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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 | ||
27c766aa JP |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | ||
b63aa731 FF |
15 | #include <linux/bitops.h> |
16 | #include <linux/errno.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/init.h> | |
626d65aa | 19 | #include <linux/io.h> |
b63aa731 FF |
20 | #include <linux/kernel.h> |
21 | #include <linux/miscdevice.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/moduleparam.h> | |
b63aa731 FF |
24 | #include <linux/types.h> |
25 | #include <linux/uaccess.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/timer.h> | |
28 | #include <linux/jiffies.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <linux/ptrace.h> | |
31 | #include <linux/resource.h> | |
32 | #include <linux/platform_device.h> | |
33 | ||
34 | #include <bcm63xx_cpu.h> | |
35 | #include <bcm63xx_io.h> | |
36 | #include <bcm63xx_regs.h> | |
37 | #include <bcm63xx_timer.h> | |
38 | ||
39 | #define PFX KBUILD_MODNAME | |
40 | ||
41 | #define WDT_HZ 50000000 /* Fclk */ | |
42 | #define WDT_DEFAULT_TIME 30 /* seconds */ | |
43 | #define WDT_MAX_TIME 256 /* seconds */ | |
44 | ||
45 | static struct { | |
46 | void __iomem *regs; | |
47 | struct timer_list timer; | |
48 | int default_ticks; | |
49 | unsigned long inuse; | |
50 | atomic_t ticks; | |
51 | } bcm63xx_wdt_device; | |
52 | ||
53 | static int expect_close; | |
54 | ||
55 | static int wdt_time = WDT_DEFAULT_TIME; | |
86a1e189 WVS |
56 | static bool nowayout = WATCHDOG_NOWAYOUT; |
57 | module_param(nowayout, bool, 0); | |
b63aa731 FF |
58 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
59 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
60 | ||
61 | /* HW functions */ | |
62 | static void bcm63xx_wdt_hw_start(void) | |
63 | { | |
64 | bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); | |
65 | bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); | |
66 | bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); | |
67 | } | |
68 | ||
69 | static void bcm63xx_wdt_hw_stop(void) | |
70 | { | |
71 | bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); | |
72 | bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); | |
73 | } | |
74 | ||
75 | static void bcm63xx_wdt_isr(void *data) | |
76 | { | |
77 | struct pt_regs *regs = get_irq_regs(); | |
78 | ||
79 | die(PFX " fire", regs); | |
80 | } | |
81 | ||
82 | static void bcm63xx_timer_tick(unsigned long unused) | |
83 | { | |
84 | if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) { | |
85 | bcm63xx_wdt_hw_start(); | |
86 | mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ); | |
87 | } else | |
27c766aa | 88 | pr_crit("watchdog will restart system\n"); |
b63aa731 FF |
89 | } |
90 | ||
91 | static void bcm63xx_wdt_pet(void) | |
92 | { | |
93 | atomic_set(&bcm63xx_wdt_device.ticks, wdt_time); | |
94 | } | |
95 | ||
96 | static void bcm63xx_wdt_start(void) | |
97 | { | |
98 | bcm63xx_wdt_pet(); | |
99 | bcm63xx_timer_tick(0); | |
100 | } | |
101 | ||
102 | static void bcm63xx_wdt_pause(void) | |
103 | { | |
104 | del_timer_sync(&bcm63xx_wdt_device.timer); | |
105 | bcm63xx_wdt_hw_stop(); | |
106 | } | |
107 | ||
108 | static int bcm63xx_wdt_settimeout(int new_time) | |
109 | { | |
110 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | |
111 | return -EINVAL; | |
112 | ||
113 | wdt_time = new_time; | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static int bcm63xx_wdt_open(struct inode *inode, struct file *file) | |
119 | { | |
120 | if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse)) | |
121 | return -EBUSY; | |
122 | ||
123 | bcm63xx_wdt_start(); | |
124 | return nonseekable_open(inode, file); | |
125 | } | |
126 | ||
127 | static int bcm63xx_wdt_release(struct inode *inode, struct file *file) | |
128 | { | |
129 | if (expect_close == 42) | |
130 | bcm63xx_wdt_pause(); | |
131 | else { | |
27c766aa | 132 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
b63aa731 FF |
133 | bcm63xx_wdt_start(); |
134 | } | |
135 | clear_bit(0, &bcm63xx_wdt_device.inuse); | |
136 | expect_close = 0; | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static ssize_t bcm63xx_wdt_write(struct file *file, const char *data, | |
141 | size_t len, loff_t *ppos) | |
142 | { | |
143 | if (len) { | |
144 | if (!nowayout) { | |
145 | size_t i; | |
146 | ||
147 | /* In case it was set long ago */ | |
148 | expect_close = 0; | |
149 | ||
150 | for (i = 0; i != len; i++) { | |
151 | char c; | |
152 | if (get_user(c, data + i)) | |
153 | return -EFAULT; | |
154 | if (c == 'V') | |
155 | expect_close = 42; | |
156 | } | |
157 | } | |
158 | bcm63xx_wdt_pet(); | |
159 | } | |
160 | return len; | |
161 | } | |
162 | ||
163 | static struct watchdog_info bcm63xx_wdt_info = { | |
164 | .identity = PFX, | |
165 | .options = WDIOF_SETTIMEOUT | | |
