2 * Watchdog driver for the wm831x PMICs
4 * Copyright (C) 2009 Wolfson Microelectronics
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 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/watchdog.h>
18 #include <linux/uaccess.h>
19 #include <linux/gpio.h>
21 #include <linux/mfd/wm831x/core.h>
22 #include <linux/mfd/wm831x/pdata.h>
23 #include <linux/mfd/wm831x/watchdog.h>
25 static bool nowayout = WATCHDOG_NOWAYOUT;
26 module_param(nowayout, bool, 0);
27 MODULE_PARM_DESC(nowayout,
28 "Watchdog cannot be stopped once started (default="
29 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
31 struct wm831x_wdt_drvdata {
32 struct watchdog_device wdt;
33 struct wm831x *wm831x;
39 /* We can't use the sub-second values here but they're included
40 * for completeness. */
42 unsigned int time; /* Seconds */
43 u16 val; /* WDOG_TO value */
44 } wm831x_wdt_cfgs[] = {
51 { 33, 7 }, /* Actually 32.768s so include both, others round down */
54 static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
56 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
57 struct wm831x *wm831x = driver_data->wm831x;
60 mutex_lock(&driver_data->lock);
62 ret = wm831x_reg_unlock(wm831x);
64 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
65 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
66 wm831x_reg_lock(wm831x);
68 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
72 mutex_unlock(&driver_data->lock);
77 static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
79 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
80 struct wm831x *wm831x = driver_data->wm831x;
83 mutex_lock(&driver_data->lock);
85 ret = wm831x_reg_unlock(wm831x);
87 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
89 wm831x_reg_lock(wm831x);
91 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
95 mutex_unlock(&driver_data->lock);
100 static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
102 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
103 struct wm831x *wm831x = driver_data->wm831x;
107 mutex_lock(&driver_data->lock);
109 if (driver_data->update_gpio) {
110 gpio_set_value_cansleep(driver_data->update_gpio,
111 driver_data->update_state);
112 driver_data->update_state = !driver_data->update_state;
117 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
119 if (!(reg & WM831X_WDOG_RST_SRC)) {
120 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
125 reg |= WM831X_WDOG_RESET;
127 ret = wm831x_reg_unlock(wm831x);
129 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
130 wm831x_reg_lock(wm831x);
132 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
137 mutex_unlock(&driver_data->lock);
142 static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
143 unsigned int timeout)
145 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
146 struct wm831x *wm831x = driver_data->wm831x;
149 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
150 if (wm831x_wdt_cfgs[i].time == timeout)
152 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
155 ret = wm831x_reg_unlock(wm831x);
157 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
159 wm831x_wdt_cfgs[i].val);
160 wm831x_reg_lock(wm831x);
162 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
166 wdt_dev->timeout = timeout;
171 static const struct watchdog_info wm831x_wdt_info = {
172 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
173 .identity = "WM831x Watchdog",
176 static const struct watchdog_ops wm831x_wdt_ops = {
177 .owner = THIS_MODULE,
178 .start = wm831x_wdt_start,
179 .stop = wm831x_wdt_stop,
180 .ping = wm831x_wdt_ping,
181 .set_timeout = wm831x_wdt_set_timeout,
184 static int wm831x_wdt_probe(struct platform_device *pdev)
186 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
187 struct wm831x_pdata *chip_pdata = dev_get_platdata(pdev->dev.parent);
188 struct wm831x_watchdog_pdata *pdata;
189 struct wm831x_wdt_drvdata *driver_data;
190 struct watchdog_device *wm831x_wdt;
193 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
195 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
201 if (reg & WM831X_WDOG_DEBUG)
202 dev_warn(wm831x->dev, "Watchdog is paused\n");
204 driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
209 mutex_init(&driver_data->lock);
210 driver_data->wm831x = wm831x;
212 wm831x_wdt = &driver_data->wdt;
214 wm831x_wdt->info = &wm831x_wdt_info;
215 wm831x_wdt->ops = &wm831x_wdt_ops;
216 wm831x_wdt->parent = &pdev->dev;
217 watchdog_set_nowayout(wm831x_wdt, nowayout);
218 watchdog_set_drvdata(wm831x_wdt, driver_data);
220 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
221 reg &= WM831X_WDOG_TO_MASK;
222 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
223 if (wm831x_wdt_cfgs[i].val == reg)
225 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
226 dev_warn(wm831x->dev,
227 "Unknown watchdog timeout: %x\n", reg);
229 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
231 /* Apply any configuration */
233 pdata = chip_pdata->watchdog;
238 reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
239 WM831X_WDOG_RST_SRC);
241 reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
242 reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
243 reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
245 if (pdata->update_gpio) {
246 ret = devm_gpio_request_one(&pdev->dev,
252 "Failed to request update GPIO: %d\n",
257 driver_data->update_gpio = pdata->update_gpio;
259 /* Make sure the watchdog takes hardware updates */
260 reg |= WM831X_WDOG_RST_SRC;
263 ret = wm831x_reg_unlock(wm831x);
265 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
266 wm831x_reg_lock(wm831x);
269 "Failed to unlock security key: %d\n", ret);
274 ret = devm_watchdog_register_device(&pdev->dev, &driver_data->wdt);
276 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
284 static struct platform_driver wm831x_wdt_driver = {
285 .probe = wm831x_wdt_probe,
287 .name = "wm831x-watchdog",
291 module_platform_driver(wm831x_wdt_driver);
293 MODULE_AUTHOR("Mark Brown");
294 MODULE_DESCRIPTION("WM831x Watchdog");
295 MODULE_LICENSE("GPL");
296 MODULE_ALIAS("platform:wm831x-watchdog");