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path: root/drivers/watchdog/imx2_wdt.c
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Diffstat (limited to 'drivers/watchdog/imx2_wdt.c')
-rw-r--r--drivers/watchdog/imx2_wdt.c43
1 files changed, 37 insertions, 6 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 68c3d379ffa8..7e12f88bb4a6 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -22,14 +22,17 @@
*/
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/notifier.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
+#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/timer.h>
#include <linux/watchdog.h>
@@ -59,6 +62,7 @@ struct imx2_wdt_device {
struct regmap *regmap;
struct timer_list timer; /* Pings the watchdog when closed */
struct watchdog_device wdog;
+ struct notifier_block restart_handler;
};
static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -77,6 +81,31 @@ static const struct watchdog_info imx2_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
};
+static int imx2_restart_handler(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ unsigned int wcr_enable = IMX2_WDT_WCR_WDE;
+ struct imx2_wdt_device *wdev = container_of(this,
+ struct imx2_wdt_device,
+ restart_handler);
+ /* Assert SRS signal */
+ regmap_write(wdev->regmap, 0, wcr_enable);
+ /*
+ * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
+ * written twice), we add another two writes to ensure there must be at
+ * least two writes happen in the same one 32kHz clock period. We save
+ * the target check here, since the writes shouldn't be a huge burden
+ * for other platforms.
+ */
+ regmap_write(wdev->regmap, 0, wcr_enable);
+ regmap_write(wdev->regmap, 0, wcr_enable);
+
+ /* wait for reset to assert... */
+ mdelay(500);
+
+ return NOTIFY_DONE;
+}
+
static inline void imx2_wdt_setup(struct watchdog_device *wdog)
{
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
@@ -191,12 +220,10 @@ static struct regmap_config imx2_wdt_regmap_config = {
static int __init imx2_wdt_probe(struct platform_device *pdev)
{
- struct device_node *np = pdev->dev.of_node;
struct imx2_wdt_device *wdev;
struct watchdog_device *wdog;
struct resource *res;
void __iomem *base;
- bool big_endian;
int ret;
u32 val;
@@ -204,10 +231,6 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
if (!wdev)
return -ENOMEM;
- big_endian = of_property_read_bool(np, "big-endian");
- if (big_endian)
- imx2_wdt_regmap_config.val_format_endian = REGMAP_ENDIAN_BIG;
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
@@ -257,6 +280,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
return ret;
}
+ wdev->restart_handler.notifier_call = imx2_restart_handler;
+ wdev->restart_handler.priority = 128;
+ ret = register_restart_handler(&wdev->restart_handler);
+ if (ret)
+ dev_err(&pdev->dev, "cannot register restart handler\n");
+
dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
wdog->timeout, nowayout);
@@ -268,6 +297,8 @@ static int __exit imx2_wdt_remove(struct platform_device *pdev)
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+ unregister_restart_handler(&wdev->restart_handler);
+
watchdog_unregister_device(wdog);
if (imx2_wdt_is_running(wdev)) {