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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 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +00008 * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
Florian Fainelli04bf3b42007-05-06 12:55:32 +02009 *
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 Fainelli2ea4e762011-06-15 19:15:41 +020069 unsigned int gstate;
Florian Fainelli04bf3b42007-05-06 12:55:32 +020070} mtx1_wdt_device;
71
72static void mtx1_wdt_trigger(unsigned long unused)
73{
Alan Coxed78c2d2008-05-19 14:07:21 +010074 spin_lock(&mtx1_wdt_device.lock);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020075 if (mtx1_wdt_device.running)
76 ticks--;
Manuel Laussb7f720d2011-05-08 10:42:20 +020077
78 /* toggle wdt gpio */
Florian Fainelli2ea4e762011-06-15 19:15:41 +020079 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
80 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020081
82 if (mtx1_wdt_device.queue && ticks)
83 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
Alan Coxed78c2d2008-05-19 14:07:21 +010084 else
Florian Fainelli04bf3b42007-05-06 12:55:32 +020085 complete(&mtx1_wdt_device.stop);
Alan Coxed78c2d2008-05-19 14:07:21 +010086 spin_unlock(&mtx1_wdt_device.lock);
Florian Fainelli04bf3b42007-05-06 12:55:32 +020087}
88
89static void mtx1_wdt_reset(void)
90{
91 ticks = mtx1_wdt_device.default_ticks;
92}
93
94
95static void mtx1_wdt_start(void)
96{
Florian Fainellif80e9192008-10-24 19:52:56 +020097 unsigned long flags;
98
Alan Coxed78c2d2008-05-19 14:07:21 +010099 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200100 if (!mtx1_wdt_device.queue) {
101 mtx1_wdt_device.queue = 1;
Manuel Laussb7f720d2011-05-08 10:42:20 +0200102 mtx1_wdt_device.gstate = 1;
Florian Fainelli2ea4e762011-06-15 19:15:41 +0200103 gpio_set_value(mtx1_wdt_device.gpio, 1);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200104 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
105 }
106 mtx1_wdt_device.running++;
Alan Coxed78c2d2008-05-19 14:07:21 +0100107 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200108}
109
110static int mtx1_wdt_stop(void)
111{
Florian Fainellif80e9192008-10-24 19:52:56 +0200112 unsigned long flags;
113
Alan Coxed78c2d2008-05-19 14:07:21 +0100114 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200115 if (mtx1_wdt_device.queue) {
116 mtx1_wdt_device.queue = 0;
Manuel Laussb7f720d2011-05-08 10:42:20 +0200117 mtx1_wdt_device.gstate = 0;
Florian Fainelli2ea4e762011-06-15 19:15:41 +0200118 gpio_set_value(mtx1_wdt_device.gpio, 0);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200119 }
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200120 ticks = mtx1_wdt_device.default_ticks;
Alan Coxed78c2d2008-05-19 14:07:21 +0100121 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200122 return 0;
123}
124
125/* Filesystem functions */
126
127static 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;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200131 return nonseekable_open(inode, file);
132}
133
134
135static int mtx1_wdt_release(struct inode *inode, struct file *file)
136{
137 clear_bit(0, &mtx1_wdt_device.inuse);
138 return 0;
139}
140
Alan Coxed78c2d2008-05-19 14:07:21 +0100141static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
142 unsigned long arg)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200143{
144 void __user *argp = (void __user *)arg;
Alan Coxed78c2d2008-05-19 14:07:21 +0100145 int __user *p = (int __user *)argp;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200146 unsigned int value;
Alan Coxed78c2d2008-05-19 14:07:21 +0100147 static const struct watchdog_info ident = {
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200148 .options = WDIOF_CARDRESET,
149 .identity = "MTX-1 WDT",
150 };
151
Alan Coxed78c2d2008-05-19 14:07:21 +0100152 switch (cmd) {
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000153 case WDIOC_GETSUPPORT:
154 if (copy_to_user(argp, &ident, sizeof(ident)))
155 return -EFAULT;
Alan Coxed78c2d2008-05-19 14:07:21 +0100156 break;
157 case WDIOC_GETSTATUS:
158 case WDIOC_GETBOOTSTATUS:
159 put_user(0, p);
160 break;
Alan Coxed78c2d2008-05-19 14:07:21 +0100161 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;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000171 case WDIOC_KEEPALIVE:
172 mtx1_wdt_reset();
173 break;
