| Message ID | 10183342.ZfePbPvRx9@diego (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Heiko, On 06.07.2014 20:42, Heiko Stübner wrote: > 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 notifiers, 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> > --- > drivers/watchdog/s3c2410_wdt.c | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c > index 7c6ccd0..3f89912 100644 > --- a/drivers/watchdog/s3c2410_wdt.c > +++ b/drivers/watchdog/s3c2410_wdt.c > @@ -41,6 +41,7 @@ > #include <linux/of.h> > #include <linux/mfd/syscon.h> > #include <linux/regmap.h> > +#include <linux/reboot.h> > > #define S3C2410_WTCON 0x00 > #define S3C2410_WTDAT 0x04 > @@ -438,6 +439,31 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) > } > #endif > > +static struct s3c2410_wdt *s3c2410wdt_restart_ctx; This isn't the most elegant way to store context data. Maybe you could embed the notifier_block struct into s3c2410_wdt struct and then use container of to retrieve it from s3c2410wdt_restart_notify()? > +static int s3c2410wdt_restart_notify(struct notifier_block *this, > + unsigned long mode, void *cmd) > +{ > + void __iomem *wdt_base = s3c2410wdt_restart_ctx->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); I wonder whether you shouldn't wait a bit here for the reset to be actually triggered. Best regards, Tomasz
On Tue, Jul 08, 2014 at 04:21:09PM +0200, Tomasz Figa wrote: > Hi Heiko, > > On 06.07.2014 20:42, Heiko Stübner wrote: > > 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 notifiers, 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> > > --- > > drivers/watchdog/s3c2410_wdt.c | 33 +++++++++++++++++++++++++++++++++ > > 1 file changed, 33 insertions(+) > > > > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c > > index 7c6ccd0..3f89912 100644 > > --- a/drivers/watchdog/s3c2410_wdt.c > > +++ b/drivers/watchdog/s3c2410_wdt.c > > @@ -41,6 +41,7 @@ > > #include <linux/of.h> > > #include <linux/mfd/syscon.h> > > #include <linux/regmap.h> > > +#include <linux/reboot.h> > > > > #define S3C2410_WTCON 0x00 > > #define S3C2410_WTDAT 0x04 > > @@ -438,6 +439,31 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) > > } > > #endif > > > > +static struct s3c2410_wdt *s3c2410wdt_restart_ctx; > > This isn't the most elegant way to store context data. Maybe you could > embed the notifier_block struct into s3c2410_wdt struct and then use > container of to retrieve it from s3c2410wdt_restart_notify()? > Excellent idea. I'll do that for the moxart handler as well. Guenter
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index 7c6ccd0..3f89912 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -41,6 +41,7 @@ #include <linux/of.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/reboot.h> #define S3C2410_WTCON 0x00 #define S3C2410_WTDAT 0x04 @@ -438,6 +439,31 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) } #endif +static struct s3c2410_wdt *s3c2410wdt_restart_ctx; +static int s3c2410wdt_restart_notify(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + void __iomem *wdt_base = s3c2410wdt_restart_ctx->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); + + return NOTIFY_DONE; +} + +static struct notifier_block s3c2410wdt_restart_notifier = { + .notifier_call = s3c2410wdt_restart_notify, +}; + static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt) { unsigned int rst_stat; @@ -592,6 +618,11 @@ static int s3c2410wdt_probe(struct platform_device *pdev) platform_set_drvdata(pdev, wdt); + s3c2410wdt_restart_ctx = wdt; + ret = register_restart_notifier(&s3c2410wdt_restart_notifier); + if (ret) + pr_err("cannot register restart notifier, %d\n", ret); + /* print out a statement of readiness */ wtcon = readl(wdt->reg_base + S3C2410_WTCON); @@ -621,6 +652,8 @@ static int s3c2410wdt_remove(struct platform_device *dev) int ret; struct s3c2410_wdt *wdt = platform_get_drvdata(dev); + unregister_restart_notifier(&s3c2410wdt_restart_notifier); + ret = s3c2410wdt_mask_and_disable_reset(wdt, true); if (ret < 0) return ret;
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 notifiers, 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> --- drivers/watchdog/s3c2410_wdt.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)