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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// 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#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 struct gpio_desc *gpiod;
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 gpiod_set_value(mtx1_wdt_device.gpiod, 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 gpiod_set_value(mtx1_wdt_device.gpiod, 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 gpiod_set_value(mtx1_wdt_device.gpiod, 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 stream_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.gpiod = devm_gpiod_get(&pdev->dev,
202 NULL, GPIOD_OUT_HIGH);
203 if (IS_ERR(mtx1_wdt_device.gpiod)) {
204 dev_err(&pdev->dev, "failed to request gpio");
205 return PTR_ERR(mtx1_wdt_device.gpiod);
206 }
207
208 spin_lock_init(&mtx1_wdt_device.lock);
209 init_completion(&mtx1_wdt_device.stop);
210 mtx1_wdt_device.queue = 0;
211 clear_bit(0, &mtx1_wdt_device.inuse);
212 timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
213 mtx1_wdt_device.default_ticks = ticks;
214
215 ret = misc_register(&mtx1_wdt_misc);
216 if (ret < 0) {
217 dev_err(&pdev->dev, "failed to register\n");
218 return ret;
219 }
220 mtx1_wdt_start();
221 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
222 return 0;
223}
224
225static int mtx1_wdt_remove(struct platform_device *pdev)
226{
227 /* FIXME: do we need to lock this test ? */
228 if (mtx1_wdt_device.queue) {
229 mtx1_wdt_device.queue = 0;
230 wait_for_completion(&mtx1_wdt_device.stop);
231 }
232
233 misc_deregister(&mtx1_wdt_misc);
234 return 0;
235}
236
237static struct platform_driver mtx1_wdt_driver = {
238 .probe = mtx1_wdt_probe,
239 .remove = mtx1_wdt_remove,
240 .driver.name = "mtx1-wdt",
241 .driver.owner = THIS_MODULE,
242};
243
244module_platform_driver(mtx1_wdt_driver);
245
246MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
247MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
248MODULE_LICENSE("GPL");
249MODULE_ALIAS("platform:mtx1-wdt");