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authorJisheng Zhang <jszhang@marvell.com>2014-09-23 15:42:12 +0800
committerWim Van Sebroeck <wim@iguana.be>2014-10-20 21:03:06 +0200
commit31228f43ab528628c9b5f1351604361aa1d78533 (patch)
treeb3e2a9be36edb5b2fb5d585377706b1056642590 /drivers/watchdog
parent69a160a0543fd569661048a8692c10afcdb1914b (diff)
watchdog: dw_wdt: add restart handler support
The kernel core now provides an API to trigger a system restart. Register with it to support restarting the system via. watchdog. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/dw_wdt.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 449c88523364..9e577a64ec9e 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -21,6 +21,7 @@
#include <linux/bitops.h>
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/fs.h>
@@ -29,9 +30,11 @@
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
+#include <linux/reboot.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
@@ -63,6 +66,7 @@ static struct {
unsigned long next_heartbeat;
struct timer_list timer;
int expect_close;
+ struct notifier_block restart_handler;
} dw_wdt;
static inline int dw_wdt_is_enabled(void)
@@ -121,6 +125,26 @@ static void dw_wdt_keepalive(void)
WDOG_COUNTER_RESTART_REG_OFFSET);
}
+static int dw_wdt_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ u32 val;
+
+ writel(0, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ val = readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
+ if (val & WDOG_CONTROL_REG_WDT_EN_MASK)
+ writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
+ WDOG_COUNTER_RESTART_REG_OFFSET);
+ else
+ writel(WDOG_CONTROL_REG_WDT_EN_MASK,
+ dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
+
+ /* wait for reset to assert... */
+ mdelay(500);
+
+ return NOTIFY_DONE;
+}
+
static void dw_wdt_ping(unsigned long data)
{
if (time_before(jiffies, dw_wdt.next_heartbeat) ||
@@ -316,6 +340,12 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
if (ret)
goto out_disable_clk;
+ dw_wdt.restart_handler.notifier_call = dw_wdt_restart_handle;
+ dw_wdt.restart_handler.priority = 128;
+ ret = register_restart_handler(&dw_wdt.restart_handler);
+ if (ret)
+ pr_warn("cannot register restart handler\n");
+
dw_wdt_set_next_heartbeat();
setup_timer(&dw_wdt.timer, dw_wdt_ping, 0);
mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
@@ -330,6 +360,8 @@ out_disable_clk:
static int dw_wdt_drv_remove(struct platform_device *pdev)
{
+ unregister_restart_handler(&dw_wdt.restart_handler);
+
misc_deregister(&dw_wdt_miscdev);
clk_disable_unprepare(dw_wdt.clk);