Re: [PATCH RFC V2 1/2] Documentation: add Device tree bindings for QCA7000

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 07/01/2014 08:36 PM, Stefan Wahren wrote:

> This patch adds the Device tree bindings for the
> Ethernet over SPI protocol driver of the Qualcomm
> QCA7000 HomePlug GreenPHY.

> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> ---
>   .../devicetree/bindings/net/qca-qca7000-spi.txt    |   47 ++++++++++++++++++++
>   1 file changed, 47 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/net/qca-qca7000-spi.txt

> diff --git a/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt b/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
> new file mode 100644
> index 0000000..66ff588
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
> @@ -0,0 +1,47 @@
> +* Qualcomm QCA7000 (Ethernet over SPI protocol)
> +
> +Note: The QCA7000 is useable as a SPI device. In this case it must be defined
> +as a child of a SPI master in the device tree.
> +
> +Required properties:
> +- compatible : Should be "qca,qca7000"
> +- reg : Should specify the SPI chip select
> +- interrupt-parent : Should specify the pHandle of the source interrupt

    This property is not really required, it could be inherited from an 
upper-level node.

> +- interrupts : The first cell should specify the index of the source interrupt
> +  and the second cell should specify the trigger type as rising edge
> +- spi-cpha : Must be set
> +- spi-cpol: Must be set
> +
> +Optional properties:
> +- spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at.
> +  Numbers smaller than 1000000 or greater than 16000000 are invalid. Missing
> +  the property will set the SPI frequency to 8000000 Hertz.
> +- local-mac-address: 6 bytes, mac address

    s/mac/MAC/.

> +- qca,legacy-mode : Set the SPI data transfer of the QCA7000 to legacy mode.
> +  In this mode the SPI master must toggle the chip select between each data
> +  word. In burst mode these gaps aren't necessary, which is faster.
> +  This setting depends on how the QCA7000 is setup via GPIO pin strapping.
> +  If the property is missing the driver defaults to burst mode.
> +
> +Example:
> +
> +/* Freescale i.MX28 SPI master*/
> +ssp2: ssp@80014000 {
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +	compatible = "fsl,imx28-spi";
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&spi2_pins_a>;
> +	status = "okay";
> +
> +	qca7000@0 {

    According to the ePAPR standard [1]:

The name of a node should be somewhat generic, reflecting the function of the 
device and not its precise programming model. If appropriate, the name should 
be one of the following choices:
[...]
  - ethernet;

> +		compatible = "qca,qca7000";
> +		interrupt-parent = <&gpio3>;      /* GPIO Bank 3 */
> +		interrupts = <25 0x1>;            /* Index: 25, rising edge */
> +		reg = <0x0>;
> +		spi-cpha;                         /* SPI mode: CPHA=1 */
> +		spi-cpol;                         /* SPI mode: CPOL=1 */
> +		spi-max-frequency = <8000000>;    /* freq: 8 MHz */
> +		local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
> +	};
> +};

[1] http://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.0.pdf

WBR, Sergei