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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Maxim MAX77620 Watchdog Driver
*
* Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
* Copyright (C) 2022 Luca Ceresoli
*
* Author: Laxman Dewangan <ldewangan@nvidia.com>
* Author: Luca Ceresoli <luca@lucaceresoli.net>
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/mfd/max77620.h>
#include <linux/mfd/max77714.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_variant - Data specific to a chip variant
* @wdt_info: watchdog descriptor
* @reg_onoff_cnfg2: ONOFF_CNFG2 register offset
* @reg_cnfg_glbl2: CNFG_GLBL2 register offset
* @reg_cnfg_glbl3: CNFG_GLBL3 register offset
* @wdtc_mask: WDTC bit mask in CNFG_GLBL3 (=bits to update to ping the watchdog)
* @bit_wd_rst_wk: WD_RST_WK bit offset within ONOFF_CNFG2
* @cnfg_glbl2_cfg_bits: configuration bits to enable in CNFG_GLBL2 register
*/
struct max77620_variant {
u8 reg_onoff_cnfg2;
u8 reg_cnfg_glbl2;
u8 reg_cnfg_glbl3;
u8 wdtc_mask;
u8 bit_wd_rst_wk;
u8 cnfg_glbl2_cfg_bits;
};
struct max77620_wdt {
struct device *dev;
struct regmap *rmap;
const struct max77620_variant *drv_data;
struct watchdog_device wdt_dev;
};
static const struct max77620_variant max77620_wdt_data = {
.reg_onoff_cnfg2 = MAX77620_REG_ONOFFCNFG2,
.reg_cnfg_glbl2 = MAX77620_REG_CNFGGLBL2,
.reg_cnfg_glbl3 = MAX77620_REG_CNFGGLBL3,
.wdtc_mask = MAX77620_WDTC_MASK,
.bit_wd_rst_wk = MAX77620_ONOFFCNFG2_WD_RST_WK,
/* Set WDT clear in OFF and sleep mode */
.cnfg_glbl2_cfg_bits = MAX77620_WDTSLPC | MAX77620_WDTOFFC,
};
static const struct max77620_variant max77714_wdt_data = {
.reg_onoff_cnfg2 = MAX77714_CNFG2_ONOFF,
.reg_cnfg_glbl2 = MAX77714_CNFG_GLBL2,
.reg_cnfg_glbl3 = MAX77714_CNFG_GLBL3,
.wdtc_mask = MAX77714_WDTC,
.bit_wd_rst_wk = MAX77714_WD_RST_WK,
/* Set WDT clear in sleep mode (there is no WDTOFFC on MAX77714) */
.cnfg_glbl2_cfg_bits = MAX77714_WDTSLPC,
};
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, wdt->drv_data->reg_cnfg_glbl2,
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, wdt->drv_data->reg_cnfg_glbl2,
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, wdt->drv_data->reg_cnfg_glbl3,
wdt->drv_data->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;
}
/*
* "If the value of TWD needs to be changed, clear the system
* watchdog timer first [...], then change the value of TWD."
* (MAX77714 datasheet but applies to MAX77620 too)
*/
ret = regmap_update_bits(wdt->rmap, wdt->drv_data->reg_cnfg_glbl3,
wdt->drv_data->wdtc_mask, 0x1);
if (ret < 0)
return ret;
ret = regmap_update_bits(wdt->rmap, wdt->drv_data->reg_cnfg_glbl2,
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)
{
const struct platform_device_id *id = platform_get_device_id(pdev);
struct device *dev = &pdev->dev;
struct max77620_wdt *wdt;
struct watchdog_device *wdt_dev;
unsigned int regval;
int ret;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->dev = dev;
wdt->drv_data = (const struct max77620_variant *) id->driver_data;
wdt->rmap = dev_get_regmap(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, wdt->drv_data->reg_onoff_cnfg2,
wdt->drv_data->bit_wd_rst_wk,
wdt->drv_data->bit_wd_rst_wk);
if (ret < 0) {
dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret);
return ret;
}
/* Set the "auto WDT clear" bits available on the chip */
ret = regmap_update_bits(wdt->rmap, wdt->drv_data->reg_cnfg_glbl2,
wdt->drv_data->cnfg_glbl2_cfg_bits,
wdt->drv_data->cnfg_glbl2_cfg_bits);
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, wdt->drv_data->reg_cnfg_glbl2, ®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);
watchdog_stop_on_unregister(wdt_dev);
return devm_watchdog_register_device(dev, wdt_dev);
}
static const struct platform_device_id max77620_wdt_devtype[] = {
{ "max77620-watchdog", (kernel_ulong_t)&max77620_wdt_data },
{ "max77714-watchdog", (kernel_ulong_t)&max77714_wdt_data },
{ },
};
MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype);
static struct platform_driver max77620_wdt_driver = {
.driver = {
.name = "max77620-watchdog",
},
.probe = max77620_wdt_probe,
.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_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
MODULE_LICENSE("GPL v2");
|
