[PATCH] I2C: move i2c-dev to use dynamic class devices

i2c-dev doesn't use the reference counting logic of struct class_device so move
it to the dynamic method.  This makes the code paths simpler and the driver
smaller.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jean Delvare <khali@linux-fr.org>

1 files changed, 20 insertions, 30 deletions

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e140dd7d6a0c..ad6e04fc2c03 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -42,8 +42,7 @@ static struct i2c_client i2cdev_client_template;
 struct i2c_dev {
         int minor;
         struct i2c_adapter *adap;
-        struct class_device class_dev;
-        struct completion released;     /* FIXME, we need a class_device_unregister() */
+        struct class_device *class_dev;
 };
 #define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
 
@@ -105,7 +104,10 @@ static void return_i2c_dev(struct i2c_dev *i2c_dev)
 
 static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
 {
-        struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);
+        struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt));
+
+        if (!i2c_dev)
+                return -ENODEV;
         return sprintf(buf, "%s\n", i2c_dev->adap->name);
 }
 static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
@@ -408,21 +410,12 @@ static struct file_operations i2cdev_fops = {
         .release        = i2cdev_release,
 };
 
-static void release_i2c_dev(struct class_device *dev)
-{
-        struct i2c_dev *i2c_dev = to_i2c_dev(dev);
-        complete(&i2c_dev->released);
-}
-
-static struct class i2c_dev_class = {
-        .name           = "i2c-dev",
-        .release        = &release_i2c_dev,
-};
+static struct class *i2c_dev_class;
 
 static int i2cdev_attach_adapter(struct i2c_adapter *adap)
 {
         struct i2c_dev *i2c_dev;
-        int retval;
+        struct device *dev;
 
         i2c_dev = get_free_i2c_dev(adap);
         if (IS_ERR(i2c_dev))
@@ -434,21 +427,20 @@ static int i2cdev_attach_adapter(struct i2c_adapter *adap)
         /* register this i2c device with the driver core */
         i2c_dev->adap = adap;
         if (adap->dev.parent == &platform_bus)
-                i2c_dev->class_dev.dev = &adap->dev;
+                dev = &adap->dev;
         else
-                i2c_dev->class_dev.dev = adap->dev.parent;
-        i2c_dev->class_dev.class = &i2c_dev_class;
-        i2c_dev->class_dev.devt = MKDEV(I2C_MAJOR, i2c_dev->minor);
-        snprintf(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor);
-        retval = class_device_register(&i2c_dev->class_dev);
-        if (retval)
+                dev = adap->dev.parent;
+        i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL,
+                                                 MKDEV(I2C_MAJOR, i2c_dev->minor),
+                                                 dev, "i2c-%d", i2c_dev->minor);
+        if (!i2c_dev->class_dev)
                 goto error;
-        class_device_create_file(&i2c_dev->class_dev, &class_device_attr_name);
+        class_device_create_file(i2c_dev->class_dev, &class_device_attr_name);
         return 0;
 error:
         return_i2c_dev(i2c_dev);
         kfree(i2c_dev);
-        return retval;
+        return -ENODEV;
 }
 
 static int i2cdev_detach_adapter(struct i2c_adapter *adap)
@@ -459,10 +451,8 @@ static int i2cdev_detach_adapter(struct i2c_adapter *adap)
         if (!i2c_dev)
                 return -ENODEV;
 
-        init_completion(&i2c_dev->released);
         return_i2c_dev(i2c_dev);
-        class_device_unregister(&i2c_dev->class_dev);
-        wait_for_completion(&i2c_dev->released);
+        class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, i2c_dev->minor));
         kfree(i2c_dev);
 
         pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
@@ -507,8 +497,8 @@ static int __init i2c_dev_init(void)
         if (res)
                 goto out;
 
-        res = class_register(&i2c_dev_class);
-        if (res)
+        i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
+        if (IS_ERR(i2c_dev_class))
                 goto out_unreg_chrdev;
 
         res = i2c_add_driver(&i2cdev_driver);
@@ -518,7 +508,7 @@ static int __init i2c_dev_init(void)
         return 0;
 
 out_unreg_class:
-        class_unregister(&i2c_dev_class);
+        class_destroy(i2c_dev_class);
 out_unreg_chrdev:
         unregister_chrdev(I2C_MAJOR, "i2c");
 out:
@@ -529,7 +519,7 @@ out:
 static void __exit i2c_dev_exit(void)
 {
         i2c_del_driver(&i2cdev_driver);
-        class_unregister(&i2c_dev_class);
+        class_destroy(i2c_dev_class);
         unregister_chrdev(I2C_MAJOR,"i2c");
 }