/*
* mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
*
* Author: James Chapman <jchapman@katalix.com>
*
* Platform-specific setup code should configure the dog to generate
* interrupt or reset as required. This code only enables/disables
* and services the watchdog.
*
* Derived from mpc8xx_wdt.c, with the following copyright.
*
* 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <asm/mv64x60.h>
#include <asm/uaccess.h>
#include <asm/io.h>
/* MV64x60 WDC (config) register access definitions */
#define MV64x60_WDC_CTL1_MASK (3 << 24)
#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
#define MV64x60_WDC_CTL2_MASK (3 << 26)
#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
/* Flags bits */
#define MV64x60_WDOG_FLAG_OPENED 0
#define MV64x60_WDOG_FLAG_ENABLED 1
static unsigned long wdt_flags;
static int wdt_status;
static void __iomem *mv64x60_regs;
static int mv64x60_wdt_timeout;
static void mv64x60_wdt_reg_write(u32 val)
{
/* Allow write only to CTL1 / CTL2 fields, retaining values in
* other fields.
*/
u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
data |= val;
writel(data, mv64x60_regs + MV64x60_WDT_WDC);
}
static void mv64x60_wdt_service(void)
{
/* Write 01 followed by 10 to CTL2 */
mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
}
static void mv64x60_wdt_handler_disable(void)
{
if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
/* Write 01 followed by 10 to CTL1 */
mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
}
}
static void mv64x60_wdt_handler_enable(void)
{
if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
/* Write 01 followed by 10 to CTL1 */
mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
}
}
static int mv64x60_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
return -EBUSY;
mv64x60_wdt_service();
mv64x60_wdt_handler_enable();
nonseekable_open(inode, file);
return 0;
}
static int mv64x60_wdt_release(struct inode *inode, struct file *file)
{
mv64x60_wdt_service();
#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
mv64x60_wdt_handler_disable();
#endif
clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
return 0;
}
static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t * ppos)
{
if (len)
mv64x60_wdt_service();
return len;
}
static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int timeout;
void __user *argp = (void __user *)arg;
static struct watchdog_info info = {
.options = WDIOF_KEEPALIVEPING,
.firmware_version = 0,
.identity = "MV64x60 watchdog",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &info, sizeof(info)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
if (put_user(wdt_status, (int __user *)argp))
return -EFAULT;
wdt_status &= ~WDIOF_KEEPALIVEPING;
break;
case WDIOC_GETTEMP:
return -EOPNOTSUPP;
case WDIOC_SETOPTIONS:
return -EOPNOTSUPP;
case WDIOC_KEEPALIVE:
mv64x60_wdt_service();
wdt_status |= WDIOF_KEEPALIVEPING;
break;
case WDIOC_SETTIMEOUT:
return -EOPNOTSUPP;
case WDIOC_GETTIMEOUT:
timeout = mv64x60_wdt_timeout * HZ;
if (put_user(timeout, (int __user *)argp))
return -EFAULT;
break;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static struct file_operations mv64x60_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mv64x60_wdt_write,
.ioctl = mv64x60_wdt_ioctl,
.open = mv64x60_wdt_open,
.release = mv64x60_wdt_release,
};
static struct miscdevice mv64x60_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mv64x60_wdt_fops,
};
static int __devinit mv64x60_wdt_probe(struct device *dev)
{
struct platform_device *pd = to_platform_device(dev);
struct mv64x60_wdt_pdata *pdata = pd->dev.platform_data;
int bus_clk = 133;
mv64x60_wdt_timeout = 10;
if (pdata) {
mv64x60_wdt_timeout = pdata->timeout;
bus_clk = pdata->bus_clk;
}
mv64x60_regs = mv64x60_get_bridge_vbase();
writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
mv64x60_regs + MV64x60_WDT_WDC);
return misc_register(&mv64x60_wdt_miscdev);
}
static int __devexit mv64x60_wdt_remove(struct device *dev)
{
misc_deregister(&mv64x60_wdt_miscdev);
mv64x60_wdt_service();
mv64x60_wdt_handler_disable();
return 0;
}
static struct device_driver mv64x60_wdt_driver = {
.name = MV64x60_WDT_NAME,
.bus = &platform_bus_type,
.probe = mv64x60_wdt_probe,
.remove = __devexit_p(mv64x60_wdt_remove),
};
static struct platform_device *mv64x60_wdt_dev;
static int __init mv64x60_wdt_init(void)
{
int ret;
printk(KERN_INFO "MV64x60 watchdog driver\n");
mv64x60_wdt_dev = platform_device_register_simple(MV64x60_WDT_NAME,
-1, NULL, 0);
if (IS_ERR(mv64x60_wdt_dev)) {
ret = PTR_ERR(mv64x60_wdt_dev);
goto out;
}
ret = driver_register(&mv64x60_wdt_driver);
out:
return ret;
}
static void __exit mv64x60_wdt_exit(void)
{
driver_unregister(&mv64x60_wdt_driver);
platform_device_unregister(mv64x60_wdt_dev);
}
module_init(mv64x60_wdt_init);
module_exit(mv64x60_wdt_exit);
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("MV64x60 watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
