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/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright 2004 Wu Qi Ming <gokimi@msn.com>
* Copyright (C) 2007 John Crispin <blogic@openwrt.org>
*/
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <linux/selection.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/kdev_t.h>
#include <linux/ioctl.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/platform_device.h>
#include <asm/amazon/amazon.h>
#include <asm/amazon/amazon_wdt.h>
#define DRV_NAME "AMAZON WDT:"
#undef AMAZON_WDT_DEBUG
static int amazon_wdt_isopen = 0;
#ifdef AMAZON_WDT_DEBUG
static struct proc_dir_entry* amazon_wdt_dir;
#endif
int wdt_enable(int timeout)
{
u32 hard_psw, ffpi;
int reload_value, divider = 1;
ffpi = amazon_get_fpi_hz();
reload_value = 65536 - timeout * ffpi / 256;
if (reload_value < 0) {
divider = 0;
reload_value = 65536 - timeout * ffpi / 16384;
}
if (reload_value < 0){
printk(KERN_INFO DRV_NAME "timeout too large %d\n", timeout);
return -EINVAL;
}
printk(KERN_INFO DRV_NAME "timeout:%d reload_value: %8x\n", timeout, reload_value);
hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) +
(amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0;
amazon_writel(hard_psw, AMAZON_WDT_CON0);
wmb();
amazon_writel((hard_psw & 0xff00) + (reload_value << 16) + 0xf2, AMAZON_WDT_CON0);
wmb();
amazon_writel(divider << 2, AMAZON_WDT_CON1);
wmb();
hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) +
(amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0;
amazon_writel(hard_psw, AMAZON_WDT_CON0);
wmb();
amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf3);
wmb();
return 0;
}
void wdt_disable(void)
{
u32 hard_psw = 0;
hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) +
(amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0;
amazon_writel(hard_psw, AMAZON_WDT_CON0);
wmb();
amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf2);
wmb();
amazon_writel_masked(AMAZON_WDT_CON1, 0x8, 0x8);
wmb();
hard_psw=(amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) +
(amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0;
amazon_writel(hard_psw, AMAZON_WDT_CON0);
wmb();
amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf3);
wmb();
return;
}
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36))
static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
#else
static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
#endif
{
int result=0;
static int timeout=-1;
switch(cmd){
case AMAZON_WDT_IOC_START:
printk(KERN_INFO DRV_NAME "enable watch dog timer!\n");
if (copy_from_user((void*)&timeout, (void*)arg, sizeof (int))) {
printk(KERN_INFO DRV_NAME "invalid argument\n");
result=-EINVAL;
} else if ((result = wdt_enable(timeout)) < 0) {
timeout = -1;
}
break;
case AMAZON_WDT_IOC_STOP:
printk(KERN_INFO DRV_NAME "disable watch dog timer\n");
timeout = -1;
wdt_disable();
break;
case AMAZON_WDT_IOC_PING:
if (timeout < 0) {
result = -EIO;
} else {
result = wdt_enable(timeout);
}
break;
default:
result=-EINVAL;
break;
}
return result;
}
static ssize_t wdt_read(struct file *file, char *buf, size_t count, loff_t *offset)
{
return 0;
}
static ssize_t wdt_write(struct file *file, const char *buf, size_t count, loff_t *offset)
{
return count;
}
static int wdt_open(struct inode *inode, struct file *file)
{
if (amazon_wdt_isopen == 1)
return -EBUSY;
amazon_wdt_isopen = 1;
printk(KERN_INFO DRV_NAME "opened\n");
return 0;
}
static int wdt_release(struct inode *inode, struct file *file)
{
amazon_wdt_isopen = 0;
printk(KERN_INFO DRV_NAME "closed\n");
return 0;
}
#ifdef AMAZON_WDT_DEBUG
int wdt_register_proc_read(char *buf, char **start, off_t offset,
int count, int *eof, void *data)
{
int len=0;
len+=sprintf(buf+len,"NMISR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_NMISR));
len+=sprintf(buf+len,"RST_REQ: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_RST_REQ));
len+=sprintf(buf+len,"RST_SR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_RST_SR));
len+=sprintf(buf+len,"WDT_CON0: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_CON0));
len+=sprintf(buf+len,"WDT_CON1: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_CON1));
len+=sprintf(buf+len,"WDT_SR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_SR));
*eof = 1;
return len;
}
#endif
static struct file_operations wdt_fops = {
read: wdt_read,
write: wdt_write,
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36))
unlocked_ioctl: wdt_ioctl,
#else
ioctl: wdt_ioctl,
#endif
open: wdt_open,
release: wdt_release,
};
static int amazon_wdt_probe(struct platform_device *dev)
{
int result = result = register_chrdev(0, "watchdog", &wdt_fops);
if (result < 0) {
printk(KERN_INFO DRV_NAME "cannot register device\n");
return result;
}
#ifdef AMAZON_WDT_DEBUG
amazon_wdt_dir=proc_mkdir("amazon_wdt",NULL);
create_proc_read_entry("wdt_register", 0, amazon_wdt_dir,
wdt_register_proc_read, NULL);
#endif
amazon_wdt_isopen=0;
printk(KERN_INFO DRV_NAME "driver loaded but inactive\n");
return 0;
}
static int amazon_wdt_remove(struct platform_device *dev)
{
unregister_chrdev(0, "watchdog");
#ifdef AMAZON_WDT_DEBUG
remove_proc_entry("wdt_register", amazon_wdt_dir);
remove_proc_entry("amazon_wdt", NULL);
#endif
printk(KERN_INFO DRV_NAME "unregistered\n");
return 0;
}
static struct platform_driver amazon_wdt_driver = {
.probe = amazon_wdt_probe,
.remove = amazon_wdt_remove,
.driver = {
.name = "amazon_wdt",
.owner = THIS_MODULE,
},
};
static int __init amazon_wdt_init(void)
{
int ret = platform_driver_register(&amazon_wdt_driver);
if (ret)
printk(KERN_WARNING "amazon_wdt: error registering platfom driver!\n");
return ret;
}
static void __exit amazon_wdt_exit(void)
{
platform_driver_unregister(&amazon_wdt_driver);
}
module_init(amazon_wdt_init);
module_exit(amazon_wdt_exit);
MODULE_LICENSE ("GPL");
MODULE_AUTHOR("Infineon / John Crispin <blogic@openwrt.org>");
MODULE_DESCRIPTION("AMAZON WDT driver");
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