diff options
Diffstat (limited to 'drivers/watchdog/imx2_wdt.c')
| -rw-r--r-- | drivers/watchdog/imx2_wdt.c | 91 |
1 files changed, 84 insertions, 7 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index 68c3d379ffa8..d6add516a7a7 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -22,14 +22,17 @@ */ #include <linux/clk.h> +#include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> +#include <linux/notifier.h> #include <linux/of_address.h> #include <linux/platform_device.h> +#include <linux/reboot.h> #include <linux/regmap.h> #include <linux/timer.h> #include <linux/watchdog.h> @@ -59,6 +62,7 @@ struct imx2_wdt_device { struct regmap *regmap; struct timer_list timer; /* Pings the watchdog when closed */ struct watchdog_device wdog; + struct notifier_block restart_handler; }; static bool nowayout = WATCHDOG_NOWAYOUT; @@ -77,6 +81,31 @@ static const struct watchdog_info imx2_wdt_info = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, }; +static int imx2_restart_handler(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + unsigned int wcr_enable = IMX2_WDT_WCR_WDE; + struct imx2_wdt_device *wdev = container_of(this, + struct imx2_wdt_device, + restart_handler); + /* Assert SRS signal */ + regmap_write(wdev->regmap, 0, wcr_enable); + /* + * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be + * written twice), we add another two writes to ensure there must be at + * least two writes happen in the same one 32kHz clock period. We save + * the target check here, since the writes shouldn't be a huge burden + * for other platforms. + */ + regmap_write(wdev->regmap, 0, wcr_enable); + regmap_write(wdev->regmap, 0, wcr_enable); + + /* wait for reset to assert... */ + mdelay(500); + + return NOTIFY_DONE; +} + static inline void imx2_wdt_setup(struct watchdog_device *wdog) { struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); @@ -191,12 +220,10 @@ static struct regmap_config imx2_wdt_regmap_config = { static int __init imx2_wdt_probe(struct platform_device *pdev) { - struct device_node *np = pdev->dev.of_node; struct imx2_wdt_device *wdev; struct watchdog_device *wdog; struct resource *res; void __iomem *base; - bool big_endian; int ret; u32 val; @@ -204,10 +231,6 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) if (!wdev) return -ENOMEM; - big_endian = of_property_read_bool(np, "big-endian"); - if (big_endian) - imx2_wdt_regmap_config.val_format_endian = REGMAP_ENDIAN_BIG; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) @@ -257,6 +280,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) return ret; } + wdev->restart_handler.notifier_call = imx2_restart_handler; + wdev->restart_handler.priority = 128; + ret = register_restart_handler(&wdev->restart_handler); + if (ret) + dev_err(&pdev->dev, "cannot register restart handler\n"); + dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n", wdog->timeout, nowayout); @@ -268,6 +297,8 @@ static int __exit imx2_wdt_remove(struct platform_device *pdev) struct watchdog_device *wdog = platform_get_drvdata(pdev); struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + unregister_restart_handler(&wdev->restart_handler); + watchdog_unregister_device(wdog); if (imx2_wdt_is_running(wdev)) { @@ -295,6 +326,52 @@ static void imx2_wdt_shutdown(struct platform_device *pdev) } } +#ifdef CONFIG_PM_SLEEP +/* Disable watchdog if it is active during suspend */ +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); + + /* Watchdog has been stopped but IP block is still running */ + if (!watchdog_active(wdog) && imx2_wdt_is_running(wdev)) + del_timer_sync(&wdev->timer); + + clk_disable_unprepare(wdev->clk); + + return 0; +} + +/* Enable watchdog and configure it if necessary */ +static int imx2_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdog = dev_get_drvdata(dev); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + + clk_prepare_enable(wdev->clk); + + if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) { + /* Resumes from deep sleep we need 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)) { + imx2_wdt_ping(wdog); + mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, + imx2_wdt_resume); + static const struct of_device_id imx2_wdt_dt_ids[] = { { .compatible = "fsl,imx21-wdt", }, { /* sentinel */ } @@ -306,7 +383,7 @@ static struct platform_driver imx2_wdt_driver = { .shutdown = imx2_wdt_shutdown, .driver = { .name = DRIVER_NAME, - .owner = THIS_MODULE, + .pm = &imx2_wdt_pm_ops, .of_match_table = imx2_wdt_dt_ids, }, }; |
