[PATCH v6 5/7] watchdog: moxart: Register restart handler with kernel restart handler

[linux@roeck-us.net (Guenter Roeck)]

The kernel now provides an API to trigger a system restart.
Register with it instead of setting arm_pm_restart.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
---
v6: No change.
v5: Functions and variables renamed: *notifier -> *handler
v4: Set notifier priority to 128.
v3: Move struct notifier_block into struct moxart_wdt_dev.
    Drop static variable previously needed to access struct moxart_wdt_dev
    from notifier function; use container_of instead.
v2: No change.

 drivers/watchdog/moxart_wdt.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c
index 4aa3a8a..a64405b 100644
--- a/drivers/watchdog/moxart_wdt.c
+++ b/drivers/watchdog/moxart_wdt.c
@@ -15,12 +15,12 @@
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
+#include <linux/notifier.h>
 #include <linux/platform_device.h>
+#include <linux/reboot.h>
 #include <linux/watchdog.h>
 #include <linux/moduleparam.h>
 
-#include <asm/system_misc.h>
-
 #define REG_COUNT			0x4
 #define REG_MODE			0x8
 #define REG_ENABLE			0xC
@@ -29,17 +29,22 @@ struct moxart_wdt_dev {
 	struct watchdog_device dev;
 	void __iomem *base;
 	unsigned int clock_frequency;
+	struct notifier_block restart_handler;
 };
 
-static struct moxart_wdt_dev *moxart_restart_ctx;
-
 static int heartbeat;
 
-static void moxart_wdt_restart(enum reboot_mode reboot_mode, const char *cmd)
+static int moxart_restart_handle(struct notifier_block *this,
+				 unsigned long mode, void *cmd)
 {
-	writel(1, moxart_restart_ctx->base + REG_COUNT);
-	writel(0x5ab9, moxart_restart_ctx->base + REG_MODE);
-	writel(0x03, moxart_restart_ctx->base + REG_ENABLE);
+	struct moxart_wdt_dev *moxart_wdt = container_of(this,
+							 struct moxart_wdt_dev,
+							 restart_handler);
+	writel(1, moxart_wdt->base + REG_COUNT);
+	writel(0x5ab9, moxart_wdt->base + REG_MODE);
+	writel(0x03, moxart_wdt->base + REG_ENABLE);
+
+	return NOTIFY_DONE;
 }
 
 static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
@@ -136,8 +141,12 @@ static int moxart_wdt_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	moxart_restart_ctx = moxart_wdt;
-	arm_pm_restart = moxart_wdt_restart;
+	moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
+	moxart_wdt->restart_handler.priority = 128;
+	err = register_restart_handler(&moxart_wdt->restart_handler);
+	if (err)
+		dev_err(dev, "cannot register restart notifier (err=%d)\n",
+			err);
 
 	dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
 		moxart_wdt->dev.timeout, nowayout);
@@ -149,9 +158,8 @@ static int moxart_wdt_remove(struct platform_device *pdev)
 {
 	struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
 
-	arm_pm_restart = NULL;
+	unregister_restart_handler(&moxart_wdt->restart_handler);
 	moxart_wdt_stop(&moxart_wdt->dev);
-	watchdog_unregister_device(&moxart_wdt->dev);
 
 	return 0;
 }
-- 
1.9.1