i2c: Add an interface to lock/unlock an I2C bus segment

[platform/kernel/linux-rpi.git] / include / linux / i2c.h

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 57d41b0..7b40cda 100644 (file)
--- 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)
        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)
+{
+       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)
+{
+       mutex_unlock(&adapter->bus_lock);
+}
+
 /*flags for the client struct: */
 #define I2C_CLIENT_PEC 0x04            /* Use Packet Error Checking */
 #define I2C_CLIENT_TEN 0x10            /* we have a ten bit chip address */