Alan Coxed78c2d2008-05-19 14:07:21 +0100174 default:
175 return -ENOTTY;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200176 }
177 return 0;
178}
179
180
Alan Coxed78c2d2008-05-19 14:07:21 +0100181static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
182 size_t count, loff_t *ppos)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200183{
184 if (!count)
185 return -EIO;
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200186 mtx1_wdt_reset();
187 return count;
188}
189
Jan Engelhardtb47a1662008-01-22 20:48:10 +0100190static const struct file_operations mtx1_wdt_fops = {
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000191 .owner = THIS_MODULE,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200192 .llseek = no_llseek,
Alan Coxed78c2d2008-05-19 14:07:21 +0100193 .unlocked_ioctl = mtx1_wdt_ioctl,
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000194 .open = mtx1_wdt_open,
195 .write = mtx1_wdt_write,
196 .release = mtx1_wdt_release,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200197};
198
199
200static struct miscdevice mtx1_wdt_misc = {
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000201 .minor = WATCHDOG_MINOR,
202 .name = "watchdog",
203 .fops = &mtx1_wdt_fops,
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200204};
205
206
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000207static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200208{
209 int ret;
210
Florian Fainelli6ea81152008-01-07 19:08:49 +0100211 mtx1_wdt_device.gpio = pdev->resource[0].start;
Florian Fainelli9b19d402011-06-15 19:15:23 +0200212 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 }
Florian Fainelli6ea81152008-01-07 19:08:49 +0100218
Alan Coxed78c2d2008-05-19 14:07:21 +0100219 spin_lock_init(&mtx1_wdt_device.lock);
220 init_completion(&mtx1_wdt_device.stop);
221 mtx1_wdt_device.queue = 0;
222 clear_bit(0, &mtx1_wdt_device.inuse);
223 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
224 mtx1_wdt_device.default_ticks = ticks;
225
226 ret = misc_register(&mtx1_wdt_misc);
227 if (ret < 0) {
Florian Fainellifad0a9d2011-06-15 19:15:09 +0200228 dev_err(&pdev->dev, "failed to register\n");
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200229 return ret;
230 }
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200231 mtx1_wdt_start();
Florian Fainellifad0a9d2011-06-15 19:15:09 +0200232 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200233 return 0;
234}
235
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000236static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200237{
Alan Coxed78c2d2008-05-19 14:07:21 +0100238 /* FIXME: do we need to lock this test ? */
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200239 if (mtx1_wdt_device.queue) {
240 mtx1_wdt_device.queue = 0;
241 wait_for_completion(&mtx1_wdt_device.stop);
242 }
Florian Fainelli9b19d402011-06-15 19:15:23 +0200243
244 gpio_free(mtx1_wdt_device.gpio);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200245 misc_deregister(&mtx1_wdt_misc);
Florian Fainelli6ea81152008-01-07 19:08:49 +0100246 return 0;
247}
248
Florian Fainellidb98f892011-06-15 19:15:52 +0200249static struct platform_driver mtx1_wdt_driver = {
Florian Fainelli6ea81152008-01-07 19:08:49 +0100250 .probe = mtx1_wdt_probe,
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000251 .remove = __devexit_p(mtx1_wdt_remove),
Florian Fainelli6ea81152008-01-07 19:08:49 +0100252 .driver.name = "mtx1-wdt",
Kay Sieversf37d1932008-04-10 21:29:23 -0700253 .driver.owner = THIS_MODULE,
Florian Fainelli6ea81152008-01-07 19:08:49 +0100254};
255
256static int __init mtx1_wdt_init(void)
257{
Florian Fainellidb98f892011-06-15 19:15:52 +0200258 return platform_driver_register(&mtx1_wdt_driver);
Florian Fainelli6ea81152008-01-07 19:08:49 +0100259}
260
261static void __exit mtx1_wdt_exit(void)
262{
Florian Fainellidb98f892011-06-15 19:15:52 +0200263 platform_driver_unregister(&mtx1_wdt_driver);
Florian Fainelli04bf3b42007-05-06 12:55:32 +0200264}
265
266module_init(mtx1_wdt_init);
267module_exit(mtx1_wdt_exit);
268
269MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
270MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
271MODULE_LICENSE("GPL");
Florian Fainelli6ea81152008-01-07 19:08:49 +0100272MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Kay Sieversf37d1932008-04-10 21:29:23 -0700273MODULE_ALIAS("platform:mtx1-wdt");