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-rw-r--r--drivers/watchdog/shwdt.c227
1 files changed, 168 insertions, 59 deletions
diff --git a/drivers/watchdog/shwdt.c b/drivers/watchdog/shwdt.c
index bee1f5865825..b7d2f8a0422b 100644
--- a/drivers/watchdog/shwdt.c
+++ b/drivers/watchdog/shwdt.c
@@ -19,6 +19,7 @@
19 */ 19 */
20#include <linux/module.h> 20#include <linux/module.h>
21#include <linux/moduleparam.h> 21#include <linux/moduleparam.h>
22#include <linux/platform_device.h>
22#include <linux/init.h> 23#include <linux/init.h>
23#include <linux/types.h> 24#include <linux/types.h>
24#include <linux/miscdevice.h> 25#include <linux/miscdevice.h>
@@ -28,11 +29,12 @@
28#include <linux/ioport.h> 29#include <linux/ioport.h>
29#include <linux/fs.h> 30#include <linux/fs.h>
30#include <linux/mm.h> 31#include <linux/mm.h>
32#include <linux/slab.h>
31#include <linux/io.h> 33#include <linux/io.h>
32#include <linux/uaccess.h> 34#include <linux/uaccess.h>
33#include <asm/watchdog.h> 35#include <asm/watchdog.h>
34 36
35#define PFX "shwdt: " 37#define DRV_NAME "sh-wdt"
36 38
37/* 39/*
38 * Default clock division ratio is 5.25 msecs. For an additional table of 40 * Default clock division ratio is 5.25 msecs. For an additional table of
@@ -62,31 +64,36 @@
62 * misses its deadline, the kernel timer will allow the WDT to overflow. 64 * misses its deadline, the kernel timer will allow the WDT to overflow.
63 */ 65 */
64static int clock_division_ratio = WTCSR_CKS_4096; 66static int clock_division_ratio = WTCSR_CKS_4096;
65
66#define next_ping_period(cks) msecs_to_jiffies(cks - 4) 67#define next_ping_period(cks) msecs_to_jiffies(cks - 4)
67 68
68static void sh_wdt_ping(unsigned long data);
69
70static unsigned long shwdt_is_open;
71static const struct watchdog_info sh_wdt_info; 69static const struct watchdog_info sh_wdt_info;
72static char shwdt_expect_close; 70static struct platform_device *sh_wdt_dev;
73static DEFINE_TIMER(timer, sh_wdt_ping, 0, 0);
74static unsigned long next_heartbeat;
75static DEFINE_SPINLOCK(shwdt_lock); 71static DEFINE_SPINLOCK(shwdt_lock);
76 72
77#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */ 73#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
78static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ 74static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
79static int nowayout = WATCHDOG_NOWAYOUT; 75static int nowayout = WATCHDOG_NOWAYOUT;
76static unsigned long next_heartbeat;
77
78struct sh_wdt {
79 void __iomem *base;
80 struct device *dev;
80 81
81static void sh_wdt_start(void) 82 struct timer_list timer;
83
84 unsigned long enabled;
85 char expect_close;
86};
87
88static void sh_wdt_start(struct sh_wdt *wdt)
82{ 89{
83 __u8 csr;
84 unsigned long flags; 90 unsigned long flags;
91 u8 csr;
85 92
86 spin_lock_irqsave(&shwdt_lock, flags); 93 spin_lock_irqsave(&shwdt_lock, flags);
87 94
88 next_heartbeat = jiffies + (heartbeat * HZ); 95 next_heartbeat = jiffies + (heartbeat * HZ);
89 mod_timer(&timer, next_ping_period(clock_division_ratio)); 96 mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
90 97
91 csr = sh_wdt_read_csr(); 98 csr = sh_wdt_read_csr();
92 csr |= WTCSR_WT | clock_division_ratio; 99 csr |= WTCSR_WT | clock_division_ratio;
@@ -115,22 +122,23 @@ static void sh_wdt_start(void)
115 spin_unlock_irqrestore(&shwdt_lock, flags); 122 spin_unlock_irqrestore(&shwdt_lock, flags);
116} 123}
117 124
118static void sh_wdt_stop(void) 125static void sh_wdt_stop(struct sh_wdt *wdt)
