diff options
author | Jean Delvare <khali@linux-fr.org> | 2009-11-07 07:10:46 -0500 |
---|---|---|
committer | Jean Delvare <khali@linux-fr.org> | 2009-11-07 07:10:46 -0500 |
commit | afa08974fe80c198b8650f73ed8ab59135ca10d0 (patch) | |
tree | b649e06dc4cb9fa10b87f1914f05c6ca2ba0d910 | |
parent | 3806e94b0148350c72f9a3214274026b6ca03f49 (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>
-rw-r--r-- | drivers/net/sfc/sfe4001.c | 4 | ||||
-rw-r--r-- | include/linux/i2c.h | 18 |
2 files changed, 20 insertions, 2 deletions
diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c index cee00ad49b57..49eb91b5f50c 100644 --- a/drivers/net/sfc/sfe4001.c +++ b/drivers/net/sfc/sfe4001.c | |||
@@ -188,7 +188,7 @@ static int sfn4111t_reset(struct efx_nic *efx) | |||
188 | efx_oword_t reg; | 188 | efx_oword_t reg; |
189 | 189 | ||
190 | /* GPIO 3 and the GPIO register are shared with I2C, so block that */ | 190 | /* GPIO 3 and the GPIO register are shared with I2C, so block that */ |
191 | mutex_lock(&efx->i2c_adap.bus_lock); | 191 | i2c_lock_adapter(&efx->i2c_adap); |
192 | 192 | ||
193 | /* Pull RST_N (GPIO 2) low then let it up again, setting the | 193 | /* Pull RST_N (GPIO 2) low then let it up again, setting the |
194 | * FLASH_CFG_1 strap (GPIO 3) appropriately. Only change the | 194 | * FLASH_CFG_1 strap (GPIO 3) appropriately. Only change the |
@@ -204,7 +204,7 @@ static int sfn4111t_reset(struct efx_nic *efx) | |||
204 | falcon_write(efx, ®, GPIO_CTL_REG_KER); | 204 | falcon_write(efx, ®, GPIO_CTL_REG_KER); |
205 | msleep(1); | 205 | msleep(1); |
206 | 206 | ||
207 | mutex_unlock(&efx->i2c_adap.bus_lock); | 207 | i2c_unlock_adapter(&efx->i2c_adap); |
208 | 208 | ||
209 | ssleep(1); | 209 | ssleep(1); |
210 | return 0; | 210 | return 0; |
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 | */ | ||
368 | static 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 | */ | ||
377 | static 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 */ |