设置看门狗的major和minor

watchdog.c

@@ -72,6 +72,9 @@
 
 static unsigned int max_units, chip_type;
 
+static int major = 56; 
+static int minor = 30; 
+
 static unsigned int timeout = DEFAULT_TIMEOUT;
 static int testmode = DEFAULT_TESTMODE;
 
@@ -84,6 +87,9 @@ MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
 
 /* Character device variables */
 static int major_number;
+static dev_t dev_num;
+
+static struct cdev cdev;
 static struct class *watchdog_class = NULL;
 static struct device *watchdog_device = NULL;
 
@@ -594,11 +600,27 @@ int watchdog_init(void)
 		timeout = wdt_round_time(timeout);
 
 	/* Register character device */
-	major_number = register_chrdev(0, DEVICE_NAME, &watchdog_fops);
-	if (major_number < 0) {
+	
+	dev_num = MKDEV(major, minor);
+	rc = register_chrdev_region(dev_num, 1, DEVICE_NAME);
+	if (rc < 0) {
 		pr_err("Failed to register character device\n");
-		return major_number;
+		return rc;
 	}
+    cdev_init(&cdev, &watchdog_fops);
+    cdev.owner = THIS_MODULE;
+	rc = cdev_add(&cdev, dev_num, 1);
+    if (rc)
+    {
+        printk(KERN_ALERT "ssegment: Failed to add cdev\n");
+        unregister_chrdev_region(dev_num, 1);
+        return rc;
+    }
+	// major_number = register_chrdev(0, DEVICE_NAME, &watchdog_fops);
+	// if (major_number < 0) {
+	// 	pr_err("Failed to register character device\n");
+	// 	return major_number;
+	// }
 
 	/* Create device class */
 	watchdog_class = class_create(THIS_MODULE, CLASS_NAME);
@@ -612,8 +634,7 @@ int watchdog_init(void)
 
 	/* Create device node /dev/watchdog */
 	watchdog_device = device_create(watchdog_class, NULL,
-					MKDEV(major_number, 0),
-					NULL, DEVICE_NAME);
+					dev_num, NULL, DEVICE_NAME);
 	if (IS_ERR(watchdog_device)) {
 		class_destroy(watchdog_class);
 		unregister_chrdev(major_number, DEVICE_NAME);
@@ -648,9 +669,9 @@ void watchdog_exit(void)
     kobject_put(watchdog_kobj);
 
 	/* Remove device */
-	device_destroy(watchdog_class, MKDEV(major_number, 0));
+	device_destroy(watchdog_class, MKDEV(major, minor));
 	class_destroy(watchdog_class);
-	unregister_chrdev(major_number, DEVICE_NAME);
+	unregister_chrdev_region(MKDEV(major, minor), 1);
 	
 	pr_info("Watchdog driver exited\n");
 }