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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; |
2ea4e76e | 69 | unsigned int gstate; |
04bf3b4f FF |
70 | } mtx1_wdt_device; |
71 | ||
72 | static void mtx1_wdt_trigger(unsigned long unused) | |
73 | { | |
ed78c2da | 74 | spin_lock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
75 | if (mtx1_wdt_device.running) |
76 | ticks--; | |
b7f720d6 ML |
77 | |
78 | /* toggle wdt gpio */ | |
2ea4e76e FF |
79 | mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate; |
80 | gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate); | |
04bf3b4f FF |
81 | |
82 | if (mtx1_wdt_device.queue && ticks) | |
83 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
ed78c2da | 84 | else |
04bf3b4f | 85 | complete(&mtx1_wdt_device.stop); |
ed78c2da | 86 | spin_unlock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
87 | } |
88 | ||
89 | static void mtx1_wdt_reset(void) | |
90 | { | |
91 | ticks = mtx1_wdt_device.default_ticks; | |
92 | } | |
93 | ||
94 | ||
95 | static void mtx1_wdt_start(void) | |
96 | { | |
f80e919b FF |
97 | unsigned long flags; |
98 | ||
ed78c2da | 99 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
100 | if (!mtx1_wdt_device.queue) { |
101 | mtx1_wdt_device.queue = 1; | |
b7f720d6 | 102 | mtx1_wdt_device.gstate = 1; |
2ea4e76e | 103 | gpio_set_value(mtx1_wdt_device.gpio, 1); |
04bf3b4f FF |
104 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
105 | } | |
106 | mtx1_wdt_device.running++; | |
ed78c2da | 107 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
108 | } |
109 | ||
110 | static int mtx1_wdt_stop(void) | |
111 | { | |
f80e919b FF |
112 | unsigned long flags; |
113 | ||
ed78c2da | 114 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
115 | if (mtx1_wdt_device.queue) { |
116 | mtx1_wdt_device.queue = 0; | |
b7f720d6 | 117 | mtx1_wdt_device.gstate = 0; |
2ea4e76e | 118 | gpio_set_value(mtx1_wdt_device.gpio, 0); |
04bf3b4f | 119 | } |
04bf3b4f | 120 | ticks = mtx1_wdt_device.default_ticks; |
ed78c2da | 121 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
122 | return 0; |
123 | } | |
124 | ||
125 | /* Filesystem functions */ | |
126 | ||
127 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
128 | { | |
129 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
130 | return -EBUSY; | |
04bf3b4f FF |
131 | return nonseekable_open(inode, file); |
132 | } | |
133 | ||
134 | ||
135 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
136 | { | |
137 | clear_bit(0, &mtx1_wdt_device.inuse); | |
138 | return 0; | |
139 | } | |
140 | ||
ed78c2da AC |
141 | static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd, |
142 | unsigned long arg) | |
04bf3b4f FF |
143 | { |
144 | void __user *argp = (void __user *)arg; | |
ed78c2da | 145 | int __user *p = (int __user *)argp; |
04bf3b4f | 146 | unsigned int value; |
ed78c2da | 147 | static const struct watchdog_info ident = { |
04bf3b4f FF |
148 | .options = WDIOF_CARDRESET, |
149 | .identity = "MTX-1 WDT", | |
150 | }; | |
151 | ||
ed78c2da | 152 | switch (cmd) { |
0c06090c WVS |
153 | case WDIOC_GETSUPPORT: |
154 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
155 | return -EFAULT; | |
ed78c2da AC |
156 | break; |
157 | case WDIOC_GETSTATUS: | |
158 | case WDIOC_GETBOOTSTATUS: | |
159 | put_user(0, p); | |
160 | break; | |
ed78c2da AC |
161 | case WDIOC_SETOPTIONS: |
162 | if (get_user(value, p)) | |
163 | return -EFAULT; | |
164 | if (value & WDIOS_ENABLECARD) | |
165 | mtx1_wdt_start(); | |
166 | else if (value & WDIOS_DISABLECARD) | |
167 | mtx1_wdt_stop(); | |
168 | else | |
169 | return -EINVAL; | |
170 | return 0; | |
0c06090c WVS |
