Commit | Line | Data |
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03ec5856 FF |
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 | * | |
29fa0586 AC |
10 | * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, |
11 | * All Rights Reserved. | |
03ec5856 FF |
12 | * |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License | |
15 | * as published by the Free Software Foundation; either version | |
16 | * 2 of the License, or (at your option) any later version. | |
17 | * | |
18 | */ | |
19 | ||
9b655e07 PS |
20 | #include <linux/module.h> /* For module specific items */ |
21 | #include <linux/moduleparam.h> /* For new moduleparam's */ | |
22 | #include <linux/types.h> /* For standard types (like size_t) */ | |
23 | #include <linux/errno.h> /* For the -ENODEV/... values */ | |
24 | #include <linux/kernel.h> /* For printk/panic/... */ | |
25 | #include <linux/fs.h> /* For file operations */ | |
26 | #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV | |
27 | (WATCHDOG_MINOR) */ | |
28 | #include <linux/watchdog.h> /* For the watchdog specific items */ | |
29 | #include <linux/init.h> /* For __init/__exit/... */ | |
30 | #include <linux/platform_device.h> /* For platform_driver framework */ | |
e455b6b4 | 31 | #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */ |
9b655e07 PS |
32 | #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ |
33 | ||
34 | #include <asm/mach-rc32434/integ.h> /* For the Watchdog registers */ | |
35 | ||
36 | #define PFX KBUILD_MODNAME ": " | |
03ec5856 | 37 | |
f296b143 | 38 | #define VERSION "1.0" |
03ec5856 FF |
39 | |
40 | static struct { | |
03ec5856 | 41 | unsigned long inuse; |
e455b6b4 | 42 | spinlock_t io_lock; |
03ec5856 FF |
43 | } rc32434_wdt_device; |
44 | ||
45 | static struct integ __iomem *wdt_reg; | |
03ec5856 FF |
46 | |
47 | static int expect_close; | |
0af98d37 PS |
48 | |
49 | /* Board internal clock speed in Hz, | |
50 | * the watchdog timer ticks at. */ | |
51 | extern unsigned int idt_cpu_freq; | |
52 | ||
53 | /* translate wtcompare value to seconds and vice versa */ | |
54 | #define WTCOMP2SEC(x) (x / idt_cpu_freq) | |
55 | #define SEC2WTCOMP(x) (x * idt_cpu_freq) | |
56 | ||
57 | /* Use a default timeout of 20s. This should be | |
58 | * safe for CPU clock speeds up to 400MHz, as | |
59 | * ((2 ^ 32) - 1) / (400MHz / 2) = 21s. */ | |
60 | #define WATCHDOG_TIMEOUT 20 | |
61 | ||
62 | static int timeout = WATCHDOG_TIMEOUT; | |
08eb2e0c PS |
63 | module_param(timeout, int, 0); |
64 | MODULE_PARM_DESC(timeout, "Watchdog timeout value, in seconds (default=" | |
810a90ae | 65 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); |
03ec5856 FF |
66 | |
67 | static int nowayout = WATCHDOG_NOWAYOUT; | |
68 | module_param(nowayout, int, 0); | |
69 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
70 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
71 | ||
0af98d37 PS |
72 | /* apply or and nand masks to data read from addr and write back */ |
73 | #define SET_BITS(addr, or, nand) \ | |
74 | writel((readl(&addr) | or) & ~nand, &addr) | |
03ec5856 | 75 | |
08eb2e0c PS |
