diff options
Diffstat (limited to 'drivers/watchdog/wm8350_wdt.c')
| -rw-r--r-- | drivers/watchdog/wm8350_wdt.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/watchdog/wm8350_wdt.c b/drivers/watchdog/wm8350_wdt.c new file mode 100644 index 00000000..3c766934 --- /dev/null +++ b/drivers/watchdog/wm8350_wdt.c @@ -0,0 +1,180 @@ +/* + * Watchdog driver for the wm8350 + * + * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> +#include <linux/uaccess.h> +#include <linux/mfd/wm8350/core.h> + +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 DEFINE_MUTEX(wdt_mutex); + +static struct { + unsigned int time; /* Seconds */ + u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */ +} wm8350_wdt_cfgs[] = { + { 1, 0x02 }, + { 2, 0x04 }, + { 4, 0x05 }, +}; + +static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); + int ret, i; + u16 reg; + + for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++) + if (wm8350_wdt_cfgs[i].time == timeout) + break; + if (i == ARRAY_SIZE(wm8350_wdt_cfgs)) + return -EINVAL; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_TO_MASK; + reg |= wm8350_wdt_cfgs[i].val; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + wdt_dev->timeout = timeout; + return ret; +} + +static int wm8350_wdt_start(struct watchdog_device *wdt_dev) +{ + struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_MODE_MASK; + reg |= 0x20; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_MODE_MASK; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + mutex_unlock(&wdt_mutex); + + return ret; +} + +static const struct watchdog_info wm8350_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "WM8350 Watchdog", +}; + +static const struct watchdog_ops wm8350_wdt_ops = { + .owner = THIS_MODULE, + .start = wm8350_wdt_start, + .stop = wm8350_wdt_stop, + .ping = wm8350_wdt_ping, + .set_timeout = wm8350_wdt_set_timeout, +}; + +static struct watchdog_device wm8350_wdt = { + .info = &wm8350_wdt_info, + .ops = &wm8350_wdt_ops, + .timeout = 4, + .min_timeout = 1, + .max_timeout = 4, +}; + +static int __devinit wm8350_wdt_probe(struct platform_device *pdev) +{ + struct wm8350 *wm8350 = platform_get_drvdata(pdev); + + if (!wm8350) { + pr_err("No driver data supplied\n"); + return -ENODEV; + } + + watchdog_set_nowayout(&wm8350_wdt, nowayout); + watchdog_set_drvdata(&wm8350_wdt, wm8350); + + /* Default to 4s timeout */ + wm8350_wdt_set_timeout(&wm8350_wdt, 4); + + return watchdog_register_device(&wm8350_wdt); +} + +static int __devexit wm8350_wdt_remove(struct platform_device *pdev) +{ + watchdog_unregister_device(&wm8350_wdt); + return 0; +} + +static struct platform_driver wm8350_wdt_driver = { + .probe = wm8350_wdt_probe, + .remove = __devexit_p(wm8350_wdt_remove), + .driver = { + .name = "wm8350-wdt", + }, +}; + +module_platform_driver(wm8350_wdt_driver); + +MODULE_AUTHOR("Mark Brown"); +MODULE_DESCRIPTION("WM8350 Watchdog"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm8350-wdt"); |