From 8650d0f9e9334f2e1c209f1e2ac8341f91e30d75 Mon Sep 17 00:00:00 2001 From: Robert Marko Date: Sat, 31 Oct 2020 13:11:15 +0100 Subject: watchdog: qcom_wdt: set WDOG_HW_RUNNING bit when appropriate If the watchdog hardware is enabled/running during boot, e.g. due to a boot loader configuring it, we must tell the watchdog framework about this fact so that it can ping the watchdog until userspace opens the device and takes over control. Do so using the WDOG_HW_RUNNING flag that exists for exactly that use-case. Signed-off-by: Robert Marko Cc: Luka Perkov Reviewed-by: Guenter Roeck Reviewed-by: Bjorn Andersson Link: https://lore.kernel.org/r/20201031121115.542752-1-robert.marko@sartura.hr Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/qcom-wdt.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index ab7465d186fd..07d399c4edc4 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -152,6 +152,13 @@ static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action, return 0; } +static int qcom_wdt_is_running(struct watchdog_device *wdd) +{ + struct qcom_wdt *wdt = to_qcom_wdt(wdd); + + return (readl(wdt_addr(wdt, WDT_EN)) & QCOM_WDT_ENABLE); +} + static const struct watchdog_ops qcom_wdt_ops = { .start = qcom_wdt_start, .stop = qcom_wdt_stop, @@ -294,6 +301,17 @@ static int qcom_wdt_probe(struct platform_device *pdev) wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U); watchdog_init_timeout(&wdt->wdd, 0, dev); + /* + * If WDT is already running, call WDT start which + * will stop the WDT, set timeouts as bootloader + * might use different ones and set running bit + * to inform the WDT subsystem to ping the WDT + */ + if (qcom_wdt_is_running(&wdt->wdd)) { + qcom_wdt_start(&wdt->wdd); + set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); + } + ret = devm_watchdog_register_device(dev, &wdt->wdd); if (ret) return ret; -- cgit v1.2.3