Re: [PATCH v14 2/4] phy: Add media type and speed serdes configuration interfaces

Hi Kishon,

On Fri, 2021-02-12 at 17:02 +0530, Kishon Vijay Abraham I wrote:

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Hi Steen,

On 10/02/21 2:22 pm, Steen Hegelund wrote:

quoted

Provide new phy configuration interfaces for media type and speed
that
allows allows e.g. PHYs used for ethernet to be configured with
this
information.

Signed-off-by: Lars Povlsen <redacted>
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/phy/phy-core.c  | 30 ++++++++++++++++++++++++++++++
 include/linux/phy/phy.h | 26 ++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 71cb10826326..ccb575b13777 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c

@@ -373,6 +373,36 @@ int phy_set_mode_ext(struct phy *phy, enum

phy_mode mode, int submode)
 }
 EXPORT_SYMBOL_GPL(phy_set_mode_ext);

+int phy_set_media(struct phy *phy, enum phy_media media)
+{
+     int ret;
+
+     if (!phy || !phy->ops->set_media)
+             return 0;
+
+     mutex_lock(&phy->mutex);
+     ret = phy->ops->set_media(phy, media);
+     mutex_unlock(&phy->mutex);
+
+     return ret;
+}
+EXPORT_SYMBOL_GPL(phy_set_media);
+
+int phy_set_speed(struct phy *phy, int speed)
+{
+     int ret;
+
+     if (!phy || !phy->ops->set_speed)
+             return 0;
+
+     mutex_lock(&phy->mutex);
+     ret = phy->ops->set_speed(phy, speed);
+     mutex_unlock(&phy->mutex);
+
+     return ret;
+}
+EXPORT_SYMBOL_GPL(phy_set_speed);

Can't speed derived from mode? Do we need a separate set_speed
function?

Thanks
Kishon

Yes the client will need to be able to choose the speed as needed: 
e.g. lower than the serdes mode supports, in case the the media or the
other end is not capable of running that speed.  

An example is a 10G and 25G serdes connected via DAC and as there is no
inband autoneg, the 25G client would have to manually select 10G speed
to communicate with its partner.

quoted

+
 int phy_reset(struct phy *phy)
 {
      int ret;

diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index e435bdb0bab3..e4fd69a1faa7 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h

@@ -44,6 +44,12 @@ enum phy_mode {

      PHY_MODE_DP
 };

+enum phy_media {
+     PHY_MEDIA_DEFAULT,
+     PHY_MEDIA_SR,
+     PHY_MEDIA_DAC,
+};
+
 /**
  * union phy_configure_opts - Opaque generic phy configuration
  *

@@ -64,6 +70,8 @@ union phy_configure_opts {

  * @power_on: powering on the phy
  * @power_off: powering off the phy
  * @set_mode: set the mode of the phy
+ * @set_media: set the media type of the phy (optional)
+ * @set_speed: set the speed of the phy (optional)
  * @reset: resetting the phy
  * @calibrate: calibrate the phy
  * @release: ops to be performed while the consumer relinquishes
the PHY

@@ -75,6 +83,8 @@ struct phy_ops {

      int     (*power_on)(struct phy *phy);
      int     (*power_off)(struct phy *phy);
      int     (*set_mode)(struct phy *phy, enum phy_mode mode, int
submode);
+     int     (*set_media)(struct phy *phy, enum phy_media media);
+     int     (*set_speed)(struct phy *phy, int speed);

      /**
       * @configure:

@@ -215,6 +225,8 @@ int phy_power_off(struct phy *phy);

 int phy_set_mode_ext(struct phy *phy, enum phy_mode mode, int
submode);
 #define phy_set_mode(phy, mode) \
      phy_set_mode_ext(phy, mode, 0)
+int phy_set_media(struct phy *phy, enum phy_media media);
+int phy_set_speed(struct phy *phy, int speed);
 int phy_configure(struct phy *phy, union phy_configure_opts
*opts);
 int phy_validate(struct phy *phy, enum phy_mode mode, int submode,
               union phy_configure_opts *opts);

@@ -344,6 +356,20 @@ static inline int phy_set_mode_ext(struct phy

*phy, enum phy_mode mode,
 #define phy_set_mode(phy, mode) \
      phy_set_mode_ext(phy, mode, 0)

+static inline int phy_set_media(struct phy *phy, enum phy_media
media)
+{
+     if (!phy)
+             return 0;
+     return -ENOSYS;
+}
+
+static inline int phy_set_speed(struct phy *phy, int speed)
+{
+     if (!phy)
+             return 0;
+     return -ENOSYS;
+}
+
 static inline enum phy_mode phy_get_mode(struct phy *phy)
 {
      return PHY_MODE_INVALID;

Thanks for your comments.


-- 
BR
Steen

-=-=-=-=-=-=-=-=-=-=-=-=-=-=
steen.hegelund@microchip.com