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04bf3b4f FF |
1 | /* |
2 | * Driver for the MTX-1 Watchdog. | |
3 | * | |
ed78c2da AC |
4 | * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, |
5 | * All Rights Reserved. | |
04bf3b4f FF |
6 | * http://www.4g-systems.biz |
7 | * | |
143a2e54 | 8 | * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org> |
04bf3b4f FF |
9 | * |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | * | |
15 | * Neither Michael Stickel nor 4G Systems admit liability nor provide | |
16 | * warranty for any of this software. This material is provided | |
17 | * "AS-IS" and at no charge. | |
18 | * | |
19 | * (c) Copyright 2005 4G Systems <info@4g-systems.biz> | |
20 | * | |
21 | * Release 0.01. | |
22 | * Author: Michael Stickel michael.stickel@4g-systems.biz | |
23 | * | |
24 | * Release 0.02. | |
25 | * Author: Florian Fainelli florian@openwrt.org | |
26 | * use the Linux watchdog/timer APIs | |
27 | * | |
28 | * The Watchdog is configured to reset the MTX-1 | |
29 | * if it is not triggered for 100 seconds. | |
30 | * It should not be triggered more often than 1.6 seconds. | |
31 | * | |
32 | * A timer triggers the watchdog every 5 seconds, until | |
33 | * it is opened for the first time. After the first open | |
34 | * it MUST be triggered every 2..95 seconds. | |
35 | */ | |
36 | ||
37 | #include <linux/module.h> | |
38 | #include <linux/moduleparam.h> | |
39 | #include <linux/types.h> | |
40 | #include <linux/errno.h> | |
41 | #include <linux/miscdevice.h> | |
42 | #include <linux/fs.h> | |
43 | #include <linux/init.h> | |
44 | #include <linux/ioport.h> | |
45 | #include <linux/timer.h> | |
46 | #include <linux/completion.h> | |
47 | #include <linux/jiffies.h> | |
48 | #include <linux/watchdog.h> | |
6ea8115b | 49 | #include <linux/platform_device.h> |
ed78c2da AC |
50 | #include <linux/io.h> |
51 | #include <linux/uaccess.h> | |
52 | #include <linux/gpio.h> | |
04bf3b4f FF |
53 | |
54 | #include <asm/mach-au1x00/au1000.h> | |
55 | ||
56 | #define MTX1_WDT_INTERVAL (5 * HZ) | |
57 | ||
58 | static int ticks = 100 * HZ; | |
59 | ||
60 | static struct { | |
61 | struct completion stop; | |
ed78c2da | 62 | spinlock_t lock; |
996d62d4 | 63 | int running; |
04bf3b4f | 64 | struct timer_list timer; |
996d62d4 | 65 | int queue; |
04bf3b4f FF |
66 | int default_ticks; |
67 | unsigned long inuse; | |
6ea8115b | 68 | unsigned gpio; |
b7f720d6 | 69 | int gstate; |
04bf3b4f FF |
70 | } mtx1_wdt_device; |
71 | ||
72 | static void mtx1_wdt_trigger(unsigned long unused) | |
73 | { | |
74 | u32 tmp; | |
75 | ||
ed78c2da | 76 | spin_lock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
77 | if (mtx1_wdt_device.running) |
78 | ticks--; | |
b7f720d6 ML |
79 | |
80 | /* toggle wdt gpio */ | |
81 | mtx1_wdt_device.gstate = ~mtx1_wdt_device.gstate; | |
82 | if (mtx1_wdt_device.gstate) | |
83 | gpio_direction_output(mtx1_wdt_device.gpio, 1); | |
84 | else | |
85 | gpio_direction_input(mtx1_wdt_device.gpio); | |
04bf3b4f FF |
86 | |
87 | if (mtx1_wdt_device.queue && ticks) | |
88 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
ed78c2da | 89 | else |
04bf3b4f | 90 | complete(&mtx1_wdt_device.stop); |
ed78c2da | 91 | spin_unlock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
92 | } |
93 | ||
94 | static void mtx1_wdt_reset(void) | |
95 | { | |
96 | ticks = mtx1_wdt_device.default_ticks; | |
97 | } | |
98 | ||
99 | ||
100 | static void mtx1_wdt_start(void) | |
101 | { | |
f80e919b FF |
102 | unsigned long flags; |
103 | ||
ed78c2da | 104 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
105 | if (!mtx1_wdt_device.queue) { |
106 | mtx1_wdt_device.queue = 1; | |
b7f720d6 ML |
107 | mtx1_wdt_device.gstate = 1; |
108 | gpio_direction_output(mtx1_wdt_device.gpio, 1); | |
04bf3b4f FF |
109 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
110 | } | |
111 | mtx1_wdt_device.running++; | |
ed78c2da | 112 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
113 | } |
114 | ||
115 | static int mtx1_wdt_stop(void) | |
116 | { | |
f80e919b FF |
117 | unsigned long flags; |
118 | ||
ed78c2da | 119 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
120 | if (mtx1_wdt_device.queue) { |
121 | mtx1_wdt_device.queue = 0; | |
b7f720d6 ML |
122 | mtx1_wdt_device.gstate = 0; |
123 | gpio_direction_output(mtx1_wdt_device.gpio, 0); | |
04bf3b4f | 124 | } |
04bf3b4f | 125 | ticks = mtx1_wdt_device.default_ticks; |
ed78c2da | 126 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
127 | return 0; |
128 | } | |
129 | ||
130 | /* Filesystem functions */ | |
131 | ||
132 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
133 | { | |
134 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
135 | return -EBUSY; | |
04bf3b4f FF |
136 | return nonseekable_open(inode, file); |
137 | } | |
138 | ||
139 | ||
140 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
141 | { | |
142 | clear_bit(0, &mtx1_wdt_device.inuse); | |
143 | return 0; | |
144 | } | |
145 | ||
ed78c2da AC |
146 | static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd, |
147 | unsigned long arg) | |
04bf3b4f FF |
148 | { |
149 | void __user *argp = (void __user *)arg; | |
ed78c2da | 150 | int __user *p = (int __user *)argp; |
04bf3b4f | 151 | unsigned int value; |
ed78c2da | 152 | static const struct watchdog_info ident = { |
04bf3b4f FF |
153 | .options = WDIOF_CARDRESET, |
154 | .identity = "MTX-1 WDT", | |
155 | }; | |
156 | ||
ed78c2da | 157 | switch (cmd) { |
0c06090c WVS |
158 | case WDIOC_GETSUPPORT: |
159 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
160 | return -EFAULT; | |
ed78c2da AC |
161 | break; |
162 | case WDIOC_GETSTATUS: | |
163 | case WDIOC_GETBOOTSTATUS: | |
164 | put_user(0, p); | |
165 | break; | |
ed78c2da AC |
166 | case WDIOC_SETOPTIONS: |
167 | if (get_user(value, p)) | |
168 | return -EFAULT; | |
169 | if (value & WDIOS_ENABLECARD) | |
170 | mtx1_wdt_start(); | |
171 | else if (value & WDIOS_DISABLECARD) | |
172 | mtx1_wdt_stop(); | |
173 | else | |
174 | return -EINVAL; | |
175 | return 0; | |
0c06090c WVS |
176 | case WDIOC_KEEPALIVE: |
177 | mtx1_wdt_reset(); | |
178 | break; | |
ed78c2da AC |
179 | default: |
180 | return -ENOTTY; | |
04bf3b4f FF |
181 | } |
182 | return 0; | |
