watchdog: alim7101: register restart handler with kernel restart handler

The kernel core now provides an API to trigger a system restart. Register
with it to restart the system instead of misusing the reboot notifier.

Signed-off-by: Guenter Roeck <[e-mail]>
Acked-by: Catalin Marinas <[e-mail]>
Acked-by: Heiko Stuebner <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: David Woodhouse <[e-mail]>
Cc: Dmitry Eremin-Solenikov <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jonas Jensen <[e-mail]>
Cc: Maxime Ripard <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Cc: Tomasz Figa <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Wim Van Sebroeck <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

drivers/watchdog/alim7101_wdt.c

···
 	.fops	=	&wdt_fops,
 };
 
+static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
+			      void *cmd)
+{
+	/*
+	 * Cobalt devices have no way of rebooting themselves other
+	 * than getting the watchdog to pull reset, so we restart the
+	 * watchdog on reboot with no heartbeat.
+	 */
+	wdt_change(WDT_ENABLE);
+
+	/* loop until the watchdog fires */
+	while (true)
+		;
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_restart_handler = {
+	.notifier_call = wdt_restart_handle,
+	.priority = 128,
+};
+
 /*
  *	Notifier for system down
  */
···
 	if (code == SYS_DOWN || code == SYS_HALT)
 		wdt_turnoff();
 
-	if (code == SYS_RESTART) {
-		/*
-		 * Cobalt devices have no way of rebooting themselves other
-		 * than getting the watchdog to pull reset, so we restart the
-		 * watchdog on reboot with no heartbeat
-		 */
-		wdt_change(WDT_ENABLE);
-		pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
-	}
 	return NOTIFY_DONE;
 }
 
···
 	/* Deregister */
 	misc_deregister(&wdt_miscdev);
 	unregister_reboot_notifier(&wdt_notifier);
+	unregister_restart_handler(&wdt_restart_handler);
 	pci_dev_put(alim7101_pmu);
 }
 
···
 		goto err_out;
 	}
 
+	rc = register_restart_handler(&wdt_restart_handler);
+	if (rc) {
+		pr_err("cannot register restart handler (err=%d)\n", rc);
+		goto err_out_reboot;
+	}
+
 	rc = misc_register(&wdt_miscdev);
 	if (rc) {
 		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 		       wdt_miscdev.minor, rc);
-		goto err_out_reboot;
+		goto err_out_restart;
 	}
 
 	if (nowayout)
···
 		timeout, nowayout);
 	return 0;
 
+err_out_restart:
+	unregister_restart_handler(&wdt_restart_handler);
 err_out_reboot:
 	unregister_reboot_notifier(&wdt_notifier);
 err_out: