Loading...
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/consumer.h>
43
44#define MTX1_WDT_INTERVAL (5 * HZ)
45
46static int ticks = 100 * HZ;
47
48static struct {
49 struct completion stop;
50 spinlock_t lock;
51 int running;
52 struct timer_list timer;
53 int queue;
54 int default_ticks;
55 unsigned long inuse;
56 struct gpio_desc *gpiod;
57 unsigned int gstate;
58} mtx1_wdt_device;
59
60static void mtx1_wdt_trigger(struct timer_list *unused)
61{
62 spin_lock(&mtx1_wdt_device.lock);
63 if (mtx1_wdt_device.running)
64 ticks--;
65
66 /* toggle wdt gpio */
67 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
68 gpiod_set_value(mtx1_wdt_device.gpiod, mtx1_wdt_device.gstate);
69
70 if (mtx1_wdt_device.queue && ticks)
71 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
72 else
73 complete(&mtx1_wdt_device.stop);
74 spin_unlock(&mtx1_wdt_device.lock);
75}
76
77static void mtx1_wdt_reset(void)
78{
79 ticks = mtx1_wdt_device.default_ticks;
80}
81
82
83static void mtx1_wdt_start(void)
84{
85 unsigned long flags;
86
87 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
88 if (!mtx1_wdt_device.queue) {
89 mtx1_wdt_device.queue = 1;
90 mtx1_wdt_device.gstate = 1;
91 gpiod_set_value(mtx1_wdt_device.gpiod, 1);
92 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
93 }
94 mtx1_wdt_device.running++;
95 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
96}
97
98static int mtx1_wdt_stop(void)
99{
100 unsigned long flags;
101
102 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
103 if (mtx1_wdt_device.queue) {
104 mtx1_wdt_device.queue = 0;
105 mtx1_wdt_device.gstate = 0;
106 gpiod_set_value(mtx1_wdt_device.gpiod, 0);
107 }
108 ticks = mtx1_wdt_device.default_ticks;
109 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
110 return 0;
111}
112
113/* Filesystem functions */
114
115static int mtx1_wdt_open(struct inode *inode, struct file *file)
116{
117 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
118 return -EBUSY;
119 return stream_open(inode, file);
120}
121
122
123static int mtx1_wdt_release(struct inode *inode, struct file *file)
124{
125 clear_bit(0, &mtx1_wdt_device.inuse);
126 return 0;
127}
128
129static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
130 unsigned long arg)
131{
132 void __user *argp = (void __user *)arg;
133 int __user *p = (int __user *)argp;
134 unsigned int value;
135 static const struct watchdog_info ident = {
136 .options = WDIOF_CARDRESET,
137 .identity = "MTX-1 WDT",
138 };
139
140 switch (cmd) {
141 case WDIOC_GETSUPPORT:
142 if (copy_to_user(argp, &ident, sizeof(ident)))
143 return -EFAULT;
144 break;
145 case WDIOC_GETSTATUS:
146 case WDIOC_GETBOOTSTATUS:
147 put_user(0, p);
148 break;
149 case WDIOC_SETOPTIONS:
150 if (get_user(value, p))
151 return -EFAULT;
152 if (value & WDIOS_ENABLECARD)
153 mtx1_wdt_start();
154 else if (value & WDIOS_DISABLECARD)
155 mtx1_wdt_stop();
156 else
157 return -EINVAL;
158 return 0;
159 case WDIOC_KEEPALIVE:
160 mtx1_wdt_reset();
161 break;
162 default:
163 return -ENOTTY;
164 }
165 return 0;
166}
167
168
169static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
170 size_t count, loff_t *ppos)
171{
172 if (!count)
173 return -EIO;
174 mtx1_wdt_reset();
175 return count;
176}
177
178static const struct file_operations mtx1_wdt_fops = {
179 .owner = THIS_MODULE,
180 .llseek = no_llseek,
181 .unlocked_ioctl = mtx1_wdt_ioctl,
182 .compat_ioctl = compat_ptr_ioctl,
183 .open = mtx1_wdt_open,
184 .write = mtx1_wdt_write,
185 .release = mtx1_wdt_release,
186};
187
188
189static struct miscdevice mtx1_wdt_misc = {
190 .minor = WATCHDOG_MINOR,
191 .name = "watchdog",
192 .fops = &mtx1_wdt_fops,
193};
194
195
196static int mtx1_wdt_probe(struct platform_device *pdev)
197{
198 int ret;
199
200 mtx1_wdt_device.gpiod = devm_gpiod_get(&pdev->dev,
201 NULL, GPIOD_OUT_HIGH);
202 if (IS_ERR(mtx1_wdt_device.gpiod)) {
203 dev_err(&pdev->dev, "failed to request gpio");
204 return PTR_ERR(mtx1_wdt_device.gpiod);
205 }
206
207 spin_lock_init(&mtx1_wdt_device.lock);
208 init_completion(&mtx1_wdt_device.stop);
209 mtx1_wdt_device.queue = 0;
210 clear_bit(0, &mtx1_wdt_device.inuse);
211 timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
212 mtx1_wdt_device.default_ticks = ticks;
213
214 ret = misc_register(&mtx1_wdt_misc);
215 if (ret < 0) {
216 dev_err(&pdev->dev, "failed to register\n");
217 return ret;
218 }
219 mtx1_wdt_start();
220 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
221 return 0;
222}
223
224static void mtx1_wdt_remove(struct platform_device *pdev)
225{
226 /* FIXME: do we need to lock this test ? */
227 if (mtx1_wdt_device.queue) {
228 mtx1_wdt_device.queue = 0;
229 wait_for_completion(&mtx1_wdt_device.stop);
230 }
231
232 misc_deregister(&mtx1_wdt_misc);
233}
234
235static struct platform_driver mtx1_wdt_driver = {
236 .probe = mtx1_wdt_probe,
237 .remove_new = mtx1_wdt_remove,
238 .driver.name = "mtx1-wdt",
239 .driver.owner = THIS_MODULE,
240};
241
242module_platform_driver(mtx1_wdt_driver);
243
244MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
245MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
246MODULE_LICENSE("GPL");
247MODULE_ALIAS("platform:mtx1-wdt");
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/ioport.h>
44#include <linux/timer.h>
45#include <linux/completion.h>
46#include <linux/jiffies.h>
47#include <linux/watchdog.h>
48#include <linux/platform_device.h>
49#include <linux/io.h>
50#include <linux/uaccess.h>
51#include <linux/gpio.h>
52
53#include <asm/mach-au1x00/au1000.h>
54
55#define MTX1_WDT_INTERVAL (5 * HZ)
56
57static int ticks = 100 * HZ;
58
59static struct {
60 struct completion stop;
61 spinlock_t lock;
62 int running;
63 struct timer_list timer;
64 int queue;
65 int default_ticks;
66 unsigned long inuse;
67 unsigned gpio;
68 unsigned int gstate;
69} mtx1_wdt_device;
70
71static void mtx1_wdt_trigger(unsigned long unused)
72{
73 spin_lock(&mtx1_wdt_device.lock);
74 if (mtx1_wdt_device.running)
75 ticks--;
76
77 /* toggle wdt gpio */
78 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
79 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
80
81 if (mtx1_wdt_device.queue && ticks)
82 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
83 else
84 complete(&mtx1_wdt_device.stop);
85 spin_unlock(&mtx1_wdt_device.lock);
86}
87
88static void mtx1_wdt_reset(void)
89{
90 ticks = mtx1_wdt_device.default_ticks;
91}
92
93
94static void mtx1_wdt_start(void)
95{
96 unsigned long flags;
97
98 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
99 if (!mtx1_wdt_device.queue) {
100 mtx1_wdt_device.queue = 1;
101 mtx1_wdt_device.gstate = 1;
102 gpio_set_value(mtx1_wdt_device.gpio, 1);
103 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
104 }
105 mtx1_wdt_device.running++;
106 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
107}
108
109static int mtx1_wdt_stop(void)
110{
111 unsigned long flags;
112
113 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
114 if (mtx1_wdt_device.queue) {
115 mtx1_wdt_device.queue = 0;
116 mtx1_wdt_device.gstate = 0;
117 gpio_set_value(mtx1_wdt_device.gpio, 0);
118 }
119 ticks = mtx1_wdt_device.default_ticks;
120 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
121 return 0;
122}
123
124/* Filesystem functions */
125
126static int mtx1_wdt_open(struct inode *inode, struct file *file)
127{
128 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
129 return -EBUSY;
130 return nonseekable_open(inode, file);
131}
132
133
134static int mtx1_wdt_release(struct inode *inode, struct file *file)
135{
136 clear_bit(0, &mtx1_wdt_device.inuse);
137 return 0;
138}
139
140static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
141 unsigned long arg)
142{
143 void __user *argp = (void __user *)arg;
144 int __user *p = (int __user *)argp;
145 unsigned int value;
146 static const struct watchdog_info ident = {
147 .options = WDIOF_CARDRESET,
148 .identity = "MTX-1 WDT",
149 };
150
151 switch (cmd) {
152 case WDIOC_GETSUPPORT:
153 if (copy_to_user(argp, &ident, sizeof(ident)))
154 return -EFAULT;
155 break;
156 case WDIOC_GETSTATUS:
157 case WDIOC_GETBOOTSTATUS:
158 put_user(0, p);
159 break;
160 case WDIOC_SETOPTIONS:
161 if (get_user(value, p))
162 return -EFAULT;
163 if (value & WDIOS_ENABLECARD)
164 mtx1_wdt_start();
165 else if (value & WDIOS_DISABLECARD)
166 mtx1_wdt_stop();
167 else
168 return -EINVAL;
169 return 0;
170 case WDIOC_KEEPALIVE:
171 mtx1_wdt_reset();
172 break;
173 default:
174 return -ENOTTY;
175 }
176 return 0;
177}
178
179
180static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
181 size_t count, loff_t *ppos)
182{
183 if (!count)
184 return -EIO;
185 mtx1_wdt_reset();
186 return count;
187}
188
189static const struct file_operations mtx1_wdt_fops = {
190 .owner = THIS_MODULE,
191 .llseek = no_llseek,
192 .unlocked_ioctl = mtx1_wdt_ioctl,
193 .open = mtx1_wdt_open,
194 .write = mtx1_wdt_write,
195 .release = mtx1_wdt_release,
196};
197
198
199static struct miscdevice mtx1_wdt_misc = {
200 .minor = WATCHDOG_MINOR,
201 .name = "watchdog",
202 .fops = &mtx1_wdt_fops,
203};
204
205
206static int mtx1_wdt_probe(struct platform_device *pdev)
207{
208 int ret;
209
210 mtx1_wdt_device.gpio = pdev->resource[0].start;
211 ret = devm_gpio_request_one(&pdev->dev, mtx1_wdt_device.gpio,
212 GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
213 if (ret < 0) {
214 dev_err(&pdev->dev, "failed to request gpio");
215 return ret;
216 }
217
218 spin_lock_init(&mtx1_wdt_device.lock);
219 init_completion(&mtx1_wdt_device.stop);
220 mtx1_wdt_device.queue = 0;
221 clear_bit(0, &mtx1_wdt_device.inuse);
222 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
223 mtx1_wdt_device.default_ticks = ticks;
224
225 ret = misc_register(&mtx1_wdt_misc);
226 if (ret < 0) {
227 dev_err(&pdev->dev, "failed to register\n");
228 return ret;
229 }
230 mtx1_wdt_start();
231 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
232 return 0;
233}
234
235static int mtx1_wdt_remove(struct platform_device *pdev)
236{
237 /* FIXME: do we need to lock this test ? */
238 if (mtx1_wdt_device.queue) {
239 mtx1_wdt_device.queue = 0;
240 wait_for_completion(&mtx1_wdt_device.stop);
241 }
242
243 misc_deregister(&mtx1_wdt_misc);
244 return 0;
245}
246
247static struct platform_driver mtx1_wdt_driver = {
248 .probe = mtx1_wdt_probe,
249 .remove = mtx1_wdt_remove,
250 .driver.name = "mtx1-wdt",
251 .driver.owner = THIS_MODULE,
252};
253
254module_platform_driver(mtx1_wdt_driver);
255
256MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
257MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
258MODULE_LICENSE("GPL");
259MODULE_ALIAS("platform:mtx1-wdt");