+++ /dev/null
-/*
- * 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.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/timer.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 <linux/uaccess.h>
-#include <mach/hardware.h>
-
-static bool nowayout = WATCHDOG_NOWAYOUT;
-static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */
-static unsigned long wdt_status;
-static DEFINE_SPINLOCK(wdt_lock);
-
-#define WDT_IN_USE 0
-#define WDT_OK_TO_CLOSE 1
-
-static unsigned long wdt_tick_rate;
-
-static void wdt_enable(void)
-{
- spin_lock(&wdt_lock);
- 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);
- spin_unlock(&wdt_lock);
-}
-
-static void wdt_disable(void)
-{
- spin_lock(&wdt_lock);
- ixp2000_reg_write(IXP2000_T4_CTL, 0);
- spin_unlock(&wdt_lock);
-}
-
-static void wdt_keepalive(void)
-{
- spin_lock(&wdt_lock);
- ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
- spin_unlock(&wdt_lock);
-}
-
-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 const struct watchdog_info ident = {
- .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
- WDIOF_KEEPALIVEPING,
- .identity = "IXP2000 Watchdog",
-};
-
-static long ixp2000_wdt_ioctl(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_KEEPALIVE:
- wdt_enable();
- ret = 0;
- 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;
- }
-
- 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
- pr_crit("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,
- .unlocked_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) {
- pr_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, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
-
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-
projects / mirror_ubuntu-eoan-kernel.git / commitdiff