i2c: Use the driver model reference counting

Don't implement our own reference counting mechanism for i2c clients
when the driver model already has one.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>

1 files changed, 2 insertions, 44 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 7788e1730063..9b9d808578b9 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -696,8 +696,6 @@ int i2c_attach_client(struct i2c_client *client)
         }
         list_add_tail(&client->list,&adapter->clients);
 
-        client->usage_count = 0;
-
         client->dev.parent = &client->adapter->dev;
         client->dev.bus = &i2c_bus_type;
 
@@ -744,12 +742,6 @@ int i2c_detach_client(struct i2c_client *client)
         struct i2c_adapter *adapter = client->adapter;
         int res = 0;
 
-        if (client->usage_count > 0) {
-                dev_warn(&client->dev, "Client [%s] still busy, "
-                         "can't detach\n", client->name);
-                return -EBUSY;
-        }
-
         if (adapter->client_unregister)  {
                 res = adapter->client_unregister(client);
                 if (res) {
@@ -772,50 +764,16 @@ int i2c_detach_client(struct i2c_client *client)
 }
 EXPORT_SYMBOL(i2c_detach_client);
 
-static int i2c_inc_use_client(struct i2c_client *client)
-{
-
-        if (!try_module_get(client->driver->driver.owner))
-                return -ENODEV;
-        if (!try_module_get(client->adapter->owner)) {
-                module_put(client->driver->driver.owner);
-                return -ENODEV;
-        }
-
-        return 0;
-}
-
-static void i2c_dec_use_client(struct i2c_client *client)
-{
-        module_put(client->driver->driver.owner);
-        module_put(client->adapter->owner);
-}
-
 int i2c_use_client(struct i2c_client *client)
 {
-        int ret;
-
-        ret = i2c_inc_use_client(client);
-        if (ret)
-                return ret;
-
-        client->usage_count++;
-
+        get_device(&client->dev);
         return 0;
 }
 EXPORT_SYMBOL(i2c_use_client);
 
 int i2c_release_client(struct i2c_client *client)
 {
-        if (!client->usage_count) {
-                pr_debug("i2c-core: %s used one too many times\n",
-                         __FUNCTION__);
-                return -EPERM;
-        }
-
-        client->usage_count--;
-        i2c_dec_use_client(client);
-
+        put_device(&client->dev);
         return 0;
 }
 EXPORT_SYMBOL(i2c_release_client);