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Florian Fainelli04bf3b42007-05-06 12:55:32 +02001/*
2 * Driver for the MTX-1 Watchdog.
3 *
Alan Coxed78c2d2008-05-19 14:07:21 +01004 * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
5 * All Rights Reserved.
Florian Fainelli04bf3b42007-05-06 12:55:32 +02006 * http://www.4g-systems.biz
7 *
8 * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
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>
Florian Fainelli6ea81152008-01-07 19:08:49 +010049#include <linux/platform_device.h>
Alan Coxed78c2d2008-05-19 14:07:21 +010050#include <linux/io.h>
51#include <linux/uaccess.h>
52#include <linux/gpio.h>
Florian Fainelli04bf3b42007-05-06 12:55:32 +020053
54#include <asm/mach-au1x00/au1000.h>
55
56#define MTX1_WDT_INTERVAL (5 * HZ)
57
58static int ticks = 100 * HZ;
59
60static struct {
61 struct completion stop;
Alan Coxed78c2d2008-05-19 14:07:21 +010062 spinlock_t lock;
Florian Fainelli996d62d2008-02-25 13:39:57 +010063 int running;
Florian Fainelli04bf3b42007-05-06 12:55:32 +020064 struct timer_list timer;
Florian Fainelli996d62d2008-02-25 13:39:57 +010065 int queue;
Florian Fainelli04bf3b42007-05-06 12:55:32 +020066 int default_ticks;
67 unsigned long inuse;
Florian Fainelli6ea81152008-01-07 19:08:49 +010068 unsigned gpio;
Florian Fainelli04bf3b42007-05-06 12:55:32 +020069} mtx1_wdt_device;
70
71static void mtx1_wdt_trigger(unsigned long unused)
72{
73 u32 tmp;
74
Alan Coxed78c2d2008-05-19 14:07:21 +010075 spin_lock(&mtx1_wdt_device.lock);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020076 if (mtx1_wdt_device.running)
77 ticks--;
78 /*
79 * toggle GPIO2_15
80 */
81 tmp = au_readl(GPIO2_DIR);
Florian Fainelli6ea81152008-01-07 19:08:49 +010082 tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) |
83 ((~tmp) & (1 << mtx1_wdt_device.gpio));
Alan Coxed78c2d2008-05-19 14:07:21 +010084 au_writel(tmp, GPIO2_DIR);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020085
86 if (mtx1_wdt_device.queue && ticks)
87 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
Alan Coxed78c2d2008-05-19 14:07:21 +010088 else
Florian Fainelli04bf3b42007-05-06 12:55:32 +020089 complete(&mtx1_wdt_device.stop);
Alan Coxed78c2d2008-05-19 14:07:21 +010090 spin_unlock(&mtx1_wdt_device.lock);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020091}
92
93static void mtx1_wdt_reset(void)
94{
95 ticks = mtx1_wdt_device.default_ticks;
96}
97
98
99static void mtx1_wdt_start(void)
100{
Florian Fainellif80e9192008-10-24 19:52:56 +0200101 unsigned long flags;
102
Alan Coxed78c2d2008-05-19 14:07:21 +0100103 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200104 if (!mtx1_wdt_device.queue) {
105 mtx1_wdt_device.queue = 1;
Florian Fainelli6ea81152008-01-07 19:08:49 +0100106 gpio_set_value(mtx1_wdt_device.gpio, 1);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200107 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
108 }
109 mtx1_wdt_device.running++;
Alan Coxed78c2d2008-05-19 14:07:21 +0100110 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200111}
112
113static int mtx1_wdt_stop(void)
114{
Florian Fainellif80e9192008-10-24 19:52:56 +0200115 unsigned long flags;
116
Alan Coxed78c2d2008-05-19 14:07:21 +0100117 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200118 if (mtx1_wdt_device.queue) {
119 mtx1_wdt_device.queue = 0;
Florian Fainelli6ea81152008-01-07 19:08:49 +0100120 gpio_set_value(mtx1_wdt_device.gpio, 0);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200121 }
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200122 ticks = mtx1_wdt_device.default_ticks;
Alan Coxed78c2d2008-05-19 14:07:21 +0100123 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200124 return 0;
125}
126
127/* Filesystem functions */
128
129static 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;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200133 return nonseekable_open(inode, file);
134}
135
136
137static int mtx1_wdt_release(struct inode *inode, struct file *file)
138{
139 clear_bit(0, &mtx1_wdt_device.inuse);
140 return 0;
141}
142
Alan Coxed78c2d2008-05-19 14:07:21 +0100143static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
144 unsigned long arg)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200145{
146 void __user *argp = (void __user *)arg;
Alan Coxed78c2d2008-05-19 14:07:21 +0100147 int __user *p = (int __user *)argp;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200148 unsigned int value;
