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7944d3a5a7
More coding style clean-up's. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
627 lines
15 KiB
C
627 lines
15 KiB
C
/*
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* SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x
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*
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* Based on acquirewdt.c by Alan Cox <alan@redhat.com>
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* and some other existing drivers
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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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* The authors do NOT admit liability nor provide warranty for
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* any of this software. This material is provided "AS-IS" in
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* the hope that it may be useful for others.
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*
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* (C) Copyright 2003-2006 Sven Anders <anders@anduras.de>
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*
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* History:
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* 2003 - Created version 1.0 for Linux 2.4.x.
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* 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
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* features. Released version 1.1
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*
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* Theory of operation:
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*
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* A Watchdog Timer (WDT) is a hardware circuit that can
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* reset the computer system in case of a software fault.
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* You probably knew that already.
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*
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* Usually a userspace daemon will notify the kernel WDT driver
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* via the /dev/watchdog special device file that userspace is
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* still alive, at regular intervals. When such a notification
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* occurs, the driver will usually tell the hardware watchdog
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* that everything is in order, and that the watchdog should wait
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* for yet another little while to reset the system.
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* If userspace fails (RAM error, kernel bug, whatever), the
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* notifications cease to occur, and the hardware watchdog will
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* reset the system (causing a reboot) after the timeout occurs.
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*
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* Create device with:
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* mknod /dev/watchdog c 10 130
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*
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* For an example userspace keep-alive daemon, see:
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* Documentation/watchdog/watchdog.txt
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*/
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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/delay.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 <linux/spinlock.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <asm/system.h>
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/* enable support for minutes as units? */
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/* (does not always work correctly, so disabled by default!) */
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#define SMSC_SUPPORT_MINUTES
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#undef SMSC_SUPPORT_MINUTES
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#define MAX_TIMEOUT 255
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#define UNIT_SECOND 0
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#define UNIT_MINUTE 1
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#define MODNAME "smsc37b787_wdt: "
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#define VERSION "1.1"
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#define IOPORT 0x3F0
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#define IOPORT_SIZE 2
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#define IODEV_NO 8
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static int unit = UNIT_SECOND; /* timer's unit */
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static int timeout = 60; /* timeout value: default is 60 "units" */
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static unsigned long timer_enabled; /* is the timer enabled? */
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static char expect_close; /* is the close expected? */
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static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
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static int nowayout = WATCHDOG_NOWAYOUT;
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/* -- Low level function ----------------------------------------*/
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/* unlock the IO chip */
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static inline void open_io_config(void)
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{
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outb(0x55, IOPORT);
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mdelay(1);
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outb(0x55, IOPORT);
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}
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/* lock the IO chip */
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static inline void close_io_config(void)
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{
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outb(0xAA, IOPORT);
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}
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/* select the IO device */
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static inline void select_io_device(unsigned char devno)
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{
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outb(0x07, IOPORT);
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outb(devno, IOPORT+1);
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}
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/* write to the control register */
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static inline void write_io_cr(unsigned char reg, unsigned char data)
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{
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outb(reg, IOPORT);
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outb(data, IOPORT+1);
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}
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/* read from the control register */
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static inline char read_io_cr(unsigned char reg)
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{
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outb(reg, IOPORT);
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return inb(IOPORT+1);
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}
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/* -- Medium level functions ------------------------------------*/
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static inline void gpio_bit12(unsigned char reg)
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{
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/* -- General Purpose I/O Bit 1.2 --
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* Bit 0, In/Out: 0 = Output, 1 = Input
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* Bit 1, Polarity: 0 = No Invert, 1 = Invert
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* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
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* Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17,
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* 11 = Either Edge Triggered Intr. 2
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* Bit 5/6 (Reserved)
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* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
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*/
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write_io_cr(0xE2, reg);
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}
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static inline void gpio_bit13(unsigned char reg)
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{
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/* -- General Purpose I/O Bit 1.3 --
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* Bit 0, In/Out: 0 = Output, 1 = Input
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* Bit 1, Polarity: 0 = No Invert, 1 = Invert
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* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
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* Bit 3, Function select: 0 = GPI/O, 1 = LED
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* Bit 4-6 (Reserved)
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* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
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*/
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write_io_cr(0xE3, reg);
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}
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static inline void wdt_timer_units(unsigned char new_units)
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{
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/* -- Watchdog timer units --
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* Bit 0-6 (Reserved)
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* Bit 7, WDT Time-out Value Units Select
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* (0 = Minutes, 1 = Seconds)
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*/
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write_io_cr(0xF1, new_units);
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}
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static inline void wdt_timeout_value(unsigned char new_timeout)
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{
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/* -- Watchdog Timer Time-out Value --
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* Bit 0-7 Binary coded units (0=Disabled, 1..255)
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*/
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write_io_cr(0xF2, new_timeout);
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}
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static inline void wdt_timer_conf(unsigned char conf)
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{
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/* -- Watchdog timer configuration --
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* Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon
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* Gameport I/O
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* Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
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* Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
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* Bit 3 Reset the timer
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* (Wrong in SMsC documentation? Given as: PowerLED Timout
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* Enabled)
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* Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
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* 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
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*/
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write_io_cr(0xF3, conf);
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}
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static inline void wdt_timer_ctrl(unsigned char reg)
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{
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/* -- Watchdog timer control --
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* Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occured
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* Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz
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* Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
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* Bit 3 P20 Force Timeout enabled:
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* 0 = P20 activity does not generate the WD timeout event
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* 1 = P20 Allows rising edge of P20, from the keyboard
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* controller, to force the WD timeout event.
