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
|
/*
* Meson Watchdog Driver
*
* Copyright (c) 2014 Carlo Caione
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define DRV_NAME "meson_wdt"
#define MESON_WDT_TC 0x00
#define MESON_WDT_DC_RESET (3 << 24)
#define MESON_WDT_RESET 0x04
#define MESON_WDT_TIMEOUT 30
#define MESON_WDT_MIN_TIMEOUT 1
#define MESON_SEC_TO_TC(s, c) ((s) * (c))
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int timeout;
struct meson_wdt_data {
unsigned int enable;
unsigned int terminal_count_mask;
unsigned int count_unit;
};
static struct meson_wdt_data meson6_wdt_data = {
.enable = BIT(22),
.terminal_count_mask = 0x3fffff,
.count_unit = 100000, /* 10 us */
};
static struct meson_wdt_data meson8b_wdt_data = {
.enable = BIT(19),
.terminal_count_mask = 0xffff,
.count_unit = 7812, /* 128 us */
};
struct meson_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
const struct meson_wdt_data *data;
};
static int meson_wdt_restart(struct watchdog_device *wdt_dev,
unsigned long action, void *data)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 tc_reboot = MESON_WDT_DC_RESET;
tc_reboot |= meson_wdt->data->enable;
while (1) {
writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
mdelay(5);
}
return 0;
}
static int meson_wdt_ping(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
return 0;
}
static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg &= ~meson_wdt->data->terminal_count_mask;
reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
}
static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
wdt_dev->timeout = timeout;
meson_wdt_change_timeout(wdt_dev, timeout);
meson_wdt_ping(wdt_dev);
return 0;
}
static int meson_wdt_stop(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg &= ~meson_wdt->data->enable;
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
return 0;
}
static int meson_wdt_start(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
meson_wdt_ping(wdt_dev);
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg |= meson_wdt->data->enable;
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
return 0;
}
static const struct watchdog_info meson_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops meson_wdt_ops = {
.owner = THIS_MODULE,
.start = meson_wdt_start,
.stop = meson_wdt_stop,
.ping = meson_wdt_ping,
.set_timeout = meson_wdt_set_timeout,
.restart = meson_wdt_restart,
};
static const struct of_device_id meson_wdt_dt_ids[] = {
{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
static int meson_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
struct meson_wdt_dev *meson_wdt;
const struct of_device_id *of_id;
int err;
meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
if (!meson_wdt)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(meson_wdt->wdt_base))
return PTR_ERR(meson_wdt->wdt_base);
of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
if (!of_id) {
dev_err(&pdev->dev, "Unable to initialize WDT data\n");
return -ENODEV;
}
meson_wdt->data = of_id->data;
meson_wdt->wdt_dev.parent = &pdev->dev;
meson_wdt->wdt_dev.info = &meson_wdt_info;
meson_wdt->wdt_dev.ops = &meson_wdt_ops;
meson_wdt->wdt_dev.max_timeout =
meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
meson_wdt->wdt_dev.timeout = min_t(unsigned int,
MESON_WDT_TIMEOUT,
meson_wdt->wdt_dev.max_timeout);
watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev);
watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
meson_wdt_stop(&meson_wdt->wdt_dev);
watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
err = devm_watchdog_register_device(&pdev->dev, &meson_wdt->wdt_dev);
if (err)
return err;
dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
meson_wdt->wdt_dev.timeout, nowayout);
return 0;
}
static struct platform_driver meson_wdt_driver = {
.probe = meson_wdt_probe,
.driver = {
.name = DRV_NAME,
.of_match_table = meson_wdt_dt_ids,
},
};
module_platform_driver(meson_wdt_driver);
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
|
