Add a new phy_notify_state() api that notifies and configures a phy for a
given state transition.

This is intended to be by phy drivers which need to do some runtime
configuration of parameters that can't be handled by phy_calibrate() or
phy_power_{on|off}().

The first usage of this API is in the Samsung UFS phy that needs to issue
some register writes when entering and exiting the hibernate link state.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
---
 drivers/phy/phy-core.c  | 25 +++++++++++++++++++++++++
 include/linux/phy/phy.h | 19 +++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 04a5a34e7a950ae94fae915673c25d476fc071c1..60be8af984bf06649ef00e695d0ed4ced597cdb9 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -520,6 +520,31 @@ int phy_notify_disconnect(struct phy *phy, int port)
 }
 EXPORT_SYMBOL_GPL(phy_notify_disconnect);
 
+/**
+ * phy_notify_state() - phy state notification
+ * @phy: the PHY returned by phy_get()
+ * @state: the PHY state
+ *
+ * Notify the PHY of a state transition. Used to notify and
+ * configure the PHY accordingly.
+ *
+ * Returns: %0 if successful, a negative error code otherwise
+ */
+int phy_notify_state(struct phy *phy, union phy_notify state)
+{
+	int ret;
+
+	if (!phy || !phy->ops->notify_phystate)
+		return 0;
+
+	mutex_lock(&phy->mutex);
+	ret = phy->ops->notify_phystate(phy, state);
+	mutex_unlock(&phy->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_notify_state);
+
 /**
  * phy_configure() - Changes the phy parameters
  * @phy: the phy returned by phy_get()
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 13add0c2c40721fe9ca3f0350d13c035cd25af45..664d0864c3a5042949cb121e982368fe0a97827f 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -53,6 +53,15 @@ enum phy_media {
 	PHY_MEDIA_DAC,
 };
 
+enum phy_ufs_state {
+	PHY_UFS_HIBERN8_ENTER,
+	PHY_UFS_HIBERN8_EXIT,
+};
+
+union phy_notify {
+	enum phy_ufs_state ufs_state;
+};
+
 /**
  * union phy_configure_opts - Opaque generic phy configuration
  *
@@ -83,6 +92,7 @@ union phy_configure_opts {
  * @set_speed: set the speed of the phy (optional)
  * @reset: resetting the phy
  * @calibrate: calibrate the phy
+ * @notify_phystate: notify and configure the phy for a particular state
  * @release: ops to be performed while the consumer relinquishes the PHY
  * @owner: the module owner containing the ops
  */
@@ -132,6 +142,7 @@ struct phy_ops {
 	int	(*connect)(struct phy *phy, int port);
 	int	(*disconnect)(struct phy *phy, int port);
 
+	int	(*notify_phystate)(struct phy *phy, union phy_notify state);
 	void	(*release)(struct phy *phy);
 	struct module *owner;
 };
@@ -255,6 +266,7 @@ int phy_reset(struct phy *phy);
 int phy_calibrate(struct phy *phy);
 int phy_notify_connect(struct phy *phy, int port);
 int phy_notify_disconnect(struct phy *phy, int port);
+int phy_notify_state(struct phy *phy, union phy_notify state);
 static inline int phy_get_bus_width(struct phy *phy)
 {
 	return phy->attrs.bus_width;
@@ -412,6 +424,13 @@ static inline int phy_notify_disconnect(struct phy *phy, int index)
 	return -ENOSYS;
 }
 
+static inline int phy_notify_phystate(struct phy *phy, union phy_notify state)
+{
+	if (!phy)
+		return 0;
+	return -ENOSYS;
+}
+
 static inline int phy_configure(struct phy *phy,
 				union phy_configure_opts *opts)
 {

-- 
2.51.0.rc0.205.g4a044479a3-goog

On 13-08-25, 16:00, Peter Griffin wrote:
> Add a new phy_notify_state() api that notifies and configures a phy for a
> given state transition.
> 
> This is intended to be by phy drivers which need to do some runtime
                    ^^^^^^^^^^
Missing 'used' possibly? 

