[PATCH 1/2] dt-bindings: spi: Document the STM32 SPI bindings

[robh@kernel.org (Rob Herring)]

On Wed, Jun 21, 2017 at 04:32:05PM +0200, Amelie Delaunay wrote:
> This patch adds the documentation of device tree bindings
> for the STM32 SPI controller.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> ---
>  .../devicetree/bindings/spi/spi-stm32.txt          | 60 ++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/spi/spi-stm32.txt
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> new file mode 100644
> index 0000000..3958bf6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
> @@ -0,0 +1,60 @@
> +STMicroelectronics STM32 SPI Controller
> +
> +The STM32 SPI controller is used to communicate with external devices using
> +the Serial Peripheral Interface. It supports full-duplex, half-duplex and
> +simplex synchronous serial communication with external devices. It supports
> +from 4 to 32-bit data size. Although it can be configured as master or slave,
> +only master is supported by the driver.
> +
> +Required properties:
> +- compatible: Must be "st,stm32-spi".
> +- reg: Offset and length of the device's register set.
> +- interrupts: Must contain the interrupt id.
> +- clocks: Must contain an entry for spiclk (which feeds the internal clock
> +	  generator).
> +- #address-cells:  Number of cells required to define a chip select address.
> +- #size-cells: Should be zero.
> +
> +Optional properties:
> +- resets: Must contain the phandle to the reset controller.
> +- A pinctrl state named "default" may be defined to set pins in mode of
> +  operation for SPI transfer.
> +- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
> +  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
> +- dma-names: DMA request names should include "tx" and "rx" if present.
> +- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
> +  Documentation/devicetree/bindings/spi/spi-bus.txt
> +
> +
> +Child nodes represent devices on the SPI bus
> +  See ../spi/spi-bus.txt
> +
> +Optional properties:
> +- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
> +		  nanoseconds inserted between two consecutive data frames.
> +
> +
> +Example:
> +	spi2: spi at 40003800 {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		compatible = "st,stm32-spi";
> +		reg = <0x40003800 0x400>;
> +		interrupts = <36>;
> +		clocks = <&rcc SPI2_CK>;
> +		resets = <&rcc 1166>;
> +		dmas = <&dmamux1 0 39 0x400 0x01>,
> +		       <&dmamux1 1 40 0x400 0x01>;
> +		dma-names = "rx", "tx";
> +		pinctrl-0 = <&spi2_pins_b>;
> +		pinctrl-names = "default";
> +		status = "okay";

Don't show status in examples.

> +		cs-gpios = <&gpioa 11 0>;
> +
> +		spidev at 0 {
> +			compatible = "spidev";

This is not a valid compatible. Pick a real device.

Rob