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

[Guenter Roeck]

On 03/09/2018 06:44 PM, Brian Norris wrote:

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

Signed-off-by: Brian Norris <briannor...@chromium.org>

Reviewed-by: Guenter Roeck <li...@roeck-us.net>

---
  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 6925d3e6c6b3..094986047194 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)

@@ -204,6 +207,9 @@ 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;

@@ -217,6 +223,9 @@ 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;