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1/*
2 * Driver for the MTX-1 Watchdog.
3 *
4 * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
5 * All Rights Reserved.
6 * 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>
49#include <linux/platform_device.h>
50#include <linux/io.h>
51#include <linux/uaccess.h>
52#include <linux/gpio.h>
53
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;
62 spinlock_t lock;
63 int running;
64 struct timer_list timer;
65 int queue;
66 int default_ticks;
67 unsigned long inuse;
68 unsigned gpio;
69 unsigned int gstate;
70} mtx1_wdt_device;
71
72static void mtx1_wdt_trigger(unsigned long unused)
73{
74 spin_lock(&mtx1_wdt_device.lock);
75 if (mtx1_wdt_device.running)
76 ticks--;
77
78 /* toggle wdt gpio */
79 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
80 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
81
82 if (mtx1_wdt_device.queue && ticks)
83 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
84 else
85 complete(&mtx1_wdt_device.stop);
86 spin_unlock(&mtx1_wdt_device.lock);
87}
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{
97 unsigned long flags;
98
99 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
100 if (!mtx1_wdt_device.queue) {
101 mtx1_wdt_device.queue = 1;
102 mtx1_wdt_device.gstate = 1;
103 gpio_set_value(mtx1_wdt_device.gpio, 1);
104 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
105 }
106 mtx1_wdt_device.running++;
107 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
108}
109
110static int mtx1_wdt_stop(void)
111{
112 unsigned long flags;
113
114 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
115 if (mtx1_wdt_device.queue) {
116 mtx1_wdt_device.queue = 0;
117 mtx1_wdt_device.gstate = 0;
118 gpio_set_value(mtx1_wdt_device.gpio, 0);
119 }
120 ticks = mtx1_wdt_device.default_ticks;
121 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
122 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;
131 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
141static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
142 unsigned long arg)
143{
144 void __user *argp = (void __user *)arg;
145 int __user *p = (int __user *)argp;
146 unsigned int value;
147 static const struct watchdog_info ident = {
148 .options = WDIOF_CARDRESET,
149 .identity = "MTX-1 WDT",
150 };
151
152 switch (cmd) {
153 case WDIOC_GETSUPPORT:
154 if (copy_to_user(argp, &ident, sizeof(ident)))
155 return -EFAULT;
156 break;
157 case WDIOC_GETSTATUS:
158 case WDIOC_GETBOOTSTATUS:
159 put_user(0, p);
160 break;
161 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;
171 case WDIOC_KEEPALIVE:
172 mtx1_wdt_reset();
173 break;
174 default:
175 return -ENOTTY;
176 }
177 return 0;
178}
179
180
181static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
182 size_t count, loff_t *ppos)
183{
184 if (!count)
185 return -EIO;
186 mtx1_wdt_reset();
187 return count;
188}
189
190static const struct file_operations mtx1_wdt_fops = {
191 .owner = THIS_MODULE,
192 .llseek = no_llseek,
193 .unlocked_ioctl = mtx1_wdt_ioctl,
194 .open = mtx1_wdt_open,
195 .write = mtx1_wdt_write,
196 .release = mtx1_wdt_release,
197};
198
199
200static struct miscdevice mtx1_wdt_misc = {
201 .minor = WATCHDOG_MINOR,
202 .name = "watchdog",
203 .fops = &mtx1_wdt_fops,
204};
205
206
207static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
208{
209 int ret;
210
211 mtx1_wdt_device.gpio = pdev->resource[0].start;
212 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 }
218
219 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) {
228 dev_err(&pdev->dev, "failed to register\n");
229 return ret;
230 }
231 mtx1_wdt_start();
232 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
233 return 0;
234}
235
236static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
237{
238 /* FIXME: do we need to lock this test ? */
239 if (mtx1_wdt_device.queue) {
240 mtx1_wdt_device.queue = 0;
241 wait_for_completion(&mtx1_wdt_device.stop);
242 }
243
244 gpio_free(mtx1_wdt_device.gpio);
245 misc_deregister(&mtx1_wdt_misc);
246 return 0;
247}
248
249static struct platform_driver mtx1_wdt_driver = {
250 .probe = mtx1_wdt_probe,
251 .remove = __devexit_p(mtx1_wdt_remove),
252 .driver.name = "mtx1-wdt",
253 .driver.owner = THIS_MODULE,
254};
255
256static int __init mtx1_wdt_init(void)
257{
258 return platform_driver_register(&mtx1_wdt_driver);
259}
260
261static void __exit mtx1_wdt_exit(void)
262{
263 platform_driver_unregister(&mtx1_wdt_driver);
264}
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");
272MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
273MODULE_ALIAS("platform:mtx1-wdt");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for the MTX-1 Watchdog.
