From mboxrd@z Thu Jan 1 00:00:00 1970 From: heiko@sntech.de (Heiko =?ISO-8859-1?Q?St=FCbner?=) Date: Sat, 02 Aug 2014 21:51:42 +0200 Subject: [PATCH v5.1 9/7] watchdog: s3c2410: add restart handler In-Reply-To: <53D9010B.7070700@roeck-us.net> References: <1405668856-13738-1-git-send-email-linux@roeck-us.net> <53D8FCEA.9020506@roeck-us.net> <53D9010B.7070700@roeck-us.net> Message-ID: <1701800.eiHDUvPYI3@diego> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 [Guenter Roeck: Update to latest API; do not require static context variable] Signed-off-by: Guenter Roeck Acked-by: Heiko Stuebner --- changes since v5: - reintroduce the mdelay(500) from the platform code, to make sure the watchdog has time to assert, as suggested by Tomasz Figa drivers/watchdog/s3c2410_wdt.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index 7c6ccd0..2955aef 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -41,6 +41,8 @@ #include #include #include +#include +#include #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; }; @@ -438,6 +441,31 @@ 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; @@ -592,6 +620,12 @@ 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); @@ -621,6 +655,8 @@ 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; -- 2.0.1