Alan Coxed78c2d2008-05-19 14:07:21 +0100149 static const struct watchdog_info ident = {
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200150 .options = WDIOF_CARDRESET,
151 .identity = "MTX-1 WDT",
152 };
153
Alan Coxed78c2d2008-05-19 14:07:21 +0100154 switch (cmd) {
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000155 case WDIOC_GETSUPPORT:
156 if (copy_to_user(argp, &ident, sizeof(ident)))
157 return -EFAULT;
Alan Coxed78c2d2008-05-19 14:07:21 +0100158 break;
159 case WDIOC_GETSTATUS:
160 case WDIOC_GETBOOTSTATUS:
161 put_user(0, p);
162 break;
Alan Coxed78c2d2008-05-19 14:07:21 +0100163 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;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000173 case WDIOC_KEEPALIVE:
174 mtx1_wdt_reset();
175 break;
Alan Coxed78c2d2008-05-19 14:07:21 +0100176 default:
177 return -ENOTTY;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200178 }
179 return 0;
180}
181
182
Alan Coxed78c2d2008-05-19 14:07:21 +0100183static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
184 size_t count, loff_t *ppos)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200185{
186 if (!count)
187 return -EIO;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200188 mtx1_wdt_reset();
189 return count;
190}
191
Jan Engelhardtb47a1662008-01-22 20:48:10 +0100192static const struct file_operations mtx1_wdt_fops = {
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200193 .owner = THIS_MODULE,
194 .llseek = no_llseek,
Alan Coxed78c2d2008-05-19 14:07:21 +0100195 .unlocked_ioctl = mtx1_wdt_ioctl,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200196 .open = mtx1_wdt_open,
197 .write = mtx1_wdt_write,
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000198 .release = mtx1_wdt_release,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200199};
200
201
202static struct miscdevice mtx1_wdt_misc = {
203 .minor = WATCHDOG_MINOR,
204 .name = "watchdog",
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000205 .fops = &mtx1_wdt_fops,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200206};
207
208
Florian Fainelli6ea81152008-01-07 19:08:49 +0100209static int mtx1_wdt_probe(struct platform_device *pdev)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200210{
211 int ret;
212
Florian Fainelli6ea81152008-01-07 19:08:49 +0100213 mtx1_wdt_device.gpio = pdev->resource[0].start;
214
Alan Coxed78c2d2008-05-19 14:07:21 +0100215 spin_lock_init(&mtx1_wdt_device.lock);
216 init_completion(&mtx1_wdt_device.stop);
217 mtx1_wdt_device.queue = 0;
218 clear_bit(0, &mtx1_wdt_device.inuse);
219 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
220 mtx1_wdt_device.default_ticks = ticks;
221
222 ret = misc_register(&mtx1_wdt_misc);
223 if (ret < 0) {
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200224 printk(KERN_ERR " mtx-1_wdt : failed to register\n");
225 return ret;
226 }
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200227 mtx1_wdt_start();
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200228 printk(KERN_INFO "MTX-1 Watchdog driver\n");
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200229 return 0;
230}
231
Florian Fainelli6ea81152008-01-07 19:08:49 +0100232static int mtx1_wdt_remove(struct platform_device *pdev)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200233{
Alan Coxed78c2d2008-05-19 14:07:21 +0100234 /* FIXME: do we need to lock this test ? */
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200235 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);
Florian Fainelli6ea81152008-01-07 19:08:49 +0100240 return 0;
241}
242
243static struct platform_driver mtx1_wdt = {
244 .probe = mtx1_wdt_probe,
245 .remove = mtx1_wdt_remove,
246 .driver.name = "mtx1-wdt",
Kay Sieversf37d1932008-04-10 21:29:23 -0700247 .driver.owner = THIS_MODULE,
Florian Fainelli6ea81152008-01-07 19:08:49 +0100248};
249
250static int __init mtx1_wdt_init(void)
251{
252 return platform_driver_register(&mtx1_wdt);
253}
254
255static void __exit mtx1_wdt_exit(void)
256{
257 platform_driver_unregister(&mtx1_wdt);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200258}
259
260module_init(mtx1_wdt_init);
261module_exit(mtx1_wdt_exit);
262
263MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
264MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
265MODULE_LICENSE("GPL");
Florian Fainelli6ea81152008-01-07 19:08:49 +0100266MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Kay Sieversf37d1932008-04-10 21:29:23 -0700267MODULE_ALIAS("platform:mtx1-wdt");