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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>
17
18#include <linux/mfd/wm831x/core.h>
19#include <linux/mfd/wm831x/pdata.h>
20#include <linux/mfd/wm831x/watchdog.h>
21
22static bool nowayout = WATCHDOG_NOWAYOUT;
23module_param(nowayout, bool, 0);
24MODULE_PARM_DESC(nowayout,
25 "Watchdog cannot be stopped once started (default="
26 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
27
28struct wm831x_wdt_drvdata {
29 struct watchdog_device wdt;
30 struct wm831x *wm831x;
31 struct mutex lock;
32 int update_gpio;
33 int update_state;
34};
35
36
37
38static struct {
39 unsigned int time;
40 u16 val;
41} wm831x_wdt_cfgs[] = {
42 { 1, 2 },
43 { 2, 3 },
44 { 4, 4 },
45 { 8, 5 },
46 { 16, 6 },
47 { 32, 7 },
48 { 33, 7 },
49};
50
51static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
52{
53 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
54 struct wm831x *wm831x = driver_data->wm831x;
55 int ret;
56
57 mutex_lock(&driver_data->lock);
58
59 ret = wm831x_reg_unlock(wm831x);
60 if (ret == 0) {
61 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
62 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
63 wm831x_reg_lock(wm831x);
64 } else {
65 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
66 ret);
67 }
68
69 mutex_unlock(&driver_data->lock);
70
71 return ret;
72}
73
74static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
75{
76 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
77 struct wm831x *wm831x = driver_data->wm831x;
78 int ret;
79
80 mutex_lock(&driver_data->lock);
81
82 ret = wm831x_reg_unlock(wm831x);
83 if (ret == 0) {
84 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
85 WM831X_WDOG_ENA, 0);
86 wm831x_reg_lock(wm831x);
87 } else {
88 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
89 ret);
90 }
91
92 mutex_unlock(&driver_data->lock);
93
94 return ret;
95}
96
97static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
98{
99 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
100 struct wm831x *wm831x = driver_data->wm831x;
101 int ret;
102 u16 reg;
103
104 mutex_lock(&driver_data->lock);
105
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;
110 ret = 0;
111 goto out;
112 }
113
114 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
115
116 if (!(reg & WM831X_WDOG_RST_SRC)) {
117 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
118 ret = -EINVAL;
119 goto out;
120 }
121
122 reg |= WM831X_WDOG_RESET;
123
124 ret = wm831x_reg_unlock(wm831x);
125 if (ret == 0) {
126 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
127 wm831x_reg_lock(wm831x);
128 } else {
129 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
130 ret);
131 }
132
133out:
134 mutex_unlock(&driver_data->lock);
135
136 return ret;
137}
138
139static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
140 unsigned int timeout)
141{
142 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
143 struct wm831x *wm831x = driver_data->wm831x;
144 int ret, i;
145
146 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
147 if (wm831x_wdt_cfgs[i].time == timeout)
148 break;
149 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
150 return -EINVAL;
151
152 ret = wm831x_reg_unlock(wm831x);
153 if (ret == 0) {
154 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
155 WM831X_WDOG_TO_MASK,
156 wm831x_wdt_cfgs[i].val);
157 wm831x_reg_lock(wm831x);
158 } else {
159 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
160 ret);
161 }
162
163 wdt_dev->timeout = timeout;
164
165 return ret;
166}
167
168static const struct watchdog_info wm831x_wdt_info = {
169 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
170 .identity = "WM831x Watchdog",
171};
172
173static 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,
179};
180
181static int wm831x_wdt_probe(struct platform_device *pdev)
182{
183 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
184 struct wm831x_pdata *chip_pdata = dev_get_platdata(pdev->dev.parent);
185 struct wm831x_watchdog_pdata *pdata;
186 struct wm831x_wdt_drvdata *driver_data;
187 struct watchdog_device *wm831x_wdt;
188 int reg, ret, i;
189
190 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
191 if (ret < 0) {
192 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
193 ret);
194 return ret;
195 }
196 reg = ret;
197
198 if (reg & WM831X_WDOG_DEBUG)
199 dev_warn(wm831x->dev, "Watchdog is paused\n");
200
201 driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
202 GFP_KERNEL);
203 if (!driver_data)
204 return -ENOMEM;
205
206 mutex_init(&driver_data->lock);
207 driver_data->wm831x = wm831x;
208
209 wm831x_wdt = &driver_data->wdt;
210
211 wm831x_wdt->info = &wm831x_wdt_info;
212 wm831x_wdt->ops = &wm831x_wdt_ops;
213 wm831x_wdt->parent = &pdev->dev;
214 watchdog_set_nowayout(wm831x_wdt, nowayout);
215 watchdog_set_drvdata(wm831x_wdt, driver_data);
216
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)
221 break;
222 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
223 dev_warn(wm831x->dev,
224 "Unknown watchdog timeout: %x\n", reg);
225 else
226 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
227
228
229 if (chip_pdata)
230 pdata = chip_pdata->watchdog;
231 else
232 pdata = NULL;
233
234 if (pdata) {
235 reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
236 WM831X_WDOG_RST_SRC);
237
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;
241
242 if (pdata->update_gpio) {
243 ret = devm_gpio_request_one(&pdev->dev,
244 pdata->update_gpio,
245 GPIOF_OUT_INIT_LOW,
246 "Watchdog update");
247 if (ret < 0) {
248 dev_err(wm831x->dev,
249 "Failed to request update GPIO: %d\n",
250 ret);
251 return ret;
252 }
253
254 driver_data->update_gpio = pdata->update_gpio;
255
256
257 reg |= WM831X_WDOG_RST_SRC;
258 }
259
260 ret = wm831x_reg_unlock(wm831x);
261 if (ret == 0) {
262 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
263 wm831x_reg_lock(wm831x);
264 } else {
265 dev_err(wm831x->dev,
266 "Failed to unlock security key: %d\n", ret);
267 return ret;
268 }
269 }
270
271 ret = devm_watchdog_register_device(&pdev->dev, &driver_data->wdt);
272 if (ret != 0) {
273 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
274 ret);
275 return ret;
276 }
277
278 return 0;
279}
280
281static struct platform_driver wm831x_wdt_driver = {
282 .probe = wm831x_wdt_probe,
283 .driver = {
284 .name = "wm831x-watchdog",
285 },
286};
287
288module_platform_driver(wm831x_wdt_driver);
289
290MODULE_AUTHOR("Mark Brown");
291MODULE_DESCRIPTION("WM831x Watchdog");
292MODULE_LICENSE("GPL");
293MODULE_ALIAS("platform:wm831x-watchdog");
294
