Re: [PATCH v2 1/2] dt-bindings: Document the STM32 QSPI bindings

From: Rob Herring
Date: Mon Apr 03 2017 - 12:57:42 EST


On Fri, Mar 31, 2017 at 07:02:03PM +0200, Ludovic Barre wrote:
> From: Ludovic Barre <ludovic.barre@xxxxxx>
>
> This patch adds documentation of device tree bindings for the STM32
> QSPI controller.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> ---
> .../devicetree/bindings/mtd/stm32-quadspi.txt | 45 ++++++++++++++++++++++
> 1 file changed, 45 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mtd/stm32-quadspi.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt b/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt
> new file mode 100644
> index 0000000..95a8ebd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/stm32-quadspi.txt
> @@ -0,0 +1,45 @@
> +* STMicroelectronics Quad Serial Peripheral Interface(QuadSPI)
> +
> +Required properties:
> +- compatible: should be "st,stm32f469-qspi"
> +- reg: contains the register location and length.
> + (optional) the memory mapping address and length

Why optional? Either the h/w has it or doesn't. If some chips don't,
they should have a different compatible string.

> +- reg-names: list of the names corresponding to the previous register
> + Should contain "qspi" to register location
> + (optional) "qspi_mm" if read in memory map mode (improve read throughput)
> +- interrupts: should contain the interrupt for the device
> +- clocks: the phandle of the clock needed by the QSPI controller
> +- A pinctrl must be defined to set pins in mode of operation for QSPI transfer
> +
> +Optional properties:
> +- resets: must contain the phandle to the reset controller.
> +
> +A spi flash must be a child of the nor_flash node and could have some
> +properties. Also see jedec,spi-nor.txt.
> +
> +Required properties:
> +- reg: chip-Select number (QSPI controller may connect 2 nor flashes)
> +- spi-max-frequency: max frequency of spi bus
> +
> +Optional property:
> +- spi-rx-bus-width: the bus width (number of data wires)

Just "see ../spi/spi-bus.txt" for the description

> +
> +Example:
> +
> +qspi: qspi@a0001000 {

spi@...

> + compatible = "st,stm32f469-qspi";
> + reg = <0xa0001000 0x1000>, <0x90000000 0x10000000>;
> + reg-names = "qspi", "qspi_mm";
> + interrupts = <91>;
> + resets = <&rcc STM32F4_AHB3_RESET(QSPI)>;
> + clocks = <&rcc 0 STM32F4_AHB3_CLOCK(QSPI)>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_qspi0>;
> +
> + flash@0 {
> + reg = <0>;
> + spi-rx-bus-width = <4>;
> + spi-max-frequency = <108000000>;
> + ...
> + };
> +};
> --
> 2.7.4
>