76 | static int rc32434_wdt_set(int new_timeout) |
77 | { | |
78 | int max_to = WTCOMP2SEC((u32)-1); | |
79 | ||
80 | if (new_timeout < 0 || new_timeout > max_to) { | |
81 | printk(KERN_ERR PFX "timeout value must be between 0 and %d", | |
82 | max_to); | |
83 | return -EINVAL; | |
84 | } | |
85 | timeout = new_timeout; | |
e455b6b4 | 86 | spin_lock(&rc32434_wdt_device.io_lock); |
08eb2e0c | 87 | writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare); |
e455b6b4 | 88 | spin_unlock(&rc32434_wdt_device.io_lock); |
08eb2e0c PS |
89 | |
90 | return 0; | |
91 | } | |
92 | ||
03ec5856 FF |
93 | static void rc32434_wdt_start(void) |
94 | { | |
0af98d37 | 95 | u32 or, nand; |
03ec5856 | 96 | |
e455b6b4 WVS |
97 | spin_lock(&rc32434_wdt_device.io_lock); |
98 | ||
0af98d37 PS |
99 | /* zero the counter before enabling */ |
100 | writel(0, &wdt_reg->wtcount); | |
03ec5856 | 101 | |
0af98d37 PS |
102 | /* don't generate a non-maskable interrupt, |
103 | * do a warm reset instead */ | |
104 | nand = 1 << RC32434_ERR_WNE; | |
105 | or = 1 << RC32434_ERR_WRE; | |
03ec5856 | 106 | |
0af98d37 PS |
107 | /* reset the ERRCS timeout bit in case it's set */ |
108 | nand |= 1 << RC32434_ERR_WTO; | |
03ec5856 | 109 | |
0af98d37 | 110 | SET_BITS(wdt_reg->errcs, or, nand); |
03ec5856 | 111 | |
08eb2e0c PS |
112 | /* set the timeout (either default or based on module param) */ |
113 | rc32434_wdt_set(timeout); | |
114 | ||
0af98d37 PS |
115 | /* reset WTC timeout bit and enable WDT */ |
116 | nand = 1 << RC32434_WTC_TO; | |
117 | or = 1 << RC32434_WTC_EN; | |
03ec5856 | 118 | |
0af98d37 | 119 | SET_BITS(wdt_reg->wtc, or, nand); |
9b655e07 | 120 | |
e455b6b4 | 121 | spin_unlock(&rc32434_wdt_device.io_lock); |
9b655e07 | 122 | printk(KERN_INFO PFX "Started watchdog timer.\n"); |
0af98d37 | 123 | } |
03ec5856 | 124 | |
0af98d37 PS |
125 | static void rc32434_wdt_stop(void) |
126 | { | |
e455b6b4 WVS |
127 | spin_lock(&rc32434_wdt_device.io_lock); |
128 | ||
0af98d37 PS |
129 | /* Disable WDT */ |
130 | SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN); | |
9b655e07 | 131 | |
e455b6b4 | 132 | spin_unlock(&rc32434_wdt_device.io_lock); |
9b655e07 | 133 | printk(KERN_INFO PFX "Stopped watchdog timer.\n"); |
03ec5856 FF |
134 | } |
135 | ||
0af98d37 | 136 | static void rc32434_wdt_ping(void) |
03ec5856 | 137 | { |
e455b6b4 | 138 | spin_lock(&rc32434_wdt_device.io_lock); |
03ec5856 | 139 | writel(0, &wdt_reg->wtcount); |
e455b6b4 | 140 | spin_unlock(&rc32434_wdt_device.io_lock); |
03ec5856 FF |
141 | } |
142 | ||
143 | static int rc32434_wdt_open(struct inode *inode, struct file *file) | |
144 | { | |
145 | if (test_and_set_bit(0, &rc32434_wdt_device.inuse)) | |
146 | return -EBUSY; | |
147 | ||
148 | if (nowayout) | |
149 | __module_get(THIS_MODULE); | |
150 | ||
0af98d37 PS |
151 | rc32434_wdt_start(); |
152 | rc32434_wdt_ping(); | |
153 | ||
03ec5856 FF |
154 | return nonseekable_open(inode, file); |
155 | } | |
156 | ||
157 | static int rc32434_wdt_release(struct inode *inode, struct file *file) | |
158 | { | |
0af98d37 | 159 | if (expect_close == 42) { |
03ec5856 | 160 | rc32434_wdt_stop(); |
