From bbd5900935be8755b6344386373174b20cd474a2 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Thu, 16 Oct 2014 11:44:15 +0800 Subject: watchdog: imx2_wdt: Improve power management support. Improve power management operations(suspend and resume) as part of dev_pm_ops for IMX2 watchdog driver. If PM will be supported, please make sure that the wdev->clk could disable the watchdog's counter input clock source or can mask watchdog's reset request to the core. If watchdog is still used by consumers and resumes from deep sleep state, we need to restart the watchdog again without enabling the timer. If watchdog been has started --> stopped by the consumers and resumes from non-deep sleep state, then start the timer again. If watchdog has been started --> stopped by the consumers and resumes from deep sleep state, will do nothing. The watchdog will be restarted by consumers next time to be used. Signed-off-by: Xiubo Li Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/imx2_wdt.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index d6add516a7a7..c50c7d85689f 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -327,18 +327,21 @@ static void imx2_wdt_shutdown(struct platform_device *pdev) } #ifdef CONFIG_PM_SLEEP -/* Disable watchdog if it is active during suspend */ +/* Disable watchdog if it is active or non-active but still running */ static int imx2_wdt_suspend(struct device *dev) { struct watchdog_device *wdog = dev_get_drvdata(dev); struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); - imx2_wdt_ping(wdog); + /* The watchdog IP block is running */ + if (imx2_wdt_is_running(wdev)) { + imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); + imx2_wdt_ping(wdog); - /* Watchdog has been stopped but IP block is still running */ - if (!watchdog_active(wdog) && imx2_wdt_is_running(wdev)) - del_timer_sync(&wdev->timer); + /* The watchdog is not active */ + if (!watchdog_active(wdog)) + del_timer_sync(&wdev->timer); + } clk_disable_unprepare(wdev->clk); @@ -354,15 +357,25 @@ static int imx2_wdt_resume(struct device *dev) clk_prepare_enable(wdev->clk); if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) { - /* Resumes from deep sleep we need restart - * the watchdog again. + /* + * If the watchdog is still active and resumes + * from deep sleep state, need to restart the + * watchdog again. */ imx2_wdt_setup(wdog); imx2_wdt_set_timeout(wdog, wdog->timeout); imx2_wdt_ping(wdog); } else if (imx2_wdt_is_running(wdev)) { + /* Resuming from non-deep sleep state. */ + imx2_wdt_set_timeout(wdog, wdog->timeout); imx2_wdt_ping(wdog); - mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2); + /* + * But the watchdog is not active, then start + * the timer again. + */ + if (!watchdog_active(wdog)) + mod_timer(&wdev->timer, + jiffies + wdog->timeout * HZ / 2); } return 0; -- cgit v1.2.3 From 5fe65ce7ccbb47b16e17a88bcdac73cffadb80fa Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Mon, 8 Sep 2014 09:14:07 +0200 Subject: watchdog: imx2_wdt: Disable power down counter on boot Disable power down counter of the watchdog to avoid system resets. The watchdog power down counter is set automatically by the chip. If it is not set to 0 in the driver, the system resets. Signed-off-by: Markus Pargmann Acked-by: Shawn Guo Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/imx2_wdt.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index c50c7d85689f..5142bbabe027 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -52,6 +52,8 @@ #define IMX2_WDT_WRSR 0x04 /* Reset Status Register */ #define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */ +#define IMX2_WDT_WMCR 0x08 /* Misc Register */ + #define IMX2_WDT_MAX_TIME 128 #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ @@ -274,6 +276,13 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) imx2_wdt_ping_if_active(wdog); + /* + * Disable the watchdog power down counter at boot. Otherwise the power + * down counter will pull down the #WDOG interrupt line for one clock + * cycle. + */ + regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0); + ret = watchdog_register_device(wdog); if (ret) { dev_err(&pdev->dev, "cannot register watchdog device\n"); -- cgit v1.2.3 From 7a32757eda68a53626f003018733d09f94138334 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Sun, 21 Dec 2014 22:14:43 +0100 Subject: watchdog: drop owner assignment from platform_drivers This platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/cadence_wdt.c | 1 - drivers/watchdog/meson_wdt.c | 1 - 2 files changed, 2 deletions(-) diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c index 5927c0a98a74..bcfd2a22208f 100644 --- a/drivers/watchdog/cadence_wdt.c +++ b/drivers/watchdog/cadence_wdt.c @@ -503,7 +503,6 @@ static struct platform_driver cdns_wdt_driver = { .shutdown = cdns_wdt_shutdown, .driver = { .name = "cdns-wdt", - .owner = THIS_MODULE, .of_match_table = cdns_wdt_of_match, .pm = &cdns_wdt_pm_ops, }, diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c index ef6a298e8c45..1f4155ee3404 100644 --- a/drivers/watchdog/meson_wdt.c +++ b/drivers/watchdog/meson_wdt.c @@ -215,7 +215,6 @@ static struct platform_driver meson_wdt_driver = { .remove = meson_wdt_remove, .shutdown = meson_wdt_shutdown, .driver = { - .owner = THIS_MODULE, .name = DRV_NAME, .of_match_table = meson_wdt_dt_ids, }, -- cgit v1.2.3