/* * 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 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 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 = 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");