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b63aa731 FF |
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> | |
b63aa731 FF |
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 | ||
b63aa731 FF |
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 | ||
b63aa731 | 237 | |
e6c3b699 | 238 | static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev) |
b63aa731 FF |
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, r->end - r->start); | |
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 | ||
b63aa731 FF |
270 | ret = misc_register(&bcm63xx_wdt_miscdev); |
271 | if (ret < 0) { | |
272 | dev_err(&pdev->dev, "failed to register watchdog device\n"); | |
e6c3b699 | 273 | goto unregister_timer; |
b63aa731 FF |
274 | } |
275 | ||
276 | dev_info(&pdev->dev, " started, timer margin: %d sec\n", | |
277 | WDT_DEFAULT_TIME); | |
278 | ||
279 | return 0; | |
280 | ||
b63aa731 FF |
281 | unregister_timer: |
282 | bcm63xx_timer_unregister(TIMER_WDT_ID); | |
283 | unmap: | |
284 | iounmap(bcm63xx_wdt_device.regs); | |
285 | return ret; | |
286 | } | |
287 | ||
e6c3b699 | 288 | static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev) |
b63aa731 FF |
289 | { |
290 | if (!nowayout) | |
291 | bcm63xx_wdt_pause(); | |
292 | ||
293 | misc_deregister(&bcm63xx_wdt_miscdev); | |
b63aa731 | 294 | bcm63xx_timer_unregister(TIMER_WDT_ID); |
e6c3b699 | 295 | iounmap(bcm63xx_wdt_device.regs); |
b63aa731 FF |
296 | return 0; |
297 | } | |
298 | ||
e6c3b699 WVS |
299 | static void bcm63xx_wdt_shutdown(struct platform_device *pdev) |
300 | { | |
301 | bcm63xx_wdt_pause(); | |
302 | } | |
303 | ||
b63aa731 FF |
304 | static struct platform_driver bcm63xx_wdt = { |
305 | .probe = bcm63xx_wdt_probe, | |
e6c3b699 WVS |
306 | .remove = __devexit_p(bcm63xx_wdt_remove), |
307 | .shutdown = bcm63xx_wdt_shutdown, | |
b63aa731 | 308 | .driver = { |
e6c3b699 | 309 | .owner = THIS_MODULE, |
b63aa731 FF |
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"); |