i2c: Constify i2c_get_clientdata's parameter

i2c_get_clientdata doesn't change the i2c_client it is passed as a
parameter, so it can be constified. Same for i2c_get_adapdata.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index d73ee11..3b01350 100644
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -83,7 +83,7 @@
 	void i2c_set_clientdata(struct i2c_client *client, void *data);
 
 	/* retrieve the value */
-	void *i2c_get_clientdata(struct i2c_client *client);
+	void *i2c_get_clientdata(const struct i2c_client *client);
 
 An example structure is below.
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 987f591..1a3686d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -450,7 +450,7 @@
 }
 #endif
 
-static inline void *dev_get_drvdata(struct device *dev)
+static inline void *dev_get_drvdata(const struct device *dev)
 {
 	return dev->driver_data;
 }
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 4ac8ec3..a411f0b 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -224,7 +224,7 @@
 	return to_i2c_client(dev);
 }
 
-static inline void *i2c_get_clientdata (struct i2c_client *dev)
+static inline void *i2c_get_clientdata(const struct i2c_client *dev)
 {
 	return dev_get_drvdata (&dev->dev);
 }
@@ -369,7 +369,7 @@
 };
 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
 
-static inline void *i2c_get_adapdata (struct i2c_adapter *dev)
+static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
 {
 	return dev_get_drvdata (&dev->dev);
 }