i2c: add i2c_trylock_bus wrapper, use it

This unifies usage with i2c_lock_bus and i2c_unlock_bus, and paves the
way for the next patch which looks a bit saner with this preparatory
work taken care of beforehand.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index da3a02ef4a3187e2c97e1a8bcb795c318544c4d1..56e50ca905ba39aaf585cdd3b40ab4260f2227d4 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2459,7 +2459,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 #endif
 
                if (in_atomic() || irqs_disabled()) {
-                       ret = adap->trylock_bus(adap, I2C_LOCK_SEGMENT);
+                       ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
                        if (!ret)
                                /* I2C activity is ongoing. */
                                return -EAGAIN;

diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 8eee98634cda57839cda747708469715d6cfa271..764f195795e406486799cfc3a640eadd94b7911f 100644 (file)
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -159,7 +159,7 @@ static int i2c_mux_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
                return 0;       /* mux_lock not locked, failure */
        if (!(flags & I2C_LOCK_ROOT_ADAPTER))
                return 1;       /* we only want mux_lock, success */
-       if (parent->trylock_bus(parent, flags))
+       if (i2c_trylock_bus(parent, flags))
                return 1;       /* parent locked too, success */
        rt_mutex_unlock(&parent->mux_lock);
        return 0;               /* parent not locked, failure */
@@ -193,7 +193,7 @@ static int i2c_parent_trylock_bus(struct i2c_adapter *adapter,
 
        if (!rt_mutex_trylock(&parent->mux_lock))
                return 0;       /* mux_lock not locked, failure */
-       if (parent->trylock_bus(parent, flags))
+       if (i2c_trylock_bus(parent, flags))
                return 1;       /* parent locked too, success */
        rt_mutex_unlock(&parent->mux_lock);
        return 0;               /* parent not locked, failure */

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index fffdc270ca18518f4e3c05b5efd2749f52b28f50..c1f60a345db7c26a7fb3b9eab6bde40319fde945 100644 (file)
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -600,6 +600,20 @@ i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
        adapter->lock_bus(adapter, flags);
 }
 
+/**
+ * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
+ *     I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
+ *
+ * Return: true if the I2C bus segment is locked, false otherwise
+ */
+static inline int
+i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+       return adapter->trylock_bus(adapter, flags);
+}
+
 /**
  * i2c_unlock_bus - Release exclusive access to an I2C bus segment
  * @adapter: Target I2C bus segment