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1/* linux/drivers/char/watchdog/s3c2410_wdt.c
2 *
3 * Copyright (c) 2004 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410 Watchdog Timer Support
7 *
8 * Based on, softdog.c by Alan Cox,
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24*/
25
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/types.h>
29#include <linux/timer.h>
30#include <linux/miscdevice.h>
31#include <linux/watchdog.h>
32#include <linux/fs.h>
33#include <linux/init.h>
34#include <linux/platform_device.h>
35#include <linux/interrupt.h>
36#include <linux/clk.h>
37#include <linux/uaccess.h>
38#include <linux/io.h>
39#include <linux/cpufreq.h>
40#include <linux/slab.h>
41
42#include <mach/map.h>
43
44#undef S3C_VA_WATCHDOG
45#define S3C_VA_WATCHDOG (0)
46
47#include <plat/regs-watchdog.h>
48
49#define PFX "s3c2410-wdt: "
50
51#define CONFIG_S3C2410_WATCHDOG_ATBOOT (0)
52#define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15)
53
54static int nowayout = WATCHDOG_NOWAYOUT;
55static int tmr_margin = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME;
56static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
57static int soft_noboot;
58static int debug;
59
60module_param(tmr_margin, int, 0);
61module_param(tmr_atboot, int, 0);
62module_param(nowayout, int, 0);
63module_param(soft_noboot, int, 0);
64module_param(debug, int, 0);
65
66MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
67 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
68MODULE_PARM_DESC(tmr_atboot,
69 "Watchdog is started at boot time if set to 1, default="
70 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
71MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
72 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
73MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
74 "0 to reboot (default 0)");
75MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
76
77static unsigned long open_lock;
78static struct device *wdt_dev; /* platform device attached to */
79static struct resource *wdt_mem;
80static struct resource *wdt_irq;
81static struct clk *wdt_clock;
82static void __iomem *wdt_base;
83static unsigned int wdt_count;
84static char expect_close;
85static DEFINE_SPINLOCK(wdt_lock);
86
87/* watchdog control routines */
88
89#define DBG(msg...) do { \
90 if (debug) \
91 printk(KERN_INFO msg); \
92 } while (0)
93
94/* functions */
95
96static void s3c2410wdt_keepalive(void)
97{
98 spin_lock(&wdt_lock);
99 writel(wdt_count, wdt_base + S3C2410_WTCNT);
100 spin_unlock(&wdt_lock);
101}
102
103static void __s3c2410wdt_stop(void)
104{
105 unsigned long wtcon;
106
107 wtcon = readl(wdt_base + S3C2410_WTCON);
108 wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
109 writel(wtcon, wdt_base + S3C2410_WTCON);
110}
111
112static void s3c2410wdt_stop(void)
113{
114 spin_lock(&wdt_lock);
115 __s3c2410wdt_stop();
116 spin_unlock(&wdt_lock);
117}
118
119static void s3c2410wdt_start(void)
120{
121 unsigned long wtcon;
122
123 spin_lock(&wdt_lock);
124
125 __s3c2410wdt_stop();
126
127 wtcon = readl(wdt_base + S3C2410_WTCON);
128 wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
129
130 if (soft_noboot) {
131 wtcon |= S3C2410_WTCON_INTEN;
132 wtcon &= ~S3C2410_WTCON_RSTEN;
133 } else {
134 wtcon &= ~S3C2410_WTCON_INTEN;
135 wtcon |= S3C2410_WTCON_RSTEN;
136 }
137
138 DBG("%s: wdt_count=0x%08x, wtcon=%08lx\n",
139 __func__, wdt_count, wtcon);
140
141 writel(wdt_count, wdt_base + S3C2410_WTDAT);
142 writel(wdt_count, wdt_base + S3C2410_WTCNT);
143 writel(wtcon, wdt_base + S3C2410_WTCON);
144 spin_unlock(&wdt_lock);
145}
146
147static inline int s3c2410wdt_is_running(void)
148{
149 return readl(wdt_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
150}
151
152static int s3c2410wdt_set_heartbeat(int timeout)
153{
154 unsigned long freq = clk_get_rate(wdt_clock);
155 unsigned int count;
156 unsigned int divisor = 1;
157 unsigned long wtcon;
158
159 if (timeout < 1)
160 return -EINVAL;
161
162 freq /= 128;
163 count = timeout * freq;
164
165 DBG("%s: count=%d, timeout=%d, freq=%lu\n",
166 __func__, count, timeout, freq);
167
168 /* if the count is bigger than the watchdog register,