183 | } | |
184 | ||
185 | ||
ed78c2da AC |
186 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, |
187 | size_t count, loff_t *ppos) | |
04bf3b4f FF |
188 | { |
189 | if (!count) | |
190 | return -EIO; | |
04bf3b4f FF |
191 | mtx1_wdt_reset(); |
192 | return count; | |
193 | } | |
194 | ||
b47a166e | 195 | static const struct file_operations mtx1_wdt_fops = { |
5f3b2756 | 196 | .owner = THIS_MODULE, |
04bf3b4f | 197 | .llseek = no_llseek, |
ed78c2da | 198 | .unlocked_ioctl = mtx1_wdt_ioctl, |
5f3b2756 WVS |
199 | .open = mtx1_wdt_open, |
200 | .write = mtx1_wdt_write, | |
201 | .release = mtx1_wdt_release, | |
04bf3b4f FF |
202 | }; |
203 | ||
204 | ||
205 | static struct miscdevice mtx1_wdt_misc = { | |
5f3b2756 WVS |
206 | .minor = WATCHDOG_MINOR, |
207 | .name = "watchdog", | |
208 | .fops = &mtx1_wdt_fops, | |
04bf3b4f FF |
209 | }; |
210 | ||
211 | ||
b6bf291f | 212 | static int __devinit mtx1_wdt_probe(struct platform_device *pdev) |
04bf3b4f FF |
213 | { |
214 | int ret; | |
215 | ||
6ea8115b FF |
216 | mtx1_wdt_device.gpio = pdev->resource[0].start; |
217 | ||
ed78c2da | 218 | spin_lock_init(&mtx1_wdt_device.lock); |
04bf3b4f FF |
219 | init_completion(&mtx1_wdt_device.stop); |
220 | mtx1_wdt_device.queue = 0; | |
04bf3b4f | 221 | clear_bit(0, &mtx1_wdt_device.inuse); |
04bf3b4f | 222 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); |
04bf3b4f FF |
223 | mtx1_wdt_device.default_ticks = ticks; |
224 | ||
ed78c2da AC |
225 | ret = misc_register(&mtx1_wdt_misc); |
226 | if (ret < 0) { | |
227 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); | |
228 | return ret; | |
229 | } | |
04bf3b4f | 230 | mtx1_wdt_start(); |
04bf3b4f | 231 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); |
04bf3b4f FF |
232 | return 0; |
233 | } | |
234 | ||
b6bf291f | 235 | static int __devexit mtx1_wdt_remove(struct platform_device *pdev) |
04bf3b4f | 236 | { |
ed78c2da | 237 | /* FIXME: do we need to lock this test ? */ |
04bf3b4f FF |
238 | if (mtx1_wdt_device.queue) { |
239 | mtx1_wdt_device.queue = 0; | |
240 | wait_for_completion(&mtx1_wdt_device.stop); | |
241 | } | |
242 | misc_deregister(&mtx1_wdt_misc); | |
6ea8115b FF |
243 | return 0; |
244 | } | |
245 | ||
246 | static struct platform_driver mtx1_wdt = { | |
247 | .probe = mtx1_wdt_probe, | |
b6bf291f | 248 | .remove = __devexit_p(mtx1_wdt_remove), |
6ea8115b | 249 | .driver.name = "mtx1-wdt", |
f37d193c | 250 | .driver.owner = THIS_MODULE, |
6ea8115b FF |
251 | }; |
252 | ||
253 | static int __init mtx1_wdt_init(void) | |
254 | { | |
255 | return platform_driver_register(&mtx1_wdt); | |
256 | } | |
257 | ||
258 | static void __exit mtx1_wdt_exit(void) | |
259 | { | |
260 | platform_driver_unregister(&mtx1_wdt); | |
04bf3b4f FF |
261 | } |
262 | ||
263 | module_init(mtx1_wdt_init); | |
264 | module_exit(mtx1_wdt_exit); | |
265 | ||
266 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
267 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
268 | MODULE_LICENSE("GPL"); | |
6ea8115b | 269 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
f37d193c | 270 | MODULE_ALIAS("platform:mtx1-wdt"); |