03ec5856 | 161 | module_put(THIS_MODULE); |
0af98d37 | 162 | } else { |
9b655e07 PS |
163 | printk(KERN_CRIT PFX |
164 | "device closed unexpectedly. WDT will not stop!\n"); | |
0af98d37 PS |
165 | rc32434_wdt_ping(); |
166 | } | |
03ec5856 FF |
167 | clear_bit(0, &rc32434_wdt_device.inuse); |
168 | return 0; | |
169 | } | |
170 | ||
171 | static ssize_t rc32434_wdt_write(struct file *file, const char *data, | |
172 | size_t len, loff_t *ppos) | |
173 | { | |
174 | if (len) { | |
175 | if (!nowayout) { | |
176 | size_t i; | |
177 | ||
178 | /* In case it was set long ago */ | |
179 | expect_close = 0; | |
180 | ||
181 | for (i = 0; i != len; i++) { | |
182 | char c; | |
183 | if (get_user(c, data + i)) | |
184 | return -EFAULT; | |
185 | if (c == 'V') | |
0af98d37 | 186 | expect_close = 42; |
03ec5856 FF |
187 | } |
188 | } | |
0af98d37 | 189 | rc32434_wdt_ping(); |
03ec5856 FF |
190 | return len; |
191 | } | |
192 | return 0; | |
193 | } | |
194 | ||
7275fc8c WVS |
195 | static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd, |
196 | unsigned long arg) | |
03ec5856 FF |
197 | { |
198 | void __user *argp = (void __user *)arg; | |
199 | int new_timeout; | |
200 | unsigned int value; | |
42747d71 | 201 | static const struct watchdog_info ident = { |
03ec5856 FF |
202 | .options = WDIOF_SETTIMEOUT | |
203 | WDIOF_KEEPALIVEPING | | |
204 | WDIOF_MAGICCLOSE, | |
205 | .identity = "RC32434_WDT Watchdog", | |
206 | }; | |
207 | switch (cmd) { | |
9b655e07 PS |
208 | case WDIOC_GETSUPPORT: |
209 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
210 | return -EFAULT; | |
03ec5856 FF |
211 | break; |
212 | case WDIOC_GETSTATUS: | |
213 | case WDIOC_GETBOOTSTATUS: | |
0af98d37 | 214 | value = 0; |
03ec5856 FF |
215 | if (copy_to_user(argp, &value, sizeof(int))) |
216 | return -EFAULT; | |
217 | break; | |
03ec5856 FF |
218 | case WDIOC_SETOPTIONS: |
219 | if (copy_from_user(&value, argp, sizeof(int))) | |
220 | return -EFAULT; | |
221 | switch (value) { | |
222 | case WDIOS_ENABLECARD: | |
223 | rc32434_wdt_start(); | |
224 | break; | |
225 | case WDIOS_DISABLECARD: | |
226 | rc32434_wdt_stop(); | |
0af98d37 | 227 | break; |
03ec5856 FF |
228 | default: |
229 | return -EINVAL; | |
230 | } | |
231 | break; | |
9b655e07 PS |
232 | case WDIOC_KEEPALIVE: |
233 | rc32434_wdt_ping(); | |
234 | break; | |
03ec5856 FF |
235 | case WDIOC_SETTIMEOUT: |
236 | if (copy_from_user(&new_timeout, argp, sizeof(int))) | |
237 | return -EFAULT; | |
0af98d37 | 238 | if (rc32434_wdt_set(new_timeout)) |
03ec5856 | 239 | return -EINVAL; |
0af98d37 | 240 | /* Fall through */ |
03ec5856 FF |
241 | case WDIOC_GETTIMEOUT: |
242 | return copy_to_user(argp, &timeout, sizeof(int)); | |
243 | default: | |
244 | return -ENOTTY; | |
245 | } | |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
d5c26a59 | 250 | static const struct file_operations rc32434_wdt_fops = { |
03ec5856 FF |
251 | .owner = THIS_MODULE, |
252 | .llseek = no_llseek, | |
253 | .write = rc32434_wdt_write, | |
7275fc8c | 254 | .unlocked_ioctl = rc32434_wdt_ioctl, |
03ec5856 FF |
255 | .open = rc32434_wdt_open, |
