watchdog: mach-moxart: add restart handler

mach-moxart lacks a separate register for reset; as a workaround,
add a function that can be hooked to arm_pm_restart.
Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/moxart_wdt.c

@@ -19,6 +19,8 @@
 #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
@@ -29,8 +31,17 @@ struct moxart_wdt_dev {
 	unsigned int clock_frequency;
 };
 
+static struct moxart_wdt_dev *moxart_restart_ctx;
+
 static int heartbeat;
 
+static void moxart_wdt_restart(enum reboot_mode reboot_mode, const char *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);
+}
+
 static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
 {
 	struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
@@ -125,6 +136,9 @@ static int moxart_wdt_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	moxart_restart_ctx = moxart_wdt;
+	arm_pm_restart = moxart_wdt_restart;
+
 	dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
 		moxart_wdt->dev.timeout, nowayout);
 
@@ -135,6 +149,7 @@ static int moxart_wdt_remove(struct platform_device *pdev)
 {
 	struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
 
+	arm_pm_restart = NULL;
 	moxart_wdt_stop(&moxart_wdt->dev);
 	watchdog_unregister_device(&moxart_wdt->dev);