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1 | /* |
2 | * RDC321x watchdog driver | |
3 | * | |
4 | * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org> | |
5 | * | |
6 | * This driver is highly inspired from the cpu5_wdt driver | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | * | |
22 | */ | |
23 | ||
24 | #include <linux/module.h> | |
25 | #include <linux/moduleparam.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/miscdevice.h> | |
29 | #include <linux/fs.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/ioport.h> | |
32 | #include <linux/timer.h> | |
33 | #include <linux/completion.h> | |
34 | #include <linux/jiffies.h> | |
35 | #include <linux/platform_device.h> | |
36 | #include <linux/watchdog.h> | |
37 | #include <linux/io.h> | |
38 | #include <linux/uaccess.h> | |
39 | ||
40 | #include <asm/mach-rdc321x/rdc321x_defs.h> | |
41 | ||
42 | #define RDC_WDT_MASK 0x80000000 /* Mask */ | |
43 | #define RDC_WDT_EN 0x00800000 /* Enable bit */ | |
44 | #define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */ | |
45 | #define RDC_WDT_RST 0x00100000 /* Reset bit */ | |
46 | #define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */ | |
47 | #define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */ | |
48 | #define RDC_WDT_CNT 0x00000001 /* WDT count */ | |
49 | ||
50 | #define RDC_CLS_TMR 0x80003844 /* Clear timer */ | |
51 | ||
52 | #define RDC_WDT_INTERVAL (HZ/10+1) | |
53 | ||
54 | static int ticks = 1000; | |
55 | ||
56 | /* some device data */ | |
57 | ||
58 | static struct { | |
59 | struct completion stop; | |
60 | int running; | |
61 | struct timer_list timer; | |
62 | int queue; | |
63 | int default_ticks; | |
64 | unsigned long inuse; | |
65 | spinlock_t lock; | |
66 | } rdc321x_wdt_device; | |
67 | ||
68 | /* generic helper functions */ | |
69 | ||
70 | static void rdc321x_wdt_trigger(unsigned long unused) | |
71 | { | |
72 | unsigned long flags; | |
73 | ||
74 | if (rdc321x_wdt_device.running) | |
75 | ticks--; | |
76 | ||
77 | /* keep watchdog alive */ | |
78 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); | |
79 | outl(RDC_WDT_EN | inl(RDC3210_CFGREG_DATA), | |
80 | RDC3210_CFGREG_DATA); | |
81 | spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); | |
82 | ||
83 | /* requeue?? */ | |
84 | if (rdc321x_wdt_device.queue && ticks) | |
85 | mod_timer(&rdc321x_wdt_device.timer, | |
86 | jiffies + RDC_WDT_INTERVAL); | |
87 | else { | |
88 | /* ticks doesn't matter anyway */ | |
89 | complete(&rdc321x_wdt_device.stop); | |
90 | } | |
91 | ||
92 | } | |
93 | ||
94 | static void rdc321x_wdt_reset(void) | |
95 | { | |
96 | ticks = rdc321x_wdt_device.default_ticks; | |
97 | } | |
98 | ||
99 | static void rdc321x_wdt_start(void) | |
100 | { | |
101 | unsigned long flags; | |
102 | ||
103 | if (!rdc321x_wdt_device.queue) { | |
104 | rdc321x_wdt_device.queue = 1; | |
105 | ||
106 | /* Clear the timer */ | |
107 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); | |
108 | outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR); | |
109 | ||
110 | /* Enable watchdog and set the timeout to 81.92 us */ | |
111 | outl(RDC_WDT_EN | RDC_WDT_CNT, RDC3210_CFGREG_DATA); | |
112 | spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); | |
113 | ||
114 | mod_timer(&rdc321x_wdt_device.timer, | |
115 | jiffies + RDC_WDT_INTERVAL); | |
116 | } | |
117 | ||
118 | /* if process dies, counter is not decremented */ | |
119 | rdc321x_wdt_device.running++; | |
120 | } | |
121 | ||
122 | static int rdc321x_wdt_stop(void) | |
123 | { | |
124 | if (rdc321x_wdt_device.running) | |
125 | rdc321x_wdt_device.running = 0; | |
126 | ||
127 | ticks = rdc321x_wdt_device.default_ticks; | |
128 | ||
129 | return -EIO; | |
130 | } | |
131 | ||
132 | /* filesystem operations */ | |
133 | static int rdc321x_wdt_open(struct inode *inode, struct file *file) | |
134 | { | |
135 | if (test_and_set_bit(0, &rdc321x_wdt_device.inuse)) | |
136 | return -EBUSY; | |
137 | ||
138 | return nonseekable_open(inode, file); | |
139 | } | |
140 | ||
141 | static int rdc321x_wdt_release(struct inode *inode, struct file *file) | |
142 | { | |
143 | clear_bit(0, &rdc321x_wdt_device.inuse); | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file, | |
148 | unsigned int cmd, unsigned long arg) | |
149 | { | |
150 | void __user *argp = (void __user *)arg; | |
151 | unsigned int value; | |
152 | static struct watchdog_info ident = { | |
153 | .options = WDIOF_CARDRESET, | |
154 | .identity = "RDC321x WDT", | |
155 | }; | |
156 | unsigned long flags; | |
157 | ||
158 | switch (cmd) { | |
159 | case WDIOC_KEEPALIVE: | |
160 | rdc321x_wdt_reset(); | |
161 | break; | |
162 | case WDIOC_GETSTATUS: | |
163 | /* Read the value from the DATA register */ | |
164 | spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); | |
165 | value = inl(RDC3210_CFGREG_DATA); | |
166 | spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); | |
167 | if (copy_to_user(argp, &value, sizeof(int))) | |
168 | return -EFAULT; | |
169 | break; | |
170 | case WDIOC_GETSUPPORT: | |
171 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
172 | return -EFAULT; | |
173 | break; | |
174 | case WDIOC_SETOPTIONS: | |
175 | if (copy_from_user(&value, argp, sizeof(int))) | |
176 | return -EFAULT; | |
177 | switch (value) { | |
178 | case WDIOS_ENABLECARD: | |
179 | rdc321x_wdt_start(); | |
180 | break; | |
181 | case WDIOS_DISABLECARD: | |
182 | return rdc321x_wdt_stop(); | |
183 | default: | |
184 | return -EINVAL; | |
185 | } | |
186 | break; | |
187 | default: | |
188 | return -ENOTTY; | |
189 | } | |
190 | return 0; | |
191 | } | |
192 | ||
193 | static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, | |
194 | size_t count, loff_t *ppos) | |
195 | { | |
196 | if (!count) | |
197 | return -EIO; | |
198 | ||
199 | rdc321x_wdt_reset(); | |
200 | ||
201 | return count; | |
202 | } | |
203 | ||
204 | static const struct file_operations rdc321x_wdt_fops = { | |
205 | .owner = THIS_MODULE, | |
206 | .llseek = no_llseek, | |
207 | .ioctl = rdc321x_wdt_ioctl, | |
208 | .open = rdc321x_wdt_open, | |
209 | .write = rdc321x_wdt_write, | |
210 | .release = rdc321x_wdt_release, | |
211 | }; | |
212 | ||
213 | static struct miscdevice rdc321x_wdt_misc = { | |
214 | .minor = WATCHDOG_MINOR, | |
215 | .name = "watchdog", | |
216 | .fops = &rdc321x_wdt_fops, | |
217 | }; | |
218 | ||
219 | static int __devinit rdc321x_wdt_probe(struct platform_device *pdev) | |
220 | { | |
221 | int err; | |
222 | ||
223 | err = misc_register(&rdc321x_wdt_misc); | |
224 | if (err < 0) { | |
225 | printk(KERN_ERR PFX "watchdog misc_register failed\n"); | |
226 | return err; | |
227 | } | |
228 | ||
229 | spin_lock_init(&rdc321x_wdt_device.lock); | |
230 | ||
231 | /* Reset the watchdog */ | |
232 | outl(RDC_WDT_RST, RDC3210_CFGREG_DATA); | |
233 | ||
234 | init_completion(&rdc321x_wdt_device.stop); | |
235 | rdc321x_wdt_device.queue = 0; | |
236 | ||
237 | clear_bit(0, &rdc321x_wdt_device.inuse); | |
238 | ||
239 | setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0); | |
240 | ||
241 | rdc321x_wdt_device.default_ticks = ticks; | |
242 | ||
243 | printk(KERN_INFO PFX "watchdog init success\n"); | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
248 | static int rdc321x_wdt_remove(struct platform_device *pdev) | |
249 | { | |
250 | if (rdc321x_wdt_device.queue) { | |
251 | rdc321x_wdt_device.queue = 0; | |
252 | wait_for_completion(&rdc321x_wdt_device.stop); | |
253 | } | |
254 | ||
255 | misc_deregister(&rdc321x_wdt_misc); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
260 | static struct platform_driver rdc321x_wdt_driver = { | |
261 | .probe = rdc321x_wdt_probe, | |
262 | .remove = rdc321x_wdt_remove, | |
263 | .driver = { | |
264 | .owner = THIS_MODULE, | |
265 | .name = "rdc321x-wdt", | |
266 | }, | |
267 | }; | |
268 | ||
269 | static int __init rdc321x_wdt_init(void) | |
270 | { | |
271 | return platform_driver_register(&rdc321x_wdt_driver); | |
272 | } | |
273 | ||
274 | static void __exit rdc321x_wdt_exit(void) | |
275 | { | |
276 | platform_driver_unregister(&rdc321x_wdt_driver); | |
277 | } | |
278 | ||
279 | module_init(rdc321x_wdt_init); | |
280 | module_exit(rdc321x_wdt_exit); | |
281 | ||
282 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); | |
283 | MODULE_DESCRIPTION("RDC321x watchdog driver"); | |
284 | MODULE_LICENSE("GPL"); | |
285 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |