641 lines
15 KiB
C
641 lines
15 KiB
C
/*
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* Industrial Computer Source WDT500/501 driver
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*
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* (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
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* http://www.redhat.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
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*
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* Release 0.10.
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*
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* Fixes
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* Dave Gregorich : Modularisation and minor bugs
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* Alan Cox : Added the watchdog ioctl() stuff
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* Alan Cox : Fixed the reboot problem (as noted by
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* Matt Crocker).
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* Alan Cox : Added wdt= boot option
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* Alan Cox : Cleaned up copy/user stuff
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* Tim Hockin : Added insmod parameters, comment cleanup
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* Parameterized timeout
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* Tigran Aivazian : Restructured wdt_init() to handle failures
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* Joel Becker : Added WDIOC_GET/SETTIMEOUT
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* Matt Domsch : Added nowayout module option
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*/
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/ioport.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include "wd501p.h"
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static unsigned long wdt_is_open;
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static char expect_close;
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/*
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* Module parameters
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*/
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#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
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static int heartbeat = WD_TIMO;
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static int wd_heartbeat;
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")");
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/* You must set these - there is no sane way to probe for this board. */
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static int io=0x240;
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static int irq=11;
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module_param(io, int, 0);
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MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
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module_param(irq, int, 0);
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MODULE_PARM_DESC(irq, "WDT irq (default=11)");
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#ifdef CONFIG_WDT_501
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/* Support for the Fan Tachometer on the WDT501-P */
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static int tachometer;
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module_param(tachometer, int, 0);
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MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)");
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#endif /* CONFIG_WDT_501 */
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/*
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* Programming support
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*/
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static void wdt_ctr_mode(int ctr, int mode)
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{
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ctr<<=6;
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ctr|=0x30;
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ctr|=(mode<<1);
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outb_p(ctr, WDT_CR);
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}
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static void wdt_ctr_load(int ctr, int val)
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{
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outb_p(val&0xFF, WDT_COUNT0+ctr);
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outb_p(val>>8, WDT_COUNT0+ctr);
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}
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/**
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* wdt_start:
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*
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* Start the watchdog driver.
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*/
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static int wdt_start(void)
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{
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inb_p(WDT_DC); /* Disable watchdog */
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wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */
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wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */
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wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */
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wdt_ctr_load(0, 8948); /* Count at 100Hz */
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wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
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wdt_ctr_load(2,65535); /* Length of reset pulse */
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outb_p(0, WDT_DC); /* Enable watchdog */
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return 0;
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}
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/**
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* wdt_stop:
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*
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* Stop the watchdog driver.
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*/
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static int wdt_stop (void)
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{
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/* Turn the card off */
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inb_p(WDT_DC); /* Disable watchdog */
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wdt_ctr_load(2,0); /* 0 length reset pulses now */
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return 0;
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}
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/**
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* wdt_ping:
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*
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* Reload counter one with the watchdog heartbeat. We don't bother reloading
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* the cascade counter.
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*/
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static int wdt_ping(void)
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{
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/* Write a watchdog value */
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inb_p(WDT_DC); /* Disable watchdog */
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wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */
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wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
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outb_p(0, WDT_DC); /* Enable watchdog */
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return 0;
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}
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/**
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* wdt_set_heartbeat:
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* @t: the new heartbeat value that needs to be set.
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*
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* Set a new heartbeat value for the watchdog device. If the heartbeat value is
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* incorrect we keep the old value and return -EINVAL. If successfull we
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* return 0.
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*/
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static int wdt_set_heartbeat(int t)
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{
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if ((t < 1) || (t > 65535))
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return -EINVAL;
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heartbeat = t;
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wd_heartbeat = t * 100;
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return 0;
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}
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/**
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* wdt_get_status:
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* @status: the new status.
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*
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* Extract the status information from a WDT watchdog device. There are
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* several board variants so we have to know which bits are valid. Some
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* bits default to one and some to zero in order to be maximally painful.
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*
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* we then map the bits onto the status ioctl flags.
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*/
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static int wdt_get_status(int *status)
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{
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unsigned char new_status=inb_p(WDT_SR);
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*status=0;
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if (new_status & WDC_SR_ISOI0)
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*status |= WDIOF_EXTERN1;
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if (new_status & WDC_SR_ISII1)
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*status |= WDIOF_EXTERN2;
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#ifdef CONFIG_WDT_501
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if (!(new_status & WDC_SR_TGOOD))
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*status |= WDIOF_OVERHEAT;
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if (!(new_status & WDC_SR_PSUOVER))
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*status |= WDIOF_POWEROVER;
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if (!(new_status & WDC_SR_PSUUNDR))
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*status |= WDIOF_POWERUNDER;
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if (tachometer) {
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if (!(new_status & WDC_SR_FANGOOD))
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*status |= WDIOF_FANFAULT;
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}
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#endif /* CONFIG_WDT_501 */
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return 0;
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}
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#ifdef CONFIG_WDT_501
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/**
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* wdt_get_temperature:
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*
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* Reports the temperature in degrees Fahrenheit. The API is in
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* farenheit. It was designed by an imperial measurement luddite.
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*/
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static int wdt_get_temperature(int *temperature)
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{
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unsigned short c=inb_p(WDT_RT);
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*temperature = (c * 11 / 15) + 7;
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return 0;
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}
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#endif /* CONFIG_WDT_501 */
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/**
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* wdt_interrupt:
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* @irq: Interrupt number
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* @dev_id: Unused as we don't allow multiple devices.
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*
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* Handle an interrupt from the board. These are raised when the status
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* map changes in what the board considers an interesting way. That means
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* a failure condition occurring.
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*/
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static irqreturn_t wdt_interrupt(int irq, void *dev_id)
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{
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/*
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* Read the status register see what is up and
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* then printk it.
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*/
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unsigned char status=inb_p(WDT_SR);
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printk(KERN_CRIT "WDT status %d\n", status);
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#ifdef CONFIG_WDT_501
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if (!(status & WDC_SR_TGOOD))
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printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
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if (!(status & WDC_SR_PSUOVER))
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printk(KERN_CRIT "PSU over voltage.\n");
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if (!(status & WDC_SR_PSUUNDR))
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printk(KERN_CRIT "PSU under voltage.\n");
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if (tachometer) {
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if (!(status & WDC_SR_FANGOOD))
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printk(KERN_CRIT "Possible fan fault.\n");
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}
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#endif /* CONFIG_WDT_501 */
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if (!(status & WDC_SR_WCCR))
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#ifdef SOFTWARE_REBOOT
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#ifdef ONLY_TESTING
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printk(KERN_CRIT "Would Reboot.\n");
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#else
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printk(KERN_CRIT "Initiating system reboot.\n");
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emergency_restart();
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#endif
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#else
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printk(KERN_CRIT "Reset in 5ms.\n");
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#endif
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return IRQ_HANDLED;
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}
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/**
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* wdt_write:
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* @file: file handle to the watchdog
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* @buf: buffer to write (unused as data does not matter here
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* @count: count of bytes
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* @ppos: pointer to the position to write. No seeks allowed
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*
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* A write to a watchdog device is defined as a keepalive signal. Any
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* write of data will do, as we we don't define content meaning.
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*/
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static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
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{
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if(count) {
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if (!nowayout) {
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size_t i;
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/* In case it was set long ago */
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expect_close = 0;
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for (i = 0; i != count; i++) {
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char c;
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if (get_user(c, buf + i))
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return -EFAULT;
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if (c == 'V')
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expect_close = 42;
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}
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}
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wdt_ping();
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}
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return count;
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}
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/**
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* wdt_ioctl:
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* @inode: inode of the device
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* @file: file handle to the device
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* @cmd: watchdog command
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* @arg: argument pointer
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*
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* The watchdog API defines a common set of functions for all watchdogs
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* according to their available features. We only actually usefully support
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* querying capabilities and current status.
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*/
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static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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int new_heartbeat;
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int status;
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static struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT|
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WDIOF_MAGICCLOSE|
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WDIOF_KEEPALIVEPING,
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.firmware_version = 1,
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.identity = "WDT500/501",
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};
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/* Add options according to the card we have */
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ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
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#ifdef CONFIG_WDT_501
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ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
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if (tachometer)
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ident.options |= WDIOF_FANFAULT;
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#endif /* CONFIG_WDT_501 */
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switch(cmd)
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{
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default:
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return -ENOTTY;
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case WDIOC_GETSUPPORT:
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return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
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case WDIOC_GETSTATUS:
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wdt_get_status(&status);
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return put_user(status, p);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_KEEPALIVE:
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wdt_ping();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_heartbeat, p))
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return -EFAULT;
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if (wdt_set_heartbeat(new_heartbeat))
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return -EINVAL;
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wdt_ping();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(heartbeat, p);
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}
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}
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/**
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* wdt_open:
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* @inode: inode of device
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* @file: file handle to device
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*
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* The watchdog device has been opened. The watchdog device is single
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* open and on opening we load the counters. Counter zero is a 100Hz
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* cascade, into counter 1 which downcounts to reboot. When the counter
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* triggers counter 2 downcounts the length of the reset pulse which
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* set set to be as long as possible.
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*/
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static int wdt_open(struct inode *inode, struct file *file)
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{
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if(test_and_set_bit(0, &wdt_is_open))
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return -EBUSY;
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/*
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* Activate
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*/
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wdt_start();
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return nonseekable_open(inode, file);
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}
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/**
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* wdt_release:
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* @inode: inode to board
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* @file: file handle to board
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*
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* The watchdog has a configurable API. There is a religious dispute
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* between people who want their watchdog to be able to shut down and
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* those who want to be sure if the watchdog manager dies the machine
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* reboots. In the former case we disable the counters, in the latter
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* case you have to open it again very soon.
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*/
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static int wdt_release(struct inode *inode, struct file *file)
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{
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if (expect_close == 42) {
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wdt_stop();
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clear_bit(0, &wdt_is_open);
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} else {
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printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n");
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wdt_ping();
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}
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expect_close = 0;
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return 0;
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}
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#ifdef CONFIG_WDT_501
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/**
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* wdt_temp_read:
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* @file: file handle to the watchdog board
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* @buf: buffer to write 1 byte into
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* @count: length of buffer
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* @ptr: offset (no seek allowed)
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*
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* Temp_read reports the temperature in degrees Fahrenheit. The API is in
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* farenheit. It was designed by an imperial measurement luddite.
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*/
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static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
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{
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int temperature;
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if (wdt_get_temperature(&temperature))
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return -EFAULT;
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if (copy_to_user (buf, &temperature, 1))
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return -EFAULT;
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return 1;
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}
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/**
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* wdt_temp_open:
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* @inode: inode of device
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* @file: file handle to device
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*
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* The temperature device has been opened.
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*/
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static int wdt_temp_open(struct inode *inode, struct file *file)
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{
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return nonseekable_open(inode, file);
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}
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/**
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* wdt_temp_release:
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* @inode: inode to board
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* @file: file handle to board
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*
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* The temperature device has been closed.
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*/
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static int wdt_temp_release(struct inode *inode, struct file *file)
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{
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return 0;
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}
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#endif /* CONFIG_WDT_501 */
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/**
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* notify_sys:
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* @this: our notifier block
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* @code: the event being reported
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* @unused: unused
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*
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* Our notifier is called on system shutdowns. We want to turn the card
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* off at reboot otherwise the machine will reboot again during memory
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* test or worse yet during the following fsck. This would suck, in fact
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* trust me - if it happens it does suck.
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*/
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static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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if(code==SYS_DOWN || code==SYS_HALT) {
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/* Turn the card off */
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wdt_stop();
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}
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return NOTIFY_DONE;
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}
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/*
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* Kernel Interfaces
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*/
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static const struct file_operations wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdt_write,
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.ioctl = wdt_ioctl,
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.open = wdt_open,
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.release = wdt_release,
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};
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static struct miscdevice wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdt_fops,
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};
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#ifdef CONFIG_WDT_501
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static const struct file_operations wdt_temp_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = wdt_temp_read,
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.open = wdt_temp_open,
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.release = wdt_temp_release,
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};
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static struct miscdevice temp_miscdev = {
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.minor = TEMP_MINOR,
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.name = "temperature",
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.fops = &wdt_temp_fops,
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};
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#endif /* CONFIG_WDT_501 */
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/*
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* The WDT card needs to learn about soft shutdowns in order to
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* turn the timebomb registers off.
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*/
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static struct notifier_block wdt_notifier = {
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.notifier_call = wdt_notify_sys,
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};
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/**
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* cleanup_module:
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*
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* Unload the watchdog. You cannot do this with any file handles open.
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* If your watchdog is set to continue ticking on close and you unload
|
|
* it, well it keeps ticking. We won't get the interrupt but the board
|
|
* will not touch PC memory so all is fine. You just have to load a new
|
|
* module in 60 seconds or reboot.
|
|
*/
|
|
|
|
static void __exit wdt_exit(void)
|
|
{
|
|
misc_deregister(&wdt_miscdev);
|
|
#ifdef CONFIG_WDT_501
|
|
misc_deregister(&temp_miscdev);
|
|
#endif /* CONFIG_WDT_501 */
|
|
unregister_reboot_notifier(&wdt_notifier);
|
|
free_irq(irq, NULL);
|
|
release_region(io,8);
|
|
}
|
|
|
|
/**
|
|
* wdt_init:
|
|
*
|
|
* Set up the WDT watchdog board. All we have to do is grab the
|
|
* resources we require and bitch if anyone beat us to them.
|
|
* The open() function will actually kick the board off.
|
|
*/
|
|
|
|
static int __init wdt_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Check that the heartbeat value is within it's range ; if not reset to the default */
|
|
if (wdt_set_heartbeat(heartbeat)) {
|
|
wdt_set_heartbeat(WD_TIMO);
|
|
printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n",
|
|
WD_TIMO);
|
|
}
|
|
|
|
if (!request_region(io, 8, "wdt501p")) {
|
|
printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io);
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL);
|
|
if(ret) {
|
|
printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
|
|
goto outreg;
|
|
}
|
|
|
|
ret = register_reboot_notifier(&wdt_notifier);
|
|
if(ret) {
|
|
printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret);
|
|
goto outirq;
|
|
}
|
|
|
|
#ifdef CONFIG_WDT_501
|
|
ret = misc_register(&temp_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
|
|
TEMP_MINOR, ret);
|
|
goto outrbt;
|
|
}
|
|
#endif /* CONFIG_WDT_501 */
|
|
|
|
ret = misc_register(&wdt_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
|
|
WATCHDOG_MINOR, ret);
|
|
goto outmisc;
|
|
}
|
|
|
|
ret = 0;
|
|
printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
|
|
io, irq, heartbeat, nowayout);
|
|
#ifdef CONFIG_WDT_501
|
|
printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
|
|
#endif /* CONFIG_WDT_501 */
|
|
|
|
out:
|
|
return ret;
|
|
|
|
outmisc:
|
|
#ifdef CONFIG_WDT_501
|
|
misc_deregister(&temp_miscdev);
|
|
outrbt:
|
|
#endif /* CONFIG_WDT_501 */
|
|
unregister_reboot_notifier(&wdt_notifier);
|
|
outirq:
|
|
free_irq(irq, NULL);
|
|
outreg:
|
|
release_region(io,8);
|
|
goto out;
|
|
}
|
|
|
|
module_init(wdt_init);
|
|
module_exit(wdt_exit);
|
|
|
|
MODULE_AUTHOR("Alan Cox");
|
|
MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
MODULE_ALIAS_MISCDEV(TEMP_MINOR);
|
|
MODULE_LICENSE("GPL");
|