Commit fe61e07e9ebc890c70d97a1f72ddaad4bee2d848
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d44f19d586
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i2c: Move adapter locking helpers to i2c-core
Uninline i2c adapter locking helper functions, move them to i2c-core, and use them in i2c-core itself. The functions are still exported for external users. This makes future updates to the locking model (which will be needed for multiplexing support) possible and transparent. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Michael Lawnick <ml.lawnick@gmx.de>
Showing 2 changed files with 37 additions and 22 deletions Side-by-side Diff
drivers/i2c/i2c-core.c
| ... | ... | @@ -430,6 +430,35 @@ |
| 430 | 430 | } |
| 431 | 431 | |
| 432 | 432 | /** |
| 433 | + * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
| 434 | + * @adapter: Target I2C bus segment | |
| 435 | + */ | |
| 436 | +void i2c_lock_adapter(struct i2c_adapter *adapter) | |
| 437 | +{ | |
| 438 | + rt_mutex_lock(&adapter->bus_lock); | |
| 439 | +} | |
| 440 | +EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
| 441 | + | |
| 442 | +/** | |
| 443 | + * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
| 444 | + * @adapter: Target I2C bus segment | |
| 445 | + */ | |
| 446 | +static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
| 447 | +{ | |
| 448 | + return rt_mutex_trylock(&adapter->bus_lock); | |
| 449 | +} | |
| 450 | + | |
| 451 | +/** | |
| 452 | + * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
| 453 | + * @adapter: Target I2C bus segment | |
| 454 | + */ | |
| 455 | +void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
| 456 | +{ | |
| 457 | + rt_mutex_unlock(&adapter->bus_lock); | |
| 458 | +} | |
| 459 | +EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
| 460 | + | |
| 461 | +/** | |
| 433 | 462 | * i2c_new_device - instantiate an i2c device |
| 434 | 463 | * @adap: the adapter managing the device |
| 435 | 464 | * @info: describes one I2C device; bus_num is ignored |
| 436 | 465 | |
| ... | ... | @@ -1238,12 +1267,12 @@ |
| 1238 | 1267 | #endif |
| 1239 | 1268 | |
| 1240 | 1269 | if (in_atomic() || irqs_disabled()) { |
| 1241 | - ret = rt_mutex_trylock(&adap->bus_lock); | |
| 1270 | + ret = i2c_trylock_adapter(adap); | |
| 1242 | 1271 | if (!ret) |
| 1243 | 1272 | /* I2C activity is ongoing. */ |
| 1244 | 1273 | return -EAGAIN; |
| 1245 | 1274 | } else { |
| 1246 | - rt_mutex_lock(&adap->bus_lock); | |
| 1275 | + i2c_lock_adapter(adap); | |
| 1247 | 1276 | } |
| 1248 | 1277 | |
| 1249 | 1278 | /* Retry automatically on arbitration loss */ |
| ... | ... | @@ -1255,7 +1284,7 @@ |
| 1255 | 1284 | if (time_after(jiffies, orig_jiffies + adap->timeout)) |
| 1256 | 1285 | break; |
| 1257 | 1286 | } |
| 1258 | - rt_mutex_unlock(&adap->bus_lock); | |
| 1287 | + i2c_unlock_adapter(adap); | |
| 1259 | 1288 | |
| 1260 | 1289 | return ret; |
| 1261 | 1290 | } else { |
| ... | ... | @@ -2013,7 +2042,7 @@ |
| 2013 | 2042 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; |
| 2014 | 2043 | |
| 2015 | 2044 | if (adapter->algo->smbus_xfer) { |
| 2016 | - rt_mutex_lock(&adapter->bus_lock); | |
| 2045 | + i2c_lock_adapter(adapter); | |
| 2017 | 2046 | |
| 2018 | 2047 | /* Retry automatically on arbitration loss */ |
| 2019 | 2048 | orig_jiffies = jiffies; |
| ... | ... | @@ -2027,7 +2056,7 @@ |
| 2027 | 2056 | orig_jiffies + adapter->timeout)) |
| 2028 | 2057 | break; |
| 2029 | 2058 | } |
| 2030 | - rt_mutex_unlock(&adapter->bus_lock); | |
| 2059 | + i2c_unlock_adapter(adapter); | |
| 2031 | 2060 | } else |
| 2032 | 2061 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
| 2033 | 2062 | command, protocol, data); |
include/linux/i2c.h
| ... | ... | @@ -382,23 +382,9 @@ |
| 382 | 382 | dev_set_drvdata(&dev->dev, data); |
| 383 | 383 | } |
| 384 | 384 | |
| 385 | -/** | |
| 386 | - * i2c_lock_adapter - Prevent access to an I2C bus segment | |
| 387 | - * @adapter: Target I2C bus segment | |
| 388 | - */ | |
| 389 | -static inline void i2c_lock_adapter(struct i2c_adapter *adapter) | |
| 390 | -{ | |
| 391 | - rt_mutex_lock(&adapter->bus_lock); | |
| 392 | -} | |
| 393 | - | |
| 394 | -/** | |
| 395 | - * i2c_unlock_adapter - Reauthorize access to an I2C bus segment | |
| 396 | - * @adapter: Target I2C bus segment | |
| 397 | - */ | |
| 398 | -static inline void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
| 399 | -{ | |
| 400 | - rt_mutex_unlock(&adapter->bus_lock); | |
| 401 | -} | |
| 385 | +/* Adapter locking functions, exported for shared pin cases */ | |
| 386 | +void i2c_lock_adapter(struct i2c_adapter *); | |
| 387 | +void i2c_unlock_adapter(struct i2c_adapter *); | |
| 402 | 388 | |
| 403 | 389 | /*flags for the client struct: */ |
| 404 | 390 | #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ |