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
286
|
#include <linux/init.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <asm/of_platform.h>
#include <asm/uaccess.h>
#include <asm/mpc52xx.h>
#define GPT_MODE_WDT (1<<15)
#define GPT_MODE_CE (1<<12)
#define GPT_MODE_MS_TIMER (0x4)
struct mpc5200_wdt {
unsigned count; /* timer ticks before watchdog kicks in */
long ipb_freq;
struct miscdevice miscdev;
struct resource mem;
struct mpc52xx_gpt __iomem *regs;
spinlock_t io_lock;
};
/* is_active stores wether or not the /dev/watchdog device is opened */
static unsigned long is_active;
/* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from
* file operations, which sucks. But there can be max 1 watchdog anyway, so...
*/
static struct mpc5200_wdt *wdt_global;
/* helper to calculate timeout in timer counts */
static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout)
{
/* use biggest prescaler of 64k */
wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout;
if (wdt->count > 0xffff)
wdt->count = 0xffff;
}
/* return timeout in seconds (calculated from timer count) */
static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt)
{
return wdt->count * 0x10000 / wdt->ipb_freq;
}
/* watchdog operations */
static int mpc5200_wdt_start(struct mpc5200_wdt *wdt)
{
spin_lock(&wdt->io_lock);
/* disable */
out_be32(&wdt->regs->mode, 0);
/* set timeout, with maximum prescaler */
out_be32(&wdt->regs->count, 0x0 | wdt->count);
/* enable watchdog */
out_be32(&wdt->regs->mode, GPT_MODE_CE | GPT_MODE_WDT | GPT_MODE_MS_TIMER);
spin_unlock(&wdt->io_lock);
return 0;
}
static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt)
{
spin_lock(&wdt->io_lock);
/* writing A5 to OCPW resets the watchdog */
out_be32(&wdt->regs->mode, 0xA5000000 | (0xffffff & in_be32(&wdt->regs->mode)));
spin_unlock(&wdt->io_lock);
return 0;
}
static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt)
{
spin_lock(&wdt->io_lock);
/* disable */
out_be32(&wdt->regs->mode, 0);
spin_unlock(&wdt->io_lock);
return 0;
}
/* file operations */
static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
struct mpc5200_wdt *wdt = file->private_data;
mpc5200_wdt_ping(wdt);
return 0;
}
static struct watchdog_info mpc5200_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "mpc5200 watchdog on GPT0",
};
static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct mpc5200_wdt *wdt = file->private_data;
int __user *data = (int __user *)arg;
int timeout;
int ret = 0;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(data, &mpc5200_wdt_info,
sizeof(mpc5200_wdt_info));
if (ret)
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, data);
break;
case WDIOC_KEEPALIVE:
mpc5200_wdt_ping(wdt);
break;
case WDIOC_SETTIMEOUT:
ret = get_user(timeout, data);
if (ret)
break;
mpc5200_wdt_set_timeout(wdt, timeout);
mpc5200_wdt_start(wdt);
/* fall through and return the timeout */
case WDIOC_GETTIMEOUT:
timeout = mpc5200_wdt_get_timeout(wdt);
ret = put_user(timeout, data);
break;
default:
ret = -ENOTTY;
}
return ret;
}
static int mpc5200_wdt_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &is_active))
return -EBUSY;
/* Set and activate the watchdog */
mpc5200_wdt_set_timeout(wdt_global, 30);
mpc5200_wdt_start(wdt_global);
file->private_data = wdt_global;
return nonseekable_open(inode, file);
}
static int mpc5200_wdt_release(struct inode *inode, struct file *file)
{
#if WATCHDOG_NOWAYOUT == 0
struct mpc5200_wdt *wdt = file->private_data;
mpc5200_wdt_stop(wdt);
wdt->count = 0; /* == disabled */
#endif
clear_bit(0, &is_active);
return 0;
}
static struct file_operations mpc5200_wdt_fops = {
.owner = THIS_MODULE,
.write = mpc5200_wdt_write,
.ioctl = mpc5200_wdt_ioctl,
.open = mpc5200_wdt_open,
.release = mpc5200_wdt_release,
};
/* module operations */
static int mpc5200_wdt_probe(struct of_device *op, const struct of_device_id *match)
{
struct mpc5200_wdt *wdt;
int err;
const void *has_wdt;
int size;
has_wdt = of_get_property(op->node, "has-wdt", NULL);
if (!has_wdt)
return -ENODEV;
wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node);
err = of_address_to_resource(op->node, 0, &wdt->mem);
if (err)
goto out_free;
size = wdt->mem.end - wdt->mem.start + 1;
if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) {
err = -ENODEV;
goto out_free;
}
wdt->regs = ioremap(wdt->mem.start, size);
if (!wdt->regs) {
err = -ENODEV;
goto out_release;
}
dev_set_drvdata(&op->dev, wdt);
spin_lock_init(&wdt->io_lock);
wdt->miscdev = (struct miscdevice) {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mpc5200_wdt_fops,
.parent = &op->dev,
};
wdt_global = wdt;
err = misc_register(&wdt->miscdev);
if (!err)
return 0;
iounmap(wdt->regs);
out_release:
release_mem_region(wdt->mem.start, size);
out_free:
kfree(wdt);
return err;
}
static int mpc5200_wdt_remove(struct of_device *op)
{
struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
mpc5200_wdt_stop(wdt);
misc_deregister(&wdt->miscdev);
iounmap(wdt->regs);
release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1);
kfree(wdt);
return 0;
}
static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state)
{
struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
mpc5200_wdt_stop(wdt);
return 0;
}
static int mpc5200_wdt_resume(struct of_device *op)
{
struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
if (wdt->count)
mpc5200_wdt_start(wdt);
return 0;
}
static int mpc5200_wdt_shutdown(struct of_device *op)
{
struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
mpc5200_wdt_stop(wdt);
return 0;
}
static struct of_device_id mpc5200_wdt_match[] = {
{ .compatible = "mpc5200-gpt", },
{},
};
static struct of_platform_driver mpc5200_wdt_driver = {
.owner = THIS_MODULE,
.name = "mpc5200-gpt-wdt",
.match_table = mpc5200_wdt_match,
.probe = mpc5200_wdt_probe,
.remove = mpc5200_wdt_remove,
.suspend = mpc5200_wdt_suspend,
.resume = mpc5200_wdt_resume,
.shutdown = mpc5200_wdt_shutdown,
};
static int __init mpc5200_wdt_init(void)
{
return of_register_platform_driver(&mpc5200_wdt_driver);
}
static void __exit mpc5200_wdt_exit(void)
{
of_unregister_platform_driver(&mpc5200_wdt_driver);
}
module_init(mpc5200_wdt_init);
module_exit(mpc5200_wdt_exit);
MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
