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Subject[PATCH v2 1/4] phy: Add provision for calibrating phy.
Date
Some PHY controllers may need to calibrate certain
PHY settings after initialization of the controller and
sometimes even after initializing the PHY-consumer too.
Add support for the same in order to let consumers do so in need.

Signed-off-by: vivek Gautam <gautam.vivek@samsung.com>
---
drivers/phy/phy-core.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/phy/phy.h | 8 ++++++++
2 files changed, 44 insertions(+)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 74d4346..92d31a3 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -376,6 +376,42 @@ int phy_power_off(struct phy *phy)
EXPORT_SYMBOL_GPL(phy_power_off);

/**
+ * phy_calibrate - calibrate a phy post initialization
+ * @phy: Pointer to 'phy' from consumer
+ *
+ * For certain PHYs, it may be needed to calibrate few phy parameters
+ * post initialization. The need to calibrate may arise after the
+ * initialization of consumer itself, in order to prevent further any
+ * loss of phy settings post consumer-initialization.
+ * example: USB 3.0 DRD PHY on Exynos5420/5800 systems is one such
+ * phy which needs calibration after the host controller reset
+ * has happened.
+ */
+int phy_calibrate(struct phy *phy)
+{
+ int ret = -ENOTSUPP;
+
+ if (!phy)
+ return 0;
+
+ mutex_lock(&phy->mutex);
+ if (phy->ops->calibrate) {
+ ret = phy->ops->calibrate(phy);
+ if (ret < 0) {
+ dev_err(&phy->dev,
+ "phy calibration failed --> %d\n", ret);
+ goto out;
+ }
+ }
+
+out:
+ mutex_unlock(&phy->mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(phy_calibrate);
+
+/**
* _of_phy_get() - lookup and obtain a reference to a phy by phandle
* @np: device_node for which to get the phy
* @index: the index of the phy
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 5a537a5..b7f33ee 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -27,6 +27,7 @@ struct phy;
* @exit: operation to be performed while exiting
* @power_on: powering on the phy
* @power_off: powering off the phy
+ * @calibrate: calibrate the phy post init
* @owner: the module owner containing the ops
*/
struct phy_ops {
@@ -34,6 +35,7 @@ struct phy_ops {
int (*exit)(struct phy *phy);
int (*power_on)(struct phy *phy);
int (*power_off)(struct phy *phy);
+ int (*calibrate)(struct phy *phy);
struct module *owner;
};

@@ -124,6 +126,7 @@ int phy_init(struct phy *phy);
int phy_exit(struct phy *phy);
int phy_power_on(struct phy *phy);
int phy_power_off(struct phy *phy);
+int phy_calibrate(struct phy *phy);
static inline int phy_get_bus_width(struct phy *phy)
{
return phy->attrs.bus_width;
@@ -227,6 +230,11 @@ static inline int phy_power_off(struct phy *phy)
return -ENOSYS;
}

+static inline int phy_calibrate(struct phy *phy)
+{
+ return -ENOSYS;
+}
+
static inline int phy_get_bus_width(struct phy *phy)
{
return -ENOSYS;
--
1.7.10.4


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