169 then work out what we need to do (and if) we can
170 actually make this value
171 */
172
173 if (count >= 0x10000) {
174 for (divisor = 1; divisor <= 0x100; divisor++) {
175 if ((count / divisor) < 0x10000)
176 break;
177 }
178
179 if ((count / divisor) >= 0x10000) {
180 dev_err(wdt_dev, "timeout %d too big\n", timeout);
181 return -EINVAL;
182 }
183 }
184
185 tmr_margin = timeout;
186
187 DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
188 __func__, timeout, divisor, count, count/divisor);
189
190 count /= divisor;
191 wdt_count = count;
192
193 /* update the pre-scaler */
194 wtcon = readl(wdt_base + S3C2410_WTCON);
195 wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
196 wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
197
198 writel(count, wdt_base + S3C2410_WTDAT);
199 writel(wtcon, wdt_base + S3C2410_WTCON);
200
201 return 0;
202}
203
204/*
205 * /dev/watchdog handling
206 */
207
208static int s3c2410wdt_open(struct inode *inode, struct file *file)
209{
210 if (test_and_set_bit(0, &open_lock))
211 return -EBUSY;
212
213 if (nowayout)
214 __module_get(THIS_MODULE);
215
216 expect_close = 0;
217
218 /* start the timer */
219 s3c2410wdt_start();
220 return nonseekable_open(inode, file);
221}
222
223static int s3c2410wdt_release(struct inode *inode, struct file *file)
224{
225 /*
226 * Shut off the timer.
227 * Lock it in if it's a module and we set nowayout
228 */
229
230 if (expect_close == 42)
231 s3c2410wdt_stop();
232 else {
233 dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
234 s3c2410wdt_keepalive();
235 }
236 expect_close = 0;
237 clear_bit(0, &open_lock);
238 return 0;
239}
240
241static ssize_t s3c2410wdt_write(struct file *file, const char __user *data,
242 size_t len, loff_t *ppos)
243{
244 /*
245 * Refresh the timer.
246 */
247 if (len) {
248 if (!nowayout) {
249 size_t i;
250
251 /* In case it was set long ago */
252 expect_close = 0;
253
254 for (i = 0; i != len; i++) {
255 char c;
256
257 if (get_user(c, data + i))
258 return -EFAULT;
259 if (c == 'V')
260 expect_close = 42;
261 }
262 }
263 s3c2410wdt_keepalive();
264 }
265 return len;
266}
267
268#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
269
270static const struct watchdog_info s3c2410_wdt_ident = {
271 .options = OPTIONS,
272 .firmware_version = 0,
273 .identity = "S3C2410 Watchdog",
274};
275
276
277static long s3c2410wdt_ioctl(struct file *file, unsigned int cmd,
278 unsigned long arg)
279{
280 void __user *argp = (void __user *)arg;
281 int __user *p = argp;
282 int new_margin;
283
284 switch (cmd) {
285 case WDIOC_GETSUPPORT:
286 return copy_to_user(argp, &s3c2410_wdt_ident,
287 sizeof(s3c2410_wdt_ident)) ? -EFAULT : 0;
288 case WDIOC_GETSTATUS:
289 case WDIOC_GETBOOTSTATUS:
290 return put_user(0, p);
291 case WDIOC_KEEPALIVE:
292 s3c2410wdt_keepalive();
293 return 0;
294 case WDIOC_SETTIMEOUT:
295 if (get_user(new_margin, p))
296 return -EFAULT;
297 if (s3c2410wdt_set_heartbeat(new_margin))
298 return -EINVAL;
299 s3c2410wdt_keepalive();
300 return put_user(tmr_margin, p);
301 case WDIOC_GETTIMEOUT:
302 return put_user(tmr_margin, p);
303 default:
304 return -ENOTTY;
305 }
306}
307
308/* kernel interface */
309
310static const struct file_operations s3c2410wdt_fops = {
311 .owner = THIS_MODULE,
312 .llseek = no_llseek,
313 .write = s3c2410wdt_write,
314 .unlocked_ioctl = s3c2410wdt_ioctl,
315 .open = s3c2410wdt_open,
316 .release = s3c2410wdt_release,
317};
318
319static struct miscdevice s3c2410wdt_miscdev = {
320 .minor = WATCHDOG_MINOR,
321 .name = "watchdog",
322 .fops = &s3c2410wdt_fops,
323};
324
325/* interrupt handler code */
326
327static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
328{
329 dev_info(wdt_dev, "watchdog timer expired (irq)\n");
330
331 s3c2410wdt_keepalive();
332 return IRQ_HANDLED;
333}
334
335
336#ifdef CONFIG_CPU_FREQ
337
338static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
339 unsigned long val, void *data)
340{
341 int ret;
342
343 if (!s3c2410wdt_is_running())
344 goto done;
345
346 if (val == CPUFREQ_PRECHANGE) {
347 /* To ensure that over the change we don't cause the
348 * watchdog to trigger, we perform an keep-alive if
349 * the watchdog is running.
