1 // SPDX-License-Identifier: GPL-2.0+
3 * Watchdog driver for the wm831x PMICs
5 * Copyright (C) 2009 Wolfson Microelectronics
8 #include <linux/module.h>
9 #include <linux/moduleparam.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/platform_device.h>
14 #include <linux/watchdog.h>
15 #include <linux/uaccess.h>
16 #include <linux/gpio.h>
18 #include <linux/mfd/wm831x/core.h>
19 #include <linux/mfd/wm831x/pdata.h>
20 #include <linux/mfd/wm831x/watchdog.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 struct wm831x_wdt_drvdata {
29 struct watchdog_device wdt;
30 struct wm831x *wm831x;
36 /* We can't use the sub-second values here but they're included
37 * for completeness. */
39 unsigned int time; /* Seconds */
40 u16 val; /* WDOG_TO value */
41 } wm831x_wdt_cfgs[] = {
48 { 33, 7 }, /* Actually 32.768s so include both, others round down */
51 static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
53 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
54 struct wm831x *wm831x = driver_data->wm831x;
57 mutex_lock(&driver_data->lock);
59 ret = wm831x_reg_unlock(wm831x);
61 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
62 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
63 wm831x_reg_lock(wm831x);
65 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
69 mutex_unlock(&driver_data->lock);
74 static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
76 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
77 struct wm831x *wm831x = driver_data->wm831x;
80 mutex_lock(&driver_data->lock);
82 ret = wm831x_reg_unlock(wm831x);
84 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
86 wm831x_reg_lock(wm831x);
88 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
92 mutex_unlock(&driver_data->lock);
97 static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
99 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
100 struct wm831x *wm831x = driver_data->wm831x;
104 mutex_lock(&driver_data->lock);
106 if (driver_data->update_gpio) {
107 gpio_set_value_cansleep(driver_data->update_gpio,
108 driver_data->update_state);
109 driver_data->update_state = !driver_data->update_state;
114 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
116 if (!(reg & WM831X_WDOG_RST_SRC)) {
117 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
122 reg |= WM831X_WDOG_RESET;
124 ret = wm831x_reg_unlock(wm831x);
126 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
127 wm831x_reg_lock(wm831x);
129 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
134 mutex_unlock(&driver_data->lock);
139 static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
140 unsigned int timeout)
142 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
143 struct wm831x *wm831x = driver_data->wm831x;
146 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
147 if (wm831x_wdt_cfgs[i].time == timeout)
149 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
152 ret = wm831x_reg_unlock(wm831x);
154 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
156 wm831x_wdt_cfgs[i].val);
157 wm831x_reg_lock(wm831x);
159 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
163 wdt_dev->timeout = timeout;
168 static const struct watchdog_info wm831x_wdt_info = {
169 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
170 .identity = "WM831x Watchdog",
173 static const struct watchdog_ops wm831x_wdt_ops = {
174 .owner = THIS_MODULE,
175 .start = wm831x_wdt_start,
176 .stop = wm831x_wdt_stop,
177 .ping = wm831x_wdt_ping,
178 .set_timeout = wm831x_wdt_set_timeout,
181 static int wm831x_wdt_probe(struct platform_device *pdev)
183 struct device *dev = &pdev->dev;
184 struct wm831x *wm831x = dev_get_drvdata(dev->parent);
185 struct wm831x_pdata *chip_pdata = dev_get_platdata(dev->parent);
186 struct wm831x_watchdog_pdata *pdata;
187 struct wm831x_wdt_drvdata *driver_data;
188 struct watchdog_device *wm831x_wdt;
191 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
193 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
199 if (reg & WM831X_WDOG_DEBUG)
200 dev_warn(wm831x->dev, "Watchdog is paused\n");
202 driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
206 mutex_init(&driver_data->lock);
207 driver_data->wm831x = wm831x;
209 wm831x_wdt = &driver_data->wdt;
211 wm831x_wdt->info = &wm831x_wdt_info;
212 wm831x_wdt->ops = &wm831x_wdt_ops;
213 wm831x_wdt->parent = dev;
214 watchdog_set_nowayout(wm831x_wdt, nowayout);
215 watchdog_set_drvdata(wm831x_wdt, driver_data);
217 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
218 reg &= WM831X_WDOG_TO_MASK;
219 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
220 if (wm831x_wdt_cfgs[i].val == reg)
222 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
223 dev_warn(wm831x->dev,
224 "Unknown watchdog timeout: %x\n", reg);
226 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
228 /* Apply any configuration */
230 pdata = chip_pdata->watchdog;
235 reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
236 WM831X_WDOG_RST_SRC);
238 reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
239 reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
240 reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
242 if (pdata->update_gpio) {
243 ret = devm_gpio_request_one(dev, pdata->update_gpio,
248 "Failed to request update GPIO: %d\n",
253 driver_data->update_gpio = pdata->update_gpio;
255 /* Make sure the watchdog takes hardware updates */
256 reg |= WM831X_WDOG_RST_SRC;
259 ret = wm831x_reg_unlock(wm831x);
261 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
262 wm831x_reg_lock(wm831x);
265 "Failed to unlock security key: %d\n", ret);
270 ret = devm_watchdog_register_device(dev, &driver_data->wdt);
272 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
280 static struct platform_driver wm831x_wdt_driver = {
281 .probe = wm831x_wdt_probe,
283 .name = "wm831x-watchdog",
287 module_platform_driver(wm831x_wdt_driver);
289 MODULE_AUTHOR("Mark Brown");
290 MODULE_DESCRIPTION("WM831x Watchdog");
291 MODULE_LICENSE("GPL");
292 MODULE_ALIAS("platform:wm831x-watchdog");