DT chaps,
Please can you take a look at this binding.
In particular the use of the 'ranges' property to store device 'mode'.
> 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@xxxxxxxxx>
> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
> ---
> .../devicetree/bindings/mfd/atmel-flexcom.txt | 68 ++++++++++++++++++++++
> 1 file changed, 68 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..588d527dbfa7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> @@ -0,0 +1,68 @@
> +* 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: Should be "atmel,sama5d2-flexcom"
> +- reg: Should be the pair (offset, size) for the Flexcom
> + dedicated I/O registers (without USART, TWI or SPI
> + registers).
> +- clocks: Should be the Flexcom peripheral clock from PMC.
> +- #address-cells: Should be <2>
> +- #size-cells: Should be <1>
> +- ranges: Should be a list of ranges.
> + One range per peripheral wrapped by the Flexcom. So each
> + range is a triplet (child_addr, parent_addr, size). The
> + first u32 of "child_addr" is the value to be set in the
> + Operating Mode bitfield of the Flexcom Mode Register.
> + Then "parent_addr" stores the base address of the
> + corresponding peripheral in the system memory. Finally,
> + "size" if the size of the memory region of this
> + peripheral.
> +
> +Required child:
> +A single available child for the serial controller to enable.
> +
> +Required properties of this child:
> +- reg: Should be a pair (child_addr, size) with child_addr
> + matching one of the parent ranges.
> +- clocks: Should be the very same phandle as for the parent's one.
> +
> +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 = <2>;
> + #size-cells = <1>;
> + ranges = <1 0 0xf8034200 0x200 /* opmode 1: USART */
> + 2 0 0xf8034400 0x200 /* opmode 2: SPI */
> + 3 0 0xf8034600 0x200>; /* opmode 3: I2C */
> +
> + spi@2,0 {
> + compatible = "atmel,at91rm9200-spi";
> + reg = <2 0 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>;
> + };
> + };
> +};
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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