diff options
Diffstat (limited to 'drivers/watchdog/bcm63xx_wdt.c')
-rw-r--r-- | drivers/watchdog/bcm63xx_wdt.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c new file mode 100644 index 000000000000..5064e8317521 --- /dev/null +++ b/drivers/watchdog/bcm63xx_wdt.c | |||
@@ -0,0 +1,332 @@ | |||
1 | /* | ||
2 | * Broadcom BCM63xx SoC watchdog driver | ||
3 | * | ||
4 | * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com> | ||
5 | * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or | ||
8 | * modify it under the terms of the GNU General Public License | ||
9 | * as published by the Free Software Foundation; either version | ||
10 | * 2 of the License, or (at your option) any later version. | ||
11 | */ | ||
12 | |||
13 | #include <linux/bitops.h> | ||
14 | #include <linux/errno.h> | ||
15 | #include <linux/fs.h> | ||
16 | #include <linux/init.h> | ||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/miscdevice.h> | ||
19 | #include <linux/module.h> | ||
20 | #include <linux/moduleparam.h> | ||
21 | #include <linux/types.h> | ||
22 | #include <linux/uaccess.h> | ||
23 | #include <linux/watchdog.h> | ||
24 | #include <linux/timer.h> | ||
25 | #include <linux/jiffies.h> | ||
26 | #include <linux/interrupt.h> | ||
27 | #include <linux/ptrace.h> | ||
28 | #include <linux/resource.h> | ||
29 | #include <linux/platform_device.h> | ||
30 | |||
31 | #include <bcm63xx_cpu.h> | ||
32 | #include <bcm63xx_io.h> | ||
33 | #include <bcm63xx_regs.h> | ||
34 | #include <bcm63xx_timer.h> | ||
35 | |||
36 | #define PFX KBUILD_MODNAME | ||
37 | |||
38 | #define WDT_HZ 50000000 /* Fclk */ | ||
39 | #define WDT_DEFAULT_TIME 30 /* seconds */ | ||
40 | #define WDT_MAX_TIME 256 /* seconds */ | ||
41 | |||
42 | static struct { | ||
43 | void __iomem *regs; | ||
44 | struct timer_list timer; | ||
45 | int default_ticks; | ||
46 | unsigned long inuse; | ||
47 | atomic_t ticks; | ||
48 | } bcm63xx_wdt_device; | ||
49 | |||
50 | static int expect_close; | ||
51 | |||
52 | static int wdt_time = WDT_DEFAULT_TIME; | ||
53 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
54 | module_param(nowayout, int, 0); | ||
55 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | ||
56 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
57 | |||
58 | /* HW functions */ | ||
59 | static void bcm63xx_wdt_hw_start(void) | ||
60 | { | ||
61 | bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); | ||
62 | bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); | ||
63 | bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); | ||
64 | } | ||
65 | |||
66 | static void bcm63xx_wdt_hw_stop(void) | ||
67 | { | ||
68 | bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); | ||
69 | bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); | ||
70 | } | ||
71 | |||
72 | static void bcm63xx_wdt_isr(void *data) | ||
73 | { | ||
74 | struct pt_regs *regs = get_irq_regs(); | ||
75 | |||
76 | die(PFX " fire", regs); | ||
77 | } | ||
78 | |||
79 | static void bcm63xx_timer_tick(unsigned long unused) | ||
80 | { | ||
81 | if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) { | ||
82 | bcm63xx_wdt_hw_start(); | ||
83 | mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ); | ||
84 | } else | ||
85 | printk(KERN_CRIT PFX ": watchdog will restart system\n"); | ||
86 | } | ||
87 | |||
88 | static void bcm63xx_wdt_pet(void) | ||
89 | { | ||
90 | atomic_set(&bcm63xx_wdt_device.ticks, wdt_time); | ||
91 | } | ||
92 | |||
93 | static void bcm63xx_wdt_start(void) | ||
94 | { | ||
95 | bcm63xx_wdt_pet(); | ||
96 | bcm63xx_timer_tick(0); | ||
97 | } | ||
98 | |||
99 | static void bcm63xx_wdt_pause(void) | ||
100 | { | ||
101 | del_timer_sync(&bcm63xx_wdt_device.timer); | ||
102 | bcm63xx_wdt_hw_stop(); | ||
103 | } | ||
104 | |||
105 | static int bcm63xx_wdt_settimeout(int new_time) | ||
106 | { | ||
107 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | ||
108 | return -EINVAL; | ||
109 | |||
110 | wdt_time = new_time; | ||
111 | |||
112 | return 0; | ||
113 | } | ||
114 | |||
115 | static int bcm63xx_wdt_open(struct inode *inode, struct file *file) | ||
116 | { | ||
117 | if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse)) | ||
118 | return -EBUSY; | ||
119 | |||
120 | bcm63xx_wdt_start(); | ||
121 | return nonseekable_open(inode, file); | ||
122 | } | ||
123 | |||
124 | static int bcm63xx_wdt_release(struct inode *inode, struct file *file) | ||
125 | { | ||
126 | if (expect_close == 42) | ||
127 | bcm63xx_wdt_pause(); | ||
128 | else { | ||
129 | printk(KERN_CRIT PFX | ||
130 | ": Unexpected close, not stopping watchdog!\n"); | ||
131 | bcm63xx_wdt_start(); | ||
132 | } | ||
133 | clear_bit(0, &bcm63xx_wdt_device.inuse); | ||
134 | expect_close = 0; | ||
135 | return 0; | ||
136 | } | ||
137 | |||
138 | static ssize_t bcm63xx_wdt_write(struct file *file, const char *data, | ||
139 | size_t len, loff_t *ppos) | ||
140 | { | ||
141 | if (len) { | ||
142 | if (!nowayout) { | ||
143 | size_t i; | ||
144 | |||
145 | /* In case it was set long ago */ | ||
146 | expect_close = 0; | ||
147 | |||
148 | for (i = 0; i != len; i++) { | ||
149 | char c; | ||
150 | if (get_user(c, data + i)) | ||
151 | return -EFAULT; | ||
152 | if (c == 'V') | ||
153 | expect_close = 42; | ||
154 | } | ||
155 | } | ||
156 | bcm63xx_wdt_pet(); | ||
157 | } | ||
158 | return len; | ||
159 | } | ||
160 | |||
161 | static struct watchdog_info bcm63xx_wdt_info = { | ||
162 | .identity = PFX, | ||
163 | .options = WDIOF_SETTIMEOUT | | ||
164 | WDIOF_KEEPALIVEPING | | ||
165 | WDIOF_MAGICCLOSE, | ||
166 | }; | ||
167 | |||
168 | |||
169 | static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd, | ||
170 | unsigned long arg) | ||
171 | { | ||
172 | void __user *argp = (void __user *)arg; | ||
173 | int __user *p = argp; | ||
174 | int new_value, retval = -EINVAL; | ||
175 | |||
176 | switch (cmd) { | ||
177 | case WDIOC_GETSUPPORT: | ||
178 | return copy_to_user(argp, &bcm63xx_wdt_info, | ||
179 | sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0; | ||
180 | |||
181 | case WDIOC_GETSTATUS: | ||
182 | case WDIOC_GETBOOTSTATUS: | ||
183 | return put_user(0, p); | ||
184 | |||
185 | case WDIOC_SETOPTIONS: | ||
186 | if (get_user(new_value, p)) | ||
187 | return -EFAULT; | ||
188 | |||
189 | if (new_value & WDIOS_DISABLECARD) { | ||
190 | bcm63xx_wdt_pause(); | ||
191 | retval = 0; | ||
192 | } | ||
193 | if (new_value & WDIOS_ENABLECARD) { | ||
194 | bcm63xx_wdt_start(); | ||
195 | retval = 0; | ||
196 | } | ||
197 | |||
198 | return retval; | ||
199 | |||
200 | case WDIOC_KEEPALIVE: | ||
201 | bcm63xx_wdt_pet(); | ||
202 | return 0; | ||
203 | |||
204 | case WDIOC_SETTIMEOUT: | ||
205 | if (get_user(new_value, p)) | ||
206 | return -EFAULT; | ||
207 | |||
208 | if (bcm63xx_wdt_settimeout(new_value)) | ||
209 | return -EINVAL; | ||
210 | |||
211 | bcm63xx_wdt_pet(); | ||
212 | |||
213 | case WDIOC_GETTIMEOUT: | ||
214 | return put_user(wdt_time, p); | ||
215 | |||
216 | default: | ||
217 | return -ENOTTY; | ||
218 | |||
219 | } | ||
220 | } | ||
221 | |||
222 | static const struct file_operations bcm63xx_wdt_fops = { | ||
223 | .owner = THIS_MODULE, | ||
224 | .llseek = no_llseek, | ||
