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13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/fs.h>
18#include <linux/miscdevice.h>
19#include <linux/platform_device.h>
20#include <linux/watchdog.h>
21#include <linux/init.h>
22#include <linux/uaccess.h>
23#include <linux/io.h>
24#include <linux/spinlock.h>
25#include <mach/bridge-regs.h>
26#include <plat/orion_wdt.h>
27
28
29
30
31#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
32#define WDT_EN 0x0010
33#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
34
35#define WDT_MAX_CYCLE_COUNT 0xffffffff
36#define WDT_IN_USE 0
37#define WDT_OK_TO_CLOSE 1
38
39static int nowayout = WATCHDOG_NOWAYOUT;
40static int heartbeat = -1;
41static unsigned int wdt_max_duration;
42static unsigned int wdt_tclk;
43static unsigned long wdt_status;
44static spinlock_t wdt_lock;
45
46static void orion_wdt_ping(void)
47{
48 spin_lock(&wdt_lock);
49
50
51 writel(wdt_tclk * heartbeat, WDT_VAL);
52
53 spin_unlock(&wdt_lock);
54}
55
56static void orion_wdt_enable(void)
57{
58 u32 reg;
59
60 spin_lock(&wdt_lock);
61
62
63 writel(wdt_tclk * heartbeat, WDT_VAL);
64
65
66 reg = readl(BRIDGE_CAUSE);
67 reg &= ~WDT_INT_REQ;
68 writel(reg, BRIDGE_CAUSE);
69
70
71 reg = readl(TIMER_CTRL);
72 reg |= WDT_EN;
73 writel(reg, TIMER_CTRL);
74
75
76 reg = readl(RSTOUTn_MASK);
77 reg |= WDT_RESET_OUT_EN;
78 writel(reg, RSTOUTn_MASK);
79
80 spin_unlock(&wdt_lock);
81}
82
83static void orion_wdt_disable(void)
84{
85 u32 reg;
86
87 spin_lock(&wdt_lock);
88
89
90 reg = readl(RSTOUTn_MASK);
91 reg &= ~WDT_RESET_OUT_EN;
92 writel(reg, RSTOUTn_MASK);
93
94
95 reg = readl(TIMER_CTRL);
96 reg &= ~WDT_EN;
97 writel(reg, TIMER_CTRL);
98
99 spin_unlock(&wdt_lock);
100}
101
102static int orion_wdt_get_timeleft(int *time_left)
103{
104 spin_lock(&wdt_lock);
105 *time_left = readl(WDT_VAL) / wdt_tclk;
106 spin_unlock(&wdt_lock);
107 return 0;
108}
109
110static int orion_wdt_open(struct inode *inode, struct file *file)
111{
112 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
113 return -EBUSY;
114 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
115 orion_wdt_enable();
116 return nonseekable_open(inode, file);
117}
118
119static ssize_t orion_wdt_write(struct file *file, const char *data,
120 size_t len, loff_t *ppos)
121{
122 if (len) {
123 if (!nowayout) {
124 size_t i;
125
126 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
127 for (i = 0; i != len; i++) {
128 char c;
129
130 if (get_user(c, data + i))
131 return -EFAULT;
132 if (c == 'V')
133 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
134 }
135 }
136 orion_wdt_ping();
137 }
138 return len;
139}
140
141static int orion_wdt_settimeout(int new_time)
142{
143 if ((new_time <= 0) || (new_time > wdt_max_duration))
144 return -EINVAL;
145
146
147
148 heartbeat = new_time;
149 return 0;
150}
151
152static const struct watchdog_info ident = {
153 .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
154 WDIOF_KEEPALIVEPING,
155 .identity = "Orion Watchdog",
156};
157
158static long orion_wdt_ioctl(struct file *file, unsigned int cmd,
159 unsigned long arg)
160{
161 int ret = -ENOTTY;
162 int time;
163
164 switch (cmd) {
165 case WDIOC_GETSUPPORT:
166 ret = copy_to_user((struct watchdog_info *)arg, &ident,
167 sizeof(ident)) ? -EFAULT : 0;
168 break;
169
170 case WDIOC_GETSTATUS:
171 case WDIOC_GETBOOTSTATUS:
172 ret = put_user(0, (int *)arg);
173 break;
174
175 case WDIOC_KEEPALIVE:
176 orion_wdt_ping();
177 ret = 0;
178 break;
179
180 case WDIOC_SETTIMEOUT:
181 ret = get_user(time, (int *)arg);
182 if (ret)
183 break;
184
185 if (orion_wdt_settimeout(time)) {
186 ret = -EINVAL;
187 break;
188 }
189 orion_wdt_ping();
190
191
192 case WDIOC_GETTIMEOUT:
193 ret = put_user(heartbeat, (int *)arg);
194 break;
195
196 case WDIOC_GETTIMELEFT:
197 if (orion_wdt_get_timeleft(&time)) {
198 ret = -EINVAL;
199 break;
200 }
201 ret = put_user(time, (int *)arg);
202 break;
203 }
204 return ret;
205}
206
207static int orion_wdt_release(struct inode *inode, struct file *file)
208{
209 if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
210 orion_wdt_disable();
211 else
212 printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
213 "timer will not stop\n");
214 clear_bit(WDT_IN_USE, &wdt_status);
215 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
216
217 return 0;
218}
219
220
221static const struct file_operations orion_wdt_fops = {
222 .owner = THIS_MODULE,
223 .llseek = no_llseek,
224 .write = orion_wdt_write,
225 .unlocked_ioctl = orion_wdt_ioctl,
226 .open = orion_wdt_open,
227 .release = orion_wdt_release,
228};
229
230static struct miscdevice orion_wdt_miscdev = {
231 .minor = WATCHDOG_MINOR,
232 .name = "watchdog",
233 .fops = &orion_wdt_fops,
234};
235
236static int __devinit orion_wdt_probe(struct platform_device *pdev)
237{
238 struct orion_wdt_platform_data *pdata = pdev->dev.platform_data;
239 int ret;
240
241 if (pdata) {
242 wdt_tclk = pdata->tclk;
243 } else {
244 printk(KERN_ERR "Orion Watchdog misses platform data\n");
245 return -ENODEV;
246 }
247
248 if (orion_wdt_miscdev.parent)
249 return -EBUSY;
250 orion_wdt_miscdev.parent = &pdev->dev;
251
252 wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
253 if (orion_wdt_settimeout(heartbeat))
254 heartbeat = wdt_max_duration;
255
256 ret = misc_register(&orion_wdt_miscdev);
257 if (ret)
258 return ret;
259
260 printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n",
261 heartbeat, nowayout ? ", nowayout" : "");
262 return 0;
263}
264
265static int __devexit orion_wdt_remove(struct platform_device *pdev)
266{
267 int ret;
268
269 if (test_bit(WDT_IN_USE, &wdt_status)) {
270 orion_wdt_disable();
271 clear_bit(WDT_IN_USE, &wdt_status);
272 }
273
274 ret = misc_deregister(&orion_wdt_miscdev);
275 if (!ret)
276 orion_wdt_miscdev.parent = NULL;
277
278 return ret;
279}
280
281static void orion_wdt_shutdown(struct platform_device *pdev)
282{
283 if (test_bit(WDT_IN_USE, &wdt_status))
284 orion_wdt_disable();
285}
286
287static struct platform_driver orion_wdt_driver = {
288 .probe = orion_wdt_probe,
289 .remove = __devexit_p(orion_wdt_remove),
290 .shutdown = orion_wdt_shutdown,
291 .driver = {
292 .owner = THIS_MODULE,
293 .name = "orion_wdt",
294 },
295};
296
297static int __init orion_wdt_init(void)
298{
299 spin_lock_init(&wdt_lock);
300 return platform_driver_register(&orion_wdt_driver);
301}
302
303static void __exit orion_wdt_exit(void)
304{
305 platform_driver_unregister(&orion_wdt_driver);
306}
307
308module_init(orion_wdt_init);
309module_exit(orion_wdt_exit);
310
311MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
312MODULE_DESCRIPTION("Orion Processor Watchdog");
313
314module_param(heartbeat, int, 0);
315MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
316
317module_param(nowayout, int, 0);
318MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
319 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
320
321MODULE_LICENSE("GPL");
322MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
323