171 | case WDIOC_KEEPALIVE: |
172 | mtx1_wdt_reset(); | |
173 | break; | |
ed78c2da AC |
174 | default: |
175 | return -ENOTTY; | |
04bf3b4f FF |
176 | } |
177 | return 0; | |
178 | } | |
179 | ||
180 | ||
ed78c2da AC |
181 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, |
182 | size_t count, loff_t *ppos) | |
04bf3b4f FF |
183 | { |
184 | if (!count) | |
185 | return -EIO; | |
04bf3b4f FF |
186 | mtx1_wdt_reset(); |
187 | return count; | |
188 | } | |
189 | ||
b47a166e | 190 | static const struct file_operations mtx1_wdt_fops = { |
5f3b2756 | 191 | .owner = THIS_MODULE, |
04bf3b4f | 192 | .llseek = no_llseek, |
ed78c2da | 193 | .unlocked_ioctl = mtx1_wdt_ioctl, |
5f3b2756 WVS |
194 | .open = mtx1_wdt_open, |
195 | .write = mtx1_wdt_write, | |
196 | .release = mtx1_wdt_release, | |
04bf3b4f FF |
197 | }; |
198 | ||
199 | ||
200 | static struct miscdevice mtx1_wdt_misc = { | |
5f3b2756 WVS |
201 | .minor = WATCHDOG_MINOR, |
202 | .name = "watchdog", | |
203 | .fops = &mtx1_wdt_fops, | |
04bf3b4f FF |
204 | }; |
205 | ||
206 | ||
b6bf291f | 207 | static int __devinit mtx1_wdt_probe(struct platform_device *pdev) |
04bf3b4f FF |
208 | { |
209 | int ret; | |
210 | ||
6ea8115b | 211 | mtx1_wdt_device.gpio = pdev->resource[0].start; |
9b19d40a FF |
212 | ret = gpio_request_one(mtx1_wdt_device.gpio, |
213 | GPIOF_OUT_INIT_HIGH, "mtx1-wdt"); | |
214 | if (ret < 0) { | |
215 | dev_err(&pdev->dev, "failed to request gpio"); | |
216 | return ret; | |
217 | } | |
6ea8115b | 218 | |
ed78c2da | 219 | spin_lock_init(&mtx1_wdt_device.lock); |
04bf3b4f FF |
220 | init_completion(&mtx1_wdt_device.stop); |
221 | mtx1_wdt_device.queue = 0; | |
04bf3b4f | 222 | clear_bit(0, &mtx1_wdt_device.inuse); |
04bf3b4f | 223 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); |
04bf3b4f FF |
224 | mtx1_wdt_device.default_ticks = ticks; |
225 | ||
ed78c2da AC |
226 | ret = misc_register(&mtx1_wdt_misc); |
227 | if (ret < 0) { | |
228 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); | |
229 | return ret; | |
230 | } | |
04bf3b4f | 231 | mtx1_wdt_start(); |
04bf3b4f | 232 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); |
04bf3b4f FF |
233 | return 0; |
234 | } | |
235 | ||
b6bf291f | 236 | static int __devexit mtx1_wdt_remove(struct platform_device *pdev) |
04bf3b4f | 237 | { |
ed78c2da | 238 | /* FIXME: do we need to lock this test ? */ |
04bf3b4f FF |
239 | if (mtx1_wdt_device.queue) { |
240 | mtx1_wdt_device.queue = 0; | |
241 | wait_for_completion(&mtx1_wdt_device.stop); | |
242 | } | |
9b19d40a FF |
243 | |
244 | gpio_free(mtx1_wdt_device.gpio); | |
04bf3b4f | 245 | misc_deregister(&mtx1_wdt_misc); |
6ea8115b FF |
246 | return 0; |
247 | } | |
248 | ||
db98f89a | 249 | static struct platform_driver mtx1_wdt_driver = { |
6ea8115b | 250 | .probe = mtx1_wdt_probe, |
b6bf291f | 251 | .remove = __devexit_p(mtx1_wdt_remove), |
6ea8115b | 252 | .driver.name = "mtx1-wdt", |
f37d193c | 253 | .driver.owner = THIS_MODULE, |
6ea8115b FF |
254 | }; |
255 | ||
256 | static int __init mtx1_wdt_init(void) | |
257 | { | |
db98f89a | 258 | return platform_driver_register(&mtx1_wdt_driver); |
6ea8115b FF |
259 | } |
260 | ||
261 | static void __exit mtx1_wdt_exit(void) | |
262 | { | |
db98f89a | 263 | platform_driver_unregister(&mtx1_wdt_driver); |
04bf3b4f FF |
264 | } |
265 | ||
266 | module_init(mtx1_wdt_init); | |
267 | module_exit(mtx1_wdt_exit); | |
268 | ||
269 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
270 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
271 | MODULE_LICENSE("GPL"); | |
6ea8115b | 272 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
f37d193c | 273 | MODULE_ALIAS("platform:mtx1-wdt"); |