diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
---|---|---|
committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/omap_wdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/omap_wdt.c')
-rw-r--r-- | drivers/watchdog/omap_wdt.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c new file mode 100644 index 000000000000..719b066f73c4 --- /dev/null +++ b/drivers/watchdog/omap_wdt.c | |||
@@ -0,0 +1,389 @@ | |||
1 | /* | ||
2 | * linux/drivers/char/watchdog/omap_wdt.c | ||
3 | * | ||
4 | * Watchdog driver for the TI OMAP 16xx & 24xx 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@redhat.com> | ||
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 | |||
43 | #include <asm/io.h> | ||
44 | #include <asm/uaccess.h> | ||
45 | #include <asm/hardware.h> | ||
46 | #include <asm/bitops.h> | ||
47 | |||
48 | #include <asm/arch/prcm.h> | ||
49 | |||
50 | #include "omap_wdt.h" | ||
51 | |||
52 | static unsigned timer_margin; | ||
53 | module_param(timer_margin, uint, 0); | ||
54 | MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)"); | ||
55 | |||
56 | static int omap_wdt_users; | ||
57 | static struct clk *armwdt_ck = NULL; | ||
58 | static struct clk *mpu_wdt_ick = NULL; | ||
59 | static struct clk *mpu_wdt_fck = NULL; | ||
60 | |||
61 | static unsigned int wdt_trgr_pattern = 0x1234; | ||
62 | |||
63 | static void omap_wdt_ping(void) | ||
64 | { | ||
65 | /* wait for posted write to complete */ | ||
66 | while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) | ||
67 | cpu_relax(); | ||
68 | wdt_trgr_pattern = ~wdt_trgr_pattern; | ||
69 | omap_writel(wdt_trgr_pattern, (OMAP_WATCHDOG_TGR)); | ||
70 | /* wait for posted write to complete */ | ||
71 | while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) | ||
72 | cpu_relax(); | ||
73 | /* reloaded WCRR from WLDR */ | ||
74 | } | ||
75 | |||
76 | static void omap_wdt_enable(void) | ||
77 | { | ||
78 | /* Sequence to enable the watchdog */ | ||
79 | omap_writel(0xBBBB, OMAP_WATCHDOG_SPR); | ||
80 | while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) | ||
81 | cpu_relax(); | ||
82 | omap_writel(0x4444, OMAP_WATCHDOG_SPR); | ||
83 | while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) | ||
84 | cpu_relax(); | ||
85 | } | ||
86 | |||
87 | static void omap_wdt_disable(void) | ||
88 | { | ||
89 | /* sequence required to disable watchdog */ | ||
90 | omap_writel(0xAAAA, OMAP_WATCHDOG_SPR); /* TIMER_MODE */ | ||
91 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) | ||
92 | cpu_relax(); | ||
93 | omap_writel(0x5555, OMAP_WATCHDOG_SPR); /* TIMER_MODE */ | ||
94 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) | ||
95 | cpu_relax(); | ||
96 | } | ||
97 | |||
98 | static void omap_wdt_adjust_timeout(unsigned new_timeout) | ||
99 | { | ||
100 | if (new_timeout < TIMER_MARGIN_MIN) | ||
101 | new_timeout = TIMER_MARGIN_DEFAULT; | ||
102 | if (new_timeout > TIMER_MARGIN_MAX) | ||
103 | new_timeout = TIMER_MARGIN_MAX; | ||
104 | timer_margin = new_timeout; | ||
105 | } | ||
