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Commit fb79e09a authored by Peter Rosin's avatar Peter Rosin Committed by Wolfram Sang
Browse files

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: default avatarPeter Rosin <peda@axentia.se>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 00f0ea70

drivers/i2c/i2c-core.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/i2c/i2c-mux.c

+2 −2
Original line number Diff line number Diff line
@@ -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 */

include/linux/i2c.h

+14 −0
Original line number Diff line number Diff line
@@ -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