[PATCH] Driver core: link device and all class devices derived from it.
Driver core: link device and all class devices derived from it.
To ease the task of locating class devices derived from a certain
device create symlinks from parent device to its class devices.
Change USB host class device name from usbX to usb_hostX to avoid
conflict when creating aforementioned links.
Tweaked by Greg to have the symlink be "class_name:class_device_name" in
order to prevent duplicate links.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 0154a16..d207296 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -452,10 +452,29 @@
INIT_LIST_HEAD(&class_dev->node);
}
+static char *make_class_name(struct class_device *class_dev)
+{
+ char *name;
+ int size;
+
+ size = strlen(class_dev->class->name) +
+ strlen(kobject_name(&class_dev->kobj)) + 2;
+
+ name = kmalloc(size, GFP_KERNEL);
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+
+ strcpy(name, class_dev->class->name);
+ strcat(name, ":");
+ strcat(name, kobject_name(&class_dev->kobj));
+ return name;
+}
+
int class_device_add(struct class_device *class_dev)
{
struct class * parent = NULL;
struct class_interface * class_intf;
+ char *class_name = NULL;
int error;
class_dev = class_device_get(class_dev);
@@ -500,9 +519,13 @@
}
class_device_add_attrs(class_dev);
- if (class_dev->dev)
+ if (class_dev->dev) {
+ class_name = make_class_name(class_dev);
sysfs_create_link(&class_dev->kobj,
&class_dev->dev->kobj, "device");
+ sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
+ class_name);
+ }
/* notify any interfaces this device is now here */
if (parent) {
@@ -519,6 +542,7 @@
if (error && parent)
class_put(parent);
class_device_put(class_dev);
+ kfree(class_name);
return error;
}
@@ -584,6 +608,7 @@
{
struct class * parent = class_dev->class;
struct class_interface * class_intf;
+ char *class_name = NULL;
if (parent) {
down(&parent->sem);
@@ -594,8 +619,11 @@
up(&parent->sem);
}
- if (class_dev->dev)
+ if (class_dev->dev) {
+ class_name = make_class_name(class_dev);
sysfs_remove_link(&class_dev->kobj, "device");
+ sysfs_remove_link(&class_dev->dev->kobj, class_name);
+ }
if (class_dev->devt_attr)
class_device_remove_file(class_dev, class_dev->devt_attr);
class_device_remove_attrs(class_dev);
@@ -605,6 +633,7 @@
if (parent)
class_put(parent);
+ kfree(class_name);
}
void class_device_unregister(struct class_device *class_dev)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 79422a3..9f44e83 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -782,7 +782,7 @@
return -E2BIG;
}
- bus->class_dev = class_device_create(usb_host_class, MKDEV(0,0), bus->controller, "usb%d", busnum);
+ bus->class_dev = class_device_create(usb_host_class, MKDEV(0,0), bus->controller, "usb_host%d", busnum);
if (IS_ERR(bus->class_dev)) {
clear_bit(busnum, busmap.busmap);
up(&usb_bus_list_lock);