On Thu, Nov 21, 2019 at 08:50:07AM +0530, Anvesh Salveru wrote:
> In some platforms, we need information of phy properties in
> the controller drivers. This patch adds a new phy_property_present()
> method which can be used to check if some property exists in PHY
> or not.
>
> In case of DesignWare PCIe controller, we need to write into controller
> register to specify about ZRX-DC compliance property of the PHY, which
> reduces the power consumption during lower power states.
>
> Signed-off-by: Anvesh Salveru <anvesh.s@xxxxxxxxxxx>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> ---
> drivers/phy/phy-core.c | 26 ++++++++++++++++++++++++++
> include/linux/phy/phy.h | 8 ++++++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index b04f4fe..0a62eca 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -420,6 +420,32 @@ int phy_calibrate(struct phy *phy)
> EXPORT_SYMBOL_GPL(phy_calibrate);
>
> /**
> + * phy_property_present() - checks if the property is present in PHY
> + * @phy: the phy returned by phy_get()
> + * @property: name of the property to check
> + *
> + * Used to check if the given property is present in PHY. PHY drivers
> + * can implement this callback function to expose PHY properties to
> + * controller drivers.
> + *
> + * Returns: true if property exists, false otherwise
> + */
> +bool phy_property_present(struct phy *phy, const char *property)
> +{
> + bool ret;
> +
> + if (!phy || !phy->ops->property_present)
> + return false;
> +
> + mutex_lock(&phy->mutex);
> + ret = phy->ops->property_present(phy, property);
I don't understand why it is necessary to require every phy driver to
implement this. Why can't the phy-core driver look up the device node
of the given phy?
Thanks,
Andrew Murray
> + mutex_unlock(&phy->mutex);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(phy_property_present);
> +
> +/**
> * phy_configure() - Changes the phy parameters
> * @phy: the phy returned by phy_get()
> * @opts: New configuration to apply
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 15032f14..3dd8f3c 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -61,6 +61,7 @@ union phy_configure_opts {
> * @reset: resetting the phy
> * @calibrate: calibrate the phy
> * @release: ops to be performed while the consumer relinquishes the PHY
> + * @property_present: check if some property is present in PHY
> * @owner: the module owner containing the ops
> */
> struct phy_ops {
> @@ -103,6 +104,7 @@ struct phy_ops {
> int (*reset)(struct phy *phy);
> int (*calibrate)(struct phy *phy);
> void (*release)(struct phy *phy);
> + bool (*property_present)(struct phy *phy, const char *property);
> struct module *owner;
> };
>
> @@ -217,6 +219,7 @@ static inline enum phy_mode phy_get_mode(struct phy *phy)
> }
> int phy_reset(struct phy *phy);
> int phy_calibrate(struct phy *phy);
> +bool phy_property_present(struct phy *phy, const char *property);
> static inline int phy_get_bus_width(struct phy *phy)
> {
> return phy->attrs.bus_width;
> @@ -354,6 +357,11 @@ static inline int phy_calibrate(struct phy *phy)
> return -ENOSYS;
> }
>
> +static inline bool phy_property_present(struct phy *phy, const char *property)
> +{
> + return false;
> +}
> +
> static inline int phy_configure(struct phy *phy,
> union phy_configure_opts *opts)
> {
> --
> 2.7.4
>
