[PATCH 1/4] net: phy: fixed: be compatible with live OF tree

[Bin Meng]

On Fri, Mar 12, 2021 at 2:34 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> On Wed, Feb 17, 2021 at 6:48 AM Vladimir Oltean <olteanv at gmail.com> 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 nastyyyyy 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>
> > ---
> >  drivers/net/phy/fixed.c | 30 ++++++++++++++++++++++--------
> >  drivers/net/phy/phy.c   | 30 +++++++++++++++---------------
> >  2 files changed, 37 insertions(+), 23 deletions(-)
> >
>
> For the record,
>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> Tested-by: Bin Meng <bmeng.cn at gmail.com>

fixedphy_probe() has to be kept, to set the PHY_FLAG_BROKEN_RESET
flag. Will fix in v2.

Regards,
Bin