106 | |||
107 | static void omap_wdt_set_timeout(void) | ||
108 | { | ||
109 | u32 pre_margin = GET_WLDR_VAL(timer_margin); | ||
110 | |||
111 | /* just count up at 32 KHz */ | ||
112 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x04) | ||
113 | cpu_relax(); | ||
114 | omap_writel(pre_margin, OMAP_WATCHDOG_LDR); | ||
115 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x04) | ||
116 | cpu_relax(); | ||
117 | } | ||
118 | |||
119 | /* | ||
120 | * Allow only one task to hold it open | ||
121 | */ | ||
122 | |||
123 | static int omap_wdt_open(struct inode *inode, struct file *file) | ||
124 | { | ||
125 | if (test_and_set_bit(1, (unsigned long *)&omap_wdt_users)) | ||
126 | return -EBUSY; | ||
127 | |||
128 | if (cpu_is_omap16xx()) | ||
129 | clk_enable(armwdt_ck); /* Enable the clock */ | ||
130 | |||
131 | if (cpu_is_omap24xx()) { | ||
132 | clk_enable(mpu_wdt_ick); /* Enable the interface clock */ | ||
133 | clk_enable(mpu_wdt_fck); /* Enable the functional clock */ | ||
134 | } | ||
135 | |||
136 | /* initialize prescaler */ | ||
137 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x01) | ||
138 | cpu_relax(); | ||
139 | omap_writel((1 << 5) | (PTV << 2), OMAP_WATCHDOG_CNTRL); | ||
140 | while (omap_readl(OMAP_WATCHDOG_WPS) & 0x01) | ||
141 | cpu_relax(); | ||
142 | |||
143 | omap_wdt_set_timeout(); | ||
144 | omap_wdt_enable(); | ||
145 | return nonseekable_open(inode, file); | ||
146 | } | ||
147 | |||
148 | static int omap_wdt_release(struct inode *inode, struct file *file) | ||
149 | { | ||
150 | /* | ||
151 | * Shut off the timer unless NOWAYOUT is defined. | ||
152 | */ | ||
153 | #ifndef CONFIG_WATCHDOG_NOWAYOUT | ||
154 | omap_wdt_disable(); | ||
155 | |||
156 | if (cpu_is_omap16xx()) { | ||
157 | clk_disable(armwdt_ck); /* Disable the clock */ | ||
158 | clk_put(armwdt_ck); | ||
159 | armwdt_ck = NULL; | ||
160 | } | ||
161 | |||
162 | if (cpu_is_omap24xx()) { | ||
163 | clk_disable(mpu_wdt_ick); /* Disable the clock */ | ||
164 | clk_disable(mpu_wdt_fck); /* Disable the clock */ | ||
165 | clk_put(mpu_wdt_ick); | ||
166 | clk_put(mpu_wdt_fck); | ||
167 | mpu_wdt_ick = NULL; | ||
168 | mpu_wdt_fck = NULL; | ||
169 | } | ||
170 | #else | ||
171 | printk(KERN_CRIT "omap_wdt: Unexpected close, not stopping!\n"); | ||
172 | #endif | ||
173 | omap_wdt_users = 0; | ||
174 | return 0; | ||
175 | } | ||
176 | |||
177 | static ssize_t | ||
178 | omap_wdt_write(struct file *file, const char __user *data, | ||
179 | size_t len, loff_t *ppos) | ||
180 | { | ||
181 | /* Refresh LOAD_TIME. */ | ||
182 | if (len) | ||
183 | omap_wdt_ping(); | ||
184 | return len; | ||
185 | } | ||
186 | |||
187 | static int | ||
188 | omap_wdt_ioctl(struct inode *inode, struct file *file, | ||
189 | unsigned int cmd, unsigned long arg) | ||
190 | { | ||
191 | int new_margin; | ||
192 | static struct watchdog_info ident = { | ||
193 | .identity = "OMAP Watchdog", | ||
194 | .options = WDIOF_SETTIMEOUT, | ||
195 | .firmware_version = 0, | ||
196 | }; | ||
197 | |||
198 | switch (cmd) { | ||
199 | default: | ||
200 | return -ENOTTY; | ||
201 | case WDIOC_GETSUPPORT: | ||
202 | return copy_to_user((struct watchdog_info __user *)arg, &ident, | ||
203 | sizeof(ident)); | ||
204 | case WDIOC_GETSTATUS: | ||
205 | return put_user(0, (int __user *)arg); | ||
206 | case WDIOC_GETBOOTSTATUS: | ||
207 | if (cpu_is_omap16xx()) | ||
208 | return put_user(omap_readw(ARM_SYSST), | ||
209 | (int __user *)arg); | ||
210 | if (cpu_is_omap24xx()) | ||
211 | return put_user(omap_prcm_get_reset_sources(), | ||
212 | (int __user *)arg); | ||
213 | case WDIOC_KEEPALIVE: | ||
214 | omap_wdt_ping(); | ||
215 | return 0; | ||
216 | case WDIOC_SETTIMEOUT: | ||
217 | if (get_user(new_margin, (int __user *)arg)) | ||
218 | return -EFAULT; | ||
219 | omap_wdt_adjust_timeout(new_margin); | ||
220 | |||
221 | omap_wdt_disable(); | ||
222 | omap_wdt_set_timeout(); | ||
223 | omap_wdt_enable(); | ||
224 | |||
225 | omap_wdt_ping(); | ||
226 | /* Fall */ | ||
227 | case WDIOC_GETTIMEOUT: | ||
228 | return put_user(timer_margin, (int __user *)arg); | ||
229 | } | ||
230 | } | ||
231 | |||
232 | static const struct file_operations omap_wdt_fops = { | ||
233 | .owner = THIS_MODULE, | ||
234 | .write = omap_wdt_write, | ||
235 | .ioctl = omap_wdt_ioctl, | ||
236 | .open = omap_wdt_open, | ||
237 | .release = omap_wdt_release, | ||
238 | }; | ||
239 | |||
240 | static struct miscdevice omap_wdt_miscdev = { | ||
241 | .minor = WATCHDOG_MINOR, | ||
242 | .name = "watchdog", | ||
243 | .fops = &omap_wdt_fops | ||
244 | }; | ||
245 | |||
246 | static int __init omap_wdt_probe(struct platform_device *pdev) | ||
247 | { | ||
248 | struct resource *res, *mem; | ||
249 | int ret; | ||
250 | |||
251 | /* reserve static register mappings */ | ||
252 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
253 | if (!res) | ||
254 | return -ENOENT; | ||
255 | |||
256 | mem = request_mem_region(res->start, res->end - res->start + 1, | ||
257 | pdev->name); | ||
258 | if (mem == NULL) | ||
259 | return -EBUSY; | ||
260 | |||
261 | platform_set_drvdata(pdev, mem); | ||
262 | |||
263 | omap_wdt_users = 0; | ||
264 | |||
265 | if (cpu_is_omap16xx()) { | ||
266 | armwdt_ck = clk_get(&pdev->dev, "armwdt_ck"); | ||
267 | if (IS_ERR(armwdt_ck)) { | ||
268 | ret = PTR_ERR(armwdt_ck); | ||
269 | armwdt_ck = NULL; | ||
270 | goto fail; | ||
271 | } | ||
272 | } | ||
273 | |||
274 | if (cpu_is_omap24xx()) { | ||
275 | mpu_wdt_ick = clk_get(&pdev->dev, "mpu_wdt_ick"); | ||
276 | if (IS_ERR(mpu_wdt_ick)) { | ||
277 | ret = PTR_ERR(mpu_wdt_ick); | ||
278 | mpu_wdt_ick = NULL; | ||
279 | goto fail; | ||
280 | } | ||
281 | mpu_wdt_fck = clk_get(&pdev->dev, "mpu_wdt_fck"); | ||
282 | if (IS_ERR(mpu_wdt_fck)) { | ||
283 | ret = PTR_ERR(mpu_wdt_fck); | ||
284 | mpu_wdt_fck = NULL; | ||
285 | goto fail; | ||
286 | } | ||
287 | } | ||
288 | |||
289 | omap_wdt_disable(); | ||
290 | omap_wdt_adjust_timeout(timer_margin); | ||
291 | |||
292 | omap_wdt_miscdev.parent = &pdev->dev; | ||