350 */
351
352 s3c2410wdt_keepalive();
353 } else if (val == CPUFREQ_POSTCHANGE) {
354 s3c2410wdt_stop();
355
356 ret = s3c2410wdt_set_heartbeat(tmr_margin);
357
358 if (ret >= 0)
359 s3c2410wdt_start();
360 else
361 goto err;
362 }
363
364done:
365 return 0;
366
367 err:
368 dev_err(wdt_dev, "cannot set new value for timeout %d\n", tmr_margin);
369 return ret;
370}
371
372static struct notifier_block s3c2410wdt_cpufreq_transition_nb = {
373 .notifier_call = s3c2410wdt_cpufreq_transition,
374};
375
376static inline int s3c2410wdt_cpufreq_register(void)
377{
378 return cpufreq_register_notifier(&s3c2410wdt_cpufreq_transition_nb,
379 CPUFREQ_TRANSITION_NOTIFIER);
380}
381
382static inline void s3c2410wdt_cpufreq_deregister(void)
383{
384 cpufreq_unregister_notifier(&s3c2410wdt_cpufreq_transition_nb,
385 CPUFREQ_TRANSITION_NOTIFIER);
386}
387
388#else
389static inline int s3c2410wdt_cpufreq_register(void)
390{
391 return 0;
392}
393
394static inline void s3c2410wdt_cpufreq_deregister(void)
395{
396}
397#endif
398
399
400
401/* device interface */
402
403static int __devinit s3c2410wdt_probe(struct platform_device *pdev)
404{
405 struct device *dev;
406 unsigned int wtcon;
407 int started = 0;
408 int ret;
409 int size;
410
411 DBG("%s: probe=%p\n", __func__, pdev);
412
413 dev = &pdev->dev;
414 wdt_dev = &pdev->dev;
415
416 /* get the memory region for the watchdog timer */
417
418 wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
419 if (wdt_mem == NULL) {
420 dev_err(dev, "no memory resource specified\n");
421 return -ENOENT;
422 }
423
424 size = resource_size(wdt_mem);
425 if (!request_mem_region(wdt_mem->start, size, pdev->name)) {
426 dev_err(dev, "failed to get memory region\n");
427 return -EBUSY;
428 }
429
430 wdt_base = ioremap(wdt_mem->start, size);
431 if (wdt_base == NULL) {
432 dev_err(dev, "failed to ioremap() region\n");
433 ret = -EINVAL;
434 goto err_req;
435 }
436
437 DBG("probe: mapped wdt_base=%p\n", wdt_base);
438
439 wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
440 if (wdt_irq == NULL) {
441 dev_err(dev, "no irq resource specified\n");
442 ret = -ENOENT;
443 goto err_map;
444 }
445
446 ret = request_irq(wdt_irq->start, s3c2410wdt_irq, 0, pdev->name, pdev);
447 if (ret != 0) {
448 dev_err(dev, "failed to install irq (%d)\n", ret);
449 goto err_map;
450 }
451
452 wdt_clock = clk_get(&pdev->dev, "watchdog");
453 if (IS_ERR(wdt_clock)) {
454 dev_err(dev, "failed to find watchdog clock source\n");
455 ret = PTR_ERR(wdt_clock);
456 goto err_irq;
457 }
458
459 clk_enable(wdt_clock);
460
461 if (s3c2410wdt_cpufreq_register() < 0) {
462 printk(KERN_ERR PFX "failed to register cpufreq\n");
463 goto err_clk;
464 }
465
466 /* see if we can actually set the requested timer margin, and if
467 * not, try the default value */
468
469 if (s3c2410wdt_set_heartbeat(tmr_margin)) {
470 started = s3c2410wdt_set_heartbeat(
471 CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
472
473 if (started == 0)
474 dev_info(dev,
475 "tmr_margin value out of range, default %d used\n",
476 CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
477 else
478 dev_info(dev, "default timer value is out of range, "
479 "cannot start\n");
480 }
481
482 ret = misc_register(&s3c2410wdt_miscdev);
483 if (ret) {
484 dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
485 WATCHDOG_MINOR, ret);
486 goto err_cpufreq;
487 }
488
489 if (tmr_atboot && started == 0) {
490 dev_info(dev, "starting watchdog timer\n");
491 s3c2410wdt_start();
492 } else if (!tmr_atboot) {
493 /* if we're not enabling the watchdog, then ensure it is
494 * disabled if it has been left running from the bootloader
495 * or other source */
496
497 s3c2410wdt_stop();
498 }
499
500 /* print out a statement of readiness */
501
502 wtcon = readl(wdt_base + S3C2410_WTCON);
503
504 dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
505 (wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
506 (wtcon & S3C2410_WTCON_RSTEN) ? "" : "dis",
507 (wtcon & S3C2410_WTCON_INTEN) ? "" : "en");
508
509 return 0;
510
511 err_cpufreq:
512 s3c2410wdt_cpufreq_deregister();
513
514 err_clk:
515 clk_disable(wdt_clock);
516 clk_put(wdt_clock);
517
518 err_irq:
519 free_irq(wdt_irq->start, pdev);
520
521 err_map:
522 iounmap(wdt_base);
523
524 err_req:
525 release_mem_region(wdt_mem->start, size);
526 wdt_mem = NULL;
527
528 return ret;
529}
530
531static int __devexit s3c2410wdt_remove(struct platform_device *dev)
532{