> configuration of parameters that can't be handled by phy_calibrate() or
> phy_power_{on|off}().
> 
> The first usage of this API is in the Samsung UFS phy that needs to issue
> some register writes when entering and exiting the hibernate link state.
> 
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> ---
>  drivers/phy/phy-core.c  | 25 +++++++++++++++++++++++++
>  include/linux/phy/phy.h | 19 +++++++++++++++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index 04a5a34e7a950ae94fae915673c25d476fc071c1..60be8af984bf06649ef00e695d0ed4ced597cdb9 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -520,6 +520,31 @@ int phy_notify_disconnect(struct phy *phy, int port)
>  }
>  EXPORT_SYMBOL_GPL(phy_notify_disconnect);
>  
> +/**
> + * phy_notify_state() - phy state notification
> + * @phy: the PHY returned by phy_get()
> + * @state: the PHY state
> + *
> + * Notify the PHY of a state transition. Used to notify and
> + * configure the PHY accordingly.
> + *
> + * Returns: %0 if successful, a negative error code otherwise
> + */
> +int phy_notify_state(struct phy *phy, union phy_notify state)
> +{
> +	int ret;
> +
> +	if (!phy || !phy->ops->notify_phystate)
> +		return 0;
> +
> +	mutex_lock(&phy->mutex);
> +	ret = phy->ops->notify_phystate(phy, state);
> +	mutex_unlock(&phy->mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(phy_notify_state);
> +
>  /**
>   * phy_configure() - Changes the phy parameters
>   * @phy: the phy returned by phy_get()
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 13add0c2c40721fe9ca3f0350d13c035cd25af45..664d0864c3a5042949cb121e982368fe0a97827f 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -53,6 +53,15 @@ enum phy_media {
>  	PHY_MEDIA_DAC,
>  };
>  
> +enum phy_ufs_state {
> +	PHY_UFS_HIBERN8_ENTER,
> +	PHY_UFS_HIBERN8_EXIT,
> +};
> +
> +union phy_notify {
> +	enum phy_ufs_state ufs_state;
> +};
> +
>  /**
>   * union phy_configure_opts - Opaque generic phy configuration
>   *
> @@ -83,6 +92,7 @@ union phy_configure_opts {
>   * @set_speed: set the speed of the phy (optional)
>   * @reset: resetting the phy
>   * @calibrate: calibrate the phy
> + * @notify_phystate: notify and configure the phy for a particular state
>   * @release: ops to be performed while the consumer relinquishes the PHY
>   * @owner: the module owner containing the ops
>   */
> @@ -132,6 +142,7 @@ struct phy_ops {
>  	int	(*connect)(struct phy *phy, int port);
>  	int	(*disconnect)(struct phy *phy, int port);
>  
> +	int	(*notify_phystate)(struct phy *phy, union phy_notify state);
>  	void	(*release)(struct phy *phy);
>  	struct module *owner;
>  };
> @@ -255,6 +266,7 @@ int phy_reset(struct phy *phy);
>  int phy_calibrate(struct phy *phy);
>  int phy_notify_connect(struct phy *phy, int port);
>  int phy_notify_disconnect(struct phy *phy, int port);
> +int phy_notify_state(struct phy *phy, union phy_notify state);
>  static inline int phy_get_bus_width(struct phy *phy)
>  {
>  	return phy->attrs.bus_width;
> @@ -412,6 +424,13 @@ static inline int phy_notify_disconnect(struct phy *phy, int index)
>  	return -ENOSYS;
>  }
>  
> +static inline int phy_notify_phystate(struct phy *phy, union phy_notify state)
> +{
> +	if (!phy)
> +		return 0;
> +	return -ENOSYS;

Should be -ENOSYS either way, right?

-- 
~Vinod

Hi Vinod,

Thanks for your review feedback.

On Wed, 20 Aug 2025 at 17:34, Vinod Koul <vkoul@kernel.org> wrote:
>
> On 13-08-25, 16:00, Peter Griffin wrote:
> > Add a new phy_notify_state() api that notifies and configures a phy for a
> > given state transition.
> >
> > This is intended to be by phy drivers which need to do some runtime
>                     ^^^^^^^^^^
> Missing 'used' possibly?

Yes your right, good spot, will fix.

