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/* Philips PCF50606 Watchdog Timer Driver
*
* (C) 2006-2008 by Openmoko, Inc.
* Author: Balaji Rao <balajirrao@openmoko.org>
* All rights reserved.
*
* Broken down from monstrous PCF50606 driver mainly by
* Harald Welte, Matt Hsu, Andy Green and Werner Almesberger
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/err.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/mfd/pcf50606/core.h>
static struct pcf50606 *pcf = NULL;
static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
#define WDT_REGION_INITED 2
#define WDT_DEVICE_INITED 3
static int allow_close;
#define CLOSE_STATE_NOT 0x0000
#define CLOSE_STATE_ALLOW 0x2342
#define PCF50606_REG_OOCC1 0x08
#define PCF50606_REG_OOCS 0x01
#define PCF50606_OOCS_WDTEXP 0x80
#define PCF50606_OOCC1_WDTRST 0x08
static void pcf50606_wdt_start(void)
{
pcf50606_reg_set_bit_mask(pcf, PCF50606_REG_OOCC1, PCF50606_OOCC1_WDTRST,
PCF50606_OOCC1_WDTRST);
}
static void pcf50606_wdt_stop(void)
{
pcf50606_reg_clear_bits(pcf, PCF50606_REG_OOCS, PCF50606_OOCS_WDTEXP);
}
static void pcf50606_wdt_keepalive(void)
{
pcf50606_wdt_start();
}
static int pcf50606_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
pcf50606_wdt_start();
return nonseekable_open(inode, file);
}
static int pcf50606_wdt_release(struct inode *inode, struct file *file)
{
if (allow_close == CLOSE_STATE_ALLOW)
pcf50606_wdt_stop();
else {
printk(KERN_CRIT "Unexpected close, not stopping watchdog!\n");
pcf50606_wdt_keepalive();
}
allow_close = CLOSE_STATE_NOT;
clear_bit(WDT_IN_USE, &wdt_status);
return 0;
}
static ssize_t pcf50606_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
size_t i;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
allow_close = CLOSE_STATE_ALLOW;
}
pcf50606_wdt_keepalive();
}
return len;
}
static struct watchdog_info pcf50606_wdt_ident = {
.options = WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "PCF50606 Watchdog",
};
static int pcf50606_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &pcf50606_wdt_ident,
sizeof(pcf50606_wdt_ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
pcf50606_wdt_keepalive();
return 0;
case WDIOC_GETTIMEOUT:
return put_user(8, p);
default:
return -ENOIOCTLCMD;
}
}
static struct file_operations pcf50606_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = &pcf50606_wdt_write,
.ioctl = &pcf50606_wdt_ioctl,
.open = &pcf50606_wdt_open,
.release = &pcf50606_wdt_release,
};
static struct miscdevice pcf50606_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &pcf50606_wdt_fops,
};
static void pcf50606_wdt_irq(int irq, void *unused)
{
pcf50606_reg_set_bit_mask(pcf, PCF50606_REG_OOCC1,
PCF50606_OOCC1_WDTRST,
PCF50606_OOCC1_WDTRST);
}
int __init pcf50606_wdt_probe(struct platform_device *pdev)
{
int err;
if (pcf) {
dev_err(pcf->dev, "Only one instance of WDT supported\n");
return -ENODEV;
}
pcf = dev_to_pcf50606(pdev->dev.parent);
err = misc_register(&pcf50606_wdt_miscdev);
if (err) {
dev_err(&pdev->dev, "cannot register miscdev on "
"minor=%d (%d)\n", WATCHDOG_MINOR, err);
return err;
}
set_bit(WDT_DEVICE_INITED, &wdt_status);
pcf50606_register_irq(pcf, PCF50606_IRQ_CHGWD10S, pcf50606_wdt_irq, NULL);
return 0;
}
static int __devexit pcf50606_wdt_remove(struct platform_device *pdev)
{
pcf50606_free_irq(pcf, PCF50606_IRQ_CHGWD10S);
misc_deregister(&pcf50606_wdt_miscdev);
pcf = NULL;
return 0;
}
struct platform_driver pcf50606_wdt_driver = {
.driver = {
.name = "pcf50606-wdt",
},
.probe = pcf50606_wdt_probe,
.remove = __devexit_p(pcf50606_wdt_remove),
};
static int __init pcf50606_wdt_init(void)
{
return platform_driver_register(&pcf50606_wdt_driver);
}
module_init(pcf50606_wdt_init);
static void __exit pcf50606_wdt_exit(void)
{
platform_driver_unregister(&pcf50606_wdt_driver);
}
module_exit(pcf50606_wdt_exit);
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_DESCRIPTION("PCF50606 wdt driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcf50606-wdt");
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