watchdog: s3c2410: add restart notifier
From: Heiko Stuebner <heiko@...> Date: Sun, 6 Jul 2014 14:59:31 +0200
Commit-Message
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@...>
Patch-Comment
drivers/watchdog/s3c2410_wdt.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)
Statistics
- 33 lines added
- 0 lines removed
Changes
------------------------ drivers/watchdog/s3c2410_wdt.c ------------------------
index 7c6ccd0..3f89912 100644
@@ -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;