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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> | |
48 | #include <asm/io.h> | |
49 | #include <asm/uaccess.h> | |
50 | ||
51 | #include <asm/mach-au1x00/au1000.h> | |
52 | ||
53 | #define MTX1_WDT_INTERVAL (5 * HZ) | |
54 | ||
55 | static int ticks = 100 * HZ; | |
56 | ||
57 | static struct { | |
58 | struct completion stop; | |
59 | volatile int running; | |
60 | struct timer_list timer; | |
61 | volatile int queue; | |
62 | int default_ticks; | |
63 | unsigned long inuse; | |
64 | } mtx1_wdt_device; | |
65 | ||
66 | static void mtx1_wdt_trigger(unsigned long unused) | |
67 | { | |
68 | u32 tmp; | |
69 | ||
70 | if (mtx1_wdt_device.running) | |
71 | ticks--; | |
72 | /* | |
73 | * toggle GPIO2_15 | |
74 | */ | |
75 | tmp = au_readl(GPIO2_DIR); | |
76 | tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15)); | |
77 | au_writel (tmp, GPIO2_DIR); | |
78 | ||
79 | if (mtx1_wdt_device.queue && ticks) | |
80 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
81 | else { | |
82 | complete(&mtx1_wdt_device.stop); | |
83 | } | |
84 | } | |
85 | ||
86 | static void mtx1_wdt_reset(void) | |
87 | { | |
88 | ticks = mtx1_wdt_device.default_ticks; | |
89 | } | |
90 | ||
91 | ||
92 | static void mtx1_wdt_start(void) | |
93 | { | |
94 | if (!mtx1_wdt_device.queue) { | |
95 | mtx1_wdt_device.queue = 1; | |
96 | au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR); | |
97 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
98 | } | |
99 | mtx1_wdt_device.running++; | |
100 | } | |
101 | ||
102 | static int mtx1_wdt_stop(void) | |
103 | { | |
104 | if (mtx1_wdt_device.queue) { | |
105 | mtx1_wdt_device.queue = 0; | |
106 | au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR); | |
107 | } | |
108 | ||
109 | ticks = mtx1_wdt_device.default_ticks; | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | /* Filesystem functions */ | |
115 | ||
116 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
117 | { | |
118 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
119 | return -EBUSY; | |
120 | ||
121 | return nonseekable_open(inode, file); | |
122 | } | |
123 | ||
124 | ||
125 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
126 | { | |
127 | clear_bit(0, &mtx1_wdt_device.inuse); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
132 | { | |
133 | void __user *argp = (void __user *)arg; | |
134 | unsigned int value; | |
135 | static struct watchdog_info ident = | |
136 | { | |
137 | .options = WDIOF_CARDRESET, | |
138 | .identity = "MTX-1 WDT", | |
139 | }; | |
140 | ||
141 | switch(cmd) { | |
142 | case WDIOC_KEEPALIVE: | |
143 | mtx1_wdt_reset(); | |
144 | break; | |
145 | case WDIOC_GETSTATUS: | |
5c4eb61b | 146 | case WDIOC_GETBOOTSTATUS: |
04bf3b4f FF |
147 | if ( copy_to_user(argp, &value, sizeof(int)) ) |
148 | return -EFAULT; | |
149 | break; | |
150 | case WDIOC_GETSUPPORT: | |
151 | if ( copy_to_user(argp, &ident, sizeof(ident)) ) | |
152 | return -EFAULT; | |
153 | break; | |
154 | case WDIOC_SETOPTIONS: | |
155 | if ( copy_from_user(&value, argp, sizeof(int)) ) | |
156 | return -EFAULT; | |
157 | switch(value) { | |
158 | case WDIOS_ENABLECARD: | |
159 | mtx1_wdt_start(); | |
160 | break; | |
161 | case WDIOS_DISABLECARD: | |
162 | return mtx1_wdt_stop(); | |
163 | default: | |
164 | return -EINVAL; | |
165 | } | |
166 | break; | |
167 | default: | |
168 | return -ENOTTY; | |
169 | } | |
170 | return 0; | |
171 | } | |
172 | ||
173 | ||
174 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) | |
175 | { | |
176 | if (!count) | |
177 | return -EIO; | |
178 | ||
179 | mtx1_wdt_reset(); | |
180 | return count; | |
181 | } | |
182 | ||
183 | static struct file_operations mtx1_wdt_fops = { | |
184 | .owner = THIS_MODULE, | |
185 | .llseek = no_llseek, | |
186 | .ioctl = mtx1_wdt_ioctl, | |
187 | .open = mtx1_wdt_open, | |
188 | .write = mtx1_wdt_write, | |
189 | .release = mtx1_wdt_release | |
190 | }; | |
191 | ||
192 | ||
193 | static struct miscdevice mtx1_wdt_misc = { | |
194 | .minor = WATCHDOG_MINOR, | |
195 | .name = "watchdog", | |
196 | .fops = &mtx1_wdt_fops | |
197 | }; | |
198 | ||
199 | ||
200 | static int __init mtx1_wdt_init(void) | |
201 | { | |
202 | int ret; | |
203 | ||
204 | if ((ret = misc_register(&mtx1_wdt_misc)) < 0) { | |
205 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); | |
206 | return ret; | |
207 | } | |
208 | ||
209 | init_completion(&mtx1_wdt_device.stop); | |
210 | mtx1_wdt_device.queue = 0; | |
211 | ||
212 | clear_bit(0, &mtx1_wdt_device.inuse); | |
213 | ||
214 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); | |
215 | ||
216 | mtx1_wdt_device.default_ticks = ticks; | |
217 | ||
218 | mtx1_wdt_start(); | |
219 | ||
220 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | static void __exit mtx1_wdt_exit(void) | |
226 | { | |
227 | if (mtx1_wdt_device.queue) { | |
228 | mtx1_wdt_device.queue = 0; | |
229 | wait_for_completion(&mtx1_wdt_device.stop); | |
230 | } | |
231 | misc_deregister(&mtx1_wdt_misc); | |
232 | } | |
233 | ||
234 | module_init(mtx1_wdt_init); | |
235 | module_exit(mtx1_wdt_exit); | |
236 | ||
237 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
238 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
239 | MODULE_LICENSE("GPL"); |