i2c: Kill the redundant client list

We used to maintain our own per-adapter list of i2c clients, but this
is redundant with what the driver core does, and no longer needed.
Just drop the redundant list.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>

drivers/i2c/i2c-core.c

@@ -276,10 +276,6 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 	if (status)
 		goto out_err;
 
-	mutex_lock(&adap->clist_lock);
-	list_add_tail(&client->list, &adap->clients);
-	mutex_unlock(&adap->clist_lock);
-
 	dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
 		client->name, dev_name(&client->dev));
 
@@ -301,12 +297,6 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
  */
 void i2c_unregister_device(struct i2c_client *client)
 {
-	struct i2c_adapter	*adapter = client->adapter;
-
-	mutex_lock(&adapter->clist_lock);
-	list_del(&client->list);
-	mutex_unlock(&adapter->clist_lock);
-
 	device_unregister(&client->dev);
 }
 EXPORT_SYMBOL_GPL(i2c_unregister_device);
@@ -432,8 +422,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 		return -EAGAIN;
 
 	mutex_init(&adap->bus_lock);
-	mutex_init(&adap->clist_lock);
-	INIT_LIST_HEAD(&adap->clients);
 
 	mutex_lock(&core_lock);
 
@@ -583,6 +571,14 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
 	return res;
 }
 
+static int __unregister_client(struct device *dev, void *dummy)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	if (client)
+		i2c_unregister_device(client);
+	return 0;
+}
+
 /**
  * i2c_del_adapter - unregister I2C adapter
  * @adap: the adapter being unregistered
@@ -593,7 +589,6 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
  */
 int i2c_del_adapter(struct i2c_adapter *adap)
 {
-	struct i2c_client *client, *_n;
 	int res = 0;
 
 	mutex_lock(&core_lock);
@@ -612,10 +607,9 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 	if (res)
 		goto out_unlock;
 
-	/* Detach any active clients */
-	list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
-		i2c_unregister_device(client);
-	}
+	/* Detach any active clients. This can't fail, thus we do not
+	   checking the returned value. */
+	res = device_for_each_child(&adap->dev, NULL, __unregister_client);
 
 	/* clean up the sysfs representation */
 	init_completion(&adap->dev_released);

include/linux/i2c.h

@@ -178,7 +178,6 @@ struct i2c_driver {
  * @driver: device's driver, hence pointer to access routines
  * @dev: Driver model device node for the slave.
  * @irq: indicates the IRQ generated by this device (if any)
- * @list: list of active/busy clients (DEPRECATED)
  * @detected: member of an i2c_driver.clients list
  *
  * An i2c_client identifies a single device (i.e. chip) connected to an
@@ -195,7 +194,6 @@ struct i2c_client {
 	struct i2c_driver *driver;	/* and our access routines	*/
 	struct device dev;		/* the device structure		*/
 	int irq;			/* irq issued by device		*/
-	struct list_head list;		/* DEPRECATED */
 	struct list_head detected;
 };
 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
@@ -339,14 +337,12 @@ struct i2c_adapter {
 	/* data fields that are valid for all devices	*/
 	u8 level; 			/* nesting level for lockdep */
 	struct mutex bus_lock;
-	struct mutex clist_lock;
 
 	int timeout;			/* in jiffies */
 	int retries;
 	struct device dev;		/* the adapter device */
 
 	int nr;
-	struct list_head clients;	/* DEPRECATED */
 	char name[48];
 	struct completion dev_released;
 };