533 misc_deregister(&s3c2410wdt_miscdev);
534
535 s3c2410wdt_cpufreq_deregister();
536
537 clk_disable(wdt_clock);
538 clk_put(wdt_clock);
539 wdt_clock = NULL;
540
541 free_irq(wdt_irq->start, dev);
542 wdt_irq = NULL;
543
544 iounmap(wdt_base);
545
546 release_mem_region(wdt_mem->start, resource_size(wdt_mem));
547 wdt_mem = NULL;
548 return 0;
549}
550
551static void s3c2410wdt_shutdown(struct platform_device *dev)
552{
553 s3c2410wdt_stop();
554}
555
556#ifdef CONFIG_PM
557
558static unsigned long wtcon_save;
559static unsigned long wtdat_save;
560
561static int s3c2410wdt_suspend(struct platform_device *dev, pm_message_t state)
562{
563 /* Save watchdog state, and turn it off. */
564 wtcon_save = readl(wdt_base + S3C2410_WTCON);
565 wtdat_save = readl(wdt_base + S3C2410_WTDAT);
566
567 /* Note that WTCNT doesn't need to be saved. */
568 s3c2410wdt_stop();
569
570 return 0;
571}
572
573static int s3c2410wdt_resume(struct platform_device *dev)
574{
575 /* Restore watchdog state. */
576
577 writel(wtdat_save, wdt_base + S3C2410_WTDAT);
578 writel(wtdat_save, wdt_base + S3C2410_WTCNT); /* Reset count */
579 writel(wtcon_save, wdt_base + S3C2410_WTCON);
580
581 printk(KERN_INFO PFX "watchdog %sabled\n",
582 (wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
583
584 return 0;
585}
586
587#else
588#define s3c2410wdt_suspend NULL
589#define s3c2410wdt_resume NULL
590#endif /* CONFIG_PM */
591
592#ifdef CONFIG_OF
593static const struct of_device_id s3c2410_wdt_match[] = {
594 { .compatible = "samsung,s3c2410-wdt" },
595 {},
596};
597MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
598#else
599#define s3c2410_wdt_match NULL
600#endif
601
602static struct platform_driver s3c2410wdt_driver = {
603 .probe = s3c2410wdt_probe,
604 .remove = __devexit_p(s3c2410wdt_remove),
605 .shutdown = s3c2410wdt_shutdown,
606 .suspend = s3c2410wdt_suspend,
607 .resume = s3c2410wdt_resume,
608 .driver = {
609 .owner = THIS_MODULE,
610 .name = "s3c2410-wdt",
611 .of_match_table = s3c2410_wdt_match,
612 },
613};
614
615
616static char banner[] __initdata =
617 KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n";
618
619static int __init watchdog_init(void)
620{
621 printk(banner);
622 return platform_driver_register(&s3c2410wdt_driver);
623}
624
625static void __exit watchdog_exit(void)
626{
627 platform_driver_unregister(&s3c2410wdt_driver);
628}
629
630module_init(watchdog_init);
631module_exit(watchdog_exit);
632
633MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
634 "Dimitry Andric <dimitry.andric@tomtom.com>");
635MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
636MODULE_LICENSE("GPL");
637MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
638MODULE_ALIAS("platform:s3c2410-wdt");
1/* linux/drivers/char/watchdog/s3c2410_wdt.c
2 *
3 * Copyright (c) 2004 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410 Watchdog Timer Support
7 *
8 * Based on, softdog.c by Alan Cox,
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24*/
25
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/types.h>
31#include <linux/timer.h>
32#include <linux/watchdog.h>
33#include <linux/platform_device.h>
34#include <linux/interrupt.h>
35#include <linux/clk.h>
36#include <linux/uaccess.h>
37#include <linux/io.h>
38#include <linux/cpufreq.h>
39#include <linux/slab.h>
40#include <linux/err.h>
41#include <linux/of.h>
42#include <linux/mfd/syscon.h>
43#include <linux/regmap.h>
44
45#define S3C2410_WTCON 0x00
46#define S3C2410_WTDAT 0x04
47#define S3C2410_WTCNT 0x08
48
49#define S3C2410_WTCON_RSTEN (1 << 0)
50#define S3C2410_WTCON_INTEN (1 << 2)
51#define S3C2410_WTCON_ENABLE (1 << 5)
52
53#define S3C2410_WTCON_DIV16 (0 << 3)
54#define S3C2410_WTCON_DIV32 (1 << 3)
55#define S3C2410_WTCON_DIV64 (2 << 3)
56#define S3C2410_WTCON_DIV128 (3 << 3)
57
58#define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
59#define S3C2410_WTCON_PRESCALE_MASK (0xff << 8)
60
61#define CONFIG_S3C2410_WATCHDOG_ATBOOT (0)
62#define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15)
63
64#define EXYNOS5_RST_STAT_REG_OFFSET 0x0404
65#define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408
66#define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c
67#define QUIRK_HAS_PMU_CONFIG (1 << 0)
68#define QUIRK_HAS_RST_STAT (1 << 1)
69
70/* These quirks require that we have a PMU register map */
71#define QUIRKS_HAVE_PMUREG (QUIRK_HAS_PMU_CONFIG | \
72 QUIRK_HAS_RST_STAT)
73
74static bool nowayout = WATCHDOG_NOWAYOUT;
