Commit | Line | Data |
---|---|---|
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; |
04bf3b4f FF |
69 | } mtx1_wdt_device; |
70 | ||
71 | static void mtx1_wdt_trigger(unsigned long unused) | |
72 | { | |
73 | u32 tmp; | |
74 | ||
ed78c2da | 75 | spin_lock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
76 | if (mtx1_wdt_device.running) |
77 | ticks--; | |
78 | /* | |
79 | * toggle GPIO2_15 | |
80 | */ | |
81 | tmp = au_readl(GPIO2_DIR); | |
6ea8115b FF |
82 | tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) | |
83 | ((~tmp) & (1 << mtx1_wdt_device.gpio)); | |
ed78c2da | 84 | au_writel(tmp, GPIO2_DIR); |
04bf3b4f FF |
85 | |
86 | if (mtx1_wdt_device.queue && ticks) | |
87 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); | |
ed78c2da | 88 | else |
04bf3b4f | 89 | complete(&mtx1_wdt_device.stop); |
ed78c2da | 90 | spin_unlock(&mtx1_wdt_device.lock); |
04bf3b4f FF |
91 | } |
92 | ||
93 | static void mtx1_wdt_reset(void) | |
94 | { | |
95 | ticks = mtx1_wdt_device.default_ticks; | |
96 | } | |
97 | ||
98 | ||
99 | static void mtx1_wdt_start(void) | |
100 | { | |
f80e919b FF |
101 | unsigned long flags; |
102 | ||
ed78c2da | 103 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
104 | if (!mtx1_wdt_device.queue) { |
105 | mtx1_wdt_device.queue = 1; | |
6ea8115b | 106 | gpio_set_value(mtx1_wdt_device.gpio, 1); |
04bf3b4f FF |
107 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
108 | } | |
109 | mtx1_wdt_device.running++; | |
ed78c2da | 110 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
111 | } |
112 | ||
113 | static int mtx1_wdt_stop(void) | |
114 | { | |
f80e919b FF |
115 | unsigned long flags; |
116 | ||
ed78c2da | 117 | spin_lock_irqsave(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
118 | if (mtx1_wdt_device.queue) { |
119 | mtx1_wdt_device.queue = 0; | |
6ea8115b | 120 | gpio_set_value(mtx1_wdt_device.gpio, 0); |
04bf3b4f | 121 | } |
04bf3b4f | 122 | ticks = mtx1_wdt_device.default_ticks; |
ed78c2da | 123 | spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags); |
04bf3b4f FF |
124 | return 0; |
125 | } | |
126 | ||
127 | /* Filesystem functions */ | |
128 | ||
129 | static int mtx1_wdt_open(struct inode *inode, struct file *file) | |
130 | { | |
131 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) | |
132 | return -EBUSY; | |
04bf3b4f FF |
133 | return nonseekable_open(inode, file); |
134 | } | |
135 | ||
136 | ||
137 | static int mtx1_wdt_release(struct inode *inode, struct file *file) | |
138 | { | |
139 | clear_bit(0, &mtx1_wdt_device.inuse); | |
140 | return 0; | |
141 | } | |
142 | ||
ed78c2da AC |
143 | static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd, |
144 | unsigned long arg) | |
04bf3b4f FF |
145 | { |
146 | void __user *argp = (void __user *)arg; | |
ed78c2da | 147 | int __user *p = (int __user *)argp; |
04bf3b4f | 148 | unsigned int value; |
ed78c2da | 149 | static const struct watchdog_info ident = { |
04bf3b4f FF |
150 | .options = WDIOF_CARDRESET, |
151 | .identity = "MTX-1 WDT", | |
152 | }; | |
153 | ||
ed78c2da | 154 | switch (cmd) { |
0c06090c WVS |
155 | case WDIOC_GETSUPPORT: |
156 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
157 | return -EFAULT; | |
ed78c2da AC |
158 | break; |
159 | case WDIOC_GETSTATUS: | |
160 | case WDIOC_GETBOOTSTATUS: | |
161 | put_user(0, p); | |
162 | break; | |
ed78c2da AC |
163 | case WDIOC_SETOPTIONS: |
164 | if (get_user(value, p)) | |
165 | return -EFAULT; | |
166 | if (value & WDIOS_ENABLECARD) | |
