patch to create sysfs char device nodes

[Paolo Galtieri <pgaltieri@mvista.com>]

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Hi,
  with DEVFS going away I discovered that no character device nodes are
created if a flash device is present which contains filesystems. The
mtd-utils package requires the existence of character device nodes for
performing erase, lock and unlock functions.  The problem is that the
flash device driver has not been modified to use sysfs instead of devfs.

I have attached a patch to mtdchar.c which uses the sysfs interface to
create the appropriate nodes.  Please let me know if you have comments.

The changes are for linux-2.6.12-rc5

Thanks
Paolo

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--- drivers/mtd/OLDmtdchar.c	2005-06-06 16:10:39.000000000 -0700
+++ drivers/mtd/mtdchar.c	2005-06-06 16:18:39.000000000 -0700
@@ -15,27 +15,29 @@
 #include <linux/fs.h>
 #include <asm/uaccess.h>
 
-#ifdef CONFIG_DEVFS_FS
-#include <linux/devfs_fs_kernel.h>
+#include <linux/device.h>
+
+static struct class_simple *mtd_class;
 
 static void mtd_notify_add(struct mtd_info* mtd)
 {
 	if (!mtd)
 		return;
 
-	devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
-		      S_IFCHR | S_IRUGO | S_IWUGO, "mtd/%d", mtd->index);
-		
-	devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
-		      S_IFCHR | S_IRUGO, "mtd/%dro", mtd->index);
+	class_simple_device_add(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
+		NULL, "mtd%d", mtd->index);
+
+	class_simple_device_add(mtd_class, 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;
-	devfs_remove("mtd/%d", mtd->index);
-	devfs_remove("mtd/%dro", mtd->index);
+	class_simple_device_remove(MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
+	class_simple_device_remove(MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
 }
 
 static struct mtd_notifier notifier = {
@@ -45,19 +47,13 @@
 
 static inline void mtdchar_devfs_init(void)
 {
-	devfs_mk_dir("mtd");
 	register_mtd_user(&notifier);
 }
 
 static inline void mtdchar_devfs_exit(void)
 {
 	unregister_mtd_user(&notifier);
-	devfs_remove("mtd");
 }
-#else /* !DEVFS */
-#define mtdchar_devfs_init() do { } while(0)
-#define mtdchar_devfs_exit() do { } while(0)
-#endif
 
 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
 {
@@ -543,6 +539,14 @@
 		return -EAGAIN;
 	}
 
+	mtd_class = class_simple_create(THIS_MODULE, "mtd");
+
+	if (IS_ERR(mtd_class)) {
+		printk(KERN_ERR "Error creating mtd class.\n");
+		unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
+		return 1;
+	}
+
 	mtdchar_devfs_init();
 	return 0;
 }
@@ -550,6 +554,7 @@
 static void __exit cleanup_mtdchar(void)
 {
 	mtdchar_devfs_exit();
+	class_simple_destroy(mtd_class);
 	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 }