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
|
/*
* sunxi Watchdog Driver
*
* Copyright (c) 2013 Carlo Caione
* 2012 Henrik Nordstrom
*
* 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.
*
* Based on xen_wdt.c
* (c) Copyright 2010 Novell, Inc.
*/
#include <linux/clk.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/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define WDT_MAX_TIMEOUT 16
#define WDT_MIN_TIMEOUT 1
#define WDT_MODE_TIMEOUT(n) ((n) << 3)
#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
#define WDT_CTRL 0x00
#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
#define WDT_MODE 0x04
#define WDT_MODE_EN (1 << 0)
#define WDT_MODE_RST_EN (1 << 1)
#define DRV_NAME "sunxi-wdt"
#define DRV_VERSION "1.0"
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int timeout = WDT_MAX_TIMEOUT;
struct sunxi_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
};
/*
* wdt_timeout_map maps the watchdog timer interval value in seconds to
* the value of the register WDT_MODE bit 3:6
*
* [timeout seconds] = register value
*
*/
static const int wdt_timeout_map[] = {
[1] = 0b0001, /* 1s */
[2] = 0b0010, /* 2s */
[3] = 0b0011, /* 3s */
[4] = 0b0100, /* 4s */
[5] = 0b0101, /* 5s */
[6] = 0b0110, /* 6s */
[8] = 0b0111, /* 8s */
[10] = 0b1000, /* 10s */
[12] = 0b1001, /* 12s */
[14] = 0b1010, /* 14s */
[16] = 0b1011, /* 16s */
};
static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
return 0;
}
static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
u32 reg;
if (wdt_timeout_map[timeout] == 0)
timeout++;
sunxi_wdt->wdt_dev.timeout = timeout;
reg = ioread32(wdt_base + WDT_MODE);
reg &= ~WDT_TIMEOUT_MASK;
reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]);
iowrite32(reg, wdt_base + WDT_MODE);
sunxi_wdt_ping(wdt_dev);
return 0;
}
static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
iowrite32(0, wdt_base + WDT_MODE);
return 0;
}
static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
{
u32 reg;
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
int ret;
ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
sunxi_wdt->wdt_dev.timeout);
if (ret < 0)
return ret;
reg = ioread32(wdt_base + WDT_MODE);
reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);
iowrite32(reg, wdt_base + WDT_MODE);
return 0;
}
static const struct watchdog_info sunxi_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops sunxi_wdt_ops = {
.owner = THIS_MODULE,
.start = sunxi_wdt_start,
.stop = sunxi_wdt_stop,
.ping = sunxi_wdt_ping,
.set_timeout = sunxi_wdt_set_timeout,
};
static int sunxi_wdt_probe(struct platform_device *pdev)
{
struct sunxi_wdt_dev *sunxi_wdt;
struct resource *res;
int err;
sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
if (!sunxi_wdt)
return -EINVAL;
platform_set_drvdata(pdev, sunxi_wdt);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sunxi_wdt->wdt_base))
return PTR_ERR(sunxi_wdt->wdt_base);
sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
sunxi_wdt->wdt_dev.parent = &pdev->dev;
watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
err = watchdog_register_device(&sunxi_wdt->wdt_dev);
if (unlikely(err))
return err;
dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
sunxi_wdt->wdt_dev.timeout, nowayout);
return 0;
}
static int sunxi_wdt_remove(struct platform_device *pdev)
{
struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(&sunxi_wdt->wdt_dev);
watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);
return 0;
}
static void sunxi_wdt_shutdown(struct platform_device *pdev)
{
struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
}
static const struct of_device_id sunxi_wdt_dt_ids[] = {
{ .compatible = "allwinner,sun4i-wdt" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
static struct platform_driver sunxi_wdt_driver = {
.probe = sunxi_wdt_probe,
.remove = sunxi_wdt_remove,
.shutdown = sunxi_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
.of_match_table = of_match_ptr(sunxi_wdt_dt_ids)
},
};
module_platform_driver(sunxi_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@gmail.com>");
MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
MODULE_VERSION(DRV_VERSION);
|
