Driver core: add name to device_type

If "name" of a device_type is specified, the uevent will
contain the device_type name in the DEVTYPE variable.
This helps userspace to distingiush between different types
of devices, belonging to the same subsystem.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/base/core.c

@@ -157,6 +157,11 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 			       "MINOR=%u", MINOR(dev->devt));
 	}
 
+	if (dev->type && dev->type->name)
+		add_uevent_var(envp, num_envp, &i,
+			       buffer, buffer_size, &length,
+			       "DEVTYPE=%s", dev->type->name);
+
 	if (dev->driver)
 		add_uevent_var(envp, num_envp, &i,
 			       buffer, buffer_size, &length,

include/linux/device.h

@@ -331,7 +331,17 @@ extern struct class_device *class_device_create(struct class *cls,
 					__attribute__((format(printf,5,6)));
 extern void class_device_destroy(struct class *cls, dev_t devt);
 
+/*
+ * The type of device, "struct device" is embedded in. A class
+ * or bus can contain devices of different types
+ * like "partitions" and "disks", "mouse" and "event".
+ * This identifies the device type and carries type-specific
+ * information, equivalent to the kobj_type of a kobject.
+ * If "name" is specified, the uevent will contain it in
+ * the DEVTYPE variable.
+ */
 struct device_type {
+	const char *name;
 	struct attribute_group **groups;
 	int (*uevent)(struct device *dev, char **envp, int num_envp,
 		      char *buffer, int buffer_size);