linux/drivers/char/watchdog/ixp2000_wdt.c
Yoann Padioleau 632155e659 potential parse error in ifdef
I have made a tool to parse the kernel that does not pre-process the
source.  That means that my parser tries to parse all the code, including
code in the #else branch or code that is not often compiled because the
driver is not very used (or not used at all).  So, my parser sometimes
reports parse error not originally detected by gcc.  Here is my (first)
patch.

[akpm@linux-foundation.org: fix amd8111e.c]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Jeff Garzik <jeff@garzik.org>
Acked-by: James Bottomley <James.Bottomley@steeleye.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:27 -07:00

219 lines
4.6 KiB
C

/*
* drivers/char/watchdog/ixp2000_wdt.c
*
* Watchdog driver for Intel IXP2000 network processors
*
* Adapted from the IXP4xx watchdog driver by Lennert Buytenhek.
* The original version carries these notices:
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2004 (c) MontaVista, Software, Inc.
* Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
*
* 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/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
static int nowayout = WATCHDOG_NOWAYOUT;
static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */
static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
static unsigned long wdt_tick_rate;
static void
wdt_enable(void)
{
ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE);
ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE);
ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE);
}
static void
wdt_disable(void)
{
ixp2000_reg_write(IXP2000_T4_CTL, 0);
}
static void
wdt_keepalive(void)
{
ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
}
static int
ixp2000_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
wdt_enable();
return nonseekable_open(inode, file);
}
static ssize_t
ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
}
wdt_keepalive();
}
return len;
}
static struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = "IXP2000 Watchdog",
};
static int
ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (time <= 0 || time > 60) {
ret = -EINVAL;
break;
}
heartbeat = time;
wdt_keepalive();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(heartbeat, (int *)arg);
break;
case WDIOC_KEEPALIVE:
wdt_enable();
ret = 0;
break;
}
return ret;
}
static int
ixp2000_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
wdt_disable();
} else {
printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
"timer will not stop\n");
}
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations ixp2000_wdt_fops =
{
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = ixp2000_wdt_write,
.ioctl = ixp2000_wdt_ioctl,
.open = ixp2000_wdt_open,
.release = ixp2000_wdt_release,
};
static struct miscdevice ixp2000_wdt_miscdev =
{
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ixp2000_wdt_fops,
};
static int __init ixp2000_wdt_init(void)
{
if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) {
printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n");
return -EIO;
}
wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256;
return misc_register(&ixp2000_wdt_miscdev);
}
static void __exit ixp2000_wdt_exit(void)
{
misc_deregister(&ixp2000_wdt_miscdev);
}
module_init(ixp2000_wdt_init);
module_exit(ixp2000_wdt_exit);
MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);