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>

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6e1c2f5..e09e143 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -429,6 +429,35 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
                                     __i2c_check_addr_busy);
 }
 
+/**
+ * i2c_lock_adapter - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_lock_adapter(struct i2c_adapter *adapter)
+{
+       rt_mutex_lock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_lock_adapter);
+
+/**
+ * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+static int i2c_trylock_adapter(struct i2c_adapter *adapter)
+{
+       return rt_mutex_trylock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_unlock_adapter - Release exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_unlock_adapter(struct i2c_adapter *adapter)
+{
+       rt_mutex_unlock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
+
 /**
  * i2c_new_device - instantiate an i2c device
  * @adap: the adapter managing the device
@@ -1238,12 +1267,12 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 #endif
 
                if (in_atomic() || irqs_disabled()) {
-                       ret = rt_mutex_trylock(&adap->bus_lock);
+                       ret = i2c_trylock_adapter(adap);
                        if (!ret)
                                /* I2C activity is ongoing. */
                                return -EAGAIN;
                } else {
-                       rt_mutex_lock(&adap->bus_lock);
+                       i2c_lock_adapter(adap);
                }
 
                /* Retry automatically on arbitration loss */
@@ -1255,7 +1284,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
                        if (time_after(jiffies, orig_jiffies + adap->timeout))
                                break;
                }
-               rt_mutex_unlock(&adap->bus_lock);
+               i2c_unlock_adapter(adap);
 
                return ret;
        } else {
@@ -2013,7 +2042,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
        flags &= I2C_M_TEN | I2C_CLIENT_PEC;
 
        if (adapter->algo->smbus_xfer) {
-               rt_mutex_lock(&adapter->bus_lock);
+               i2c_lock_adapter(adapter);
 
                /* Retry automatically on arbitration loss */
                orig_jiffies = jiffies;
@@ -2027,7 +2056,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
                                       orig_jiffies + adapter->timeout))
                                break;
                }
-               rt_mutex_unlock(&adapter->bus_lock);
+               i2c_unlock_adapter(adapter);
        } else
                res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
                                              command, protocol, data);

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index c8627e4..5bf0f4b 100644 (file)
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -382,23 +382,9 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
        dev_set_drvdata(&dev->dev, data);
 }
 
-/**
- * i2c_lock_adapter - Prevent access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
-{
-       rt_mutex_lock(&adapter->bus_lock);
-}
-
-/**
- * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
-{
-       rt_mutex_unlock(&adapter->bus_lock);
-}
+/* Adapter locking functions, exported for shared pin cases */
+void i2c_lock_adapter(struct i2c_adapter *);
+void i2c_unlock_adapter(struct i2c_adapter *);
 
 /*flags for the client struct: */
 #define I2C_CLIENT_PEC 0x04            /* Use Packet Error Checking */