4 *
5 * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
6 * All Rights Reserved.
7 * http://www.4g-systems.biz
8 *
9 * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
10 * (c) Copyright 2005 4G Systems <info@4g-systems.biz>
11 *
12 * Release 0.01.
13 * Author: Michael Stickel michael.stickel@4g-systems.biz
14 *
15 * Release 0.02.
16 * Author: Florian Fainelli florian@openwrt.org
17 * use the Linux watchdog/timer APIs
18 *
19 * The Watchdog is configured to reset the MTX-1
20 * if it is not triggered for 100 seconds.
21 * It should not be triggered more often than 1.6 seconds.
22 *
23 * A timer triggers the watchdog every 5 seconds, until
24 * it is opened for the first time. After the first open
25 * it MUST be triggered every 2..95 seconds.
26 */
27
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/types.h>
31#include <linux/errno.h>
32#include <linux/miscdevice.h>
33#include <linux/fs.h>
34#include <linux/ioport.h>
35#include <linux/timer.h>
36#include <linux/completion.h>
37#include <linux/jiffies.h>
38#include <linux/watchdog.h>
39#include <linux/platform_device.h>
40#include <linux/io.h>
41#include <linux/uaccess.h>
42#include <linux/gpio.h>
43
44#include <asm/mach-au1x00/au1000.h>
45
46#define MTX1_WDT_INTERVAL (5 * HZ)
47
48static int ticks = 100 * HZ;
49
50static struct {
51 struct completion stop;
52 spinlock_t lock;
53 int running;
54 struct timer_list timer;
55 int queue;
56 int default_ticks;
57 unsigned long inuse;
58 unsigned gpio;
59 unsigned int gstate;
60} mtx1_wdt_device;
61
62static void mtx1_wdt_trigger(struct timer_list *unused)
63{
64 spin_lock(&mtx1_wdt_device.lock);
65 if (mtx1_wdt_device.running)
66 ticks--;
67
68 /* toggle wdt gpio */
69 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
70 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
71
72 if (mtx1_wdt_device.queue && ticks)
73 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
74 else
75 complete(&mtx1_wdt_device.stop);
76 spin_unlock(&mtx1_wdt_device.lock);
77}
78
79static void mtx1_wdt_reset(void)
80{
81 ticks = mtx1_wdt_device.default_ticks;
82}
83
84
85static void mtx1_wdt_start(void)
86{
87 unsigned long flags;
88
89 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
90 if (!mtx1_wdt_device.queue) {
91 mtx1_wdt_device.queue = 1;
92 mtx1_wdt_device.gstate = 1;
93 gpio_set_value(mtx1_wdt_device.gpio, 1);
94 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
95 }
96 mtx1_wdt_device.running++;
97 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
98}
99
100static int mtx1_wdt_stop(void)
101{
102 unsigned long flags;
103
104 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
105 if (mtx1_wdt_device.queue) {
106 mtx1_wdt_device.queue = 0;
107 mtx1_wdt_device.gstate = 0;
108 gpio_set_value(mtx1_wdt_device.gpio, 0);
109 }
110 ticks = mtx1_wdt_device.default_ticks;
111 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
112 return 0;
113}
114
115/* Filesystem functions */
116
117static int mtx1_wdt_open(struct inode *inode, struct file *file)
118{
119 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
120 return -EBUSY;
121 return nonseekable_open(inode, file);
122}
123
124
125static int mtx1_wdt_release(struct inode *inode, struct file *file)
126{
127 clear_bit(0, &mtx1_wdt_device.inuse);
128 return 0;
129}
130
131static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
132 unsigned long arg)
133{
134 void __user *argp = (void __user *)arg;
135 int __user *p = (int __user *)argp;
136 unsigned int value;
137 static const struct watchdog_info ident = {
138 .options = WDIOF_CARDRESET,
139 .identity = "MTX-1 WDT",
140 };
141
142 switch (cmd) {
143 case WDIOC_GETSUPPORT:
144 if (copy_to_user(argp, &ident, sizeof(ident)))
145 return -EFAULT;
146 break;
147 case WDIOC_GETSTATUS:
148 case WDIOC_GETBOOTSTATUS:
149 put_user(0, p);
150 break;
151 case WDIOC_SETOPTIONS:
152 if (get_user(value, p))
153 return -EFAULT;
154 if (value & WDIOS_ENABLECARD)
155 mtx1_wdt_start();
156 else if (value & WDIOS_DISABLECARD)
157 mtx1_wdt_stop();
158 else
159 return -EINVAL;
160 return 0;
161 case WDIOC_KEEPALIVE:
162 mtx1_wdt_reset();
163 break;
164 default:
165 return -ENOTTY;
166 }
167 return 0;
168}
169
170
171static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
172 size_t count, loff_t *ppos)
173{
174 if (!count)
175 return -EIO;
176 mtx1_wdt_reset();
177 return count;
178}
179
180static const struct file_operations mtx1_wdt_fops = {
181 .owner = THIS_MODULE,
182 .llseek = no_llseek,
183 .unlocked_ioctl = mtx1_wdt_ioctl,
184 .open = mtx1_wdt_open,
185 .write = mtx1_wdt_write,
186 .release = mtx1_wdt_release,
187};
188
189
190static struct miscdevice mtx1_wdt_misc = {
191 .minor = WATCHDOG_MINOR,
192 .name = "watchdog",
193 .fops = &mtx1_wdt_fops,
194};
195
196
197static int mtx1_wdt_probe(struct platform_device *pdev)
198{
199 int ret;
200
201 mtx1_wdt_device.gpio = pdev->resource[0].start;
202 ret = devm_gpio_request_one(&pdev->dev, mtx1_wdt_device.gpio,
203 GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
204 if (ret < 0) {
205 dev_err(&pdev->dev, "failed to request gpio");
206 return ret;
207 }
208
209 spin_lock_init(&mtx1_wdt_device.lock);
210 init_completion(&mtx1_wdt_device.stop);
211 mtx1_wdt_device.queue = 0;
212 clear_bit(0, &mtx1_wdt_device.inuse);
213 timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
214 mtx1_wdt_device.default_ticks = ticks;
215
216 ret = misc_register(&mtx1_wdt_misc);
217 if (ret < 0) {
218 dev_err(&pdev->dev, "failed to register\n");
219 return ret;
220 }
221 mtx1_wdt_start();
222 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
223 return 0;
224}
225
226static int mtx1_wdt_remove(struct platform_device *pdev)
227{
228 /* FIXME: do we need to lock this test ? */
229 if (mtx1_wdt_device.queue) {
230 mtx1_wdt_device.queue = 0;
231 wait_for_completion(&mtx1_wdt_device.stop);
232 }
233
234 misc_deregister(&mtx1_wdt_misc);
235 return 0;
236}
237
238static struct platform_driver mtx1_wdt_driver = {
239 .probe = mtx1_wdt_probe,
240 .remove = mtx1_wdt_remove,
241 .driver.name = "mtx1-wdt",
242 .driver.owner = THIS_MODULE,
243};
244
245module_platform_driver(mtx1_wdt_driver);
246
247MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
248MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
249MODULE_LICENSE("GPL");
250MODULE_ALIAS("platform:mtx1-wdt");