166 | WDIOF_KEEPALIVEPING | | |
167 | WDIOF_MAGICCLOSE, | |
168 | }; | |
169 | ||
170 | ||
171 | static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd, | |
172 | unsigned long arg) | |
173 | { | |
174 | void __user *argp = (void __user *)arg; | |
175 | int __user *p = argp; | |
176 | int new_value, retval = -EINVAL; | |
177 | ||
178 | switch (cmd) { | |
179 | case WDIOC_GETSUPPORT: | |
180 | return copy_to_user(argp, &bcm63xx_wdt_info, | |
181 | sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0; | |
182 | ||
183 | case WDIOC_GETSTATUS: | |
184 | case WDIOC_GETBOOTSTATUS: | |
185 | return put_user(0, p); | |
186 | ||
187 | case WDIOC_SETOPTIONS: | |
188 | if (get_user(new_value, p)) | |
189 | return -EFAULT; | |
190 | ||
191 | if (new_value & WDIOS_DISABLECARD) { | |
192 | bcm63xx_wdt_pause(); | |
193 | retval = 0; | |
194 | } | |
195 | if (new_value & WDIOS_ENABLECARD) { | |
196 | bcm63xx_wdt_start(); | |
197 | retval = 0; | |
198 | } | |
199 | ||
200 | return retval; | |
201 | ||
202 | case WDIOC_KEEPALIVE: | |
203 | bcm63xx_wdt_pet(); | |
204 | return 0; | |
205 | ||
206 | case WDIOC_SETTIMEOUT: | |
207 | if (get_user(new_value, p)) | |
208 | return -EFAULT; | |
209 | ||
210 | if (bcm63xx_wdt_settimeout(new_value)) | |
211 | return -EINVAL; | |
212 | ||
213 | bcm63xx_wdt_pet(); | |
214 | ||
215 | case WDIOC_GETTIMEOUT: | |
216 | return put_user(wdt_time, p); | |
217 | ||
218 | default: | |
219 | return -ENOTTY; | |
220 | ||
221 | } | |
222 | } | |
223 | ||
b63aa731 FF |
224 | static const struct file_operations bcm63xx_wdt_fops = { |
225 | .owner = THIS_MODULE, | |
226 | .llseek = no_llseek, | |
227 | .write = bcm63xx_wdt_write, | |
228 | .unlocked_ioctl = bcm63xx_wdt_ioctl, | |
229 | .open = bcm63xx_wdt_open, | |
230 | .release = bcm63xx_wdt_release, | |
231 | }; | |
232 | ||
233 | static struct miscdevice bcm63xx_wdt_miscdev = { | |
234 | .minor = WATCHDOG_MINOR, | |
235 | .name = "watchdog", | |
236 | .fops = &bcm63xx_wdt_fops, | |
237 | }; | |
238 | ||
b63aa731 | 239 | |
2d991a16 | 240 | static int bcm63xx_wdt_probe(struct platform_device *pdev) |
b63aa731 FF |
241 | { |
242 | int ret; | |
243 | struct resource *r; | |
244 | ||
245 | setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L); | |
246 | ||
247 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
248 | if (!r) { | |
249 | dev_err(&pdev->dev, "failed to get resources\n"); | |
250 | return -ENODEV; | |
251 | } | |
252 | ||
626d65aa JH |
253 | bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start, |
254 | resource_size(r)); | |
b63aa731 FF |
255 | if (!bcm63xx_wdt_device.regs) { |
256 | dev_err(&pdev->dev, "failed to remap I/O resources\n"); | |
257 | return -ENXIO; | |
258 | } | |
259 | ||
260 | ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL); | |
261 | if (ret < 0) { | |
262 | dev_err(&pdev->dev, "failed to register wdt timer isr\n"); | |
626d65aa | 263 | return ret; |
b63aa731 FF |
264 | } |
265 | ||
266 | if (bcm63xx_wdt_settimeout(wdt_time)) { | |
267 | bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME); | |
268 | dev_info(&pdev->dev, | |
269 | ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n", | |
270 | wdt_time); | |
271 | } | |
272 | ||
b63aa731 FF |
273 | ret = misc_register(&bcm63xx_wdt_miscdev); |
274 | if (ret < 0) { | |
275 | dev_err(&pdev->dev, "failed to register watchdog device\n"); | |
e6c3b699 | 276 | goto unregister_timer; |
b63aa731 FF |
277 | } |
278 | ||
279 | dev_info(&pdev->dev, " started, timer margin: %d sec\n", | |
280 | WDT_DEFAULT_TIME); | |
281 | ||
282 | return 0; | |
283 | ||
b63aa731 FF |
284 | unregister_timer: |
285 | bcm63xx_timer_unregister(TIMER_WDT_ID); | |
b63aa731 FF |
286 | return ret; |
287 | } | |
288 | ||
4b12b896 | 289 | static int bcm63xx_wdt_remove(struct platform_device *pdev) |
b63aa731 FF |
290 | { |
291 | if (!nowayout) | |
292 | bcm63xx_wdt_pause(); | |
293 | ||
294 | misc_deregister(&bcm63xx_wdt_miscdev); | |
b63aa731 | 295 | bcm63xx_timer_unregister(TIMER_WDT_ID); |
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 | ||
5a135f3c | 304 | static struct platform_driver bcm63xx_wdt_driver = { |
b63aa731 | 305 | .probe = bcm63xx_wdt_probe, |
82268714 | 306 | .remove = bcm63xx_wdt_remove, |
e6c3b699 | 307 | .shutdown = bcm63xx_wdt_shutdown, |
b63aa731 | 308 | .driver = { |
e6c3b699 | 309 | .owner = THIS_MODULE, |
b63aa731 FF |
310 | .name = "bcm63xx-wdt", |
311 | } | |
312 | }; | |
313 | ||
5a135f3c | 314 | module_platform_driver(bcm63xx_wdt_driver); |
b63aa731 FF |
315 | |
316 | MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>"); | |
317 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); | |
318 | MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog"); | |
319 | MODULE_LICENSE("GPL"); | |
320 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
321 | MODULE_ALIAS("platform:bcm63xx-wdt"); |