[PATCH v2 05/21] net: phy: fixed: Be compatible with live OF tree

[Vladimir Oltean]

On Fri, Mar 12, 2021 at 09:35:46PM +0800, Bin Meng wrote:
> From: Vladimir Oltean <vladimir.oltean at nxp.com>
> 
> On systems that use CONFIG_OF_LIVE, the "ofnode" type is defined
> as const struct device_node *np, while on the flat DT systems it
> is defined as a long of_offset into gd->fdt_blob.
> 
> It is desirable that the fixed PHY driver uses the higher-level
> ofnode abstraction instead of parsing gd->fdt_blob directly,
> because that enables it to work on live OF systems.
> 
> The fixed PHY driver has used a nasty hack since its introduction in
> commit db40c1aa1c10 ("drivers/net/phy: add fixed-phy / fixed-link support"),
> which is to pass the long gd->fdt_blob offset inside int phydev->addr
> (a value that normally holds the MDIO bus address at which the PHY
> responds). Even ignoring the fact that the types were already
> mismatched leading to a potential truncation (flat OF offset was
> supposed to be a long and not an int), we really cannot extend this
> hack any longer, because there's no way an int will hold the other
> representation of ofnode, the struct device_node *np.
> 
> So we unfortunately need to do the right thing, which is to use the
> framework introduced by Grygorii Strashko in
> commit eef0b8a930d1 ("net: phy: add ofnode node to struct phy_device").
> This will populate phydev->node for the fixed PHY.
> 
> Note that phydev->node will not be valid in the probe function, since
> that is called synchronously from phy_device_create and we really have
> no way of passing the ofnode directly through the phy_device_create API.
> So we do what other drivers do too: we move the OF parsing logic from
> the .probe to the .config method of the PHY driver. The new function
> will be called at phy_config() time.
> 
> I do believe I've converted all the possible call paths for creating
> a PHY with PHY_FIXED_ID, so there is really no reason to maintain
> compatibility with the old logic of retrieving a flat OF tree offset
> from phydev->addr. We just pass 0 to phydev->addr now.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean at nxp.com>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> Tested-by: Bin Meng <bmeng.cn at gmail.com>
> Message-Id: <20210216224804.3355044-2-olteanv at gmail.com>
> [bmeng: keep fixedphy_probe(); update mdio-uclass.c to handle fixed phy]
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---

Reviewed-by: Vladimir Oltean <vladimir.oltean at nxp.com>