[2/3] net: of_mdio: add of_mdiobus_link_phydev()

Add a function to Walk the list of subnodes of a mdio bus and look for
a node that matches the phy's address with its 'reg' property. If found,
set the of_node pointer for the phy. This allows auto-probed pyh
devices to be augmented by information passed in via DT.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 drivers/net/phy/mdio_bus.c |  6 ++++++
 drivers/of/of_mdio.c       | 33 +++++++++++++++++++++++++++++++++
 include/linux/of_mdio.h    |  8 ++++++++
 3 files changed, 47 insertions(+)

2014-05-10 9:37 GMT-07:00 Daniel Mack <zonque@gmail.com>:
> Add a function to Walk the list of subnodes of a mdio bus and look for
> a node that matches the phy's address with its 'reg' property. If found,
> set the of_node pointer for the phy. This allows auto-probed pyh
> devices to be augmented by information passed in via DT.
>
> Signed-off-by: Daniel Mack <zonque@gmail.com>
> ---
>  drivers/net/phy/mdio_bus.c |  6 ++++++
>  drivers/of/of_mdio.c       | 33 +++++++++++++++++++++++++++++++++
>  include/linux/of_mdio.h    |  8 ++++++++
>  3 files changed, 47 insertions(+)
>
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 76f54b3..e1444b2 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -233,6 +233,12 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
>         if (IS_ERR(phydev) || phydev == NULL)
>                 return phydev;
>
> +       /*
> +        * For DT, see if the auto-probed phy has a correspoding child
> +        * in the bus node, and set the of_node pointer in this case.
> +        */
> +       of_mdiobus_link_phydev(bus, phydev);
> +
>         err = phy_device_register(phydev);
>         if (err) {
>                 phy_device_free(phydev);
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index 171f9d5..931a977 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -211,6 +211,39 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>  }
>  EXPORT_SYMBOL(of_mdiobus_register);
>
> +/**
> + * of_mdiobus_link_phydev - Find a device node for a phy
> + * @mdio: pointer to mii_bus structure
> + * @phydev: phydev for which the of_node pointer should be set
> + *
> + * Walk the list of subnodes of a mdio bus and look for a node that matches the
> + * phy's address with its 'reg' property. If found, set the of_node pointer for
> + * the phy. This allows auto-probed pyh devices to be supplied with information
> + * passed in via DT.
> + */
> +void of_mdiobus_link_phydev(struct mii_bus *mdio,
> +                           struct phy_device *phydev)
> +{
> +       struct device *dev = &phydev->dev;
> +       struct device_node *child;
> +
> +       if (dev->of_node)
> +               return;

This should be:

            if (dev->of_node || !mdio->dev_of_node)
                    return;

a system with for instance non-DT probed MDIO busses such as the
special fixed MDIO bus will not have such an of_node pointer and we
will have a null pointer during the first iteration of the for_each_*
loop.

arguably of_get_next_available_child() could be updated to handle a
NULL parent device_node, but I think it clearer to add this check
here.

> +
> +       for_each_available_child_of_node(mdio->dev.of_node, child) {
> +               int addr;
> +
> +               addr = of_mdio_parse_addr(&mdio->dev, child);
> +               if (addr < 0)
> +                       continue;
> +
> +               if (addr == phydev->addr) {
> +                       dev->of_node = child;
> +                       return;
> +               }
> +       }
> +}
> +
>  /* Helper function for of_phy_find_device */
>  static int of_phy_match(struct device *dev, void *phy_np)
>  {
> diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
> index 881a7c3..de72206 100644
> --- a/include/linux/of_mdio.h
> +++ b/include/linux/of_mdio.h
> @@ -28,6 +28,9 @@ extern struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
>
>  extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np);
>
> +extern void of_mdiobus_link_phydev(struct mii_bus *mdio,
> +                                  struct phy_device *phydev);
> +
>  #else /* CONFIG_OF */
>  static inline int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>  {
> @@ -70,6 +73,11 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np)
>  {
>         return NULL;
>  }
> +
> +static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
> +                                         struct phy_device *phydev)
> +{
> +}
>  #endif /* CONFIG_OF */
>
>  #endif /* __LINUX_OF_MDIO_H */
> --
> 1.9.0
>

On 05/23/2014 09:35 PM, Florian Fainelli wrote:
> 2014-05-10 9:37 GMT-07:00 Daniel Mack <zonque@gmail.com>:

>> +/**
>> + * of_mdiobus_link_phydev - Find a device node for a phy
>> + * @mdio: pointer to mii_bus structure
>> + * @phydev: phydev for which the of_node pointer should be set
>> + *
>> + * Walk the list of subnodes of a mdio bus and look for a node that matches the
>> + * phy's address with its 'reg' property. If found, set the of_node pointer for
>> + * the phy. This allows auto-probed pyh devices to be supplied with information
>> + * passed in via DT.
>> + */
>> +void of_mdiobus_link_phydev(struct mii_bus *mdio,
>> +                           struct phy_device *phydev)
>> +{
>> +       struct device *dev = &phydev->dev;
>> +       struct device_node *child;
>> +
>> +       if (dev->of_node)
>> +               return;
> 
> This should be:
> 
>             if (dev->of_node || !mdio->dev_of_node)
>                     return;
> 
> a system with for instance non-DT probed MDIO busses such as the
> special fixed MDIO bus will not have such an of_node pointer and we
> will have a null pointer during the first iteration of the for_each_*
> loop.
> 
> arguably of_get_next_available_child() could be updated to handle a
> NULL parent device_node, but I think it clearer to add this check
> here.

Good catch! I'll change that, add your Reviewed-by and resend!


Thanks,
Daniel

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