diff options
Diffstat (limited to 'drivers/watchdog/rc32434_wdt.c')
-rw-r--r-- | drivers/watchdog/rc32434_wdt.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c new file mode 100644 index 000000000000..6756bcb009ed --- /dev/null +++ b/drivers/watchdog/rc32434_wdt.c | |||
@@ -0,0 +1,344 @@ | |||
1 | /* | ||
2 | * IDT Interprise 79RC32434 watchdog driver | ||
3 | * | ||
4 | * Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org> | ||
5 | * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> | ||
6 | * | ||
7 | * based on | ||
8 | * SoftDog 0.05: A Software Watchdog Device | ||
9 | * | ||
10 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version | ||
15 | * 2 of the License, or (at your option) any later version. | ||
16 | * | ||
17 | */ | ||
18 | |||
19 | #include <linux/module.h> | ||
20 | #include <linux/types.h> | ||
21 | #include <linux/kernel.h> | ||
22 | #include <linux/fs.h> | ||
23 | #include <linux/mm.h> | ||
24 | #include <linux/miscdevice.h> | ||
25 | #include <linux/watchdog.h> | ||
26 | #include <linux/reboot.h> | ||
27 | #include <linux/smp_lock.h> | ||
28 | #include <linux/init.h> | ||
29 | #include <linux/platform_device.h> | ||
30 | #include <linux/uaccess.h> | ||
31 | |||
32 | #include <asm/bootinfo.h> | ||
33 | #include <asm/time.h> | ||
34 | #include <asm/mach-rc32434/integ.h> | ||
35 | |||
36 | #define MAX_TIMEOUT 20 | ||
37 | #define RC32434_WDT_INTERVAL (15 * HZ) | ||
38 | |||
39 | #define VERSION "0.2" | ||
40 | |||
41 | static struct { | ||
42 | struct completion stop; | ||
43 | int running; | ||
44 | struct timer_list timer; | ||
45 | int queue; | ||
46 | int default_ticks; | ||
47 | unsigned long inuse; | ||
48 | } rc32434_wdt_device; | ||
49 | |||
50 | static struct integ __iomem *wdt_reg; | ||
51 | static int ticks = 100 * HZ; | ||
52 | |||
53 | static int expect_close; | ||
54 | static int timeout; | ||
55 | |||
56 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
57 | module_param(nowayout, int, 0); | ||
58 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | ||
59 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
60 | |||
61 | |||
62 | static void rc32434_wdt_start(void) | ||
63 | { | ||
64 | u32 val; | ||
65 | |||
66 | if (!rc32434_wdt_device.inuse) { | ||
67 | writel(0, &wdt_reg->wtcount); | ||
68 | |||
69 | val = RC32434_ERR_WRE; | ||
70 | writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs); | ||
71 | |||
72 | val = RC32434_WTC_EN; | ||
73 | writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc); | ||
74 | } | ||
75 | rc32434_wdt_device.running++; | ||
76 | } | ||
77 | |||
78 | static void rc32434_wdt_stop(void) | ||
79 | { | ||
80 | u32 val; | ||
81 | |||
82 | if (rc32434_wdt_device.running) { | ||
83 | |||
84 | val = ~RC32434_WTC_EN; | ||
85 | writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc); | ||
86 | |||
87 | val = ~RC32434_ERR_WRE; | ||
88 | writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs); | ||
89 | |||
90 | rc32434_wdt_device.running = 0; | ||
91 | } | ||
92 | } | ||
93 | |||
94 | static void rc32434_wdt_set(int new_timeout) | ||
95 | { | ||
96 | u32 cmp = new_timeout * HZ; | ||
97 | u32 state, val; | ||
98 | |||
99 | timeout = new_timeout; | ||
100 | /* | ||
101 | * store and disable WTC | ||
102 | */ | ||
103 | state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN); | ||
104 | val = ~RC32434_WTC_EN; | ||
105 | writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc); | ||
106 | |||
107 | writel(0, &wdt_reg->wtcount); | ||
108 | writel(cmp, &wdt_reg->wtcompare); | ||
109 | |||
110 | /* | ||
111 | * restore WTC | ||
112 | */ | ||
113 | |||
114 | writel(readl(&wdt_reg->wtc) | state, &wdt_reg); | ||
115 | } | ||
116 | |||
117 | static void rc32434_wdt_reset(void) | ||
118 | { | ||
119 | ticks = rc32434_wdt_device.default_ticks; | ||
120 | } | ||
121 | |||
122 | static void rc32434_wdt_update(unsigned long unused) | ||
123 | { | ||
124 | if (rc32434_wdt_device.running) | ||
125 | ticks--; | ||
126 | |||
127 | writel(0, &wdt_reg->wtcount); | ||
128 | |||
129 | if (rc32434_wdt_device.queue && ticks) | ||
130 | mod_timer(&rc32434_wdt_device.timer, | ||
131 | jiffies + RC32434_WDT_INTERVAL); | ||
132 | else | ||
133 | complete(&rc32434_wdt_device.stop); | ||
134 | } | ||
135 | |||
136 | static int rc32434_wdt_open(struct inode *inode, struct file *file) | ||
137 | { | ||
138 | if (test_and_set_bit(0, &rc32434_wdt_device.inuse)) | ||
139 | return -EBUSY; | ||
140 | |||
141 | if (nowayout) | ||
142 | __module_get(THIS_MODULE); | ||
143 | |||
144 | return nonseekable_open(inode, file); | ||
145 | } | ||
146 | |||
147 | static int rc32434_wdt_release(struct inode *inode, struct file *file) | ||
148 | { | ||
149 | if (expect_close && nowayout == 0) { | ||
150 | rc32434_wdt_stop(); | ||
151 | printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n"); | ||
152 | module_put(THIS_MODULE); | ||
153 | } else | ||
154 | printk(KERN_CRIT KBUILD_MODNAME | ||
155 | ": device closed unexpectedly. WDT will not stop !\n"); | ||
156 | |||
157 | clear_bit(0, &rc32434_wdt_device.inuse); | ||
158 | return 0; | ||
159 | } | ||
160 | |||
161 | static ssize_t rc32434_wdt_write(struct file *file, const char *data, | ||
162 | size_t len, loff_t *ppos) | ||
163 | { | ||
164 | if (len) { | ||
165 | if (!nowayout) { | ||
166 | size_t i; | ||
167 | |||
168 | /* In case it was set long ago */ | ||
169 | expect_close = 0; | ||
170 | |||
171 | for (i = 0; i != len; i++) { | ||
172 | char c; | ||
173 | if (get_user(c, data + i)) | ||
174 | return -EFAULT; | ||
175 | if (c == 'V') | ||
176 | expect_close = 1; | ||
177 | } | ||
178 | } | ||
179 | rc32434_wdt_update(0); | ||
180 | return len; | ||
181 | } | ||
182 | return 0; | ||
183 | } | ||
184 | |||
185 | static int rc32434_wdt_ioctl(struct inode *inode, struct file *file, | ||
186 | unsigned int cmd, unsigned long arg) | ||
187 | { | ||
188 | void __user *argp = (void __user *)arg; | ||
189 | int new_timeout; | ||
190 | unsigned int value; | ||
191 | static struct watchdog_info ident = { | ||
192 | .options = WDIOF_SETTIMEOUT | | ||
193 | WDIOF_KEEPALIVEPING | | ||
194 | WDIOF_MAGICCLOSE, | ||
195 | .identity = "RC32434_WDT Watchdog", | ||
196 | }; | ||
197 | switch (cmd) { | ||
198 | case WDIOC_KEEPALIVE: | ||
199 | rc32434_wdt_reset(); | ||
200 | break; | ||
201 | case WDIOC_GETSTATUS: | ||
202 | case WDIOC_GETBOOTSTATUS: | ||
203 | value = readl(&wdt_reg->wtcount); | ||
204 | if (copy_to_user(argp, &value, sizeof(int))) | ||
205 | return -EFAULT; | ||
206 | break; | ||
207 | case WDIOC_GETSUPPORT: | ||
208 | if (copy_to_user(argp, &ident, sizeof(ident))) | ||
209 | return -EFAULT; | ||
210 | break; | ||
211 | case WDIOC_SETOPTIONS: | ||
212 | if (copy_from_user(&value, argp, sizeof(int))) | ||
213 | return -EFAULT; | ||
214 | switch (value) { | ||
215 | case WDIOS_ENABLECARD: | ||
216 | rc32434_wdt_start(); | ||
217 | break; | ||
218 | case WDIOS_DISABLECARD: | ||
219 | rc32434_wdt_stop(); | ||
220 | default: | ||
221 | return -EINVAL; | ||
222 | } | ||
223 | break; | ||
224 | case WDIOC_SETTIMEOUT: | ||
225 | if (copy_from_user(&new_timeout, argp, sizeof(int))) | ||
226 | return -EFAULT; | ||
227 | if (new_timeout < 1) | ||
228 | return -EINVAL; | ||
229 | if (new_timeout > MAX_TIMEOUT) | ||
230 | return -EINVAL; | ||
231 | rc32434_wdt_set(new_timeout); | ||
232 | case WDIOC_GETTIMEOUT: | ||
233 | return copy_to_user(argp, &timeout, sizeof(int)); | ||
234 | default: | ||
235 | return -ENOTTY; | ||
236 | } | ||
237 | |||
238 | return 0; | ||
239 | } | ||
240 | |||
241 | static struct file_operations rc32434_wdt_fops = { | ||
242 | .owner = THIS_MODULE, | ||
243 | .llseek = no_llseek, | ||
244 | .write = rc32434_wdt_write, | ||
245 | .ioctl = rc32434_wdt_ioctl, | ||
246 | .open = rc32434_wdt_open, | ||
247 | .release = rc32434_wdt_release, | ||
248 | }; | ||
249 | |||
250 | static struct miscdevice rc32434_wdt_miscdev = { | ||
251 | .minor = WATCHDOG_MINOR, | ||
252 | .name = "watchdog", | ||
253 | .fops = &rc32434_wdt_fops, | ||
254 | }; | ||
255 | |||
256 | static char banner[] = KERN_INFO KBUILD_MODNAME | ||
257 | ": Watchdog Timer version " VERSION ", timer margin: %d sec\n"; | ||
258 | |||
259 | static int rc32434_wdt_probe(struct platform_device *pdev) | ||
260 | { | ||
261 | int ret; | ||
262 | struct resource *r; | ||
263 | |||
264 | r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res"); | ||
265 | if (!r) { | ||
266 | printk(KERN_ERR KBUILD_MODNAME | ||
267 | "failed to retrieve resources\n"); | ||
268 | return -ENODEV; | ||
269 | } | ||
270 | |||
271 | wdt_reg = ioremap_nocache(r->start, r->end - r->start); | ||
272 | if (!wdt_reg) { | ||
273 | printk(KERN_ERR KBUILD_MODNAME | ||
274 | "failed to remap I/O resources\n"); | ||
275 | return -ENXIO; | ||
276 | } | ||
277 | |||
278 | ret = misc_register(&rc32434_wdt_miscdev); | ||
279 | |||
280 | if (ret < 0) { | ||
281 | printk(KERN_ERR KBUILD_MODNAME | ||
282 | "failed to register watchdog device\n"); | ||
283 | goto unmap; | ||
284 | } | ||
285 | |||
286 | init_completion(&rc32434_wdt_device.stop); | ||
287 | rc32434_wdt_device.queue = 0; | ||
288 | |||
289 | clear_bit(0, &rc32434_wdt_device.inuse); | ||
290 | |||
291 | setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L); | ||
292 | |||
293 | rc32434_wdt_device.default_ticks = ticks; | ||
294 | |||
295 | rc32434_wdt_start(); | ||
296 | |||
297 | printk(banner, timeout); | ||
298 | |||
299 | return 0; | ||
300 | |||
301 | unmap: | ||
302 | iounmap(wdt_reg); | ||
303 | return ret; | ||
304 | } | ||
305 | |||
306 | static int rc32434_wdt_remove(struct platform_device *pdev) | ||
307 | { | ||
308 | if (rc32434_wdt_device.queue) { | ||
309 | rc32434_wdt_device.queue = 0; | ||
310 | wait_for_completion(&rc32434_wdt_device.stop); | ||
311 | } | ||
312 | misc_deregister(&rc32434_wdt_miscdev); | ||
313 | |||
314 | iounmap(wdt_reg); | ||
315 | |||
316 | return 0; | ||
317 | } | ||
318 | |||
319 | static struct platform_driver rc32434_wdt = { | ||
320 | .probe = rc32434_wdt_probe, | ||
321 | .remove = rc32434_wdt_remove, | ||
322 | .driver = { | ||
323 | .name = "rc32434_wdt", | ||
324 | } | ||
325 | }; | ||
326 | |||
327 | static int __init rc32434_wdt_init(void) | ||
328 | { | ||
329 | return platform_driver_register(&rc32434_wdt); | ||
330 | } | ||
331 | |||
332 | static void __exit rc32434_wdt_exit(void) | ||
333 | { | ||
334 | platform_driver_unregister(&rc32434_wdt); | ||
335 | } | ||
336 | |||
337 | module_init(rc32434_wdt_init); | ||
338 | module_exit(rc32434_wdt_exit); | ||
339 | |||
340 | MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>," | ||
341 | "Florian Fainelli <florian@openwrt.org>"); | ||
342 | MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog"); | ||
343 | MODULE_LICENSE("GPL"); | ||
344 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||