Re: [PATCH v2 net-next] net: ethernet: enc28j60: add device tree support

[Rob Herring <robh@kernel.org>]

On Sun, Apr 24, 2016 at 11:28:03PM +0200, Michael Heimpold wrote:
> The following patch adds the required match table for device tree support
> (and while at, fix the indent). It's also possible to specify the
> MAC address in the DT blob.
> 
> Also add the corresponding binding documentation file.
> 
> Signed-off-by: Michael Heimpold <mhei@heimpold.de>
> ---
> 
> v2: * took care of Arnd Bergmann's review comments
>       - allow to specify MAC address via DT
>       - unconditionally define DT id table
>     * increased the driver version minor number
>     * driver author's email address bounces, removed from address list
> 
>  .../devicetree/bindings/net/microchip-enc28j60.txt | 50 ++++++++++++++++++++++

Matching the compatible string is preferred here: microchip,enc28j60.txt

>  drivers/net/ethernet/microchip/enc28j60.c          | 20 +++++++--
>  2 files changed, 67 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/net/microchip-enc28j60.txt
> 
> diff --git a/Documentation/devicetree/bindings/net/microchip-enc28j60.txt b/Documentation/devicetree/bindings/net/microchip-enc28j60.txt
> new file mode 100644
> index 0000000..847a97b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/microchip-enc28j60.txt
> @@ -0,0 +1,50 @@
> +* Microchip ENC28J60
> +
> +This is a standalone 10 MBit ethernet controller with SPI interface.
> +
> +For each device connected to a SPI bus, define a child node within
> +the SPI master node.
> +
> +Required properties:
> +- compatible: Should be "microchip,enc28j60"
> +- reg: Specify the SPI chip select the ENC28J60 is wired to
> +- interrupts: Specify the interrupt and interrupt type (usually falling edge)
> +
> +Optional properties:
> +- interrupt-parent: Specify the pHandle of the source interrupt

This is required in the sense that either the node or a parent node must 
define it. In this case, since the SPI controller likely has a different 
parent, you will pretty much always need it defined in this node.

> +- spi-max-frequency: Maximum frequency of the SPI bus when accessing the ENC28J60.
> +  According to the ENC28J80 datasheet, the chip allows a maximum of 20 MHz, however,
> +  board designs may need to limit this value.
> +- local-mac-address: See ethernet.txt in the same directory.
> +
> +
> +Example (for NXP i.MX28 with pin control stuff for GPIO irq):
> +
> +        ssp2: ssp@80014000 {
> +                compatible = "fsl,imx28-spi";
> +                pinctrl-names = "default";
> +                pinctrl-0 = <&spi2_pins_b &spi2_sck_cfg>;
> +                status = "okay";
> +
> +                enc28j60: ethernet@0 {
> +                        compatible = "microchip,enc28j60";
> +                        pinctrl-names = "default";
> +                        pinctrl-0 = <&enc28j60_pins>;

Need to document using the pinctrl binding.

> +                        reg = <0>;
> +                        interrupt-parent = <&gpio3>;
> +                        interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
> +                        spi-max-frequency = <12000000>;
> +                };
> +        };
> +