/*
* IDT Interprise 79RC32434 watchdog driver
*
* Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
*
* based on
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
*
* 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/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <asm/bootinfo.h>
#include <asm/time.h>
#include <asm/mach-rc32434/integ.h>
#define MAX_TIMEOUT 20
#define RC32434_WDT_INTERVAL (15 * HZ)
#define VERSION "0.2"
static struct {
struct completion stop;
int running;
struct timer_list timer;
int queue;
int default_ticks;
unsigned long inuse;
} rc32434_wdt_device;
static struct integ __iomem *wdt_reg;
static int ticks = 100 * HZ;
static int expect_close;
static int timeout;
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static void rc32434_wdt_start(void)
{
u32 val;
if (!rc32434_wdt_device.inuse) {
writel(0, &wdt_reg->wtcount);
val = RC32434_ERR_WRE;
writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);
val = RC32434_WTC_EN;
writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
}
rc32434_wdt_device.running++;
}
static void rc32434_wdt_stop(void)
{
u32 val;
if (rc32434_wdt_device.running) {
val = ~RC32434_WTC_EN;
writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
val = ~RC32434_ERR_WRE;
writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);
rc32434_wdt_device.running = 0;
}
}
static void rc32434_wdt_set(int new_timeout)
{
u32 cmp = new_timeout * HZ;
u32 state, val;
timeout = new_timeout;
/*
* store and disable WTC
*/
state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
val = ~RC32434_WTC_EN;
writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
writel(0, &wdt_reg->wtcount);
writel(cmp, &wdt_reg->wtcompare);
/*
* restore WTC
*/
writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
}
static void rc32434_wdt_reset(void)
{
ticks = rc32434_wdt_device.default_ticks;
}
static void rc32434_wdt_update(unsigned long unused)
{
if (rc32434_wdt_device.running)
ticks--;
writel(0, &wdt_reg->wtcount);
if (rc32434_wdt_device.queue && ticks)
mod_timer(&rc32434_wdt_device.timer,
jiffies + RC32434_WDT_INTERVAL);
else
complete(&rc32434_wdt_device.stop);
}
static int rc32434_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
return nonseekable_open(inode, file);
}
static int rc32434_wdt_release(struct inode *inode, struct file *file)
{
if (expect_close && nowayout == 0) {
rc32434_wdt_stop();
printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
module_put(THIS_MODULE);
} else
printk(KERN_CRIT KBUILD_MODNAME
": device closed unexpectedly. WDT will not stop !\n");
clear_bit(0, &rc32434_wdt_device.inuse);
return 0;
}
static ssize_t rc32434_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 1;
}
}
rc32434_wdt_update(0);
return len;
}
return 0;
}
static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int new_timeout;
unsigned int value;
static struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "RC32434_WDT Watchdog",
};
switch (cmd) {
case WDIOC_KEEPALIVE:
rc32434_wdt_reset();
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
value = readl(&wdt_reg->wtcount);
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:
rc32434_wdt_start();
break;
case WDIOS_DISABLECARD:
rc32434_wdt_stop();
default:
return -EINVAL;
}
break;
case WDIOC_SETTIMEOUT:
if (copy_from_user(&new_timeout, argp, sizeof(int)))
return -EFAULT;
if (new_timeout < 1)
return -EINVAL;
if (new_timeout > MAX_TIMEOUT)
return -EINVAL;
rc32434_wdt_set(new_timeout);
case WDIOC_GETTIMEOUT:
return copy_to_user(argp, &timeout, sizeof(int));
default:
return -ENOTTY;
}
return 0;
}
static struct file_operations rc32434_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = rc32434_wdt_write,
.unlocked_ioctl = rc32434_wdt_ioctl,
.open = rc32434_wdt_open,
.release = rc32434_wdt_release,
};
static struct miscdevice rc32434_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &rc32434_wdt_fops,
};
static char banner[] = KERN_INFO KBUILD_MODNAME
": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
static int rc32434_wdt_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
if (!r) {
printk(KERN_ERR KBUILD_MODNAME
"failed to retrieve resources\n");
return -ENODEV;
}
wdt_reg = ioremap_nocache(r->start, r->end - r->start);
if (!wdt_reg) {
printk(KERN_ERR KBUILD_MODNAME
"failed to remap I/O resources\n");
return -ENXIO;
}
ret = misc_register(&rc32434_wdt_miscdev);
if (ret < 0) {
printk(KERN_ERR KBUILD_MODNAME
"failed to register watchdog device\n");
goto unmap;
}
init_completion(&rc32434_wdt_device.stop);
rc32434_wdt_device.queue = 0;
clear_bit(0, &rc32434_wdt_device.inuse);
setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);
rc32434_wdt_device.default_ticks = ticks;
rc32434_wdt_start();
printk(banner, timeout);
return 0;
unmap:
iounmap(wdt_reg);
return ret;
}
static int rc32434_wdt_remove(struct platform_device *pdev)
{
if (rc32434_wdt_device.queue) {
rc32434_wdt_device.queue = 0;
wait_for_completion(&rc32434_wdt_device.stop);
}
misc_deregister(&rc32434_wdt_miscdev);
iounmap(wdt_reg);
return 0;
}
static struct platform_driver rc32434_wdt = {
.probe = rc32434_wdt_probe,
.remove = rc32434_wdt_remove,
.driver = {
.name = "rc32434_wdt",
}
};
static int __init rc32434_wdt_init(void)
{
return platform_driver_register(&rc32434_wdt);
}
static void __exit rc32434_wdt_exit(void)
{
platform_driver_unregister(&rc32434_wdt);
}
module_init(rc32434_wdt_init);
module_exit(rc32434_wdt_exit);
MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
"Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