225 | .write = bcm63xx_wdt_write, | ||
226 | .unlocked_ioctl = bcm63xx_wdt_ioctl, | ||
227 | .open = bcm63xx_wdt_open, | ||
228 | .release = bcm63xx_wdt_release, | ||
229 | }; | ||
230 | |||
231 | static struct miscdevice bcm63xx_wdt_miscdev = { | ||
232 | .minor = WATCHDOG_MINOR, | ||
233 | .name = "watchdog", | ||
234 | .fops = &bcm63xx_wdt_fops, | ||
235 | }; | ||
236 | |||
237 | |||
238 | static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev) | ||
239 | { | ||
240 | int ret; | ||
241 | struct resource *r; | ||
242 | |||
243 | setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L); | ||
244 | |||
245 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
246 | if (!r) { | ||
247 | dev_err(&pdev->dev, "failed to get resources\n"); | ||
248 | return -ENODEV; | ||
249 | } | ||
250 | |||
251 | bcm63xx_wdt_device.regs = ioremap_nocache(r->start, resource_size(r)); | ||
252 | if (!bcm63xx_wdt_device.regs) { | ||
253 | dev_err(&pdev->dev, "failed to remap I/O resources\n"); | ||
254 | return -ENXIO; | ||
255 | } | ||
256 | |||
257 | ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL); | ||
258 | if (ret < 0) { | ||
259 | dev_err(&pdev->dev, "failed to register wdt timer isr\n"); | ||
260 | goto unmap; | ||
261 | } | ||
262 | |||
263 | if (bcm63xx_wdt_settimeout(wdt_time)) { | ||
264 | bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME); | ||
265 | dev_info(&pdev->dev, | ||
266 | ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n", | ||
267 | wdt_time); | ||
268 | } | ||
269 | |||
270 | ret = misc_register(&bcm63xx_wdt_miscdev); | ||
271 | if (ret < 0) { | ||
272 | dev_err(&pdev->dev, "failed to register watchdog device\n"); | ||
273 | goto unregister_timer; | ||
274 | } | ||
275 | |||
276 | dev_info(&pdev->dev, " started, timer margin: %d sec\n", | ||
277 | WDT_DEFAULT_TIME); | ||
278 | |||
279 | return 0; | ||
280 | |||
281 | unregister_timer: | ||
282 | bcm63xx_timer_unregister(TIMER_WDT_ID); | ||
283 | unmap: | ||
284 | iounmap(bcm63xx_wdt_device.regs); | ||
285 | return ret; | ||
286 | } | ||
287 | |||
288 | static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev) | ||
289 | { | ||
290 | if (!nowayout) | ||
291 | bcm63xx_wdt_pause(); | ||
292 | |||
293 | misc_deregister(&bcm63xx_wdt_miscdev); | ||
294 | bcm63xx_timer_unregister(TIMER_WDT_ID); | ||
295 | iounmap(bcm63xx_wdt_device.regs); | ||
296 | return 0; | ||
297 | } | ||
298 | |||
299 | static void bcm63xx_wdt_shutdown(struct platform_device *pdev) | ||
300 | { | ||
301 | bcm63xx_wdt_pause(); | ||
302 | } | ||
303 | |||
304 | static struct platform_driver bcm63xx_wdt = { | ||
305 | .probe = bcm63xx_wdt_probe, | ||
306 | .remove = __devexit_p(bcm63xx_wdt_remove), | ||
307 | .shutdown = bcm63xx_wdt_shutdown, | ||
308 | .driver = { | ||
309 | .owner = THIS_MODULE, | ||
310 | .name = "bcm63xx-wdt", | ||
311 | } | ||
312 | }; | ||
313 | |||
314 | static int __init bcm63xx_wdt_init(void) | ||
315 | { | ||
316 | return platform_driver_register(&bcm63xx_wdt); | ||
317 | } | ||
318 | |||
319 | static void __exit bcm63xx_wdt_exit(void) | ||
320 | { | ||
321 | platform_driver_unregister(&bcm63xx_wdt); | ||
322 | } | ||
323 | |||
324 | module_init(bcm63xx_wdt_init); | ||
325 | module_exit(bcm63xx_wdt_exit); | ||
326 | |||
327 | MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>"); | ||
328 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); | ||
329 | MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog"); | ||
330 | MODULE_LICENSE("GPL"); | ||
331 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
332 | MODULE_ALIAS("platform:bcm63xx-wdt"); | ||