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| author | Heiko Stuebner <heiko@sntech.de> | 2014-08-19 17:45:36 -0700 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2014-10-20 21:03:37 +0200 |
| commit | f286e1335f579dfd970c7fc3f62b248773a47a5c (patch) | |
| tree | 0e9dc970d01ce89dc7b0d729f6c79d85de901200 | |
| parent | 31228f43ab528628c9b5f1351604361aa1d78533 (diff) | |
| download | lwn-f286e1335f579dfd970c7fc3f62b248773a47a5c.tar.gz lwn-f286e1335f579dfd970c7fc3f62b248773a47a5c.zip | |
watchdog: s3c2410: add restart handler
On a lot of Samsung systems the watchdog is responsible for restarting the
system and until now this code was contained in plat-samsung/watchdog-reset.c.
With the introduction of the restart handlers, this code can now move into
driver itself, removing the need for arch-specific code.
Tested on a S3C2442 based GTA02
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | drivers/watchdog/s3c2410_wdt.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index 015256e496ae..8532c3e2aea7 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -41,6 +41,8 @@ #include <linux/of.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/reboot.h> +#include <linux/delay.h> #define S3C2410_WTCON 0x00 #define S3C2410_WTDAT 0x04 @@ -128,6 +130,7 @@ struct s3c2410_wdt { unsigned long wtdat_save; struct watchdog_device wdt_device; struct notifier_block freq_transition; + struct notifier_block restart_handler; struct s3c2410_wdt_variant *drv_data; struct regmap *pmureg; }; @@ -449,6 +452,31 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) } #endif +static int s3c2410wdt_restart(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + struct s3c2410_wdt *wdt = container_of(this, struct s3c2410_wdt, + restart_handler); + void __iomem *wdt_base = wdt->reg_base; + + /* disable watchdog, to be safe */ + writel(0, wdt_base + S3C2410_WTCON); + + /* put initial values into count and data */ + writel(0x80, wdt_base + S3C2410_WTCNT); + writel(0x80, wdt_base + S3C2410_WTDAT); + + /* set the watchdog to go and reset... */ + writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 | + S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20), + wdt_base + S3C2410_WTCON); + + /* wait for reset to assert... */ + mdelay(500); + + return NOTIFY_DONE; +} + static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt) { unsigned int rst_stat; @@ -603,6 +631,12 @@ static int s3c2410wdt_probe(struct platform_device *pdev) platform_set_drvdata(pdev, wdt); + wdt->restart_handler.notifier_call = s3c2410wdt_restart; + wdt->restart_handler.priority = 128; + ret = register_restart_handler(&wdt->restart_handler); + if (ret) + pr_err("cannot register restart handler, %d\n", ret); + /* print out a statement of readiness */ wtcon = readl(wdt->reg_base + S3C2410_WTCON); @@ -632,6 +666,8 @@ static int s3c2410wdt_remove(struct platform_device *dev) int ret; struct s3c2410_wdt *wdt = platform_get_drvdata(dev); + unregister_restart_handler(&wdt->restart_handler); + ret = s3c2410wdt_mask_and_disable_reset(wdt, true); if (ret < 0) return ret; |