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>
This commit is contained in:
Peter Rosin 2016-06-29 15:04:03 +02:00 committed by Wolfram Sang
parent 00f0ea70d2
commit fb79e09a74
3 changed files with 17 additions and 3 deletions

View file

@ -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;

View file

@ -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 */

View file

@ -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