75static int tmr_margin;
76static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
77static int soft_noboot;
78static int debug;
79
80module_param(tmr_margin, int, 0);
81module_param(tmr_atboot, int, 0);
82module_param(nowayout, bool, 0);
83module_param(soft_noboot, int, 0);
84module_param(debug, int, 0);
85
86MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
87 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
88MODULE_PARM_DESC(tmr_atboot,
89 "Watchdog is started at boot time if set to 1, default="
90 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
91MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
92 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
93MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
94 "0 to reboot (default 0)");
95MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
96
97/**
98 * struct s3c2410_wdt_variant - Per-variant config data
99 *
100 * @disable_reg: Offset in pmureg for the register that disables the watchdog
101 * timer reset functionality.
102 * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
103 * timer reset functionality.
104 * @mask_bit: Bit number for the watchdog timer in the disable register and the
105 * mask reset register.
106 * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
107 * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
108 * reset.
109 * @quirks: A bitfield of quirks.
110 */
111
112struct s3c2410_wdt_variant {
113 int disable_reg;
114 int mask_reset_reg;
115 int mask_bit;
116 int rst_stat_reg;
117 int rst_stat_bit;
118 u32 quirks;
119};
120
121struct s3c2410_wdt {
122 struct device *dev;
123 struct clk *clock;
124 void __iomem *reg_base;
125 unsigned int count;
126 spinlock_t lock;
127 unsigned long wtcon_save;
128 unsigned long wtdat_save;
129 struct watchdog_device wdt_device;
130 struct notifier_block freq_transition;
131 struct s3c2410_wdt_variant *drv_data;
132 struct regmap *pmureg;
133};
134
135static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
136 .quirks = 0
137};
138
139#ifdef CONFIG_OF
140static const struct s3c2410_wdt_variant drv_data_exynos5250 = {
141 .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
142 .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
143 .mask_bit = 20,
144 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
145 .rst_stat_bit = 20,
146 .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
147};
148
149static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
150 .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
151 .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
152 .mask_bit = 0,
153 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
154 .rst_stat_bit = 9,
155 .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
156};
157
158static const struct of_device_id s3c2410_wdt_match[] = {
159 { .compatible = "samsung,s3c2410-wdt",
160 .data = &drv_data_s3c2410 },
161 { .compatible = "samsung,exynos5250-wdt",
162 .data = &drv_data_exynos5250 },
163 { .compatible = "samsung,exynos5420-wdt",
164 .data = &drv_data_exynos5420 },
165 {},
166};
167MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
168#endif
169
170static const struct platform_device_id s3c2410_wdt_ids[] = {
171 {
172 .name = "s3c2410-wdt",
173 .driver_data = (unsigned long)&drv_data_s3c2410,
174 },
175 {}
176};
177MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
178
179/* watchdog control routines */
180
181#define DBG(fmt, ...) \
182do { \
183 if (debug) \
184 pr_info(fmt, ##__VA_ARGS__); \
185} while (0)
186
187/* functions */
188
189static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
190{
191 return container_of(nb, struct s3c2410_wdt, freq_transition);
192}
193
194static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
195{
196 int ret;
197 u32 mask_val = 1 << wdt->drv_data->mask_bit;
198 u32 val = 0;
199
200 /* No need to do anything if no PMU CONFIG needed */
201 if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
202 return 0;
203
204 if (mask)
205 val = mask_val;
206
207 ret = regmap_update_bits(wdt->pmureg,
208 wdt->drv_data->disable_reg,
209 mask_val, val);
210 if (ret < 0)
211 goto error;
212
213 ret = regmap_update_bits(wdt->pmureg,
214 wdt->drv_data->mask_reset_reg,
215 mask_val, val);
216 error:
217 if (ret < 0)
218 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
219
220 return ret;
221}
222
223static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
224{
225 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
