[PATCH v4 2/6] watchdog: pnx4008: add restart handler
From: Sylvain Lemieux <hidden>
Date: 2016-02-25 18:31:36
Also in:
linux-watchdog
Subsystem:
arm/lpc32xx soc support, the rest, watchdog device drivers · Maintainers:
Vladimir Zapolskiy, Piotr Wojtaszczyk, Linus Torvalds, Wim Van Sebroeck, Guenter Roeck
From: Sylvain Lemieux <redacted>
Add restart handler capability to the driver;
the restart handler implementation was taken from
"mach-lpc32xx" ("lpc23xx_restart" function).
Signed-off-by: Sylvain Lemieux <redacted>
---
Changes from v3 to v4:
- none.
Changes from v2 to v3:
- remove explicit clock enable from restart handler.
- verify "register_restart_handler" return value.
- add call to unregister_restart_handler".
- do the restart handling directly in "pnx4008_restart_handler".
Changes from v1 to v2:
- new patch in v2.
drivers/watchdog/pnx4008_wdt.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/watchdog/pnx4008_wdt.c b/drivers/watchdog/pnx4008_wdt.c
index 88264a2..80ee4af 100644
--- a/drivers/watchdog/pnx4008_wdt.c
+++ b/drivers/watchdog/pnx4008_wdt.c@@ -31,6 +31,8 @@ #include <linux/slab.h> #include <linux/err.h> #include <linux/of.h> +#include <linux/delay.h> +#include <linux/reboot.h> #include <mach/hardware.h> /* WatchDog Timer - Chapter 23 Page 207 */
@@ -77,6 +79,7 @@ static bool nowayout = WATCHDOG_NOWAYOUT; static unsigned int heartbeat = DEFAULT_HEARTBEAT; +static struct notifier_block restart_handler; static DEFINE_SPINLOCK(io_lock); static void __iomem *wdt_base;
@@ -124,6 +127,19 @@ static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd, return 0; } +static int pnx4008_restart_handler(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + /* Instant assert of RESETOUT_N with pulse length 1mS */ + writel(13000, WDTIM_PULSE(wdt_base)); + writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base)); + + /* Wait for watchdog to reset system */ + mdelay(1000); + + return NOTIFY_DONE; +} + static const struct watchdog_info pnx4008_wdt_ident = { .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
@@ -157,6 +173,15 @@ static int pnx4008_wdt_probe(struct platform_device *pdev) if (IS_ERR(wdt_base)) return PTR_ERR(wdt_base); + /* Register restart handler. */ + restart_handler.notifier_call = pnx4008_restart_handler; + restart_handler.priority = 128; + ret = register_restart_handler(&restart_handler); + if (ret) { + dev_warn(&pdev->dev, "cannot register restart handler\n"); + return ret; + } + wdt_clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(wdt_clk)) return PTR_ERR(wdt_clk);
@@ -189,6 +214,7 @@ disable_clk: static int pnx4008_wdt_remove(struct platform_device *pdev) { + unregister_restart_handler(&restart_handler); watchdog_unregister_device(&pnx4008_wdd); clk_disable_unprepare(wdt_clk);
--
1.8.3.1