Re: [RFC PATCHv2 0/4] Add DT support for fixed PHYs

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Sep 06, 2013 at 05:18:17PM +0200, Thomas Petazzoni wrote:
> Hello,
> 
> Here is a second version of the patch set that adds a Device Tree
> binding and the related code to support fixed PHYs. Marked as RFC,
> this patch set is obviously not intended for merging in 3.12.
> 
> Since the first version, the changes have been:
> 
>  * Instead of using a 'fixed-link' property inside the Ethernet device
>    DT node, with a fairly cryptic succession of integer values, we now
>    use a PHY subnode under the Ethernet device DT node, with explicit
>    properties to configure the duplex, speed, pause and other PHY
>    properties.
> 
>  * The PHY address is automatically allocated by the kernel and no
>    longer visible in the Device Tree binding.
> 
>  * The PHY device is created directly when the network driver calls
>    of_phy_connect_fixed_link(), and associated to the PHY DT node,
>    which allows the existing of_phy_connect() function to work,
>    without the need to use the deprecated of_phy_connect_fixed_link().
> 
> The things I am not entirely happy with yet are:
> 
>  * The PHY ID is hardcoded to 0xdeadbeef. Ideally, it should be a
>    properly reserved vendor/device identifier, but it isn't clear how
>    to get one allocated for this purpose.
> 
>  * The fixed_phy_register() function in drivers/net/phy/fixed.c has
>    some OF references. So ideally, I would have preferred to put this
>    code in drivers/of/of_mdio.c, but to call get_phy_device(), we need
>    a reference to the mii_bus structure that represents the fixed MDIO
>    bus.
> 
>  * There is some error management missing in fixed_phy_register(), but
>    it can certainly be added easily. This RFC is meant to sort out the
>    general idea.

+1 for the general idea. This really looks good now. I've not much more
to say. Maybe someone from the devicetree corner has a few words for the
binding?

Sascha

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