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/*
* Watchdog driver for the BCM963xx devices
*
* Copyright (C) 2007 OpenWrt.org
* Florian Fainelli <florian@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/completion.h>
#include <linux/ioport.h>
typedef struct bcm963xx_timer {
unsigned short unused0;
unsigned char timer_mask;
#define TIMER0EN 0x01
#define TIMER1EN 0x02
#define TIMER2EN 0x04
unsigned char timer_ints;
#define TIMER0 0x01
#define TIMER1 0x02
#define TIMER2 0x04
#define WATCHDOG 0x08
unsigned long timer_ctl0;
unsigned long timer_ctl1;
unsigned long timer_ctl2;
#define TIMERENABLE 0x80000000
#define RSTCNTCLR 0x40000000
unsigned long timer_cnt0;
unsigned long timer_cnt1;
unsigned long timer_cnt2;
unsigned long wdt_def_count;
/* Write 0xff00 0x00ff to Start timer
* Write 0xee00 0x00ee to Stop and re-load default count
* Read from this register returns current watch dog count
*/
unsigned long wdt_ctl;
/* Number of 40-MHz ticks for WD Reset pulse to last */
unsigned long wdt_rst_count;
} bcm963xx_timer;
static struct bcm963xx_wdt_device {
struct completion stop;
volatile int running;
struct timer_list timer;
volatile int queue;
int default_ticks;
unsigned long inuse;
} bcm963xx_wdt_device;
static int ticks = 1000;
#define WDT_BASE 0xfffe0200
#define WDT ((volatile bcm963xx_timer * const) WDT_BASE)
#define BCM963XX_INTERVAL (HZ/10+1)
static void bcm963xx_wdt_trigger(unsigned long unused)
{
if (bcm963xx_wdt_device.running)
ticks--;
/* Load the default ticking value into the reset counter register */
WDT->wdt_rst_count = bcm963xx_wdt_device.default_ticks;
if (bcm963xx_wdt_device.queue && ticks) {
bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
add_timer(&bcm963xx_wdt_device.timer);
}
else {
complete(&bcm963xx_wdt_device.stop);
}
}
static void bcm963xx_wdt_reset(void)
{
ticks = bcm963xx_wdt_device.default_ticks;
/* Also reload default count */
WDT->wdt_def_count = ticks;
WDT->wdt_ctl = 0xee00;
WDT->wdt_ctl = 0x00ee;
}
static void bcm963xx_wdt_start(void)
{
if (!bcm963xx_wdt_device.queue) {
bcm963xx_wdt_device.queue;
/* Enable the watchdog by writing 0xff00 ,then 0x00ff to the control register */
WDT->wdt_ctl = 0xff00;
WDT->wdt_ctl = 0x00ff;
bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
add_timer(&bcm963xx_wdt_device.timer);
}
bcm963xx_wdt_device.running++;
}
static int bcm963xx_wdt_stop(void)
{
if (bcm963xx_wdt_device.running)
bcm963xx_wdt_device.running = 0;
ticks = bcm963xx_wdt_device.default_ticks;
/* Stop the watchdog by writing 0xee00 then 0x00ee to the control register */
WDT->wdt_ctl = 0xee00;
WDT->wdt_ctl = 0x00ee;
return -EIO;
}
static int bcm963xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &bcm963xx_wdt_device.inuse))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int bcm963xx_wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &bcm963xx_wdt_device.inuse);
return 0;
}
static int bcm963xx_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
unsigned int value;
static struct watchdog_info ident = {
.options = WDIOF_CARDRESET,
.identity = "BCM963xx WDT",
};
switch (cmd) {
case WDIOC_KEEPALIVE:
bcm963xx_wdt_reset();
break;
case WDIOC_GETSTATUS:
/* Reading from the control register will return the current value */
value = WDT->wdt_ctl;
if ( copy_to_user(argp, &value, sizeof(int)) )
return -EFAULT;
break;
case WDIOC_GETSUPPORT:
if ( copy_to_user(argp, &ident, sizeof(ident)) )
return -EFAULT;
break;
case WDIOC_SETOPTIONS:
if ( copy_from_user(&value, argp, sizeof(int)) )
return -EFAULT;
switch(value) {
case WDIOS_ENABLECARD:
bcm963xx_wdt_start();
break;
case WDIOS_DISABLECARD:
bcm963xx_wdt_stop();
break;
default:
return -EINVAL;
}
break;
default:
return -ENOTTY;
}
return 0;
}
static int bcm963xx_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
if (!count)
return -EIO;
bcm963xx_wdt_reset();
return count;
}
static const struct file_operations bcm963xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = bcm963xx_wdt_write,
.ioctl = bcm963xx_wdt_ioctl,
.open = bcm963xx_wdt_open,
.release = bcm963xx_wdt_release,
};
static struct miscdevice bcm963xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &bcm963xx_wdt_fops,
};
static void __exit bcm963xx_wdt_exit(void)
{
if (bcm963xx_wdt_device.queue ){
bcm963xx_wdt_device.queue = 0;
wait_for_completion(&bcm963xx_wdt_device.stop);
}
misc_deregister(&bcm963xx_wdt_miscdev);
}
static int __init bcm963xx_wdt_init(void)
{
int ret = 0;
printk("Broadcom BCM963xx Watchdog timer\n");
ret = misc_register(&bcm963xx_wdt_miscdev);
if (ret) {
printk(KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret);
return ret;
}
init_completion(&bcm963xx_wdt_device.stop);
bcm963xx_wdt_device.queue = 0;
clear_bit(0, &bcm963xx_wdt_device.inuse);
init_timer(&bcm963xx_wdt_device.timer);
bcm963xx_wdt_device.timer.function = bcm963xx_wdt_trigger;
bcm963xx_wdt_device.timer.data = 0;
bcm963xx_wdt_device.default_ticks = ticks;
return ret;
}
module_init(bcm963xx_wdt_init);
module_exit(bcm963xx_wdt_exit);
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("Broadcom BCM963xx Watchdog driver");
MODULE_LICENSE("GPL");
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