[PATCH v2 2/2] watchdog: dw: save/restore control and timeout across suspend/resume

From: Brian Norris
Date: Fri Mar 09 2018 - 22:46:31 EST


Some platforms lose this state in suspend. It should be safe to do this
unconditionally.

Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v2: no change
---
drivers/watchdog/dw_wdt.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 918357bccf5e..501aebb5b81f 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -57,6 +57,9 @@ struct dw_wdt {
unsigned long rate;
struct watchdog_device wdd;
struct reset_control *rst;
+ /* Save/restore */
+ u32 control;
+ u32 timeout;
};

#define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd)
@@ -205,6 +208,9 @@ static int dw_wdt_suspend(struct device *dev)
{
struct dw_wdt *dw_wdt = dev_get_drvdata(dev);

+ dw_wdt->control = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+ dw_wdt->timeout = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+
clk_disable_unprepare(dw_wdt->clk);

return 0;
@@ -218,6 +224,9 @@ static int dw_wdt_resume(struct device *dev)
if (err)
return err;

+ writel(dw_wdt->timeout, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ writel(dw_wdt->control, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+
dw_wdt_ping(&dw_wdt->wdd);

return 0;
--
2.16.2.660.g709887971b-goog