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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * sma cpu5 watchdog driver
3 *
4 * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21
Joe Perches27c766a2012-02-15 15:06:19 -080022#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/types.h>
27#include <linux/errno.h>
28#include <linux/miscdevice.h>
29#include <linux/fs.h>
30#include <linux/init.h>
31#include <linux/ioport.h>
32#include <linux/timer.h>
Steven Rostedt3fe0c272006-01-09 15:59:26 -080033#include <linux/completion.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080034#include <linux/jiffies.h>
Alan Cox6f932f12008-05-19 14:05:24 +010035#include <linux/io.h>
36#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/watchdog.h>
38
39/* adjustable parameters */
40
Alan Cox6f932f12008-05-19 14:05:24 +010041static int verbose;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042static int port = 0x91;
43static int ticks = 10000;
Axel Lin1334f322011-11-29 13:54:01 +080044static DEFINE_SPINLOCK(cpu5wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46#define PFX "cpu5wdt: "
47
48#define CPU5WDT_EXTENT 0x0A
49
50#define CPU5WDT_STATUS_REG 0x00
51#define CPU5WDT_TIME_A_REG 0x02
52#define CPU5WDT_TIME_B_REG 0x03
53#define CPU5WDT_MODE_REG 0x04
54#define CPU5WDT_TRIGGER_REG 0x07
55#define CPU5WDT_ENABLE_REG 0x08
56#define CPU5WDT_RESET_REG 0x09
57
58#define CPU5WDT_INTERVAL (HZ/10+1)
59
60/* some device data */
61
62static struct {
Steven Rostedt3fe0c272006-01-09 15:59:26 -080063 struct completion stop;
Florian Fainelli996d62d2008-02-25 13:39:57 +010064 int running;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 struct timer_list timer;
Florian Fainelli996d62d2008-02-25 13:39:57 +010066 int queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 int default_ticks;
68 unsigned long inuse;
69} cpu5wdt_device;
70
71/* generic helper functions */
72
73static void cpu5wdt_trigger(unsigned long unused)
74{
Alan Cox6f932f12008-05-19 14:05:24 +010075 if (verbose > 2)
Joe Perches27c766a2012-02-15 15:06:19 -080076 pr_debug("trigger at %i ticks\n", ticks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Alan Cox6f932f12008-05-19 14:05:24 +010078 if (cpu5wdt_device.running)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 ticks--;
80
Alan Cox6f932f12008-05-19 14:05:24 +010081 spin_lock(&cpu5wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 /* keep watchdog alive */
83 outb(1, port + CPU5WDT_TRIGGER_REG);
84
85 /* requeue?? */
Jiri Slaby82eb7c52007-02-08 18:39:36 +010086 if (cpu5wdt_device.queue && ticks)
87 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 else {
89 /* ticks doesn't matter anyway */
Steven Rostedt3fe0c272006-01-09 15:59:26 -080090 complete(&cpu5wdt_device.stop);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 }
Alan Cox6f932f12008-05-19 14:05:24 +010092 spin_unlock(&cpu5wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94}
95
96static void cpu5wdt_reset(void)
97{
98 ticks = cpu5wdt_device.default_ticks;
99
Alan Cox6f932f12008-05-19 14:05:24 +0100100 if (verbose)
Joe Perches27c766a2012-02-15 15:06:19 -0800101 pr_debug("reset (%i ticks)\n", (int) ticks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103}
104
105static void cpu5wdt_start(void)
106{
Alan Cox6f932f12008-05-19 14:05:24 +0100107 unsigned long flags;
108
109 spin_lock_irqsave(&cpu5wdt_lock, flags);
110 if (!cpu5wdt_device.queue) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 cpu5wdt_device.queue = 1;
112 outb(0, port + CPU5WDT_TIME_A_REG);
113 outb(0, port + CPU5WDT_TIME_B_REG);
114 outb(1, port + CPU5WDT_MODE_REG);
115 outb(0, port + CPU5WDT_RESET_REG);
116 outb(0, port + CPU5WDT_ENABLE_REG);
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100117 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 }
119 /* if process dies, counter is not decremented */
120 cpu5wdt_device.running++;
Alan Cox6f932f12008-05-19 14:05:24 +0100121 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122}
123
124static int cpu5wdt_stop(void)
125{
Alan Cox6f932f12008-05-19 14:05:24 +0100126 unsigned long flags;
127
128 spin_lock_irqsave(&cpu5wdt_lock, flags);
129 if (cpu5wdt_device.running)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 cpu5wdt_device.running = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 ticks = cpu5wdt_device.default_ticks;
Alan Cox6f932f12008-05-19 14:05:24 +0100132 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
133 if (verbose)
Joe Perches27c766a2012-02-15 15:06:19 -0800134 pr_crit("stop not possible\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return -EIO;
136}
137
138/* filesystem operations */
139
140static int cpu5wdt_open(struct inode *inode, struct file *file)
141{
Alan Cox6f932f12008-05-19 14:05:24 +0100142 if (test_and_set_bit(0, &cpu5wdt_device.inuse))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 return -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 return nonseekable_open(inode, file);
145}
146
147static int cpu5wdt_release(struct inode *inode, struct file *file)
148{
149 clear_bit(0, &cpu5wdt_device.inuse);
150 return 0;
151}
152
Alan Cox6f932f12008-05-19 14:05:24 +0100153static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
154 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
156 void __user *argp = (void __user *)arg;
Alan Cox6f932f12008-05-19 14:05:24 +0100157 int __user *p = argp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 unsigned int value;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000159 static const struct watchdog_info ident = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 .options = WDIOF_CARDRESET,
161 .identity = "CPU5 WDT",
162 };
163
Alan Cox6f932f12008-05-19 14:05:24 +0100164 switch (cmd) {
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000165 case WDIOC_GETSUPPORT:
166 if (copy_to_user(argp, &ident, sizeof(ident)))
167 return -EFAULT;
Alan Cox6f932f12008-05-19 14:05:24 +0100168 break;
169 case WDIOC_GETSTATUS:
170 value = inb(port + CPU5WDT_STATUS_REG);
171 value = (value >> 2) & 1;
172 return put_user(value, p);
173 case WDIOC_GETBOOTSTATUS:
174 return put_user(0, p);
Alan Cox6f932f12008-05-19 14:05:24 +0100175 case WDIOC_SETOPTIONS:
176 if (get_user(value, p))
177 return -EFAULT;
178 if (value & WDIOS_ENABLECARD)
179 cpu5wdt_start();
180 if (value & WDIOS_DISABLECARD)
181 cpu5wdt_stop();
182 break;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000183 case WDIOC_KEEPALIVE:
184 cpu5wdt_reset();
185 break;
Alan Cox6f932f12008-05-19 14:05:24 +0100186 default:
187 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 }
189 return 0;
190}
191
Alan Cox6f932f12008-05-19 14:05:24 +0100192static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
193 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
Alan Cox6f932f12008-05-19 14:05:24 +0100195 if (!count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 cpu5wdt_reset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 return count;
199}
200
Arjan van de Ven62322d22006-07-03 00:24:21 -0700201static const struct file_operations cpu5wdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 .owner = THIS_MODULE,
203 .llseek = no_llseek,
Alan Cox6f932f12008-05-19 14:05:24 +0100204 .unlocked_ioctl = cpu5wdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 .open = cpu5wdt_open,
206 .write = cpu5wdt_write,
207 .release = cpu5wdt_release,
208};
209
210static struct miscdevice cpu5wdt_misc = {
211 .minor = WATCHDOG_MINOR,
212 .name = "watchdog",
213 .fops = &cpu5wdt_fops,
214};
215
216/* init/exit function */
217
Bill Pemberton2d991a12012-11-19 13:21:41 -0500218static int cpu5wdt_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
220 unsigned int val;
221 int err;
222
Alan Cox6f932f12008-05-19 14:05:24 +0100223 if (verbose)
Joe Perches27c766a2012-02-15 15:06:19 -0800224 pr_debug("port=0x%x, verbose=%i\n", port, verbose);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Alan Cox6f932f12008-05-19 14:05:24 +0100226 init_completion(&cpu5wdt_device.stop);
Alan Cox6f932f12008-05-19 14:05:24 +0100227 cpu5wdt_device.queue = 0;
228 setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
229 cpu5wdt_device.default_ticks = ticks;
230
231 if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800232 pr_err("request_region failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 err = -EBUSY;
234 goto no_port;
235 }
236
Alan Cox6f932f12008-05-19 14:05:24 +0100237 /* watchdog reboot? */
238 val = inb(port + CPU5WDT_STATUS_REG);
239 val = (val >> 2) & 1;
240 if (!val)
Joe Perches27c766a2012-02-15 15:06:19 -0800241 pr_info("sorry, was my fault\n");
Alan Cox6f932f12008-05-19 14:05:24 +0100242
243 err = misc_register(&cpu5wdt_misc);
244 if (err < 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800245 pr_err("misc_register failed\n");
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300246 goto no_misc;
247 }
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Joe Perches27c766a2012-02-15 15:06:19 -0800250 pr_info("init success\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 return 0;
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253no_misc:
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300254 release_region(port, CPU5WDT_EXTENT);
255no_port:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 return err;
257}
258
Bill Pemberton2d991a12012-11-19 13:21:41 -0500259static int cpu5wdt_init_module(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260{
261 return cpu5wdt_init();
262}
263
Bill Pemberton4b12b892012-11-19 13:26:24 -0500264static void cpu5wdt_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265{
Alan Cox6f932f12008-05-19 14:05:24 +0100266 if (cpu5wdt_device.queue) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 cpu5wdt_device.queue = 0;
Steven Rostedt3fe0c272006-01-09 15:59:26 -0800268 wait_for_completion(&cpu5wdt_device.stop);
devendra.aarue09d9c32012-06-26 14:48:26 +0530269 del_timer(&cpu5wdt_device.timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 }
271
272 misc_deregister(&cpu5wdt_misc);
273
274 release_region(port, CPU5WDT_EXTENT);
275
276}
277
Bill Pemberton4b12b892012-11-19 13:26:24 -0500278static void cpu5wdt_exit_module(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279{
280 cpu5wdt_exit();
281}
282
283/* module entry points */
284
285module_init(cpu5wdt_init_module);
286module_exit(cpu5wdt_exit_module);
287
288MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
289MODULE_DESCRIPTION("sma cpu5 watchdog driver");
290MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
291MODULE_LICENSE("GPL");
292MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
293
294module_param(port, int, 0);
295MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
296
297module_param(verbose, int, 0);
298MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
299
300module_param(ticks, int, 0);
301MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");