1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog driver for the wm831x PMICs
*
* Copyright (C) 2009 Wolfson Microelectronics
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/watchdog.h>
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
struct wm831x_wdt_drvdata {
struct watchdog_device wdt;
struct wm831x *wm831x;
struct mutex lock;
int update_gpio;
int update_state;
};
/* We can't use the sub-second values here but they're included
* for completeness. */
static struct {
unsigned int time; /* Seconds */
u16 val; /* WDOG_TO value */
} wm831x_wdt_cfgs[] = {
{ 1, 2 },
{ 2, 3 },
{ 4, 4 },
{ 8, 5 },
{ 16, 6 },
{ 32, 7 },
{ 33, 7 }, /* Actually 32.768s so include both, others round down */
};
static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
mutex_lock(&driver_data->lock);
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_ENA, WM831X_WDOG_ENA);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
mutex_lock(&driver_data->lock);
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_ENA, 0);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
u16 reg;
mutex_lock(&driver_data->lock);
if (driver_data->update_gpio) {
gpio_set_value_cansleep(driver_data->update_gpio,
driver_data->update_state);
driver_data->update_state = !driver_data->update_state;
ret = 0;
goto out;
}
reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
if (!(reg & WM831X_WDOG_RST_SRC)) {
dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
ret = -EINVAL;
goto out;
}
reg |= WM831X_WDOG_RESET;
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
out:
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret, i;
for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
if (wm831x_wdt_cfgs[i].time == timeout)
break;
if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
return -EINVAL;
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_TO_MASK,
wm831x_wdt_cfgs[i].val);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
wdt_dev->timeout = timeout;
return ret;
}
static const struct watchdog_info wm831x_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "WM831x Watchdog",
};
static const struct watchdog_ops wm831x_wdt_ops = {
.owner = THIS_MODULE,
.start = wm831x_wdt_start,
.stop = wm831x_wdt_stop,
.ping = wm831x_wdt_ping,
.set_timeout = wm831x_wdt_set_timeout,
};
static int wm831x_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct wm831x *wm831x = dev_get_drvdata(dev->parent);
struct wm831x_pdata *chip_pdata = dev_get_platdata(dev->parent);
struct wm831x_watchdog_pdata *pdata;
struct wm831x_wdt_drvdata *driver_data;
struct watchdog_device *wm831x_wdt;
int reg, ret, i;
ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
if (ret < 0) {
dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
ret);
return ret;
}
reg = ret;
if (reg & WM831X_WDOG_DEBUG)
dev_warn(wm831x->dev, "Watchdog is paused\n");
driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
if (!driver_data)
return -ENOMEM;
mutex_init(&driver_data->lock);
driver_data->wm831x = wm831x;
wm831x_wdt = &driver_data->wdt;
wm831x_wdt->info = &wm831x_wdt_info;
wm831x_wdt->ops = &wm831x_wdt_ops;
wm831x_wdt->parent = dev;
watchdog_set_nowayout(wm831x_wdt, nowayout);
watchdog_set_drvdata(wm831x_wdt, driver_data);
reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
reg &= WM831X_WDOG_TO_MASK;
for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
if (wm831x_wdt_cfgs[i].val == reg)
break;
if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
dev_warn(wm831x->dev,
"Unknown watchdog timeout: %x\n", reg);
else
wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
/* Apply any configuration */
if (chip_pdata)
pdata = chip_pdata->watchdog;
else
pdata = NULL;
if (pdata) {
reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
WM831X_WDOG_RST_SRC);
reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
if (pdata->update_gpio) {
ret = devm_gpio_request_one(dev, pdata->update_gpio,
GPIOF_OUT_INIT_LOW,
"Watchdog update");
if (ret < 0) {
dev_err(wm831x->dev,
"Failed to request update GPIO: %d\n",
ret);
return ret;
}
driver_data->update_gpio = pdata->update_gpio;
/* Make sure the watchdog takes hardware updates */
reg |= WM831X_WDOG_RST_SRC;
}
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev,
"Failed to unlock security key: %d\n", ret);
return ret;
}
}
return devm_watchdog_register_device(dev, &driver_data->wdt);
}
static struct platform_driver wm831x_wdt_driver = {
.probe = wm831x_wdt_probe,
.driver = {
.name = "wm831x-watchdog",
},
};
module_platform_driver(wm831x_wdt_driver);
MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM831x Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-watchdog");
|