293 | ret = misc_register(&omap_wdt_miscdev); | ||
294 | if (ret) | ||
295 | goto fail; | ||
296 | |||
297 | pr_info("OMAP Watchdog Timer: initial timeout %d sec\n", timer_margin); | ||
298 | |||
299 | /* autogate OCP interface clock */ | ||
300 | omap_writel(0x01, OMAP_WATCHDOG_SYS_CONFIG); | ||
301 | return 0; | ||
302 | |||
303 | fail: | ||
304 | if (armwdt_ck) | ||
305 | clk_put(armwdt_ck); | ||
306 | if (mpu_wdt_ick) | ||
307 | clk_put(mpu_wdt_ick); | ||
308 | if (mpu_wdt_fck) | ||
309 | clk_put(mpu_wdt_fck); | ||
310 | release_resource(mem); | ||
311 | return ret; | ||
312 | } | ||
313 | |||
314 | static void omap_wdt_shutdown(struct platform_device *pdev) | ||
315 | { | ||
316 | omap_wdt_disable(); | ||
317 | } | ||
318 | |||
319 | static int omap_wdt_remove(struct platform_device *pdev) | ||
320 | { | ||
321 | struct resource *mem = platform_get_drvdata(pdev); | ||
322 | misc_deregister(&omap_wdt_miscdev); | ||
323 | release_resource(mem); | ||
324 | if (armwdt_ck) | ||
325 | clk_put(armwdt_ck); | ||
326 | if (mpu_wdt_ick) | ||
327 | clk_put(mpu_wdt_ick); | ||
328 | if (mpu_wdt_fck) | ||
329 | clk_put(mpu_wdt_fck); | ||
330 | return 0; | ||
331 | } | ||
332 | |||
333 | #ifdef CONFIG_PM | ||
334 | |||
335 | /* REVISIT ... not clear this is the best way to handle system suspend; and | ||
336 | * it's very inappropriate for selective device suspend (e.g. suspending this | ||
337 | * through sysfs rather than by stopping the watchdog daemon). Also, this | ||
338 | * may not play well enough with NOWAYOUT... | ||
339 | */ | ||
340 | |||
341 | static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state) | ||
342 | { | ||
343 | if (omap_wdt_users) | ||
344 | omap_wdt_disable(); | ||
345 | return 0; | ||
346 | } | ||
347 | |||
348 | static int omap_wdt_resume(struct platform_device *pdev) | ||
349 | { | ||
350 | if (omap_wdt_users) { | ||
351 | omap_wdt_enable(); | ||
352 | omap_wdt_ping(); | ||
353 | } | ||
354 | return 0; | ||
355 | } | ||
356 | |||
357 | #else | ||
358 | #define omap_wdt_suspend NULL | ||
359 | #define omap_wdt_resume NULL | ||
360 | #endif | ||
361 | |||
362 | static struct platform_driver omap_wdt_driver = { | ||
363 | .probe = omap_wdt_probe, | ||
364 | .remove = omap_wdt_remove, | ||
365 | .shutdown = omap_wdt_shutdown, | ||
366 | .suspend = omap_wdt_suspend, | ||
367 | .resume = omap_wdt_resume, | ||
368 | .driver = { | ||
369 | .owner = THIS_MODULE, | ||
370 | .name = "omap_wdt", | ||
371 | }, | ||
372 | }; | ||
373 | |||
374 | static int __init omap_wdt_init(void) | ||
375 | { | ||
376 | return platform_driver_register(&omap_wdt_driver); | ||
377 | } | ||
378 | |||
379 | static void __exit omap_wdt_exit(void) | ||
380 | { | ||
381 | platform_driver_unregister(&omap_wdt_driver); | ||
382 | } | ||
383 | |||
384 | module_init(omap_wdt_init); | ||
385 | module_exit(omap_wdt_exit); | ||
386 | |||
387 | MODULE_AUTHOR("George G. Davis"); | ||
388 | MODULE_LICENSE("GPL"); | ||
389 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||