openwrtv3/target/linux/brcm63xx/files/drivers/watchdog/bcm63xx_wdt.c
Florian Fainelli 7ab973e1af Add bcm63xx_wdt but do not enable it yet
SVN-Revision: 13677
2008-12-17 14:06:03 +00:00

315 lines
7 KiB
C

/*
* Broadcom BCM63xx SoC watchdog driver
*
* Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
* Copyright (C) 2008, 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/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 <linux/timer.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>
#define PFX KBUILD_MODNAME
#define WDT_HZ 50000000 /* Fclk */
#define WDT_INTERVAL (40) /* in seconds */
static struct {
void __iomem *regs;
struct completion stop;
int running;
struct timer_list timer;
int queue;
int default_ticks;
unsigned long inuse;
} bcm63xx_wdt_device;
static int ticks = 100 * WDT_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 bcm63xx_wdt_toggle(void)
{
bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
}
static void bcm63xx_wdt_start(void)
{
if (!bcm63xx_wdt_device.inuse) {
bcm63xx_wdt_toggle();
mod_timer(&bcm63xx_wdt_device.timer, jiffies + WDT_INTERVAL);
}
bcm63xx_wdt_device.running++;
}
static void bcm63xx_wdt_stop(void)
{
if (bcm63xx_wdt_device.running) {
bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
bcm63xx_wdt_device.running = 0;
}
}
static void bcm63xx_wdt_set(int new_timeout)
{
new_timeout *= WDT_HZ;
bcm_writel(new_timeout, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
}
static void bcm63xx_wdt_reset(void)
{
ticks = bcm63xx_wdt_device.default_ticks;
}
static void bcm63xx_wdt_update(unsigned long unused)
{
if (bcm63xx_wdt_device.running)
ticks--;
bcm63xx_wdt_toggle();
if (bcm63xx_wdt_device.queue && ticks)
mod_timer(&bcm63xx_wdt_device.timer,
jiffies + WDT_INTERVAL);
else
complete(&bcm63xx_wdt_device.stop);
}
static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
return nonseekable_open(inode, file);
}
static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
{
if (expect_close && nowayout == 0) {
bcm63xx_wdt_stop();
printk(KERN_INFO PFX ": disabling watchdog timer\n");
module_put(THIS_MODULE);
} else
printk(KERN_CRIT PFX
": device closed unexpectedly. WDT will not stop !\n");
clear_bit(0, &bcm63xx_wdt_device.inuse);
return 0;
}
static ssize_t bcm63xx_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;
}
}
bcm63xx_wdt_update(0);
return len;
}
return 0;
}
static long bcm63xx_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 = "BCM63xx Watchdog",
};
switch (cmd) {
case WDIOC_KEEPALIVE:
bcm63xx_wdt_reset();
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
value = bcm_readl(bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
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:
bcm63xx_wdt_start();
break;
case WDIOS_DISABLECARD:
bcm63xx_wdt_stop();
default:
return -EINVAL;
}
break;
case WDIOC_SETTIMEOUT:
if (copy_from_user(&new_timeout, argp, sizeof(int)))
return -EFAULT;
if (new_timeout < 5)
return -EINVAL;
if (new_timeout > 40)
return -EINVAL;
bcm63xx_wdt_set(new_timeout);
bcm63xx_wdt_toggle();
case WDIOC_GETTIMEOUT:
return copy_to_user(argp, &timeout, sizeof(int));
default:
return -ENOTTY;
}
return 0;
}
static struct file_operations bcm63xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = bcm63xx_wdt_write,
.unlocked_ioctl = bcm63xx_wdt_ioctl,
.open = bcm63xx_wdt_open,
.release = bcm63xx_wdt_release,
};
static struct miscdevice bcm63xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &bcm63xx_wdt_fops,
};
static int bcm63xx_wdt_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
printk(KERN_ERR PFX
"failed to retrieve resources\n");
return -ENODEV;
}
bcm63xx_wdt_device.regs = ioremap_nocache(r->start, r->end - r->start);
if (!bcm63xx_wdt_device.regs) {
printk(KERN_ERR PFX
"failed to remap I/O resources\n");
return -ENXIO;
}
ret = misc_register(&bcm63xx_wdt_miscdev);
if (ret < 0) {
printk(KERN_ERR PFX
"failed to register watchdog device\n");
goto unmap;
}
init_completion(&bcm63xx_wdt_device.stop);
bcm63xx_wdt_device.queue = 0;
clear_bit(0, &bcm63xx_wdt_device.inuse);
setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_wdt_update, 0L);
bcm63xx_wdt_device.default_ticks = ticks;
bcm63xx_wdt_set(ticks);
bcm63xx_wdt_start();
printk(KERN_INFO PFX " started, timer margin: %d sec\n", WDT_INTERVAL);
return 0;
unmap:
iounmap(bcm63xx_wdt_device.regs);
return ret;
}
static int bcm63xx_wdt_remove(struct platform_device *pdev)
{
if (bcm63xx_wdt_device.queue) {
bcm63xx_wdt_device.queue = 0;
wait_for_completion(&bcm63xx_wdt_device.stop);
}
misc_deregister(&bcm63xx_wdt_miscdev);
iounmap(bcm63xx_wdt_device.regs);
return 0;
}
static struct platform_driver bcm63xx_wdt = {
.probe = bcm63xx_wdt_probe,
.remove = bcm63xx_wdt_remove,
.driver = {
.name = "bcm63xx-wdt",
}
};
static int __init bcm63xx_wdt_init(void)
{
return platform_driver_register(&bcm63xx_wdt);
}
static void __exit bcm63xx_wdt_exit(void)
{
platform_driver_unregister(&bcm63xx_wdt);
}
module_init(bcm63xx_wdt_init);
module_exit(bcm63xx_wdt_exit);
MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:bcm63xx-wdt");