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20#include <linux/module.h>
21#include <linux/moduleparam.h>
22#include <linux/types.h>
23#include <linux/errno.h>
24#include <linux/kernel.h>
25#include <linux/fs.h>
26#include <linux/miscdevice.h>
27
28#include <linux/watchdog.h>
29#include <linux/init.h>
30#include <linux/platform_device.h>
31#include <linux/spinlock.h>
32#include <linux/uaccess.h>
33
34#include <asm/mach-rc32434/integ.h>
35
36#define PFX KBUILD_MODNAME ": "
37
38#define VERSION "1.0"
39
40static struct {
41 unsigned long inuse;
42 spinlock_t io_lock;
43} rc32434_wdt_device;
44
45static struct integ __iomem *wdt_reg;
46
47static int expect_close;
48
49
50
51extern unsigned int idt_cpu_freq;
52
53
54#define WTCOMP2SEC(x) (x / idt_cpu_freq)
55#define SEC2WTCOMP(x) (x * idt_cpu_freq)
56
57
58
59
60#define WATCHDOG_TIMEOUT 20
61
62static int timeout = WATCHDOG_TIMEOUT;
63module_param(timeout, int, 0);
64MODULE_PARM_DESC(timeout, "Watchdog timeout value, in seconds (default="
65 WATCHDOG_TIMEOUT ")");
66
67static int nowayout = WATCHDOG_NOWAYOUT;
68module_param(nowayout, int, 0);
69MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
70 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
71
72
73#define SET_BITS(addr, or, nand) \
74 writel((readl(&addr) | or) & ~nand, &addr)
75
76static int rc32434_wdt_set(int new_timeout)
77{
78 int max_to = WTCOMP2SEC((u32)-1);
79
80 if (new_timeout < 0 || new_timeout > max_to) {
81 printk(KERN_ERR PFX "timeout value must be between 0 and %d",
82 max_to);
83 return -EINVAL;
84 }
85 timeout = new_timeout;
86 spin_lock(&rc32434_wdt_device.io_lock);
87 writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
88 spin_unlock(&rc32434_wdt_device.io_lock);
89
90 return 0;
91}
92
93static void rc32434_wdt_start(void)
94{
95 u32 or, nand;
96
97 spin_lock(&rc32434_wdt_device.io_lock);
98
99
100 writel(0, &wdt_reg->wtcount);
101
102
103
104 nand = 1 << RC32434_ERR_WNE;
105 or = 1 << RC32434_ERR_WRE;
106
107
108 nand |= 1 << RC32434_ERR_WTO;
109
110 SET_BITS(wdt_reg->errcs, or, nand);
111
112
113 rc32434_wdt_set(timeout);
114
115
116 nand = 1 << RC32434_WTC_TO;
117 or = 1 << RC32434_WTC_EN;
118
119 SET_BITS(wdt_reg->wtc, or, nand);
120
121 spin_unlock(&rc32434_wdt_device.io_lock);
122 printk(KERN_INFO PFX "Started watchdog timer.\n");
123}
124
125static void rc32434_wdt_stop(void)
126{
127 spin_lock(&rc32434_wdt_device.io_lock);
128
129
130 SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
131
132 spin_unlock(&rc32434_wdt_device.io_lock);
133 printk(KERN_INFO PFX "Stopped watchdog timer.\n");
134}
135
136static void rc32434_wdt_ping(void)
137{
138 spin_lock(&rc32434_wdt_device.io_lock);
139 writel(0, &wdt_reg->wtcount);
140 spin_unlock(&rc32434_wdt_device.io_lock);
141}
142
143static int rc32434_wdt_open(struct inode *inode, struct file *file)
144{
145 if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
146 return -EBUSY;
147
148 if (nowayout)
149 __module_get(THIS_MODULE);
150
151 rc32434_wdt_start();
152 rc32434_wdt_ping();
153
154 return nonseekable_open(inode, file);
155}
156
157static int rc32434_wdt_release(struct inode *inode, struct file *file)
158{
159 if (expect_close == 42) {
160 rc32434_wdt_stop();
161 module_put(THIS_MODULE);
162 } else {
163 printk(KERN_CRIT PFX
164 "device closed unexpectedly. WDT will not stop!\n");
165 rc32434_wdt_ping();
166 }
167 clear_bit(0, &rc32434_wdt_device.inuse);
168 return 0;
169}
170
171static ssize_t rc32434_wdt_write(struct file *file, const char *data,
172 size_t len, loff_t *ppos)
173{
174 if (len) {
175 if (!nowayout) {
176 size_t i;
177
178
179 expect_close = 0;
180
181 for (i = 0; i != len; i++) {
182 char c;
183 if (get_user(c, data + i))
184 return -EFAULT;
185 if (c == 'V')
186 expect_close = 42;
187 }
188 }
189 rc32434_wdt_ping();
190 return len;
191 }
192 return 0;
193}
194