226
227 spin_lock(&wdt->lock);
228 writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
229 spin_unlock(&wdt->lock);
230
231 return 0;
232}
233
234static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
235{
236 unsigned long wtcon;
237
238 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
239 wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
240 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
241}
242
243static int s3c2410wdt_stop(struct watchdog_device *wdd)
244{
245 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
246
247 spin_lock(&wdt->lock);
248 __s3c2410wdt_stop(wdt);
249 spin_unlock(&wdt->lock);
250
251 return 0;
252}
253
254static int s3c2410wdt_start(struct watchdog_device *wdd)
255{
256 unsigned long wtcon;
257 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
258
259 spin_lock(&wdt->lock);
260
261 __s3c2410wdt_stop(wdt);
262
263 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
264 wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
265
266 if (soft_noboot) {
267 wtcon |= S3C2410_WTCON_INTEN;
268 wtcon &= ~S3C2410_WTCON_RSTEN;
269 } else {
270 wtcon &= ~S3C2410_WTCON_INTEN;
271 wtcon |= S3C2410_WTCON_RSTEN;
272 }
273
274 DBG("%s: count=0x%08x, wtcon=%08lx\n",
275 __func__, wdt->count, wtcon);
276
277 writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
278 writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
279 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
280 spin_unlock(&wdt->lock);
281
282 return 0;
283}
284
285static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
286{
287 return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
288}
289
290static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
291{
292 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
293 unsigned long freq = clk_get_rate(wdt->clock);
294 unsigned int count;
295 unsigned int divisor = 1;
296 unsigned long wtcon;
297
298 if (timeout < 1)
299 return -EINVAL;
300
301 freq = DIV_ROUND_UP(freq, 128);
302 count = timeout * freq;
303
304 DBG("%s: count=%d, timeout=%d, freq=%lu\n",
305 __func__, count, timeout, freq);
306
307 /* if the count is bigger than the watchdog register,
308 then work out what we need to do (and if) we can
309 actually make this value
310 */
311
312 if (count >= 0x10000) {
313 divisor = DIV_ROUND_UP(count, 0xffff);
314
315 if (divisor > 0x100) {
316 dev_err(wdt->dev, "timeout %d too big\n", timeout);
317 return -EINVAL;
318 }
319 }
320
321 DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
322 __func__, timeout, divisor, count, DIV_ROUND_UP(count, divisor));
323
324 count = DIV_ROUND_UP(count, divisor);
325 wdt->count = count;
326
327 /* update the pre-scaler */
328 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
329 wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
330 wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
331
332 writel(count, wdt->reg_base + S3C2410_WTDAT);
333 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
334
335 wdd->timeout = (count * divisor) / freq;
336
337 return 0;
338}
339
340#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
341
342static const struct watchdog_info s3c2410_wdt_ident = {
343 .options = OPTIONS,
344 .firmware_version = 0,
345 .identity = "S3C2410 Watchdog",
346};
347
348static struct watchdog_ops s3c2410wdt_ops = {
349 .owner = THIS_MODULE,
350 .start = s3c2410wdt_start,
351 .stop = s3c2410wdt_stop,
352 .ping = s3c2410wdt_keepalive,
353 .set_timeout = s3c2410wdt_set_heartbeat,
354};
355
356static struct watchdog_device s3c2410_wdd = {
357 .info = &s3c2410_wdt_ident,
358 .ops = &s3c2410wdt_ops,
359 .timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME,
360};
361
362/* interrupt handler code */
363
364static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
365{
366 struct s3c2410_wdt *wdt = platform_get_drvdata(param);
367
368 dev_info(wdt->dev, "watchdog timer expired (irq)\n");
369
370 s3c2410wdt_keepalive(&wdt->wdt_device);
371 return IRQ_HANDLED;
372}
373
374#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
375
376static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
377 unsigned long val, void *data)
378{
379 int ret;
380 struct s3c2410_wdt *wdt = freq_to_wdt(nb);
381
382 if (!s3c2410wdt_is_running(wdt))
383 goto done;
384
385 if (val == CPUFREQ_PRECHANGE) {
386 /* To ensure that over the change we don't cause the
387 * watchdog to trigger, we perform an keep-alive if
388 * the watchdog is running.
