Loading...
1/*
2 * Intel 21285 watchdog driver
3 * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
4 *
5 * based on
6 *
7 * SoftDog 0.05: A Software Watchdog Device
8 *
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
10 * All Rights Reserved.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 */
18
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/fs.h>
24#include <linux/mm.h>
25#include <linux/miscdevice.h>
26#include <linux/watchdog.h>
27#include <linux/reboot.h>
28#include <linux/init.h>
29#include <linux/interrupt.h>
30#include <linux/uaccess.h>
31#include <linux/irq.h>
32#include <mach/hardware.h>
33
34#include <asm/mach-types.h>
35#include <asm/hardware/dec21285.h>
36
37/*
38 * Define this to stop the watchdog actually rebooting the machine.
39 */
40#undef ONLY_TESTING
41
42static unsigned int soft_margin = 60; /* in seconds */
43static unsigned int reload;
44static unsigned long timer_alive;
45
46#ifdef ONLY_TESTING
47/*
48 * If the timer expires..
49 */
50static void watchdog_fire(int irq, void *dev_id)
51{
52 printk(KERN_CRIT "Watchdog: Would Reboot.\n");
53 *CSR_TIMER4_CNTL = 0;
54 *CSR_TIMER4_CLR = 0;
55}
56#endif
57
58/*
59 * Refresh the timer.
60 */
61static void watchdog_ping(void)
62{
63 *CSR_TIMER4_LOAD = reload;
64}
65
66/*
67 * Allow only one person to hold it open
68 */
69static int watchdog_open(struct inode *inode, struct file *file)
70{
71 int ret;
72
73 if (*CSR_SA110_CNTL & (1 << 13))
74 return -EBUSY;
75
76 if (test_and_set_bit(1, &timer_alive))
77 return -EBUSY;
78
79 reload = soft_margin * (mem_fclk_21285 / 256);
80
81 *CSR_TIMER4_CLR = 0;
82 watchdog_ping();
83 *CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD
84 | TIMER_CNTL_DIV256;
85
86#ifdef ONLY_TESTING
87 ret = request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
88 if (ret) {
89 *CSR_TIMER4_CNTL = 0;
90 clear_bit(1, &timer_alive);
91 }
92#else
93 /*
94 * Setting this bit is irreversible; once enabled, there is
95 * no way to disable the watchdog.
96 */
97 *CSR_SA110_CNTL |= 1 << 13;
98
99 ret = 0;
100#endif
101 nonseekable_open(inode, file);
102 return ret;
103}
104
105/*
106 * Shut off the timer.
107 * Note: if we really have enabled the watchdog, there
108 * is no way to turn off.
109 */
110static int watchdog_release(struct inode *inode, struct file *file)
111{
112#ifdef ONLY_TESTING
113 free_irq(IRQ_TIMER4, NULL);
114 clear_bit(1, &timer_alive);
115#endif
116 return 0;
117}
118
119static ssize_t watchdog_write(struct file *file, const char __user *data,
120 size_t len, loff_t *ppos)
121{
122 /*
123 * Refresh the timer.
124 */
125 if (len)
126 watchdog_ping();
127
128 return len;
129}
130
131static const struct watchdog_info ident = {
132 .options = WDIOF_SETTIMEOUT,
133 .identity = "Footbridge Watchdog",
134};
135
136static long watchdog_ioctl(struct file *file, unsigned int cmd,
137 unsigned long arg)
138{
139 unsigned int new_margin;
140 int __user *int_arg = (int __user *)arg;
141 int ret = -ENOTTY;
142
143 switch (cmd) {
144 case WDIOC_GETSUPPORT:
145 ret = 0;
146 if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
147 ret = -EFAULT;
148 break;
149
150 case WDIOC_GETSTATUS:
151 case WDIOC_GETBOOTSTATUS:
152 ret = put_user(0, int_arg);
153 break;
154
155 case WDIOC_KEEPALIVE:
156 watchdog_ping();
157 ret = 0;
158 break;
159
160 case WDIOC_SETTIMEOUT:
161 ret = get_user(new_margin, int_arg);
162 if (ret)
163 break;
164
165 /* Arbitrary, can't find the card's limits */
166 if (new_margin < 0 || new_margin > 60) {
167 ret = -EINVAL;
168 break;
169 }
170
171 soft_margin = new_margin;
172 reload = soft_margin * (mem_fclk_21285 / 256);
173 watchdog_ping();
174 /* Fall */
175 case WDIOC_GETTIMEOUT:
176 ret = put_user(soft_margin, int_arg);
177 break;
178 }
179 return ret;
180}
181
182static const struct file_operations watchdog_fops = {
183 .owner = THIS_MODULE,
184 .llseek = no_llseek,
185 .write = watchdog_write,
186 .unlocked_ioctl = watchdog_ioctl,
187 .open = watchdog_open,
188 .release = watchdog_release,
189};
190
191static struct miscdevice watchdog_miscdev = {
192 .minor = WATCHDOG_MINOR,
193 .name = "watchdog",
194 .fops = &watchdog_fops,
195};
196
197static int __init footbridge_watchdog_init(void)
198{
199 int retval;
200
201 if (machine_is_netwinder())
202 return -ENODEV;
203
204 retval = misc_register(&watchdog_miscdev);
205 if (retval < 0)
206 return retval;
207
208 printk(KERN_INFO
209 "Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
210 soft_margin);
211
212 if (machine_is_cats())
213 printk(KERN_WARNING
214 "Warning: Watchdog reset may not work on this machine.\n");
215 return 0;
216}
217
218static void __exit footbridge_watchdog_exit(void)
219{
220 misc_deregister(&watchdog_miscdev);
221}
222
223MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
224MODULE_DESCRIPTION("Footbridge watchdog driver");
225MODULE_LICENSE("GPL");
226MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
227
228module_param(soft_margin, int, 0);
229MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
230
231module_init(footbridge_watchdog_init);
232module_exit(footbridge_watchdog_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Intel 21285 watchdog driver
4 * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
5 *
6 * based on
7 *
8 * SoftDog 0.05: A Software Watchdog Device
9 *
10 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
11 * All Rights Reserved.
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/types.h>
19#include <linux/kernel.h>
20#include <linux/fs.h>
21#include <linux/mm.h>
22#include <linux/miscdevice.h>
23#include <linux/watchdog.h>
24#include <linux/reboot.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/uaccess.h>
28#include <linux/irq.h>
29#include <mach/hardware.h>
30
31#include <asm/mach-types.h>
32#include <asm/system_info.h>
33#include <asm/hardware/dec21285.h>
34
35/*
36 * Define this to stop the watchdog actually rebooting the machine.
37 */
38#undef ONLY_TESTING
39
40static unsigned int soft_margin = 60; /* in seconds */
41static unsigned int reload;
42static unsigned long timer_alive;
43
44#ifdef ONLY_TESTING
45/*
46 * If the timer expires..
47 */
48static void watchdog_fire(int irq, void *dev_id)
49{
50 pr_crit("Would Reboot\n");
51 *CSR_TIMER4_CNTL = 0;
52 *CSR_TIMER4_CLR = 0;
53}
54#endif
55
56/*
57 * Refresh the timer.
58 */
59static void watchdog_ping(void)
60{
61 *CSR_TIMER4_LOAD = reload;
62}
63
64/*
65 * Allow only one person to hold it open
66 */
67static int watchdog_open(struct inode *inode, struct file *file)
68{
69 int ret;
70
71 if (*CSR_SA110_CNTL & (1 << 13))
72 return -EBUSY;
73
74 if (test_and_set_bit(1, &timer_alive))
75 return -EBUSY;
76
77 reload = soft_margin * (mem_fclk_21285 / 256);
78
79 *CSR_TIMER4_CLR = 0;
80 watchdog_ping();
81 *CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD
82 | TIMER_CNTL_DIV256;
83
84#ifdef ONLY_TESTING
85 ret = request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
86 if (ret) {
87 *CSR_TIMER4_CNTL = 0;
88 clear_bit(1, &timer_alive);
89 }
90#else
91 /*
92 * Setting this bit is irreversible; once enabled, there is
93 * no way to disable the watchdog.
94 */
95 *CSR_SA110_CNTL |= 1 << 13;
96
97 ret = 0;
98#endif
99 stream_open(inode, file);
100 return ret;
101}
102
103/*
104 * Shut off the timer.
105 * Note: if we really have enabled the watchdog, there
106 * is no way to turn off.
107 */
108static int watchdog_release(struct inode *inode, struct file *file)
109{
110#ifdef ONLY_TESTING
111 free_irq(IRQ_TIMER4, NULL);
112 clear_bit(1, &timer_alive);
113#endif
114 return 0;
115}
116
117static ssize_t watchdog_write(struct file *file, const char __user *data,
118 size_t len, loff_t *ppos)
119{
120 /*
121 * Refresh the timer.
122 */
123 if (len)
124 watchdog_ping();
125
126 return len;
127}
128
129static const struct watchdog_info ident = {
130 .options = WDIOF_SETTIMEOUT,
131 .identity = "Footbridge Watchdog",
132};
133
134static long watchdog_ioctl(struct file *file, unsigned int cmd,
135 unsigned long arg)
136{
137 int __user *int_arg = (int __user *)arg;
138 int new_margin, ret = -ENOTTY;
139
140 switch (cmd) {
141 case WDIOC_GETSUPPORT:
142 ret = 0;
143 if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
144 ret = -EFAULT;
145 break;
146
147 case WDIOC_GETSTATUS:
148 case WDIOC_GETBOOTSTATUS:
149 ret = put_user(0, int_arg);
150 break;
151
152 case WDIOC_KEEPALIVE:
153 watchdog_ping();
154 ret = 0;
155 break;
156
157 case WDIOC_SETTIMEOUT:
158 ret = get_user(new_margin, int_arg);
159 if (ret)
160 break;
161
162 /* Arbitrary, can't find the card's limits */
163 if (new_margin < 0 || new_margin > 60) {
164 ret = -EINVAL;
165 break;
166 }
167
168 soft_margin = new_margin;
169 reload = soft_margin * (mem_fclk_21285 / 256);
170 watchdog_ping();
171 fallthrough;
172 case WDIOC_GETTIMEOUT:
173 ret = put_user(soft_margin, int_arg);
174 break;
175 }
176 return ret;
177}
178
179static const struct file_operations watchdog_fops = {
180 .owner = THIS_MODULE,
181 .llseek = no_llseek,
182 .write = watchdog_write,
183 .unlocked_ioctl = watchdog_ioctl,
184 .compat_ioctl = compat_ptr_ioctl,
185 .open = watchdog_open,
186 .release = watchdog_release,
187};
188
189static struct miscdevice watchdog_miscdev = {
190 .minor = WATCHDOG_MINOR,
191 .name = "watchdog",
192 .fops = &watchdog_fops,
193};
194
195static int __init footbridge_watchdog_init(void)
196{
197 int retval;
198
199 if (machine_is_netwinder())
200 return -ENODEV;
201
202 retval = misc_register(&watchdog_miscdev);
203 if (retval < 0)
204 return retval;
205
206 pr_info("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
207 soft_margin);
208
209 if (machine_is_cats())
210 pr_warn("Warning: Watchdog reset may not work on this machine\n");
211 return 0;
212}
213
214static void __exit footbridge_watchdog_exit(void)
215{
216 misc_deregister(&watchdog_miscdev);
217}
218
219MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
220MODULE_DESCRIPTION("Footbridge watchdog driver");
221MODULE_LICENSE("GPL");
222
223module_param(soft_margin, int, 0);
224MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
225
226module_init(footbridge_watchdog_init);
227module_exit(footbridge_watchdog_exit);