>
> > configuration of parameters that can't be handled by phy_calibrate() or
> > phy_power_{on|off}().
> >
> > The first usage of this API is in the Samsung UFS phy that needs to issue
> > some register writes when entering and exiting the hibernate link state.
> >
> > Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
> > ---
> >  drivers/phy/phy-core.c  | 25 +++++++++++++++++++++++++
> >  include/linux/phy/phy.h | 19 +++++++++++++++++++
> >  2 files changed, 44 insertions(+)
> >
> > diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> > index 04a5a34e7a950ae94fae915673c25d476fc071c1..60be8af984bf06649ef00e695d0ed4ced597cdb9 100644
> > --- a/drivers/phy/phy-core.c
> > +++ b/drivers/phy/phy-core.c
> > @@ -520,6 +520,31 @@ int phy_notify_disconnect(struct phy *phy, int port)
> >  }
> >  EXPORT_SYMBOL_GPL(phy_notify_disconnect);
> >
> > +/**
> > + * phy_notify_state() - phy state notification
> > + * @phy: the PHY returned by phy_get()
> > + * @state: the PHY state
> > + *
> > + * Notify the PHY of a state transition. Used to notify and
> > + * configure the PHY accordingly.
> > + *
> > + * Returns: %0 if successful, a negative error code otherwise
> > + */
> > +int phy_notify_state(struct phy *phy, union phy_notify state)
> > +{
> > +     int ret;
> > +
> > +     if (!phy || !phy->ops->notify_phystate)
> > +             return 0;
> > +
> > +     mutex_lock(&phy->mutex);
> > +     ret = phy->ops->notify_phystate(phy, state);
> > +     mutex_unlock(&phy->mutex);
> > +
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(phy_notify_state);
> > +
> >  /**
> >   * phy_configure() - Changes the phy parameters
> >   * @phy: the phy returned by phy_get()
> > diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> > index 13add0c2c40721fe9ca3f0350d13c035cd25af45..664d0864c3a5042949cb121e982368fe0a97827f 100644
> > --- a/include/linux/phy/phy.h
> > +++ b/include/linux/phy/phy.h
> > @@ -53,6 +53,15 @@ enum phy_media {
> >       PHY_MEDIA_DAC,
> >  };
> >
> > +enum phy_ufs_state {
> > +     PHY_UFS_HIBERN8_ENTER,
> > +     PHY_UFS_HIBERN8_EXIT,
> > +};
> > +
> > +union phy_notify {
> > +     enum phy_ufs_state ufs_state;
> > +};
> > +
> >  /**
> >   * union phy_configure_opts - Opaque generic phy configuration
> >   *
> > @@ -83,6 +92,7 @@ union phy_configure_opts {
> >   * @set_speed: set the speed of the phy (optional)
> >   * @reset: resetting the phy
> >   * @calibrate: calibrate the phy
> > + * @notify_phystate: notify and configure the phy for a particular state
> >   * @release: ops to be performed while the consumer relinquishes the PHY
> >   * @owner: the module owner containing the ops
> >   */
> > @@ -132,6 +142,7 @@ struct phy_ops {
> >       int     (*connect)(struct phy *phy, int port);
> >       int     (*disconnect)(struct phy *phy, int port);
> >
> > +     int     (*notify_phystate)(struct phy *phy, union phy_notify state);
> >       void    (*release)(struct phy *phy);
> >       struct module *owner;
> >  };
> > @@ -255,6 +266,7 @@ int phy_reset(struct phy *phy);
> >  int phy_calibrate(struct phy *phy);
> >  int phy_notify_connect(struct phy *phy, int port);
> >  int phy_notify_disconnect(struct phy *phy, int port);
> > +int phy_notify_state(struct phy *phy, union phy_notify state);
> >  static inline int phy_get_bus_width(struct phy *phy)
> >  {
> >       return phy->attrs.bus_width;
> > @@ -412,6 +424,13 @@ static inline int phy_notify_disconnect(struct phy *phy, int index)
> >       return -ENOSYS;
> >  }
> >
> > +static inline int phy_notify_phystate(struct phy *phy, union phy_notify state)
> > +{
> > +     if (!phy)
> > +             return 0;
> > +     return -ENOSYS;
>
> Should be -ENOSYS either way, right?

I initially thought the same, but I followed the pattern that is used
by many of the other phy API calls like phy_init/exit,
phy_power_on/off phy_calibrate, phy_notify_connect in
include/linux/phy/phy.h. I can update it if you like, but I was trying
to keep it consistent.

The only API I can see (that isn't a *phy_get* or *phy_create*) which
returns -ENOSYS unconditionally is phy_get_bus_width()

Thanks,

Peter