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authorJean Delvare <khali@linux-fr.org>2009-11-07 07:10:46 -0500
committerJean Delvare <khali@linux-fr.org>2009-11-07 07:10:46 -0500
commitafa08974fe80c198b8650f73ed8ab59135ca10d0 (patch)
treeb649e06dc4cb9fa10b87f1914f05c6ca2ba0d910 /include
parent3806e94b0148350c72f9a3214274026b6ca03f49 (diff)
i2c: Add an interface to lock/unlock an I2C bus segment
Some drivers need to be able to prevent access to an I2C bus segment for a specific period of time. Add an interface for them to do so without twiddling with i2c-core internals. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/i2c.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 57d41b0abce2..7b40cda57a70 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -361,6 +361,24 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
361 dev_set_drvdata(&dev->dev, data); 361 dev_set_drvdata(&dev->dev, data);
362} 362}
363 363
364/**
365 * i2c_lock_adapter - Prevent access to an I2C bus segment
366 * @adapter: Target I2C bus segment
367 */
368static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
369{
370 mutex_lock(&adapter->bus_lock);
371}
372
373/**
374 * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
375 * @adapter: Target I2C bus segment
376 */
377static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
378{
379 mutex_unlock(&adapter->bus_lock);
380}
381
364/*flags for the client struct: */ 382/*flags for the client struct: */
365#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 383#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
366#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 384#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */