watchdog: s3c2410: add restart handler
From: =?UTF-8?q?Heiko=20St=C3=BCbner?= <heiko@...> Date: Sun, 6 Jul 2014 20:42:50 +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 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@...> [Guenter Roeck: Update to latest API; do not require static context variable] Signed-off-by: Guenter Roeck <linux@...> Acked-by: Heiko Stuebner <heiko@...>
Patch-Comment
drivers/watchdog/s3c2410_wdt.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
Statistics
- 36 lines added
- 0 lines removed
Changes
------------------------ drivers/watchdog/s3c2410_wdt.c ------------------------
index 7c6ccd0..2955aef 100644
@@ -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;
};
@@ -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;