i2c: Convert i2c adapters to bus devices

Kay says i2c adapters shouldn't be class devices but bus devices.
Convert them that way, using a device type.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>

1 files changed, 40 insertions, 35 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f236b34296ee..a18a251dabf9 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -46,6 +46,7 @@ static DEFINE_MUTEX(core_lock);
 static DEFINE_IDR(i2c_adapter_idr);
 static LIST_HEAD(userspace_devices);
 
+static struct device_type i2c_client_type;
 static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
 
@@ -186,10 +187,10 @@ static void i2c_client_dev_release(struct device *dev)
 }
 
 static ssize_t
-show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
+show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
-        struct i2c_client *client = to_i2c_client(dev);
-        return sprintf(buf, "%s\n", client->name);
+        return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
+                       to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
 }
 
 static ssize_t
@@ -199,7 +200,7 @@ show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
         return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 }
 
-static DEVICE_ATTR(name, S_IRUGO, show_client_name, NULL);
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
 
 static struct attribute *i2c_dev_attrs[] = {
@@ -395,13 +396,6 @@ static void i2c_adapter_dev_release(struct device *dev)
         complete(&adap->dev_released);
 }
 
-static ssize_t
-show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
-{
-        struct i2c_adapter *adap = to_i2c_adapter(dev);
-        return sprintf(buf, "%s\n", adap->name);
-}
-
 /*
  * Let users instantiate I2C devices through sysfs. This can be used when
  * platform initialization code doesn't contain the proper data for
@@ -520,17 +514,28 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
         return res;
 }
 
-static struct device_attribute i2c_adapter_attrs[] = {
-        __ATTR(name, S_IRUGO, show_adapter_name, NULL),
-        __ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device),
-        __ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device),
-        { },
+static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
+static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device);
+
+static struct attribute *i2c_adapter_attrs[] = {
+        &dev_attr_name.attr,
+        &dev_attr_new_device.attr,
+        &dev_attr_delete_device.attr,
+        NULL
+};
+
+static struct attribute_group i2c_adapter_attr_group = {
+        .attrs          = i2c_adapter_attrs,
 };
 
-static struct class i2c_adapter_class = {
-        .owner                  = THIS_MODULE,
-        .name                   = "i2c-adapter",
-        .dev_attrs              = i2c_adapter_attrs,
+static const struct attribute_group *i2c_adapter_attr_groups[] = {
+        &i2c_adapter_attr_group,
+        NULL
+};
+
+static struct device_type i2c_adapter_type = {
+        .groups         = i2c_adapter_attr_groups,
+        .release        = i2c_adapter_dev_release,
 };
 
 static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
@@ -582,8 +587,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
                 adap->timeout = HZ;
 
         dev_set_name(&adap->dev, "i2c-%d", adap->nr);
-        adap->dev.release = &i2c_adapter_dev_release;
-        adap->dev.class = &i2c_adapter_class;
+        adap->dev.bus = &i2c_bus_type;
+        adap->dev.type = &i2c_adapter_type;
         res = device_register(&adap->dev);
         if (res)
                 goto out_list;
@@ -795,9 +800,13 @@ EXPORT_SYMBOL(i2c_del_adapter);
 
 static int __attach_adapter(struct device *dev, void *data)
 {
-        struct i2c_adapter *adapter = to_i2c_adapter(dev);
+        struct i2c_adapter *adapter;
         struct i2c_driver *driver = data;
 
+        if (dev->type != &i2c_adapter_type)
+                return 0;
+        adapter = to_i2c_adapter(dev);
+
         i2c_detect(adapter, driver);
 
         /* Legacy drivers scan i2c busses directly */
@@ -836,8 +845,7 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
         INIT_LIST_HEAD(&driver->clients);
         /* Walk the adapters that are already present */
         mutex_lock(&core_lock);
-        class_for_each_device(&i2c_adapter_class, NULL, driver,
-                              __attach_adapter);
+        bus_for_each_dev(&i2c_bus_type, NULL, driver, __attach_adapter);
         mutex_unlock(&core_lock);
 
         return 0;
@@ -846,10 +854,14 @@ EXPORT_SYMBOL(i2c_register_driver);
 
 static int __detach_adapter(struct device *dev, void *data)
 {
-        struct i2c_adapter *adapter = to_i2c_adapter(dev);
+        struct i2c_adapter *adapter;
         struct i2c_driver *driver = data;
         struct i2c_client *client, *_n;
 
+        if (dev->type != &i2c_adapter_type)
+                return 0;
+        adapter = to_i2c_adapter(dev);
+
         /* Remove the devices we created ourselves as the result of hardware
          * probing (using a driver's detect method) */
         list_for_each_entry_safe(client, _n, &driver->clients, detected) {
@@ -877,8 +889,7 @@ static int __detach_adapter(struct device *dev, void *data)
 void i2c_del_driver(struct i2c_driver *driver)
 {
         mutex_lock(&core_lock);
-        class_for_each_device(&i2c_adapter_class, NULL, driver,
-                              __detach_adapter);
+        bus_for_each_dev(&i2c_bus_type, NULL, driver, __detach_adapter);
         mutex_unlock(&core_lock);
 
         driver_unregister(&driver->driver);
@@ -967,16 +978,11 @@ static int __init i2c_init(void)
         retval = bus_register(&i2c_bus_type);
         if (retval)
                 return retval;
-        retval = class_register(&i2c_adapter_class);
-        if (retval)
-                goto bus_err;
         retval = i2c_add_driver(&dummy_driver);
         if (retval)
-                goto class_err;
+                goto bus_err;
         return 0;
 
-class_err:
-        class_unregister(&i2c_adapter_class);
 bus_err:
         bus_unregister(&i2c_bus_type);
         return retval;
@@ -985,7 +991,6 @@ bus_err:
 static void __exit i2c_exit(void)
 {
         i2c_del_driver(&dummy_driver);
-        class_unregister(&i2c_adapter_class);
         bus_unregister(&i2c_bus_type);
 }