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path: root/drivers/watchdog/dw_wdt.c
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Diffstat (limited to 'drivers/watchdog/dw_wdt.c')
-rw-r--r--drivers/watchdog/dw_wdt.c36
1 files changed, 35 insertions, 1 deletions
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 9f21029..9e577a6 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>
@@ -40,6 +43,7 @@
#define WDOG_CONTROL_REG_OFFSET 0x00
#define WDOG_CONTROL_REG_WDT_EN_MASK 0x01
#define WDOG_TIMEOUT_RANGE_REG_OFFSET 0x04
+#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT 4
#define WDOG_CURRENT_COUNT_REG_OFFSET 0x08
#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c
#define WDOG_COUNTER_RESTART_KICK_VALUE 0x76
@@ -62,6 +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)
@@ -106,7 +111,8 @@ static int dw_wdt_set_top(unsigned top_s)
}
/* Set the new value in the watchdog. */
- writel(top_val, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
+ dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
dw_wdt_set_next_heartbeat();
@@ -119,6 +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) ||
@@ -314,6 +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);
@@ -328,6 +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);
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