diff options
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/imx2_wdt.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index f37bb05e7ec0..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); @@ -251,6 +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); @@ -262,6 +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)) { |