195static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
196 unsigned long arg)
197{
198 void __user *argp = (void __user *)arg;
199 int new_timeout;
200 unsigned int value;
201 static struct watchdog_info ident = {
202 .options = WDIOF_SETTIMEOUT |
203 WDIOF_KEEPALIVEPING |
204 WDIOF_MAGICCLOSE,
205 .identity = "RC32434_WDT Watchdog",
206 };
207 switch (cmd) {
208 case WDIOC_GETSUPPORT:
209 if (copy_to_user(argp, &ident, sizeof(ident)))
210 return -EFAULT;
211 break;
212 case WDIOC_GETSTATUS:
213 case WDIOC_GETBOOTSTATUS:
214 value = 0;
215 if (copy_to_user(argp, &value, sizeof(int)))
216 return -EFAULT;
217 break;
218 case WDIOC_SETOPTIONS:
219 if (copy_from_user(&value, argp, sizeof(int)))
220 return -EFAULT;
221 switch (value) {
222 case WDIOS_ENABLECARD:
223 rc32434_wdt_start();
224 break;
225 case WDIOS_DISABLECARD:
226 rc32434_wdt_stop();
227 break;
228 default:
229 return -EINVAL;
230 }
231 break;
232 case WDIOC_KEEPALIVE:
233 rc32434_wdt_ping();
234 break;
235 case WDIOC_SETTIMEOUT:
236 if (copy_from_user(&new_timeout, argp, sizeof(int)))
237 return -EFAULT;
238 if (rc32434_wdt_set(new_timeout))
239 return -EINVAL;
240
241 case WDIOC_GETTIMEOUT:
242 return copy_to_user(argp, &timeout, sizeof(int));
243 default:
244 return -ENOTTY;
245 }
246
247 return 0;
248}
249
250static const struct file_operations rc32434_wdt_fops = {
251 .owner = THIS_MODULE,
252 .llseek = no_llseek,
253 .write = rc32434_wdt_write,
254 .unlocked_ioctl = rc32434_wdt_ioctl,
255 .open = rc32434_wdt_open,
256 .release = rc32434_wdt_release,
257};
258
259static struct miscdevice rc32434_wdt_miscdev = {
260 .minor = WATCHDOG_MINOR,
261 .name = "watchdog",
262 .fops = &rc32434_wdt_fops,
263};
264
265static char banner[] __devinitdata = KERN_INFO PFX
266 "Watchdog Timer version " VERSION ", timer margin: %d sec\n";
267
268static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
269{
270 int ret;
271 struct resource *r;
272
273 r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
274 if (!r) {
275 printk(KERN_ERR PFX "failed to retrieve resources\n");
276 return -ENODEV;
277 }
278
279 wdt_reg = ioremap_nocache(r->start, r->end - r->start);
280 if (!wdt_reg) {
281 printk(KERN_ERR PFX "failed to remap I/O resources\n");
282 return -ENXIO;
283 }
284
285 spin_lock_init(&rc32434_wdt_device.io_lock);
286
287
288 rc32434_wdt_stop();
289
290
291
292 if (rc32434_wdt_set(timeout)) {
293 rc32434_wdt_set(WATCHDOG_TIMEOUT);
294 printk(KERN_INFO PFX
295 "timeout value must be between 0 and %d\n",
296 WTCOMP2SEC((u32)-1));
297 }
298
299 ret = misc_register(&rc32434_wdt_miscdev);
300 if (ret < 0) {
301 printk(KERN_ERR PFX "failed to register watchdog device\n");
302 goto unmap;
303 }
304
305 printk(banner, timeout);
306
307 return 0;
308
309unmap:
310 iounmap(wdt_reg);
311 return ret;
312}
313
314static int __devexit rc32434_wdt_remove(struct platform_device *pdev)
315{
316 misc_deregister(&rc32434_wdt_miscdev);
317 iounmap(wdt_reg);
318 return 0;
319}
320
321static void rc32434_wdt_shutdown(struct platform_device *pdev)
322{
323 rc32434_wdt_stop();
324}
325
326static struct platform_driver rc32434_wdt_driver = {
327 .probe = rc32434_wdt_probe,
328 .remove = __devexit_p(rc32434_wdt_remove),
329 .shutdown = rc32434_wdt_shutdown,
330 .driver = {
331 .name = "rc32434_wdt",
332 }
333};
334
335static int __init rc32434_wdt_init(void)
336{
337 return platform_driver_register(&rc32434_wdt_driver);
338}
339
340static void __exit rc32434_wdt_exit(void)
341{
342 platform_driver_unregister(&rc32434_wdt_driver);
343}
344
345module_init(rc32434_wdt_init);
346module_exit(rc32434_wdt_exit);
347
348MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
349 "Florian Fainelli <florian@openwrt.org>");
350MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
351MODULE_LICENSE("GPL");
352MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
353
