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authorAndrew Lunn <andrew@lunn.ch>2014-02-04 17:33:12 (GMT)
committerMarek Szyprowski <m.szyprowski@samsung.com>2014-05-15 05:29:19 (GMT)
commitbb46d90d6cc73d9170f100e92feab0eed604bf1d (patch)
tree51f80486aadc60cbf019be60f8ba46d6767b6f47
parent54018807f6d7eb0726356439ebe49ccce8dc5bcd (diff)
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drivers: phy: Add support for optional phys
Add devm_phy_optional_get and phy_optional_get, which should be used when the phy is optional. They does not return an error when the phy does not exist, rather they returns NULL, which is considered as a valid phy, but results in NOPs when used with the consumer API. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Acked-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net> [backport from upstream commit 788a4d56ff378bff0b8e685d03a962b36903a149] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Change-Id: I76c9bb54d4bd11b742522c91c28f48b82ca4aa41
-rw-r--r--Documentation/phy.txt20
-rw-r--r--drivers/phy/phy-core.c45
-rw-r--r--include/linux/phy/phy.h14
3 files changed, 72 insertions, 7 deletions
diff --git a/Documentation/phy.txt b/Documentation/phy.txt
index 2e24b99..ebff6ee 100644
--- a/Documentation/phy.txt
+++ b/Documentation/phy.txt
@@ -75,14 +75,20 @@ Before the controller can make use of the PHY, it has to get a reference to
it. This framework provides the following APIs to get a reference to the PHY.
struct phy *phy_get(struct device *dev, const char *string);
+struct phy *phy_optional_get(struct device *dev, const char *string);
struct phy *devm_phy_get(struct device *dev, const char *string);
-
-phy_get and devm_phy_get can be used to get the PHY. In the case of dt boot,
-the string arguments should contain the phy name as given in the dt data and
-in the case of non-dt boot, it should contain the label of the PHY.
-The only difference between the two APIs is that devm_phy_get associates the
-device with the PHY using devres on successful PHY get. On driver detach,
-release function is invoked on the the devres data and devres data is freed.
+struct phy *devm_phy_optional_get(struct device *dev, const char *string);
+
+phy_get, phy_optional_get, devm_phy_get and devm_phy_optional_get can
+be used to get the PHY. In the case of dt boot, the string arguments
+should contain the phy name as given in the dt data and in the case of
+non-dt boot, it should contain the label of the PHY. The two
+devm_phy_get associates the device with the PHY using devres on
+successful PHY get. On driver detach, release function is invoked on
+the the devres data and devres data is freed. phy_optional_get and
+devm_phy_optional_get should be used when the phy is optional. These
+two functions will never return -ENODEV, but instead returns NULL when
+the phy cannot be found.
It should be noted that NULL is a valid phy reference. All phy
consumer calls on the NULL phy become NOPs. That is the release calls,
diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index a9cdeee2..5f5b0f4 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -426,6 +426,27 @@ struct phy *phy_get(struct device *dev, const char *string)
EXPORT_SYMBOL_GPL(phy_get);
/**
+ * phy_optional_get() - lookup and obtain a reference to an optional phy.
+ * @dev: device that requests this phy
+ * @string: the phy name as given in the dt data or the name of the controller
+ * port for non-dt case
+ *
+ * Returns the phy driver, after getting a refcount to it; or
+ * NULL if there is no such phy. The caller is responsible for
+ * calling phy_put() to release that count.
+ */
+struct phy *phy_optional_get(struct device *dev, const char *string)
+{
+ struct phy *phy = phy_get(dev, string);
+
+ if (PTR_ERR(phy) == -ENODEV)
+ phy = NULL;
+
+ return phy;
+}
+EXPORT_SYMBOL_GPL(phy_optional_get);
+
+/**
* devm_phy_get() - lookup and obtain a reference to a phy.
* @dev: device that requests this phy
* @string: the phy name as given in the dt data or phy device name
@@ -456,6 +477,30 @@ struct phy *devm_phy_get(struct device *dev, const char *string)
EXPORT_SYMBOL_GPL(devm_phy_get);
/**
+ * devm_phy_optional_get() - lookup and obtain a reference to an optional phy.
+ * @dev: device that requests this phy
+ * @string: the phy name as given in the dt data or phy device name
+ * for non-dt case
+ *
+ * Gets the phy using phy_get(), and associates a device with it using
+ * devres. On driver detach, release function is invoked on the devres
+ * data, then, devres data is freed. This differs to devm_phy_get() in
+ * that if the phy does not exist, it is not considered an error and
+ * -ENODEV will not be returned. Instead the NULL phy is returned,
+ * which can be passed to all other phy consumer calls.
+ */
+struct phy *devm_phy_optional_get(struct device *dev, const char *string)
+{
+ struct phy *phy = devm_phy_get(dev, string);
+
+ if (PTR_ERR(phy) == -ENODEV)
+ phy = NULL;
+
+ return phy;
+}
+EXPORT_SYMBOL_GPL(devm_phy_optional_get);
+
+/**
* phy_create() - create a new phy
* @dev: device that is creating the new phy
* @ops: function pointers for performing phy operations
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index e273e5a..3f83459 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -146,7 +146,9 @@ static inline void phy_set_bus_width(struct phy *phy, int bus_width)
phy->attrs.bus_width = bus_width;
}
struct phy *phy_get(struct device *dev, const char *string);
+struct phy *phy_optional_get(struct device *dev, const char *string);
struct phy *devm_phy_get(struct device *dev, const char *string);
+struct phy *devm_phy_optional_get(struct device *dev, const char *string);
void phy_put(struct phy *phy);
void devm_phy_put(struct device *dev, struct phy *phy);
struct phy *of_phy_simple_xlate(struct device *dev,
@@ -232,11 +234,23 @@ static inline struct phy *phy_get(struct device *dev, const char *string)
return ERR_PTR(-ENOSYS);
}
+static inline struct phy *phy_optional_get(struct device *dev,
+ const char *string)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline struct phy *devm_phy_get(struct device *dev, const char *string)
{
return ERR_PTR(-ENOSYS);
}
+static inline struct phy *devm_phy_optional_get(struct device *dev,
+ const char *string)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline void phy_put(struct phy *phy)
{
}