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
|
/*
* Maxim MAX77620 Watchdog Driver
*
* Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
*
* Author: Laxman Dewangan <ldewangan@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/max77620.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/watchdog.h>
static bool nowayout = WATCHDOG_NOWAYOUT;
struct max77620_wdt {
struct device *dev;
struct regmap *rmap;
struct watchdog_device wdt_dev;
};
static int max77620_wdt_start(struct watchdog_device *wdt_dev)
{
struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
MAX77620_WDTEN, MAX77620_WDTEN);
}
static int max77620_wdt_stop(struct watchdog_device *wdt_dev)
{
struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
MAX77620_WDTEN, 0);
}
static int max77620_wdt_ping(struct watchdog_device *wdt_dev)
{
struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
MAX77620_WDTC_MASK, 0x1);
}
static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
unsigned int wdt_timeout;
u8 regval;
int ret;
switch (timeout) {
case 0 ... 2:
regval = MAX77620_TWD_2s;
wdt_timeout = 2;
break;
case 3 ... 16:
regval = MAX77620_TWD_16s;
wdt_timeout = 16;
break;
case 17 ... 64:
regval = MAX77620_TWD_64s;
wdt_timeout = 64;
break;
default:
regval = MAX77620_TWD_128s;
wdt_timeout = 128;
break;
}
ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
MAX77620_WDTC_MASK, 0x1);
if (ret < 0)
return ret;
ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
MAX77620_TWD_MASK, regval);
if (ret < 0)
return ret;
wdt_dev->timeout = wdt_timeout;
return 0;
}
static const struct watchdog_info max77620_wdt_info = {
.identity = "max77620-watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops max77620_wdt_ops = {
.start = max77620_wdt_start,
.stop = max77620_wdt_stop,
.ping = max77620_wdt_ping,
.set_timeout = max77620_wdt_set_timeout,
};
static int max77620_wdt_probe(struct platform_device *pdev)
{
struct max77620_wdt *wdt;
struct watchdog_device *wdt_dev;
unsigned int regval;
int ret;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->dev = &pdev->dev;
wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!wdt->rmap) {
dev_err(wdt->dev, "Failed to get parent regmap\n");
return -ENODEV;
}
wdt_dev = &wdt->wdt_dev;
wdt_dev->info = &max77620_wdt_info;
wdt_dev->ops = &max77620_wdt_ops;
wdt_dev->min_timeout = 2;
wdt_dev->max_timeout = 128;
wdt_dev->max_hw_heartbeat_ms = 128 * 1000;
platform_set_drvdata(pdev, wdt);
/* Enable WD_RST_WK - WDT expire results in a restart */
ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2,
MAX77620_ONOFFCNFG2_WD_RST_WK,
MAX77620_ONOFFCNFG2_WD_RST_WK);
if (ret < 0) {
dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret);
return ret;
}
/* Set WDT clear in OFF and sleep mode */
ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
MAX77620_WDTOFFC | MAX77620_WDTSLPC,
MAX77620_WDTOFFC | MAX77620_WDTSLPC);
if (ret < 0) {
dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret);
return ret;
}
/* Check if WDT running and if yes then set flags properly */
ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, ®val);
if (ret < 0) {
dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret);
return ret;
}
switch (regval & MAX77620_TWD_MASK) {
case MAX77620_TWD_2s:
wdt_dev->timeout = 2;
break;
case MAX77620_TWD_16s:
wdt_dev->timeout = 16;
break;
case MAX77620_TWD_64s:
wdt_dev->timeout = 64;
break;
default:
wdt_dev->timeout = 128;
break;
}
if (regval & MAX77620_WDTEN)
set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
watchdog_set_nowayout(wdt_dev, nowayout);
watchdog_set_drvdata(wdt_dev, wdt);
ret = watchdog_register_device(wdt_dev);
if (ret < 0) {
dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
return ret;
}
return 0;
}
static int max77620_wdt_remove(struct platform_device *pdev)
{
struct max77620_wdt *wdt = platform_get_drvdata(pdev);
max77620_wdt_stop(&wdt->wdt_dev);
watchdog_unregister_device(&wdt->wdt_dev);
return 0;
}
static struct platform_device_id max77620_wdt_devtype[] = {
{ .name = "max77620-watchdog", },
{ },
};
static struct platform_driver max77620_wdt_driver = {
.driver = {
.name = "max77620-watchdog",
},
.probe = max77620_wdt_probe,
.remove = max77620_wdt_remove,
.id_table = max77620_wdt_devtype,
};
module_platform_driver(max77620_wdt_driver);
MODULE_DESCRIPTION("Max77620 watchdog timer driver");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");
|
