200>;
> +		interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_flx0_default>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		clocks = <&flx0_clk>;
> +		clock-names = "spi_clk";
> +		atmel,fifo-size = <32>;
> +
> +		mtd_dataflash@0 {
> +			compatible = "atmel,at25f512b";
> +			reg = <0>;
> +			spi-max-frequency = <20000000>;
> +		};
> +	};
> +};