[MTD] driver model updates

Update driver model support in the MTD framework, so it fits
better into the current udev-based hotplug framework:

 - Each mtd_info now has a device node.  MTD drivers should set
   the dev.parent field to point to the physical device, before
   setting up partitions or otherwise declaring MTDs.

 - Those device nodes always map to /sys/class/mtdX device nodes,
   which no longer depend on MTD_CHARDEV.

 - Those mtdX sysfs nodes have a "starter set" of attributes;
   it's not yet sufficient to replace /proc/mtd.

 - Enabling MTD_CHARDEV provides /sys/class/mtdXro/ nodes and the
   /sys/class/mtd*/dev attributes (for udev, mdev, etc).

 - Include a MODULE_ALIAS_CHARDEV_MAJOR macro.  It'll work with
   udev creating the /dev/mtd* nodes, not just a static rootfs.

So the sysfs structure is pretty much what you'd expect, except
that readonly chardev nodes are a bit quirky.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 41 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index f478f1fc3949..763d3f0a1f42 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -20,33 +20,6 @@
 
 #include <asm/uaccess.h>
 
-static struct class *mtd_class;
-
-static void mtd_notify_add(struct mtd_info* mtd)
-{
-        if (!mtd)
-                return;
-
-        device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
-                      NULL, "mtd%d", mtd->index);
-
-        device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
-                      NULL, "mtd%dro", mtd->index);
-}
-
-static void mtd_notify_remove(struct mtd_info* mtd)
-{
-        if (!mtd)
-                return;
-
-        device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
-        device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
-}
-
-static struct mtd_notifier notifier = {
-        .add    = mtd_notify_add,
-        .remove = mtd_notify_remove,
-};
 
 /*
  * Data structure to hold the pointer to the mtd device as well
@@ -854,34 +827,26 @@ static const struct file_operations mtd_fops = {
 
 static int __init init_mtdchar(void)
 {
-        if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
+        int status;
+
+        status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
+        if (status < 0) {
                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
                        MTD_CHAR_MAJOR);
-                return -EAGAIN;
-        }
-
-        mtd_class = class_create(THIS_MODULE, "mtd");
-
-        if (IS_ERR(mtd_class)) {
-                printk(KERN_ERR "Error creating mtd class.\n");
-                unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
-                return PTR_ERR(mtd_class);
         }
 
-        register_mtd_user(&notifier);
-        return 0;
+        return status;
 }
 
 static void __exit cleanup_mtdchar(void)
 {
-        unregister_mtd_user(&notifier);
-        class_destroy(mtd_class);
         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 }
 
 module_init(init_mtdchar);
 module_exit(cleanup_mtdchar);
 
+MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");