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04bf3b4f FF |
1 | /* |
2 | * Driver for the MTX-1 Watchdog. | |
3 | * | |
4 | * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved. | |
5 | * http://www.4g-systems.biz | |
6 | * | |
7 | * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | * | |
14 | * Neither Michael Stickel nor 4G Systems admit liability nor provide | |
15 | * warranty for any of this software. This material is provided | |
16 | * "AS-IS" and at no charge. | |
17 | * | |
18 | * (c) Copyright 2005 4G Systems <info@4g-systems.biz> | |
19 | * | |
20 | * Release 0.01. | |
21 | * Author: Michael Stickel michael.stickel@4g-systems.biz | |
22 | * | |
23 | * Release 0.02. | |
24 | * Author: Florian Fainelli florian@openwrt.org | |
25 | * use the Linux watchdog/timer APIs | |
26 | * | |
27 | * The Watchdog is configured to reset the MTX-1 | |
28 | * if it is not triggered for 100 seconds. | |
29 | * It should not be triggered more often than 1.6 seconds. | |
30 | * | |
31 | * A timer triggers the watchdog every 5 seconds, until | |
32 | * it is opened for the first time. After the first open | |
33 | * it MUST be triggered every 2..95 seconds. | |
34 | */ | |
35 | ||
36 | #include <linux/module.h> | |
37 | #include <linux/moduleparam.h> | |
38 | #include <linux/types.h> | |
39 | #include <linux/errno.h> | |
40 | #include <linux/miscdevice.h> | |
41 | #include <linux/fs.h> | |
42 | #include <linux/init.h> | |
43 | #include <linux/ioport.h> | |
44 | #include <linux/timer.h> | |
45 | #include <linux/completion.h> | |
46 | #include <linux/jiffies.h> | |
47 | #include <linux/watchdog.h> | |
6ea8115b FF |
48 | #include <linux/platform_device.h> |
49 | ||
04bf3b4f FF |
50 | #include <asm/io.h> |
51 | #include <asm/uaccess.h> | |
52 | ||
53 | #include <asm/mach-au1x00/au1000.h> | |
6ea8115b | 54 | #include <asm/gpio.h> |
04bf3b4f FF |
55 | |
56 | #define MTX1_WDT_INTERVAL (5 * HZ) | |
57 | ||
58 | static int ticks = 100 * HZ; | |
59 | ||
60 | static struct { | |
61 | struct completion stop; | |
996d62d4 | 62 | int running; |
04bf3b4f | 63 | struct timer_list timer; |
996d62d4 | 64 | int queue; |
04bf3b4f FF |
65 | int default_ticks; |
66 | unsigned long inuse; | |
6ea8115b | 67 | unsigned gpio; |
04bf3b4f FF |
68 | } mtx1_wdt_device; |
69 | ||
70 | static void mtx1_wdt_trigger(unsigned long unused) | |
71 | { | |
72 | u32 tmp; | |
73 | ||
74 | if (mtx1_wdt_device.running) | |
75 | ticks--; | |
76 | /* | |
77 | * toggle GPIO2_15 | |
78 | */ | |
79 | tmp = au_readl(GPIO2_DIR); | |
6ea8115b FF |
80 | tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) | |
81 | ((~tmp) & (1 << mtx1_wdt_device.gpio)); | |
04bf3b4f FF |
82 | au_writel (tmp, GPIO2_DIR); |
83 | ||
84 | if (mtx1_wdt_device.queue && ticks) | |
85 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
86 | else { | |
87 | complete(&mtx1_wdt_device.stop); | |
88 | } | |
89 | } | |
90 | ||
91 | static void mtx1_wdt_reset(void) | |
92 | { | |
93 | ticks = mtx1_wdt_device.default_ticks; | |
94 | } | |
95 | ||
96 | ||
97 | static void mtx1_wdt_start(void) | |
98 | { | |
99 | if (!mtx1_wdt_device.queue) { | |
100 | mtx1_wdt_device.queue = 1; | |
6ea8115b | 101 | gpio_set_value(mtx1_wdt_device.gpio, 1); |
04bf3b4f FF |
102 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
103 | } | |
104 | mtx1_wdt_device.running++; | |
105 | } | |
106 | ||
107 | static int mtx1_wdt_stop(void) | |
108 | { | |
109 | if (mtx1_wdt_device.queue) { | |
110 | mtx1_wdt_device.queue = 0; | |
6ea8115b | 111 | gpio_set_value(mtx1_wdt_device.gpio, 0); |
04bf3b4f FF |
112 | } |
113 | ||
114 | ticks = mtx1_wdt_device.default_ticks; | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | /* Filesystem functions */ | |
120 | ||
121 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
122 | { | |
123 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
124 | return -EBUSY; | |
125 | ||
126 | return nonseekable_open(inode, file); | |
127 | } | |
128 | ||
129 | ||
130 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
131 | { | |
132 | clear_bit(0, &mtx1_wdt_device.inuse); | |
133 | return 0; | |
134 | } | |
135 | ||
136 | static int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
137 | { | |
138 | void __user *argp = (void __user *)arg; | |
139 | unsigned int value; | |
140 | static struct watchdog_info ident = | |
141 | { | |
142 | .options = WDIOF_CARDRESET, | |
143 | .identity = "MTX-1 WDT", | |
144 | }; | |
145 | ||
146 | switch(cmd) { | |
147 | case WDIOC_KEEPALIVE: | |
148 | mtx1_wdt_reset(); | |
149 | break; | |
150 | case WDIOC_GETSTATUS: | |
5c4eb61b | 151 | case WDIOC_GETBOOTSTATUS: |
04bf3b4f FF |
152 | if ( copy_to_user(argp, &value, sizeof(int)) ) |
153 | return -EFAULT; | |
154 | break; | |
155 | case WDIOC_GETSUPPORT: | |
156 | if ( copy_to_user(argp, &ident, sizeof(ident)) ) | |
157 | return -EFAULT; | |
158 | break; | |
159 | case WDIOC_SETOPTIONS: | |
160 | if ( copy_from_user(&value, argp, sizeof(int)) ) | |
161 | return -EFAULT; | |
162 | switch(value) { | |
163 | case WDIOS_ENABLECARD: | |
164 | mtx1_wdt_start(); | |
165 | break; | |
166 | case WDIOS_DISABLECARD: | |
167 | return mtx1_wdt_stop(); | |
168 | default: | |
169 | return -EINVAL; | |
170 | } | |
171 | break; | |
172 | default: | |
173 | return -ENOTTY; | |
174 | } | |
175 | return 0; | |
176 | } | |
177 | ||
178 | ||
179 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) | |
180 | { | |
181 | if (!count) | |
182 | return -EIO; | |
183 | ||
184 | mtx1_wdt_reset(); | |
185 | return count; | |
186 | } | |
187 | ||
b47a166e | 188 | static const struct file_operations mtx1_wdt_fops = { |
04bf3b4f FF |
189 | .owner = THIS_MODULE, |
190 | .llseek = no_llseek, | |
191 | .ioctl = mtx1_wdt_ioctl, | |
192 | .open = mtx1_wdt_open, | |
193 | .write = mtx1_wdt_write, | |
194 | .release = mtx1_wdt_release | |
195 | }; | |
196 | ||
197 | ||
198 | static struct miscdevice mtx1_wdt_misc = { | |
199 | .minor = WATCHDOG_MINOR, | |
200 | .name = "watchdog", | |
201 | .fops = &mtx1_wdt_fops | |
202 | }; | |
203 | ||
204 | ||
6ea8115b | 205 | static int mtx1_wdt_probe(struct platform_device *pdev) |
04bf3b4f FF |
206 | { |
207 | int ret; | |
208 | ||
6ea8115b FF |
209 | mtx1_wdt_device.gpio = pdev->resource[0].start; |
210 | ||
04bf3b4f FF |
211 | if ((ret = misc_register(&mtx1_wdt_misc)) < 0) { |
212 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); | |
213 | return ret; | |
214 | } | |
215 | ||
216 | init_completion(&mtx1_wdt_device.stop); | |
217 | mtx1_wdt_device.queue = 0; | |
218 | ||
219 | clear_bit(0, &mtx1_wdt_device.inuse); | |
220 | ||
221 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); | |
222 | ||
223 | mtx1_wdt_device.default_ticks = ticks; | |
224 | ||
225 | mtx1_wdt_start(); | |
226 | ||
227 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
6ea8115b | 232 | static int mtx1_wdt_remove(struct platform_device *pdev) |
04bf3b4f FF |
233 | { |
234 | if (mtx1_wdt_device.queue) { | |
235 | mtx1_wdt_device.queue = 0; | |
236 | wait_for_completion(&mtx1_wdt_device.stop); | |
237 | } | |
238 | misc_deregister(&mtx1_wdt_misc); | |
6ea8115b FF |
239 | return 0; |
240 | } | |
241 | ||
242 | static struct platform_driver mtx1_wdt = { | |
243 | .probe = mtx1_wdt_probe, | |
244 | .remove = mtx1_wdt_remove, | |
245 | .driver.name = "mtx1-wdt", | |
f37d193c | 246 | .driver.owner = THIS_MODULE, |
6ea8115b FF |
247 | }; |
248 | ||
249 | static int __init mtx1_wdt_init(void) | |
250 | { | |
251 | return platform_driver_register(&mtx1_wdt); | |
252 | } | |
253 | ||
254 | static void __exit mtx1_wdt_exit(void) | |
255 | { | |
256 | platform_driver_unregister(&mtx1_wdt); | |
04bf3b4f FF |
257 | } |
258 | ||
259 | module_init(mtx1_wdt_init); | |
260 | module_exit(mtx1_wdt_exit); | |
261 | ||
262 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
263 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
264 | MODULE_LICENSE("GPL"); | |
6ea8115b | 265 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
f37d193c | 266 | MODULE_ALIAS("platform:mtx1-wdt"); |