diff options
Diffstat (limited to 'drivers/watchdog/db8500_wdt.c')
| -rw-r--r-- | drivers/watchdog/db8500_wdt.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/watchdog/db8500_wdt.c b/drivers/watchdog/db8500_wdt.c new file mode 100644 index 000000000000..6ed8b63d310d --- /dev/null +++ b/drivers/watchdog/db8500_wdt.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) ST-Ericsson SA 2011-2013 + * + * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson + * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/moduleparam.h> +#include <linux/err.h> +#include <linux/uaccess.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> + +#include <linux/mfd/dbx500-prcmu.h> + +#define WATCHDOG_TIMEOUT 600 /* 10 minutes */ + +#define WATCHDOG_MIN 0 +#define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */ + +static unsigned int timeout = WATCHDOG_TIMEOUT; +module_param(timeout, uint, 0); +MODULE_PARM_DESC(timeout, + "Watchdog timeout in seconds. default=" + __MODULE_STRING(WATCHDOG_TIMEOUT) "."); + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static int db8500_wdt_start(struct watchdog_device *wdd) +{ + return prcmu_enable_a9wdog(PRCMU_WDOG_ALL); +} + +static int db8500_wdt_stop(struct watchdog_device *wdd) +{ + return prcmu_disable_a9wdog(PRCMU_WDOG_ALL); +} + +static int db8500_wdt_keepalive(struct watchdog_device *wdd) +{ + return prcmu_kick_a9wdog(PRCMU_WDOG_ALL); +} + +static int db8500_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + db8500_wdt_stop(wdd); + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + db8500_wdt_start(wdd); + + return 0; +} + +static const struct watchdog_info db8500_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "DB8500 WDT", + .firmware_version = 1, +}; + +static const struct watchdog_ops db8500_wdt_ops = { + .owner = THIS_MODULE, + .start = db8500_wdt_start, + .stop = db8500_wdt_stop, + .ping = db8500_wdt_keepalive, + .set_timeout = db8500_wdt_set_timeout, +}; + +static struct watchdog_device db8500_wdt = { + .info = &db8500_wdt_info, + .ops = &db8500_wdt_ops, + .min_timeout = WATCHDOG_MIN, + .max_timeout = WATCHDOG_MAX28, +}; + +static int db8500_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int ret; + + timeout = 600; /* Default to 10 minutes */ + db8500_wdt.parent = dev; + watchdog_set_nowayout(&db8500_wdt, nowayout); + + /* disable auto off on sleep */ + prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false); + + /* set HW initial value */ + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + + ret = devm_watchdog_register_device(dev, &db8500_wdt); + if (ret) + return ret; + + dev_info(dev, "initialized\n"); + + return 0; +} + +#ifdef CONFIG_PM +static int db8500_wdt_suspend(struct platform_device *pdev, + pm_message_t state) +{ + if (watchdog_active(&db8500_wdt)) { + db8500_wdt_stop(&db8500_wdt); + prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true); + + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + db8500_wdt_start(&db8500_wdt); + } + return 0; +} + +static int db8500_wdt_resume(struct platform_device *pdev) +{ + if (watchdog_active(&db8500_wdt)) { + db8500_wdt_stop(&db8500_wdt); + prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false); + + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + db8500_wdt_start(&db8500_wdt); + } + return 0; +} +#else +#define db8500_wdt_suspend NULL +#define db8500_wdt_resume NULL +#endif + +static struct platform_driver db8500_wdt_driver = { + .probe = db8500_wdt_probe, + .suspend = db8500_wdt_suspend, + .resume = db8500_wdt_resume, + .driver = { + .name = "db8500_wdt", + }, +}; + +module_platform_driver(db8500_wdt_driver); + +MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>"); +MODULE_DESCRIPTION("DB8500 Watchdog Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:db8500_wdt"); |