256 | .release = rc32434_wdt_release, | |
257 | }; | |
258 | ||
259 | static struct miscdevice rc32434_wdt_miscdev = { | |
260 | .minor = WATCHDOG_MINOR, | |
261 | .name = "watchdog", | |
262 | .fops = &rc32434_wdt_fops, | |
263 | }; | |
264 | ||
9b655e07 PS |
265 | static char banner[] __devinitdata = KERN_INFO PFX |
266 | "Watchdog Timer version " VERSION ", timer margin: %d sec\n"; | |
03ec5856 | 267 | |
d9a8798c | 268 | static int __devinit rc32434_wdt_probe(struct platform_device *pdev) |
03ec5856 FF |
269 | { |
270 | int ret; | |
271 | struct resource *r; | |
272 | ||
0af98d37 | 273 | r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res"); |
03ec5856 | 274 | if (!r) { |
9b655e07 | 275 | printk(KERN_ERR PFX "failed to retrieve resources\n"); |
03ec5856 FF |
276 | return -ENODEV; |
277 | } | |
278 | ||
be088b13 | 279 | wdt_reg = ioremap_nocache(r->start, resource_size(r)); |
03ec5856 | 280 | if (!wdt_reg) { |
9b655e07 | 281 | printk(KERN_ERR PFX "failed to remap I/O resources\n"); |
03ec5856 FF |
282 | return -ENXIO; |
283 | } | |
284 | ||
e455b6b4 WVS |
285 | spin_lock_init(&rc32434_wdt_device.io_lock); |
286 | ||
f296b143 WVS |
287 | /* Make sure the watchdog is not running */ |
288 | rc32434_wdt_stop(); | |
289 | ||
08eb2e0c PS |
290 | /* Check that the heartbeat value is within it's range; |
291 | * if not reset to the default */ | |
292 | if (rc32434_wdt_set(timeout)) { | |
293 | rc32434_wdt_set(WATCHDOG_TIMEOUT); | |
294 | printk(KERN_INFO PFX | |
295 | "timeout value must be between 0 and %d\n", | |
296 | WTCOMP2SEC((u32)-1)); | |
297 | } | |
298 | ||
03ec5856 | 299 | ret = misc_register(&rc32434_wdt_miscdev); |
03ec5856 | 300 | if (ret < 0) { |
9b655e07 | 301 | printk(KERN_ERR PFX "failed to register watchdog device\n"); |
03ec5856 FF |
302 | goto unmap; |
303 | } | |
304 | ||
03ec5856 FF |
305 | printk(banner, timeout); |
306 | ||
307 | return 0; | |
308 | ||
309 | unmap: | |
310 | iounmap(wdt_reg); | |
311 | return ret; | |
312 | } | |
313 | ||
d9a8798c | 314 | static int __devexit rc32434_wdt_remove(struct platform_device *pdev) |
03ec5856 | 315 | { |
03ec5856 | 316 | misc_deregister(&rc32434_wdt_miscdev); |
03ec5856 | 317 | iounmap(wdt_reg); |
03ec5856 FF |
318 | return 0; |
319 | } | |
320 | ||
0aaae661 WVS |
321 | static void rc32434_wdt_shutdown(struct platform_device *pdev) |
322 | { | |
323 | rc32434_wdt_stop(); | |
324 | } | |
325 | ||
9b655e07 | 326 | static struct platform_driver rc32434_wdt_driver = { |
0aaae661 WVS |
327 | .probe = rc32434_wdt_probe, |
328 | .remove = __devexit_p(rc32434_wdt_remove), | |
329 | .shutdown = rc32434_wdt_shutdown, | |
330 | .driver = { | |
331 | .name = "rc32434_wdt", | |
03ec5856 FF |
332 | } |
333 | }; | |
334 | ||
b8ec6118 | 335 | module_platform_driver(rc32434_wdt_driver); |
03ec5856 FF |
336 | |
337 | MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>," | |
338 | "Florian Fainelli <florian@openwrt.org>"); | |
339 | MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog"); | |
340 | MODULE_LICENSE("GPL"); | |
341 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |