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Staging: strip: delete the driver
[linux/fpc-iii.git] / drivers / watchdog / omap_wdt.c
blob76b58abf445182d6708e39f7801c77c062004769
1 /*
2 * omap_wdt.c
3 *
4 * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
5 *
6 * Author: MontaVista Software, Inc.
7 * <gdavis@mvista.com> or <source@mvista.com>
8 *
9 * 2003 (c) MontaVista Software, Inc. This file is licensed under the
10 * terms of the GNU General Public License version 2. This program is
11 * licensed "as is" without any warranty of any kind, whether express
12 * or implied.
13 *
14 * History:
15 *
16 * 20030527: George G. Davis <gdavis@mvista.com>
17 * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
18 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
19 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
20 *
21 * Copyright (c) 2004 Texas Instruments.
22 * 1. Modified to support OMAP1610 32-KHz watchdog timer
23 * 2. Ported to 2.6 kernel
24 *
25 * Copyright (c) 2005 David Brownell
26 * Use the driver model and standard identifiers; handle bigger timeouts.
27 */
28
29 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/kernel.h>
32 #include <linux/fs.h>
33 #include <linux/mm.h>
34 #include <linux/miscdevice.h>
35 #include <linux/watchdog.h>
36 #include <linux/reboot.h>
37 #include <linux/init.h>
38 #include <linux/err.h>
39 #include <linux/platform_device.h>
40 #include <linux/moduleparam.h>
41 #include <linux/clk.h>
42 #include <linux/bitops.h>
43 #include <linux/io.h>
44 #include <linux/uaccess.h>
45 #include <linux/slab.h>
46 #include <mach/hardware.h>
47 #include <plat/prcm.h>
48
49 #include "omap_wdt.h"
50
51 static struct platform_device *omap_wdt_dev;
52
53 static unsigned timer_margin;
54 module_param(timer_margin, uint, 0);
55 MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
56
57 static unsigned int wdt_trgr_pattern = 0x1234;
58 static spinlock_t wdt_lock;
59
60 struct omap_wdt_dev {
61 void __iomem *base; /* physical */
62 struct device *dev;
63 int omap_wdt_users;
64 struct clk *ick;
65 struct clk *fck;
66 struct resource *mem;
67 struct miscdevice omap_wdt_miscdev;
68 };
69
70 static void omap_wdt_ping(struct omap_wdt_dev *wdev)
71 {
72 void __iomem *base = wdev->base;
73
74 /* wait for posted write to complete */
75 while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
76 cpu_relax();
77
78 wdt_trgr_pattern = ~wdt_trgr_pattern;
79 __raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
80
81 /* wait for posted write to complete */
82 while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
83 cpu_relax();
84 /* reloaded WCRR from WLDR */
85 }
86
87 static void omap_wdt_enable(struct omap_wdt_dev *wdev)
88 {
89 void __iomem *base = wdev->base;
90
91 /* Sequence to enable the watchdog */
92 __raw_writel(0xBBBB, base + OMAP_WATCHDOG_SPR);
93 while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x10)
94 cpu_relax();
95
96 __raw_writel(0x4444, base + OMAP_WATCHDOG_SPR);
97 while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x10)
98 cpu_relax();
99 }
100
101 static void omap_wdt_disable(struct omap_wdt_dev *wdev)
102 {
103 void __iomem *base = wdev->base;
104
105 /* sequence required to disable watchdog */
106 __raw_writel(0xAAAA, base + OMAP_WATCHDOG_SPR); /* TIMER_MODE */
107 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x10)
108 cpu_relax();
109
110 __raw_writel(0x5555, base + OMAP_WATCHDOG_SPR); /* TIMER_MODE */
111 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x10)
112 cpu_relax();
113 }
114
115 static void omap_wdt_adjust_timeout(unsigned new_timeout)
116 {
117 if (new_timeout < TIMER_MARGIN_MIN)
118 new_timeout = TIMER_MARGIN_DEFAULT;
119 if (new_timeout > TIMER_MARGIN_MAX)
120 new_timeout = TIMER_MARGIN_MAX;
121 timer_margin = new_timeout;
122 }
123
124 static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
125 {
126 u32 pre_margin = GET_WLDR_VAL(timer_margin);
127 void __iomem *base = wdev->base;
128
129 /* just count up at 32 KHz */
130 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
131 cpu_relax();
132
133 __raw_writel(pre_margin, base + OMAP_WATCHDOG_LDR);
134 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
135 cpu_relax();
136 }
137
138 /*
139 * Allow only one task to hold it open
140 */
141 static int omap_wdt_open(struct inode *inode, struct file *file)
142 {
143 struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
144 void __iomem *base = wdev->base;
145
146 if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
147 return -EBUSY;
148
149 clk_enable(wdev->ick); /* Enable the interface clock */
150 clk_enable(wdev->fck); /* Enable the functional clock */
151
152 /* initialize prescaler */
153 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
154 cpu_relax();
155
156 __raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
157 while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
158 cpu_relax();
159
160 file->private_data = (void *) wdev;
161
162 omap_wdt_set_timeout(wdev);
163 omap_wdt_ping(wdev); /* trigger loading of new timeout value */
164 omap_wdt_enable(wdev);
165
166 return nonseekable_open(inode, file);
167 }
168
169 static int omap_wdt_release(struct inode *inode, struct file *file)
170 {
171 struct omap_wdt_dev *wdev = file->private_data;
172
173 /*
174 * Shut off the timer unless NOWAYOUT is defined.
175 */
176 #ifndef CONFIG_WATCHDOG_NOWAYOUT
177
178 omap_wdt_disable(wdev);
179
180 clk_disable(wdev->ick);
181 clk_disable(wdev->fck);
182 #else
183 printk(KERN_CRIT "omap_wdt: Unexpected close, not stopping!\n");
184 #endif
185 wdev->omap_wdt_users = 0;
186
187 return 0;
188 }
189
190 static ssize_t omap_wdt_write(struct file *file, const char __user *data,
191 size_t len, loff_t *ppos)
192 {
193 struct omap_wdt_dev *wdev = file->private_data;
194
195 /* Refresh LOAD_TIME. */
196 if (len) {
197 spin_lock(&wdt_lock);
198 omap_wdt_ping(wdev);
199 spin_unlock(&wdt_lock);
200 }
201 return len;
202 }
203
204 static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
205 unsigned long arg)
206 {
207 struct omap_wdt_dev *wdev;
208 int new_margin;
209 static const struct watchdog_info ident = {
210 .identity = "OMAP Watchdog",
211 .options = WDIOF_SETTIMEOUT,
212 .firmware_version = 0,
213 };
214
215 wdev = file->private_data;
216
217 switch (cmd) {
218 case WDIOC_GETSUPPORT:
219 return copy_to_user((struct watchdog_info __user *)arg, &ident,
220 sizeof(ident));
221 case WDIOC_GETSTATUS:
222 return put_user(0, (int __user *)arg);
223 case WDIOC_GETBOOTSTATUS:
224 if (cpu_is_omap16xx())
225 return put_user(__raw_readw(ARM_SYSST),
226 (int __user *)arg);
227 if (cpu_is_omap24xx())
228 return put_user(omap_prcm_get_reset_sources(),
229 (int __user *)arg);
230 case WDIOC_KEEPALIVE:
231 spin_lock(&wdt_lock);
232 omap_wdt_ping(wdev);
233 spin_unlock(&wdt_lock);
234 return 0;
235 case WDIOC_SETTIMEOUT:
236 if (get_user(new_margin, (int __user *)arg))
237 return -EFAULT;
238 omap_wdt_adjust_timeout(new_margin);
239
240 spin_lock(&wdt_lock);
241 omap_wdt_disable(wdev);
242 omap_wdt_set_timeout(wdev);
243 omap_wdt_enable(wdev);
244
245 omap_wdt_ping(wdev);
246 spin_unlock(&wdt_lock);
247 /* Fall */
248 case WDIOC_GETTIMEOUT:
249 return put_user(timer_margin, (int __user *)arg);
250 default:
251 return -ENOTTY;
252 }
253 }
254
255 static const struct file_operations omap_wdt_fops = {
256 .owner = THIS_MODULE,
257 .write = omap_wdt_write,
258 .unlocked_ioctl = omap_wdt_ioctl,
259 .open = omap_wdt_open,
260 .release = omap_wdt_release,
261 };
262
263 static int __devinit omap_wdt_probe(struct platform_device *pdev)
264 {
265 struct resource *res, *mem;
266 struct omap_wdt_dev *wdev;
267 int ret;
268
269 /* reserve static register mappings */
270 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
271 if (!res) {
272 ret = -ENOENT;
273 goto err_get_resource;
274 }
275
276 if (omap_wdt_dev) {
277 ret = -EBUSY;
278 goto err_busy;
279 }
280
281 mem = request_mem_region(res->start, resource_size(res), pdev->name);
282 if (!mem) {
283 ret = -EBUSY;
284 goto err_busy;
285 }
286
287 wdev = kzalloc(sizeof(struct omap_wdt_dev), GFP_KERNEL);
288 if (!wdev) {
289 ret = -ENOMEM;
290 goto err_kzalloc;
291 }
292
293 wdev->omap_wdt_users = 0;
294 wdev->mem = mem;
295
296 wdev->ick = clk_get(&pdev->dev, "ick");
297 if (IS_ERR(wdev->ick)) {
298 ret = PTR_ERR(wdev->ick);
299 wdev->ick = NULL;
300 goto err_clk;
301 }
302 wdev->fck = clk_get(&pdev->dev, "fck");
303 if (IS_ERR(wdev->fck)) {
304 ret = PTR_ERR(wdev->fck);
305 wdev->fck = NULL;
306 goto err_clk;
307 }
308
309 wdev->base = ioremap(res->start, resource_size(res));
310 if (!wdev->base) {
311 ret = -ENOMEM;
312 goto err_ioremap;
313 }
314
315 platform_set_drvdata(pdev, wdev);
316
317 clk_enable(wdev->ick);
318 clk_enable(wdev->fck);
319
320 omap_wdt_disable(wdev);
321 omap_wdt_adjust_timeout(timer_margin);
322
323 wdev->omap_wdt_miscdev.parent = &pdev->dev;
324 wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR;
325 wdev->omap_wdt_miscdev.name = "watchdog";
326 wdev->omap_wdt_miscdev.fops = &omap_wdt_fops;
327
328 ret = misc_register(&(wdev->omap_wdt_miscdev));
329 if (ret)
330 goto err_misc;
331
332 pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
333 __raw_readl(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
334 timer_margin);
335
336 /* autogate OCP interface clock */
337 __raw_writel(0x01, wdev->base + OMAP_WATCHDOG_SYS_CONFIG);
338
339 clk_disable(wdev->ick);
340 clk_disable(wdev->fck);
341
342 omap_wdt_dev = pdev;
343
344 return 0;
345
346 err_misc:
347 platform_set_drvdata(pdev, NULL);
348 iounmap(wdev->base);
349
350 err_ioremap:
351 wdev->base = NULL;
352
353 err_clk:
354 if (wdev->ick)
355 clk_put(wdev->ick);
356 if (wdev->fck)
357 clk_put(wdev->fck);
358 kfree(wdev);
359
360 err_kzalloc:
361 release_mem_region(res->start, resource_size(res));
362
363 err_busy:
364 err_get_resource:
365
366 return ret;
367 }
368
369 static void omap_wdt_shutdown(struct platform_device *pdev)
370 {
371 struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
372
373 if (wdev->omap_wdt_users)
374 omap_wdt_disable(wdev);
375 }
376
377 static int __devexit omap_wdt_remove(struct platform_device *pdev)
378 {
379 struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
380 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
381
382 if (!res)
383 return -ENOENT;
384
385 misc_deregister(&(wdev->omap_wdt_miscdev));
386 release_mem_region(res->start, resource_size(res));
387 platform_set_drvdata(pdev, NULL);
388
389 clk_put(wdev->ick);
390 clk_put(wdev->fck);
391 iounmap(wdev->base);
392
393 kfree(wdev);
394 omap_wdt_dev = NULL;
395
396 return 0;
397 }
398
399 #ifdef CONFIG_PM
400
401 /* REVISIT ... not clear this is the best way to handle system suspend; and
402 * it's very inappropriate for selective device suspend (e.g. suspending this
403 * through sysfs rather than by stopping the watchdog daemon). Also, this
404 * may not play well enough with NOWAYOUT...
405 */
406
407 static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
408 {
409 struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
410
411 if (wdev->omap_wdt_users)
412 omap_wdt_disable(wdev);
413
414 return 0;
415 }
416
417 static int omap_wdt_resume(struct platform_device *pdev)
418 {
419 struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
420
421 if (wdev->omap_wdt_users) {
422 omap_wdt_enable(wdev);
423 omap_wdt_ping(wdev);
424 }
425
426 return 0;
427 }
428
429 #else
430 #define omap_wdt_suspend NULL
431 #define omap_wdt_resume NULL
432 #endif
433
434 static struct platform_driver omap_wdt_driver = {
435 .probe = omap_wdt_probe,
436 .remove = __devexit_p(omap_wdt_remove),
437 .shutdown = omap_wdt_shutdown,
438 .suspend = omap_wdt_suspend,
439 .resume = omap_wdt_resume,
440 .driver = {
441 .owner = THIS_MODULE,
442 .name = "omap_wdt",
443 },
444 };
445
446 static int __init omap_wdt_init(void)
447 {
448 spin_lock_init(&wdt_lock);
449 return platform_driver_register(&omap_wdt_driver);
450 }
451
452 static void __exit omap_wdt_exit(void)
453 {
454 platform_driver_unregister(&omap_wdt_driver);
455 }
456
457 module_init(omap_wdt_init);
458 module_exit(omap_wdt_exit);
459
460 MODULE_AUTHOR("George G. Davis");
461 MODULE_LICENSE("GPL");
462 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
463 MODULE_ALIAS("platform:omap_wdt");
Linux with added FPC-III support