diff options
Diffstat (limited to 'drivers/watchdog/ux500_wdt.c')
| -rw-r--r-- | drivers/watchdog/ux500_wdt.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/watchdog/ux500_wdt.c b/drivers/watchdog/ux500_wdt.c new file mode 100644 index 000000000000..a614d84121c3 --- /dev/null +++ b/drivers/watchdog/ux500_wdt.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) ST-Ericsson SA 2011-2013 + * + * License Terms: GNU General Public License v2 + * + * 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/miscdevice.h> +#include <linux/err.h> +#include <linux/uaccess.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> +#include <linux/platform_data/ux500_wdt.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 */ +#define WATCHDOG_MAX32 4294967 /* 32 bit resolution in ms == 4294967.295 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 ux500_wdt_start(struct watchdog_device *wdd) +{ + return prcmu_enable_a9wdog(PRCMU_WDOG_ALL); +} + +static int ux500_wdt_stop(struct watchdog_device *wdd) +{ + return prcmu_disable_a9wdog(PRCMU_WDOG_ALL); +} + +static int ux500_wdt_keepalive(struct watchdog_device *wdd) +{ + return prcmu_kick_a9wdog(PRCMU_WDOG_ALL); +} + +static int ux500_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + ux500_wdt_stop(wdd); + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + ux500_wdt_start(wdd); + + return 0; +} + +static const struct watchdog_info ux500_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "Ux500 WDT", + .firmware_version = 1, +}; + +static const struct watchdog_ops ux500_wdt_ops = { + .owner = THIS_MODULE, + .start = ux500_wdt_start, + .stop = ux500_wdt_stop, + .ping = ux500_wdt_keepalive, + .set_timeout = ux500_wdt_set_timeout, +}; + +static struct watchdog_device ux500_wdt = { + .info = &ux500_wdt_info, + .ops = &ux500_wdt_ops, + .min_timeout = WATCHDOG_MIN, + .max_timeout = WATCHDOG_MAX32, +}; + +static int ux500_wdt_probe(struct platform_device *pdev) +{ + int ret; + struct ux500_wdt_data *pdata = pdev->dev.platform_data; + + if (pdata) { + if (pdata->timeout > 0) + timeout = pdata->timeout; + if (pdata->has_28_bits_resolution) + ux500_wdt.max_timeout = WATCHDOG_MAX28; + } + + watchdog_set_nowayout(&ux500_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 = watchdog_register_device(&ux500_wdt); + if (ret) + return ret; + + dev_info(&pdev->dev, "initialized\n"); + + return 0; +} + +static int ux500_wdt_remove(struct platform_device *dev) +{ + watchdog_unregister_device(&ux500_wdt); + + return 0; +} + +#ifdef CONFIG_PM +static int ux500_wdt_suspend(struct platform_device *pdev, + pm_message_t state) +{ + if (watchdog_active(&ux500_wdt)) { + ux500_wdt_stop(&ux500_wdt); + prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true); + + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + ux500_wdt_start(&ux500_wdt); + } + return 0; +} + +static int ux500_wdt_resume(struct platform_device *pdev) +{ + if (watchdog_active(&ux500_wdt)) { + ux500_wdt_stop(&ux500_wdt); + prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false); + + prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); + ux500_wdt_start(&ux500_wdt); + } + return 0; +} +#else +#define ux500_wdt_suspend NULL +#define ux500_wdt_resume NULL +#endif + +static struct platform_driver ux500_wdt_driver = { + .probe = ux500_wdt_probe, + .remove = ux500_wdt_remove, + .suspend = ux500_wdt_suspend, + .resume = ux500_wdt_resume, + .driver = { + .owner = THIS_MODULE, + .name = "ux500_wdt", + }, +}; + +module_platform_driver(ux500_wdt_driver); + +MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>"); +MODULE_DESCRIPTION("Ux500 Watchdog Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:ux500_wdt"); |