/*
* 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/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/resource.h>
#include <linux/platform_device.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>
#include <bcm63xx_timer.h>
#define PFX KBUILD_MODNAME
#define WDT_HZ 50000000 /* Fclk */
#define WDT_DEFAULT_TIME 30 /* seconds */
#define WDT_MAX_TIME 256 /* seconds */
static struct {
void __iomem *regs;
struct timer_list timer;
int default_ticks;
unsigned long inuse;
atomic_t ticks;
} bcm63xx_wdt_device;
static int expect_close;
static int wdt_time = WDT_DEFAULT_TIME;
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) ")");
/* HW functions */
static void bcm63xx_wdt_hw_start(void)
{
bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
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_hw_stop(void)
{
bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
}
static void bcm63xx_wdt_isr(void *data)
{
struct pt_regs *regs = get_irq_regs();
die(PFX " fire", regs);
}
static void bcm63xx_timer_tick(unsigned long unused)
{
if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
bcm63xx_wdt_hw_start();
mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
} else
printk(KERN_CRIT PFX ": watchdog will restart system\n");
}
static void bcm63xx_wdt_pet(void)
{
atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
}
static void bcm63xx_wdt_start(void)
{
bcm63xx_wdt_pet();
bcm63xx_timer_tick(0);
}
static void bcm63xx_wdt_pause(void)
{
del_timer_sync(&bcm63xx_wdt_device.timer);
bcm63xx_wdt_hw_stop();
}
static int bcm63xx_wdt_settimeout(int new_time)
{
if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
return -EINVAL;
wdt_time = new_time;
return 0;
}
static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
return -EBUSY;
bcm63xx_wdt_start();
return nonseekable_open(inode, file);
}
static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
{
if (expect_close == 42)
bcm63xx_wdt_pause();
else {
printk(KERN_CRIT PFX
": Unexpected close, not stopping watchdog!\n");
bcm63xx_wdt_start();
}
clear_bit(0, &bcm63xx_wdt_device.inuse);
expect_close = 0;
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 = 42;
}
}
bcm63xx_wdt_pet();
}
return len;
}
static struct watchdog_info bcm63xx_wdt_info = {
.identity = PFX,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_value, retval = -EINVAL;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &bcm63xx_wdt_info,
sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
if (get_user(new_value, p))
return -EFAULT;
if (new_value & WDIOS_DISABLECARD) {
bcm63xx_wdt_pause();
retval = 0;
}
if (new_value & WDIOS_ENABLECARD) {
bcm63xx_wdt_start();
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
bcm63xx_wdt_pet();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_value, p))
return -EFAULT;
if (bcm63xx_wdt_settimeout(new_value))
return -EINVAL;
bcm63xx_wdt_pet();
case WDIOC_GETTIMEOUT:
return put_user(wdt_time, p);
default:
return -ENOTTY;
}
}
static const 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 __devinit bcm63xx_wdt_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "failed to get resources\n");
return -ENODEV;
}
bcm63xx_wdt_device.regs = ioremap_nocache(r->start, resource_size(r));
if (!bcm63xx_wdt_device.regs) {
dev_err(&pdev->dev, "failed to remap I/O resources\n");
return -ENXIO;
}
ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register wdt timer isr\n");
goto unmap;
}
if (bcm63xx_wdt_settimeout(wdt_time)) {
bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
dev_info(&pdev->dev,
": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
wdt_time);
}
ret = misc_register(&bcm63xx_wdt_miscdev);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register watchdog device\n");
goto unregister_timer;
}
dev_info(&pdev->dev, " started, timer margin: %d sec\n",
WDT_DEFAULT_TIME);
return 0;
unregister_timer:
bcm63xx_timer_unregister(TIMER_WDT_ID);
unmap:
iounmap(bcm63xx_wdt_device.regs);
return ret;
}
static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev)
{
if (!nowayout)
bcm63xx_wdt_pause();
misc_deregister(&bcm63xx_wdt_miscdev);
bcm63xx_timer_unregister(TIMER_WDT_ID);
iounmap(bcm63xx_wdt_device.regs);
return 0;
}
static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
{
bcm63xx_wdt_pause();
}
static struct platform_driver bcm63xx_wdt = {
.probe = bcm63xx_wdt_probe,
.remove = __devexit_p(bcm63xx_wdt_remove),
.shutdown = bcm63xx_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.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");