167 | mtx1_wdt_start(); | |
168 | else if (value & WDIOS_DISABLECARD) | |
169 | mtx1_wdt_stop(); | |
170 | else | |
171 | return -EINVAL; | |
172 | return 0; | |
0c06090c WVS |
173 | case WDIOC_KEEPALIVE: |
174 | mtx1_wdt_reset(); | |
175 | break; | |
ed78c2da AC |
176 | default: |
177 | return -ENOTTY; | |
04bf3b4f FF |
178 | } |
179 | return 0; | |
180 | } | |
181 | ||
182 | ||
ed78c2da AC |
183 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, |
184 | size_t count, loff_t *ppos) | |
04bf3b4f FF |
185 | { |
186 | if (!count) | |
187 | return -EIO; | |
04bf3b4f FF |
188 | mtx1_wdt_reset(); |
189 | return count; | |
190 | } | |
191 | ||
b47a166e | 192 | static const struct file_operations mtx1_wdt_fops = { |
04bf3b4f FF |
193 | .owner = THIS_MODULE, |
194 | .llseek = no_llseek, | |
ed78c2da | 195 | .unlocked_ioctl = mtx1_wdt_ioctl, |
04bf3b4f FF |
196 | .open = mtx1_wdt_open, |
197 | .write = mtx1_wdt_write, | |
7944d3a5 | 198 | .release = mtx1_wdt_release, |
04bf3b4f FF |
199 | }; |
200 | ||
201 | ||
202 | static struct miscdevice mtx1_wdt_misc = { | |
203 | .minor = WATCHDOG_MINOR, | |
204 | .name = "watchdog", | |
7944d3a5 | 205 | .fops = &mtx1_wdt_fops, |
04bf3b4f FF |
206 | }; |
207 | ||
208 | ||
b6bf291f | 209 | static int __devinit mtx1_wdt_probe(struct platform_device *pdev) |
04bf3b4f FF |
210 | { |
211 | int ret; | |
212 | ||
6ea8115b FF |
213 | mtx1_wdt_device.gpio = pdev->resource[0].start; |
214 | ||
ed78c2da | 215 | spin_lock_init(&mtx1_wdt_device.lock); |
04bf3b4f FF |
216 | init_completion(&mtx1_wdt_device.stop); |
217 | mtx1_wdt_device.queue = 0; | |
04bf3b4f | 218 | clear_bit(0, &mtx1_wdt_device.inuse); |
04bf3b4f | 219 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); |
04bf3b4f FF |
220 | mtx1_wdt_device.default_ticks = ticks; |
221 | ||
ed78c2da AC |
222 | ret = misc_register(&mtx1_wdt_misc); |
223 | if (ret < 0) { | |
224 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); | |
225 | return ret; | |
226 | } | |
04bf3b4f | 227 | mtx1_wdt_start(); |
04bf3b4f | 228 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); |
04bf3b4f FF |
229 | return 0; |
230 | } | |
231 | ||
b6bf291f | 232 | static int __devexit mtx1_wdt_remove(struct platform_device *pdev) |
04bf3b4f | 233 | { |
ed78c2da | 234 | /* FIXME: do we need to lock this test ? */ |
04bf3b4f FF |
235 | if (mtx1_wdt_device.queue) { |
236 | mtx1_wdt_device.queue = 0; | |
237 | wait_for_completion(&mtx1_wdt_device.stop); | |
238 | } | |
239 | misc_deregister(&mtx1_wdt_misc); | |
6ea8115b FF |
240 | return 0; |
241 | } | |
242 | ||
243 | static struct platform_driver mtx1_wdt = { | |
244 | .probe = mtx1_wdt_probe, | |
b6bf291f | 245 | .remove = __devexit_p(mtx1_wdt_remove), |
6ea8115b | 246 | .driver.name = "mtx1-wdt", |
f37d193c | 247 | .driver.owner = THIS_MODULE, |
6ea8115b FF |
248 | }; |
249 | ||
250 | static int __init mtx1_wdt_init(void) | |
251 | { | |
252 | return platform_driver_register(&mtx1_wdt); | |
253 | } | |
254 | ||
255 | static void __exit mtx1_wdt_exit(void) | |
256 | { | |
257 | platform_driver_unregister(&mtx1_wdt); | |
04bf3b4f FF |
258 | } |
259 | ||
260 | module_init(mtx1_wdt_init); | |
261 | module_exit(mtx1_wdt_exit); | |
262 | ||
263 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); | |
264 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); | |
265 | MODULE_LICENSE("GPL"); | |
6ea8115b | 266 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
f37d193c | 267 | MODULE_ALIAS("platform:mtx1-wdt"); |