2 * Watchdog driver for the wm8350
4 * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/platform_device.h>
18 #include <linux/watchdog.h>
19 #include <linux/uaccess.h>
20 #include <linux/mfd/wm8350/core.h>
22 static bool nowayout = WATCHDOG_NOWAYOUT;
23 module_param(nowayout, bool, 0);
24 MODULE_PARM_DESC(nowayout,
25 "Watchdog cannot be stopped once started (default="
26 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
28 static DEFINE_MUTEX(wdt_mutex);
31 unsigned int time; /* Seconds */
32 u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
33 } wm8350_wdt_cfgs[] = {
39 static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
42 struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
46 for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
47 if (wm8350_wdt_cfgs[i].time == timeout)
49 if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
52 mutex_lock(&wdt_mutex);
53 wm8350_reg_unlock(wm8350);
55 reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
56 reg &= ~WM8350_WDOG_TO_MASK;
57 reg |= wm8350_wdt_cfgs[i].val;
58 ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
60 wm8350_reg_lock(wm8350);
61 mutex_unlock(&wdt_mutex);
66 static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
68 struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
72 mutex_lock(&wdt_mutex);
73 wm8350_reg_unlock(wm8350);
75 reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
76 reg &= ~WM8350_WDOG_MODE_MASK;
78 ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
80 wm8350_reg_lock(wm8350);
81 mutex_unlock(&wdt_mutex);
86 static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
88 struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
92 mutex_lock(&wdt_mutex);
93 wm8350_reg_unlock(wm8350);
95 reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
96 reg &= ~WM8350_WDOG_MODE_MASK;
97 ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
99 wm8350_reg_lock(wm8350);
100 mutex_unlock(&wdt_mutex);
105 static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
107 struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
111 mutex_lock(&wdt_mutex);
113 reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
114 ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
116 mutex_unlock(&wdt_mutex);
121 static const struct watchdog_info wm8350_wdt_info = {
122 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
123 .identity = "WM8350 Watchdog",
126 static const struct watchdog_ops wm8350_wdt_ops = {
127 .owner = THIS_MODULE,
128 .start = wm8350_wdt_start,
129 .stop = wm8350_wdt_stop,
130 .ping = wm8350_wdt_ping,
131 .set_timeout = wm8350_wdt_set_timeout,
134 static struct watchdog_device wm8350_wdt = {
135 .info = &wm8350_wdt_info,
136 .ops = &wm8350_wdt_ops,
142 static int __devinit wm8350_wdt_probe(struct platform_device *pdev)
144 struct wm8350 *wm8350 = platform_get_drvdata(pdev);
147 pr_err("No driver data supplied\n");
151 watchdog_set_nowayout(&wm8350_wdt, nowayout);
152 watchdog_set_drvdata(&wm8350_wdt, wm8350);
154 /* Default to 4s timeout */
155 wm8350_wdt_set_timeout(&wm8350_wdt, 4);
157 return watchdog_register_device(&wm8350_wdt);
160 static int __devexit wm8350_wdt_remove(struct platform_device *pdev)
162 watchdog_unregister_device(&wm8350_wdt);
166 static struct platform_driver wm8350_wdt_driver = {
167 .probe = wm8350_wdt_probe,
168 .remove = __devexit_p(wm8350_wdt_remove),
170 .name = "wm8350-wdt",
174 module_platform_driver(wm8350_wdt_driver);
176 MODULE_AUTHOR("Mark Brown");
177 MODULE_DESCRIPTION("WM8350 Watchdog");
178 MODULE_LICENSE("GPL");
179 MODULE_ALIAS("platform:wm8350-wdt");