389 */
390
391 s3c2410wdt_keepalive(&wdt->wdt_device);
392 } else if (val == CPUFREQ_POSTCHANGE) {
393 s3c2410wdt_stop(&wdt->wdt_device);
394
395 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
396 wdt->wdt_device.timeout);
397
398 if (ret >= 0)
399 s3c2410wdt_start(&wdt->wdt_device);
400 else
401 goto err;
402 }
403
404done:
405 return 0;
406
407 err:
408 dev_err(wdt->dev, "cannot set new value for timeout %d\n",
409 wdt->wdt_device.timeout);
410 return ret;
411}
412
413static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
414{
415 wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
416
417 return cpufreq_register_notifier(&wdt->freq_transition,
418 CPUFREQ_TRANSITION_NOTIFIER);
419}
420
421static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
422{
423 wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
424
425 cpufreq_unregister_notifier(&wdt->freq_transition,
426 CPUFREQ_TRANSITION_NOTIFIER);
427}
428
429#else
430
431static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
432{
433 return 0;
434}
435
436static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
437{
438}
439#endif
440
441static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
442{
443 unsigned int rst_stat;
444 int ret;
445
446 if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
447 return 0;
448
449 ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
450 if (ret)
451 dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
452 else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
453 return WDIOF_CARDRESET;
454
455 return 0;
456}
457
458/* s3c2410_get_wdt_driver_data */
459static inline struct s3c2410_wdt_variant *
460get_wdt_drv_data(struct platform_device *pdev)
461{
462 if (pdev->dev.of_node) {
463 const struct of_device_id *match;
464 match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
465 return (struct s3c2410_wdt_variant *)match->data;
466 } else {
467 return (struct s3c2410_wdt_variant *)
468 platform_get_device_id(pdev)->driver_data;
469 }
470}
471
472static int s3c2410wdt_probe(struct platform_device *pdev)
473{
474 struct device *dev;
475 struct s3c2410_wdt *wdt;
476 struct resource *wdt_mem;
477 struct resource *wdt_irq;
478 unsigned int wtcon;
479 int started = 0;
480 int ret;
481
482 DBG("%s: probe=%p\n", __func__, pdev);
483
484 dev = &pdev->dev;
485
486 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
487 if (!wdt)
488 return -ENOMEM;
489
490 wdt->dev = &pdev->dev;
491 spin_lock_init(&wdt->lock);
492 wdt->wdt_device = s3c2410_wdd;
493
494 wdt->drv_data = get_wdt_drv_data(pdev);
495 if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
496 wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
497 "samsung,syscon-phandle");
498 if (IS_ERR(wdt->pmureg)) {
499 dev_err(dev, "syscon regmap lookup failed.\n");
500 return PTR_ERR(wdt->pmureg);
501 }
502 }
503
504 wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
505 if (wdt_irq == NULL) {
506 dev_err(dev, "no irq resource specified\n");
507 ret = -ENOENT;
508 goto err;
509 }
510
511 /* get the memory region for the watchdog timer */
512 wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
513 wdt->reg_base = devm_ioremap_resource(dev, wdt_mem);
514 if (IS_ERR(wdt->reg_base)) {
515 ret = PTR_ERR(wdt->reg_base);
516 goto err;
517 }
518
519 DBG("probe: mapped reg_base=%p\n", wdt->reg_base);
520
521 wdt->clock = devm_clk_get(dev, "watchdog");
522 if (IS_ERR(wdt->clock)) {
523 dev_err(dev, "failed to find watchdog clock source\n");
524 ret = PTR_ERR(wdt->clock);
525 goto err;
526 }
527
528 ret = clk_prepare_enable(wdt->clock);
529 if (ret < 0) {
530 dev_err(dev, "failed to enable clock\n");
531 return ret;
532 }
533
534 ret = s3c2410wdt_cpufreq_register(wdt);
535 if (ret < 0) {
536 dev_err(dev, "failed to register cpufreq\n");
537 goto err_clk;
538 }
539
540 watchdog_set_drvdata(&wdt->wdt_device, wdt);
541
542 /* see if we can actually set the requested timer margin, and if
543 * not, try the default value */
544
545 watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev);
546 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
547 wdt->wdt_device.timeout);
548 if (ret) {
549 started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
550 CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
551
552 if (started == 0)
