i2c: __must_check fixes (chip drivers)

i2c: __must_check fixes (chip drivers)

Check for error on sysfs file creation.
Delete sysfs files on device removal.

The approach taken for the most complex case (pcf8591) is similar to
what Mark M. Hoffman proposed for hardware monitoring chip drivers.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <bgardner@wabtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 17 insertions, 5 deletions

diff --git a/drivers/i2c/chips/pcf8574.c b/drivers/i2c/chips/pcf8574.c
index c3e6449c4481..32b25427eaba 100644
--- a/drivers/i2c/chips/pcf8574.c
+++ b/drivers/i2c/chips/pcf8574.c
@@ -105,6 +105,16 @@ static ssize_t set_write(struct device *dev, struct device_attribute *attr, cons
 
 static DEVICE_ATTR(write, S_IWUSR | S_IRUGO, show_write, set_write);
 
+static struct attribute *pcf8574_attributes[] = {
+        &dev_attr_read.attr,
+        &dev_attr_write.attr,
+        NULL
+};
+
+static const struct attribute_group pcf8574_attr_group = {
+        .attrs = pcf8574_attributes,
+};
+
 /*
  * Real code
  */
@@ -166,13 +176,13 @@ static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
         pcf8574_init_client(new_client);
 
         /* Register sysfs hooks */
-        device_create_file(&new_client->dev, &dev_attr_read);
-        device_create_file(&new_client->dev, &dev_attr_write);
+        err = sysfs_create_group(&new_client->dev.kobj, &pcf8574_attr_group);
+        if (err)
+                goto exit_detach;
         return 0;
 
-/* OK, this is not exactly good programming practice, usually. But it is
-   very code-efficient in this case. */
-
+      exit_detach:
+        i2c_detach_client(new_client);
       exit_free:
         kfree(data);
       exit:
@@ -183,6 +193,8 @@ static int pcf8574_detach_client(struct i2c_client *client)
 {
         int err;
 
+        sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group);
+
         if ((err = i2c_detach_client(client)))
                 return err;