119{ 126{
120 __u8 csr;
121 unsigned long flags; 127 unsigned long flags;
128 u8 csr;
122 129
123 spin_lock_irqsave(&shwdt_lock, flags); 130 spin_lock_irqsave(&shwdt_lock, flags);
124 131
125 del_timer(&timer); 132 del_timer(&wdt->timer);
126 133
127 csr = sh_wdt_read_csr(); 134 csr = sh_wdt_read_csr();
128 csr &= ~WTCSR_TME; 135 csr &= ~WTCSR_TME;
129 sh_wdt_write_csr(csr); 136 sh_wdt_write_csr(csr);
137
130 spin_unlock_irqrestore(&shwdt_lock, flags); 138 spin_unlock_irqrestore(&shwdt_lock, flags);
131} 139}
132 140
133static inline void sh_wdt_keepalive(void) 141static inline void sh_wdt_keepalive(struct sh_wdt *wdt)
134{ 142{
135 unsigned long flags; 143 unsigned long flags;
136 144
@@ -154,11 +162,12 @@ static int sh_wdt_set_heartbeat(int t)
154 162
155static void sh_wdt_ping(unsigned long data) 163static void sh_wdt_ping(unsigned long data)
156{ 164{
165 struct sh_wdt *wdt = (struct sh_wdt *)data;
157 unsigned long flags; 166 unsigned long flags;
158 167
159 spin_lock_irqsave(&shwdt_lock, flags); 168 spin_lock_irqsave(&shwdt_lock, flags);
160 if (time_before(jiffies, next_heartbeat)) { 169 if (time_before(jiffies, next_heartbeat)) {
161 __u8 csr; 170 u8 csr;
162 171
163 csr = sh_wdt_read_csr(); 172 csr = sh_wdt_read_csr();
164 csr &= ~WTCSR_IOVF; 173 csr &= ~WTCSR_IOVF;
@@ -166,37 +175,43 @@ static void sh_wdt_ping(unsigned long data)
166 175
167 sh_wdt_write_cnt(0); 176 sh_wdt_write_cnt(0);
168 177
169 mod_timer(&timer, next_ping_period(clock_division_ratio)); 178 mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
170 } else 179 } else
171 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping " 180 dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
172 "the watchdog\n"); 181 "the watchdog\n");
173 spin_unlock_irqrestore(&shwdt_lock, flags); 182 spin_unlock_irqrestore(&shwdt_lock, flags);
174} 183}
175 184
176static int sh_wdt_open(struct inode *inode, struct file *file) 185static int sh_wdt_open(struct inode *inode, struct file *file)
177{ 186{
178 if (test_and_set_bit(0, &shwdt_is_open)) 187 struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
188
189 if (test_and_set_bit(0, &wdt->enabled))
179 return -EBUSY; 190 return -EBUSY;
180 if (nowayout) 191 if (nowayout)
181 __module_get(THIS_MODULE); 192 __module_get(THIS_MODULE);
182 193
183 sh_wdt_start(); 194 file->private_data = wdt;
195
196 sh_wdt_start(wdt);
184 197
185 return nonseekable_open(inode, file); 198 return nonseekable_open(inode, file);
186} 199}
187 200
188static int sh_wdt_close(struct inode *inode, struct file *file) 201static int sh_wdt_close(struct inode *inode, struct file *file)
189{ 202{
190 if (shwdt_expect_close == 42) { 203 struct sh_wdt *wdt = file->private_data;
191 sh_wdt_stop(); 204
205 if (wdt->expect_close == 42) {
206 sh_wdt_stop(wdt);
192 } else { 207 } else {
193 printk(KERN_CRIT PFX "Unexpected close, not " 208 dev_crit(wdt->dev, "Unexpected close, not "
194 "stopping watchdog!\n"); 209 "stopping watchdog!\n");
195 sh_wdt_keepalive(); 210 sh_wdt_keepalive(wdt);
196 } 211 }
197 212
198 clear_bit(0, &shwdt_is_open); 213 clear_bit(0, &wdt->enabled);
199 shwdt_expect_close = 0; 214 wdt->expect_close = 0;
200 215
201 return 0; 216 return 0;
202} 217}
@@ -204,21 +219,23 @@ static int sh_wdt_close(struct inode *inode, struct file *file)
204static ssize_t sh_wdt_write(struct file *file, const char *buf, 219static ssize_t sh_wdt_write(struct file *file, const char *buf,
205 size_t count, loff_t *ppos) 220 size_t count, loff_t *ppos)
206{ 221{
222 struct sh_wdt *wdt = file->private_data;
223
207 if (count) { 224 if (count) {
208 if (!nowayout) { 225 if (!nowayout) {
209 size_t i; 226 size_t i;
210 227
211 shwdt_expect_close = 0; 228 wdt->expect_close = 0;
212 229
213 for (i = 0; i != count; i++) { 230 for (i = 0; i != count; i++) {
214 char c; 231 char c;
215 if (get_user(c, buf + i)) 232 if (get_user(c, buf + i))
216 return -EFAULT; 233 return -EFAULT;
217 if (c == 'V') 234 if (c == 'V')
218 shwdt_expect_close = 42; 235 wdt->expect_close = 42;
219 } 236 }
220 } 237 }
221 sh_wdt_keepalive(); 238 sh_wdt_keepalive(wdt);
222 } 239 }
223 240
224 return count; 241 return count;
@@ -227,6 +244,7 @@ static ssize_t sh_wdt_write(struct file *file, const char *buf,
227static long sh_wdt_ioctl(struct file *file, unsigned int cmd, 244static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
228 unsigned long arg) 245 unsigned long arg)
229{ 246{
247 struct sh_wdt *wdt = file->private_data;
230 int new_heartbeat; 248 int new_heartbeat;
231 int options, retval = -EINVAL; 249 int options, retval = -EINVAL;
232 250
@@ -242,18 +260,18 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
242 return -EFAULT; 260 return -EFAULT;
243 261
244 if (options & WDIOS_DISABLECARD) { 262 if (options & WDIOS_DISABLECARD) {
245 sh_wdt_stop(); 263 sh_wdt_stop(wdt);
246 retval = 0; 264 retval = 0;
247 } 265 }
248 266
249 if (options & WDIOS_ENABLECARD) { 267 if (options & WDIOS_ENABLECARD) {
250 sh_wdt_start(); 268 sh_wdt_start(wdt);
251 retval = 0; 269 retval = 0;
252 } 270 }
253 271
254 return retval; 272 return retval;
255 case WDIOC_KEEPALIVE: 273 case WDIOC_KEEPALIVE:
256 sh_wdt_keepalive(); 274 sh_wdt_keepalive(wdt);
257 return 0; 275 return 0;
258 case WDIOC_SETTIMEOUT: 276 case WDIOC_SETTIMEOUT:
259 if (get_user(new_heartbeat, (int *)arg)) 277 if (get_user(new_heartbeat, (int *)arg))
@@ -262,7 +280,7 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
262 if (sh_wdt_set_heartbeat(new_heartbeat)) 280 if (sh_wdt_set_heartbeat(new_heartbeat))
263 return -EINVAL; 281 return -EINVAL;
264 282
265 sh_wdt_keepalive(); 283 sh_wdt_keepalive(wdt);
266 /* Fall */ 284 /* Fall */
267 case WDIOC_GETTIMEOUT: 285 case WDIOC_GETTIMEOUT:
268 return put_user(heartbeat, (int *)arg); 286 return put_user(heartbeat, (int *)arg);
@@ -275,8 +293,10 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
275static int sh_wdt_notify_sys(struct notifier_block *this, 293static int sh_wdt_notify_sys(struct notifier_block *this,
276 unsigned long code, void *unused) 294 unsigned long code, void *unused)
277{ 295{
296 struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
297
278 if (code == SYS_DOWN || code == SYS_HALT) 298 if (code == SYS_DOWN || code == SYS_HALT)
279 sh_wdt_stop(); 299 sh_wdt_stop(wdt);
280 300
281 return NOTIFY_DONE; 301 return NOTIFY_DONE;
282} 302}
@@ -307,56 +327,148 @@ static struct miscdevice sh_wdt_miscdev = {
307 .fops = &sh_wdt_fops, 327 .fops = &sh_wdt_fops,
308}; 328};
309 329
310static int __init sh_wdt_init(void) 330static int __devinit sh_wdt_probe(struct platform_device *pdev)
311{ 331{
332 struct sh_wdt *wdt;
333 struct resource *res;
312 int rc; 334 int rc;
313 335
314 if (clock_division_ratio < 0x5 || clock_division_ratio > 0x7) { 336 /*
315 clock_division_ratio = WTCSR_CKS_4096; 337 * As this driver only covers the global watchdog case, reject
316 printk(KERN_INFO PFX 338 * any attempts to register per-CPU watchdogs.
317 "clock_division_ratio value must be 0x5<=x<=0x7, using %d\n", 339 */
318 clock_division_ratio); 340 if (pdev->id != -1)
341 return -EINVAL;
342
343 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
344 if (unlikely(!res))
345 return -EINVAL;
346
347 if (!devm_request_mem_region(&pdev->dev, res->start,
348 resource_size(res), DRV_NAME))
349 return -EBUSY;
350
351 wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL);
352 if (unlikely(!wdt)) {
353 rc = -ENOMEM;
354 goto out_release;
319 } 355 }
320 356
321 rc = sh_wdt_set_heartbeat(heartbeat); 357 wdt->dev = &pdev->dev;
322 if (unlikely(rc)) { 358
323 heartbeat = WATCHDOG_HEARTBEAT; 359 wdt->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
324 printk(KERN_INFO PFX 360 if (unlikely(!wdt->base)) {
325 "heartbeat value must be 1<=x<=3600, using %d\n", 361 rc = -ENXIO;
326 heartbeat); 362 goto out_err;
327 } 363 }
328 364
329 rc = register_reboot_notifier(&sh_wdt_notifier); 365 rc = register_reboot_notifier(&sh_wdt_notifier);
330 if (unlikely(rc)) { 366 if (unlikely(rc)) {
331 printk(KERN_ERR PFX 367 dev_err(&pdev->dev,
332 "Can't register reboot notifier (err=%d)\n", rc); 368 "Can't register reboot notifier (err=%d)\n", rc);
333 return rc; 369 goto out_unmap;
334 } 370 }
335 371
372 sh_wdt_miscdev.parent = wdt->dev;
373
336 rc = misc_register(&sh_wdt_miscdev); 374 rc = misc_register(&sh_wdt_miscdev);
337 if (unlikely(rc)) { 375 if (unlikely(rc)) {
338 printk(KERN_ERR PFX 376 dev_err(&pdev->dev,
339 "Can't register miscdev on minor=%d (err=%d)\n", 377 "Can't register miscdev on minor=%d (err=%d)\n",
340 sh_wdt_miscdev.minor, rc); 378 sh_wdt_miscdev.minor, rc);
341 unregister_reboot_notifier(&sh_wdt_notifier); 379 goto out_unreg;
342 return rc;
343 } 380 }
344 381
345 printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n", 382 init_timer(&wdt->timer);
346 heartbeat, nowayout); 383 wdt->timer.function = sh_wdt_ping;
384 wdt->timer.data = (unsigned long)wdt;
385 wdt->timer.expires = next_ping_period(clock_division_ratio);
386
387 platform_set_drvdata(pdev, wdt);
388 sh_wdt_dev = pdev;
389
390 dev_info(&pdev->dev, "initialized.\n");
347 391
348 return 0; 392 return 0;
393
394out_unreg:
395 unregister_reboot_notifier(&sh_wdt_notifier);
396out_unmap:
397 devm_iounmap(&pdev->dev, wdt->base);
398out_err:
399 devm_kfree(&pdev->dev, wdt);
400out_release:
401 devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
402
403 return rc;
349} 404}
350 405
351static void __exit sh_wdt_exit(void) 406static int __devexit sh_wdt_remove(struct platform_device *pdev)
352{ 407{
408 struct sh_wdt *wdt = platform_get_drvdata(pdev);
409 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
410
411 platform_set_drvdata(pdev, NULL);
412
353 misc_deregister(&sh_wdt_miscdev); 413 misc_deregister(&sh_wdt_miscdev);
414
415 sh_wdt_dev = NULL;
416
354 unregister_reboot_notifier(&sh_wdt_notifier); 417 unregister_reboot_notifier(&sh_wdt_notifier);
418 devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
419 devm_iounmap(&pdev->dev, wdt->base);
420 devm_kfree(&pdev->dev, wdt);
421
422 return 0;
423}
424
425static struct platform_driver sh_wdt_driver = {
426 .driver = {
427 .name = DRV_NAME,
428 .owner = THIS_MODULE,
429 },
430
431 .probe = sh_wdt_probe,
432 .remove = __devexit_p(sh_wdt_remove),
433};
434
435static int __init sh_wdt_init(void)
436{
437 int rc;
438
439 if (unlikely(clock_division_ratio < 0x5 ||
440 clock_division_ratio > 0x7)) {
441 clock_division_ratio = WTCSR_CKS_4096;
442
443 pr_info("%s: divisor must be 0x5<=x<=0x7, using %d\n",
444 DRV_NAME, clock_division_ratio);
445 }
446
447 rc = sh_wdt_set_heartbeat(heartbeat);
448 if (unlikely(rc)) {
449 heartbeat = WATCHDOG_HEARTBEAT;
450
451 pr_info("%s: heartbeat value must be 1<=x<=3600, using %d\n",
452 DRV_NAME, heartbeat);
453 }
454
455 pr_info("%s: configured with heartbeat=%d sec (nowayout=%d)\n",
456 DRV_NAME, heartbeat, nowayout);
457
458 return platform_driver_register(&sh_wdt_driver);
355} 459}
356 460
461static void __exit sh_wdt_exit(void)
462{
463 platform_driver_unregister(&sh_wdt_driver);
464}
465module_init(sh_wdt_init);
466module_exit(sh_wdt_exit);
467
357MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); 468MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
358MODULE_DESCRIPTION("SuperH watchdog driver"); 469MODULE_DESCRIPTION("SuperH watchdog driver");
359MODULE_LICENSE("GPL"); 470MODULE_LICENSE("GPL");
471MODULE_ALIAS("platform:" DRV_NAME);
360MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 472MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
361 473
362module_param(clock_division_ratio, int, 0); 474module_param(clock_division_ratio, int, 0);
@@ -373,6 +485,3 @@ module_param(nowayout, int, 0);
373MODULE_PARM_DESC(nowayout, 485MODULE_PARM_DESC(nowayout,
374 "Watchdog cannot be stopped once started (default=" 486 "Watchdog cannot be stopped once started (default="
375 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 487 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
376
377module_init(sh_wdt_init);
378module_exit(sh_wdt_exit);