[PATCH] [v2] netdev/phy: add MDIO bus multiplexer driven by a memory-mapped device
Tabi Timur-B04825
B04825 at freescale.com
Fri Aug 24 10:28:10 EST 2012
Stephen Warren wrote:
> On 08/23/2012 01:44 PM, Timur Tabi wrote:
>> Add support for an MDIO bus multiplexer controlled by a simple memory-mapped
>> device, like an FPGA. The device must be memory-mapped and contain only
>> 8-bit registers (which keeps things simple).
>
>> +++ b/Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt
>
>> + /* The FPGA node */
>> + fpga: board-control at 3,0 {
>> + compatible = "fsl,p5020ds-fpga", "fsl,fpga-ngpixis";
>> + reg = <3 0 0x30>;
>
> Why not add the following here:
>
> #address-cells = <1>:
> #size-cells = <1>;
> ranges = <...>;
I forgot to add them in the txt file. They are in the real device tree.
>
>> +
>> + mdio-mux-emi2 {
>> + compatible = "mdio-mux-mmioreg", "mdio-mux";
>> + mdio-parent-bus = <&xmdio0>;
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + reg = <9>; // BRDCFG1
>
> Then, that'd have to be <9 1>;
Actually, I had #size-cells = <0>.
>
> That way, ...
>
>> diff --git a/drivers/net/phy/mdio-mux-mmioreg.c b/drivers/net/phy/mdio-mux-mmioreg.c
>
>> +static int __devinit mdio_mux_mmioreg_probe(struct platform_device *pdev)
>
>> + /* The MMIO device is the parent of this device */
>> + np2 = of_get_parent(np);
>> + if (!np2) {
>> + dev_err(&pdev->dev, "could not find parent MMIO device\n");
>> + return -ENODEV;
>> + }
>> +
>> + ret = of_address_to_resource(np2, 0, &res);
>> + if (ret) {
>> + dev_err(&pdev->dev, "could not obtain memory map for node %s\n",
>> + np2->full_name);
>> + return ret;
>> + }
>> + s->phys = res.start;
>
> You could simplify all that into just "of_iomap(np, 0)", and all the
> address translation etc. happens entirely automatically, in the standard
> fashion for DT.
Ah! You're right. I don't need to look for the parent node. Duh.
--
Timur Tabi
Linux kernel developer at Freescale
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