266 lines
6.3 KiB
C
266 lines
6.3 KiB
C
/*
|
|
* Copyright (C) Nokia Corporation
|
|
*
|
|
* Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
|
|
*
|
|
* 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.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/i2c/twl.h>
|
|
|
|
#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3
|
|
|
|
#define TWL4030_WDT_STATE_OPEN 0x1
|
|
#define TWL4030_WDT_STATE_ACTIVE 0x8
|
|
|
|
static struct platform_device *twl4030_wdt_dev;
|
|
|
|
struct twl4030_wdt {
|
|
struct miscdevice miscdev;
|
|
int timer_margin;
|
|
unsigned long state;
|
|
};
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
|
|
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static int twl4030_wdt_write(unsigned char val)
|
|
{
|
|
return twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val,
|
|
TWL4030_WATCHDOG_CFG_REG_OFFS);
|
|
}
|
|
|
|
static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
|
|
{
|
|
return twl4030_wdt_write(wdt->timer_margin + 1);
|
|
}
|
|
|
|
static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
|
|
{
|
|
return twl4030_wdt_write(0);
|
|
}
|
|
|
|
static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
|
|
{
|
|
if (timeout < 0 || timeout > 30) {
|
|
dev_warn(wdt->miscdev.parent,
|
|
"Timeout can only be in the range [0-30] seconds");
|
|
return -EINVAL;
|
|
}
|
|
wdt->timer_margin = timeout;
|
|
return twl4030_wdt_enable(wdt);
|
|
}
|
|
|
|
static ssize_t twl4030_wdt_write_fop(struct file *file,
|
|
const char __user *data, size_t len, loff_t *ppos)
|
|
{
|
|
struct twl4030_wdt *wdt = file->private_data;
|
|
|
|
if (len)
|
|
twl4030_wdt_enable(wdt);
|
|
|
|
return len;
|
|
}
|
|
|
|
static long twl4030_wdt_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int new_margin;
|
|
struct twl4030_wdt *wdt = file->private_data;
|
|
|
|
static const struct watchdog_info twl4030_wd_ident = {
|
|
.identity = "TWL4030 Watchdog",
|
|
.options = WDIOF_SETTIMEOUT,
|
|
.firmware_version = 0,
|
|
};
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &twl4030_wd_ident,
|
|
sizeof(twl4030_wd_ident)) ? -EFAULT : 0;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
twl4030_wdt_enable(wdt);
|
|
break;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_margin, p))
|
|
return -EFAULT;
|
|
if (twl4030_wdt_set_timeout(wdt, new_margin))
|
|
return -EINVAL;
|
|
return put_user(wdt->timer_margin, p);
|
|
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(wdt->timer_margin, p);
|
|
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int twl4030_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);
|
|
|
|
/* /dev/watchdog can only be opened once */
|
|
if (test_and_set_bit(0, &wdt->state))
|
|
return -EBUSY;
|
|
|
|
wdt->state |= TWL4030_WDT_STATE_ACTIVE;
|
|
file->private_data = (void *) wdt;
|
|
|
|
twl4030_wdt_enable(wdt);
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int twl4030_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct twl4030_wdt *wdt = file->private_data;
|
|
if (nowayout) {
|
|
dev_alert(wdt->miscdev.parent,
|
|
"Unexpected close, watchdog still running!\n");
|
|
twl4030_wdt_enable(wdt);
|
|
} else {
|
|
if (twl4030_wdt_disable(wdt))
|
|
return -EFAULT;
|
|
wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
|
|
}
|
|
|
|
clear_bit(0, &wdt->state);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations twl4030_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.open = twl4030_wdt_open,
|
|
.release = twl4030_wdt_release,
|
|
.unlocked_ioctl = twl4030_wdt_ioctl,
|
|
.write = twl4030_wdt_write_fop,
|
|
};
|
|
|
|
static int __devinit twl4030_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
int ret = 0;
|
|
struct twl4030_wdt *wdt;
|
|
|
|
wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
|
|
if (!wdt)
|
|
return -ENOMEM;
|
|
|
|
wdt->state = 0;
|
|
wdt->timer_margin = 30;
|
|
wdt->miscdev.parent = &pdev->dev;
|
|
wdt->miscdev.fops = &twl4030_wdt_fops;
|
|
wdt->miscdev.minor = WATCHDOG_MINOR;
|
|
wdt->miscdev.name = "watchdog";
|
|
|
|
platform_set_drvdata(pdev, wdt);
|
|
|
|
twl4030_wdt_dev = pdev;
|
|
|
|
twl4030_wdt_disable(wdt);
|
|
|
|
ret = misc_register(&wdt->miscdev);
|
|
if (ret) {
|
|
dev_err(wdt->miscdev.parent,
|
|
"Failed to register misc device\n");
|
|
platform_set_drvdata(pdev, NULL);
|
|
kfree(wdt);
|
|
twl4030_wdt_dev = NULL;
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int __devexit twl4030_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
|
|
|
|
if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
|
|
if (twl4030_wdt_disable(wdt))
|
|
return -EFAULT;
|
|
|
|
wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
|
|
misc_deregister(&wdt->miscdev);
|
|
|
|
platform_set_drvdata(pdev, NULL);
|
|
kfree(wdt);
|
|
twl4030_wdt_dev = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
|
|
{
|
|
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
|
|
if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
|
|
return twl4030_wdt_disable(wdt);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int twl4030_wdt_resume(struct platform_device *pdev)
|
|
{
|
|
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
|
|
if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
|
|
return twl4030_wdt_enable(wdt);
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
#define twl4030_wdt_suspend NULL
|
|
#define twl4030_wdt_resume NULL
|
|
#endif
|
|
|
|
static struct platform_driver twl4030_wdt_driver = {
|
|
.probe = twl4030_wdt_probe,
|
|
.remove = __devexit_p(twl4030_wdt_remove),
|
|
.suspend = twl4030_wdt_suspend,
|
|
.resume = twl4030_wdt_resume,
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "twl4030_wdt",
|
|
},
|
|
};
|
|
|
|
module_platform_driver(twl4030_wdt_driver);
|
|
|
|
MODULE_AUTHOR("Nokia Corporation");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
MODULE_ALIAS("platform:twl4030_wdt");
|
|
|