[MTD] Restore suspend/resume support for mtd devices

This is intended to suspend/resume the _chip_, while we leave board
drivers to handle their own suspend/resume for the controller.

Signed-off-by: David Woodhouse <[e-mail]>

drivers/mtd/mtdcore.c

···
 
 #include "mtdcore.h"
 
+static int mtd_cls_suspend(struct device *dev, pm_message_t state);
+static int mtd_cls_resume(struct device *dev);
 
-static struct class *mtd_class;
+static struct class mtd_class = {
+	.name = "mtd",
+	.owner = THIS_MODULE,
+	.suspend = mtd_cls_suspend,
+	.resume = mtd_cls_resume,
+};
 
 /* These are exported solely for the purpose of mtd_blkdevs.c. You
    should not use them for _anything_ else */
···
 
 	/* remove /dev/mtdXro node if needed */
 	if (index)
-		device_destroy(mtd_class, index + 1);
+		device_destroy(&mtd_class, index + 1);
+}
+
+static int mtd_cls_suspend(struct device *dev, pm_message_t state)
+{
+	struct mtd_info *mtd = dev_to_mtd(dev);
+	
+	if (mtd->suspend)
+		return mtd->suspend(mtd);
+	else
+		return 0;
+}
+
+static int mtd_cls_resume(struct device *dev)
+{
+	struct mtd_info *mtd = dev_to_mtd(dev);
+	
+	if (mtd->resume)
+		mtd->resume(mtd);
+	return 0;
 }
 
 static ssize_t mtd_type_show(struct device *dev,
···
 			 * physical device.
 			 */
 			mtd->dev.type = &mtd_devtype;
-			mtd->dev.class = mtd_class;
+			mtd->dev.class = &mtd_class;
 			mtd->dev.devt = MTD_DEVT(i);
 			dev_set_name(&mtd->dev, "mtd%d", i);
 			if (device_register(&mtd->dev) != 0) {
···
 			}
 
 			if (MTD_DEVT(i))
-				device_create(mtd_class, mtd->dev.parent,
+				device_create(&mtd_class, mtd->dev.parent,
 						MTD_DEVT(i) + 1,
 						NULL, "mtd%dro", i);
 
···
 
 static int __init init_mtd(void)
 {
-	mtd_class = class_create(THIS_MODULE, "mtd");
+	int ret;
+	ret = class_register(&mtd_class);
 
-	if (IS_ERR(mtd_class)) {
-		pr_err("Error creating mtd class.\n");
-		return PTR_ERR(mtd_class);
+	if (ret) {
+		pr_err("Error registering mtd class: %d\n", ret);
+		return ret;
 	}
 #ifdef CONFIG_PROC_FS
 	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
···
         if (proc_mtd)
 		remove_proc_entry( "mtd", NULL);
 #endif /* CONFIG_PROC_FS */
-	class_destroy(mtd_class);
+	class_unregister(&mtd_class);
 }
 
 module_init(init_mtd);