553 dev_info(dev,
554 "tmr_margin value out of range, default %d used\n",
555 CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
556 else
557 dev_info(dev, "default timer value is out of range, "
558 "cannot start\n");
559 }
560
561 ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
562 pdev->name, pdev);
563 if (ret != 0) {
564 dev_err(dev, "failed to install irq (%d)\n", ret);
565 goto err_cpufreq;
566 }
567
568 watchdog_set_nowayout(&wdt->wdt_device, nowayout);
569
570 wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
571
572 ret = watchdog_register_device(&wdt->wdt_device);
573 if (ret) {
574 dev_err(dev, "cannot register watchdog (%d)\n", ret);
575 goto err_cpufreq;
576 }
577
578 ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
579 if (ret < 0)
580 goto err_unregister;
581
582 if (tmr_atboot && started == 0) {
583 dev_info(dev, "starting watchdog timer\n");
584 s3c2410wdt_start(&wdt->wdt_device);
585 } else if (!tmr_atboot) {
586 /* if we're not enabling the watchdog, then ensure it is
587 * disabled if it has been left running from the bootloader
588 * or other source */
589
590 s3c2410wdt_stop(&wdt->wdt_device);
591 }
592
593 platform_set_drvdata(pdev, wdt);
594
595 /* print out a statement of readiness */
596
597 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
598
599 dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
600 (wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
601 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
602 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
603
604 return 0;
605
606 err_unregister:
607 watchdog_unregister_device(&wdt->wdt_device);
608
609 err_cpufreq:
610 s3c2410wdt_cpufreq_deregister(wdt);
611
612 err_clk:
613 clk_disable_unprepare(wdt->clock);
614
615 err:
616 return ret;
617}
618
619static int s3c2410wdt_remove(struct platform_device *dev)
620{
621 int ret;
622 struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
623
624 ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
625 if (ret < 0)
626 return ret;
627
628 watchdog_unregister_device(&wdt->wdt_device);
629
630 s3c2410wdt_cpufreq_deregister(wdt);
631
632 clk_disable_unprepare(wdt->clock);
633
634 return 0;
635}
636
637static void s3c2410wdt_shutdown(struct platform_device *dev)
638{
639 struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
640
641 s3c2410wdt_mask_and_disable_reset(wdt, true);
642
643 s3c2410wdt_stop(&wdt->wdt_device);
644}
645
646#ifdef CONFIG_PM_SLEEP
647
648static int s3c2410wdt_suspend(struct device *dev)
649{
650 int ret;
651 struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
652
653 /* Save watchdog state, and turn it off. */
654 wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
655 wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
656
657 ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
658 if (ret < 0)
659 return ret;
660
661 /* Note that WTCNT doesn't need to be saved. */
662 s3c2410wdt_stop(&wdt->wdt_device);
663
664 return 0;
665}
666
667static int s3c2410wdt_resume(struct device *dev)
668{
669 int ret;
670 struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
671
672 /* Restore watchdog state. */
673 writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
674 writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
675 writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
676
677 ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
678 if (ret < 0)
679 return ret;
680
681 dev_info(dev, "watchdog %sabled\n",
682 (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
683
684 return 0;
685}
686#endif
687
688static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
689 s3c2410wdt_resume);
690
691static struct platform_driver s3c2410wdt_driver = {
692 .probe = s3c2410wdt_probe,
693 .remove = s3c2410wdt_remove,
694 .shutdown = s3c2410wdt_shutdown,
695 .id_table = s3c2410_wdt_ids,
696 .driver = {
697 .owner = THIS_MODULE,
698 .name = "s3c2410-wdt",
699 .pm = &s3c2410wdt_pm_ops,
700 .of_match_table = of_match_ptr(s3c2410_wdt_match),
701 },
702};
703
704module_platform_driver(s3c2410wdt_driver);
705
706MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
707 "Dimitry Andric <dimitry.andric@tomtom.com>");
708MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
709MODULE_LICENSE("GPL");