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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>
20
21#include <linux/mfd/wm831x/core.h>
22#include <linux/mfd/wm831x/pdata.h>
23#include <linux/mfd/wm831x/watchdog.h>
24
25static bool nowayout = WATCHDOG_NOWAYOUT;
26module_param(nowayout, bool, 0);
27MODULE_PARM_DESC(nowayout,
28 "Watchdog cannot be stopped once started (default="
29 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
30
31struct wm831x_wdt_drvdata {
32 struct watchdog_device wdt;
33 struct wm831x *wm831x;
34 struct mutex lock;
35 int update_gpio;
36 int update_state;
37};
38
39
40
41static struct {
42 unsigned int time;
43 u16 val;
44} wm831x_wdt_cfgs[] = {
45 { 1, 2 },
46 { 2, 3 },
47 { 4, 4 },
48 { 8, 5 },
49 { 16, 6 },
50 { 32, 7 },
51 { 33, 7 },
52};
53
54static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
55{
56 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
57 struct wm831x *wm831x = driver_data->wm831x;
58 int ret;
59
60 mutex_lock(&driver_data->lock);
61
62 ret = wm831x_reg_unlock(wm831x);
63 if (ret == 0) {
64 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
65 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
66 wm831x_reg_lock(wm831x);
67 } else {
68 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
69 ret);
70 }
71
72 mutex_unlock(&driver_data->lock);
73
74 return ret;
75}
76
77static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
78{
79 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
80 struct wm831x *wm831x = driver_data->wm831x;
81 int ret;
82
83 mutex_lock(&driver_data->lock);
84
85 ret = wm831x_reg_unlock(wm831x);
86 if (ret == 0) {
87 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
88 WM831X_WDOG_ENA, 0);
89 wm831x_reg_lock(wm831x);
90 } else {
91 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
92 ret);
93 }
94
95 mutex_unlock(&driver_data->lock);
96
97 return ret;
98}
99
100static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
101{
102 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
103 struct wm831x *wm831x = driver_data->wm831x;
104 int ret;
105 u16 reg;
106
107 mutex_lock(&driver_data->lock);
108
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;
113 ret = 0;
114 goto out;
115 }
116
117 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
118
119 if (!(reg & WM831X_WDOG_RST_SRC)) {
120 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
121 ret = -EINVAL;
122 goto out;
123 }
124
125 reg |= WM831X_WDOG_RESET;
126
127 ret = wm831x_reg_unlock(wm831x);
128 if (ret == 0) {
129 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
130 wm831x_reg_lock(wm831x);
131 } else {
132 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
133 ret);
134 }
135
136out:
137 mutex_unlock(&driver_data->lock);
138
139 return ret;
140}
141
142static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
143 unsigned int timeout)
144{
145 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
146 struct wm831x *wm831x = driver_data->wm831x;
147 int ret, i;
148
149 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
150 if (wm831x_wdt_cfgs[i].time == timeout)
151 break;
152 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
153 return -EINVAL;
154
155 ret = wm831x_reg_unlock(wm831x);
156 if (ret == 0) {
157 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
158 WM831X_WDOG_TO_MASK,
159 wm831x_wdt_cfgs[i].val);
160 wm831x_reg_lock(wm831x);
161 } else {
162 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
163 ret);
164 }
165
166 wdt_dev->timeout = timeout;
167
168 return ret;
169}
170
171static const struct watchdog_info wm831x_wdt_info = {
172 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
173 .identity = "WM831x Watchdog",
174};
175
176static 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,
182};
183
184static int wm831x_wdt_probe(struct platform_device *pdev)
185{
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;
191 int reg, ret, i;
192
193 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
194 if (ret < 0) {
195 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
196 ret);
197 goto err;
198 }
199 reg = ret;
200
201 if (reg & WM831X_WDOG_DEBUG)
202 dev_warn(wm831x->dev, "Watchdog is paused\n");
203
204 driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
205 GFP_KERNEL);
206 if (!driver_data) {
207 ret = -ENOMEM;
208 goto err;
209 }
210
211 mutex_init(&driver_data->lock);
212 driver_data->wm831x = wm831x;
213
214 wm831x_wdt = &driver_data->wdt;
215
216 wm831x_wdt->info = &wm831x_wdt_info;
217 wm831x_wdt->ops = &wm831x_wdt_ops;
218 wm831x_wdt->parent = &pdev->dev;
219 watchdog_set_nowayout(wm831x_wdt, nowayout);
220 watchdog_set_drvdata(wm831x_wdt, driver_data);
221
222 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
223 reg &= WM831X_WDOG_TO_MASK;
224 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
225 if (wm831x_wdt_cfgs[i].val == reg)
226 break;
227 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
228 dev_warn(wm831x->dev,
229 "Unknown watchdog timeout: %x\n", reg);
230 else
231 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
232
233
234 if (chip_pdata)
235 pdata = chip_pdata->watchdog;
236 else
237 pdata = NULL;
238
239 if (pdata) {
240 reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
241 WM831X_WDOG_RST_SRC);
242
243 reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
244 reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
245 reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
246
247 if (pdata->update_gpio) {
248 ret = devm_gpio_request_one(&pdev->dev,
249 pdata->update_gpio,
250 GPIOF_OUT_INIT_LOW,
251 "Watchdog update");
252 if (ret < 0) {
253 dev_err(wm831x->dev,
254 "Failed to request update GPIO: %d\n",
255 ret);
256 goto err;
257 }
258
259 driver_data->update_gpio = pdata->update_gpio;
260
261
262 reg |= WM831X_WDOG_RST_SRC;
263 }
264
265 ret = wm831x_reg_unlock(wm831x);
266 if (ret == 0) {
267 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
268 wm831x_reg_lock(wm831x);
269 } else {
270 dev_err(wm831x->dev,
271 "Failed to unlock security key: %d\n", ret);
272 goto err;
273 }
274 }
275
276 ret = watchdog_register_device(&driver_data->wdt);
277 if (ret != 0) {
278 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
279 ret);
280 goto err;
281 }
282
283 platform_set_drvdata(pdev, driver_data);
284
285 return 0;
286
287err:
288 return ret;
289}
290
291static int wm831x_wdt_remove(struct platform_device *pdev)
292{
293 struct wm831x_wdt_drvdata *driver_data = platform_get_drvdata(pdev);
294
295 watchdog_unregister_device(&driver_data->wdt);
296
297 return 0;
298}
299
300static struct platform_driver wm831x_wdt_driver = {
301 .probe = wm831x_wdt_probe,
302 .remove = wm831x_wdt_remove,
303 .driver = {
304 .name = "wm831x-watchdog",
305 },
306};
307
308module_platform_driver(wm831x_wdt_driver);
309
310MODULE_AUTHOR("Mark Brown");
311MODULE_DESCRIPTION("WM831x Watchdog");
312MODULE_LICENSE("GPL");
313MODULE_ALIAS("platform:wm831x-watchdog");
314