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* Bit 4 (Reserved)
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* -- Soft power management --
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* Bit 5 Stop Counter: 1 = Stop software power down counter
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* set via register 0xB8, (self-cleaning)
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* (Upon read: 0 = Counter running, 1 = Counter stopped)
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* Bit 6 Restart Counter: 1 = Restart software power down counter
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* set via register 0xB8, (self-cleaning)
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* Bit 7 SPOFF: 1 = Force software power down (self-cleaning)
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*/
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write_io_cr(0xF4, reg);
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}
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/* -- Higher level functions ------------------------------------*/
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/* initialize watchdog */
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static void wb_smsc_wdt_initialize(void)
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{
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unsigned char old;
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spin_lock(&io_lock);
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open_io_config();
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select_io_device(IODEV_NO);
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/* enable the watchdog */
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gpio_bit13(0x08); /* Select pin 80 = LED not GPIO */
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gpio_bit12(0x0A); /* Set pin 79 = WDT not
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GPIO/Output/Polarity=Invert */
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/* disable the timeout */
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wdt_timeout_value(0);
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/* reset control register */
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wdt_timer_ctrl(0x00);
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/* reset configuration register */
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wdt_timer_conf(0x00);
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/* read old (timer units) register */
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old = read_io_cr(0xF1) & 0x7F;
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if (unit == UNIT_SECOND)
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old |= 0x80; /* set to seconds */
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/* set the watchdog timer units */
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wdt_timer_units(old);
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close_io_config();
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spin_unlock(&io_lock);
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}
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/* shutdown the watchdog */
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static void wb_smsc_wdt_shutdown(void)
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{
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spin_lock(&io_lock);
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open_io_config();
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select_io_device(IODEV_NO);
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/* disable the watchdog */
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gpio_bit13(0x09);
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gpio_bit12(0x09);
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/* reset watchdog config register */
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wdt_timer_conf(0x00);
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/* reset watchdog control register */
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wdt_timer_ctrl(0x00);
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/* disable timeout */
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wdt_timeout_value(0x00);
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close_io_config();
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spin_unlock(&io_lock);
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}
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/* set timeout => enable watchdog */
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static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)
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{
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spin_lock(&io_lock);
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open_io_config();
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select_io_device(IODEV_NO);
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/* set Power LED to blink, if we enable the timeout */
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wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02);
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/* set timeout value */
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wdt_timeout_value(new_timeout);
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close_io_config();
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spin_unlock(&io_lock);
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}
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/* get timeout */
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static unsigned char wb_smsc_wdt_get_timeout(void)
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{
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unsigned char set_timeout;
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spin_lock(&io_lock);
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open_io_config();
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select_io_device(IODEV_NO);
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set_timeout = read_io_cr(0xF2);
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close_io_config();
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spin_unlock(&io_lock);
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return set_timeout;
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}
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/* disable watchdog */
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static void wb_smsc_wdt_disable(void)
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{
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/* set the timeout to 0 to disable the watchdog */
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wb_smsc_wdt_set_timeout(0);
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}
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/* enable watchdog by setting the current timeout */
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static void wb_smsc_wdt_enable(void)
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{
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/* set the current timeout... */
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wb_smsc_wdt_set_timeout(timeout);
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}
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/* reset the timer */
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static void wb_smsc_wdt_reset_timer(void)
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{
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spin_lock(&io_lock);
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open_io_config();
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select_io_device(IODEV_NO);
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/* reset the timer */
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wdt_timeout_value(timeout);
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wdt_timer_conf(0x08);
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close_io_config();
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spin_unlock(&io_lock);
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}
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/* return, if the watchdog is enabled (timeout is set...) */
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static int wb_smsc_wdt_status(void)
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{
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return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING;
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}
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/* -- File operations -------------------------------------------*/
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/* open => enable watchdog and set initial timeout */
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static int wb_smsc_wdt_open(struct inode *inode, struct file *file)
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{
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/* /dev/watchdog can only be opened once */
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if (test_and_set_bit(0, &timer_enabled))
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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/* Reload and activate timer */
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wb_smsc_wdt_enable();
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printk(KERN_INFO MODNAME
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"Watchdog enabled. Timeout set to %d %s.\n",
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timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
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return nonseekable_open(inode, file);
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}
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/* close => shut off the timer */
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static int wb_smsc_wdt_release(struct inode *inode, struct file *file)
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{
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/* Shut off the timer. */
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if (expect_close == 42) {
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wb_smsc_wdt_disable();
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printk(KERN_INFO MODNAME
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"Watchdog disabled, sleeping again...\n");
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} else {
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printk(KERN_CRIT MODNAME
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"Unexpected close, not stopping watchdog!\n");
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wb_smsc_wdt_reset_timer();
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}
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clear_bit(0, &timer_enabled);
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expect_close = 0;
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return 0;
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}
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/* write => update the timer to keep the machine alive */
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static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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/* See if we got the magic character 'V' and reload the timer */
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if (len) {
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if (!nowayout) {
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size_t i;
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/* reset expect flag */
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expect_close = 0;
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/* scan to see whether or not we got the
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magic character */
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + 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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/* someone wrote to us, we should reload the timer */
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wb_smsc_wdt_reset_timer();
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}
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return len;
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}
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/* ioctl => control interface */
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static long wb_smsc_wdt_ioctl(struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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int new_timeout;
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union {
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struct watchdog_info __user *ident;
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int __user *i;
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} uarg;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING |
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WDIOF_SETTIMEOUT |
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WDIOF_MAGICCLOSE,
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.firmware_version = 0,
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.identity = "SMsC 37B787 Watchdog",
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};
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uarg.i = (int __user *)arg;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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return copy_to_user(uarg.ident, &ident, sizeof(ident))
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? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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return put_user(wb_smsc_wdt_status(), uarg.i);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, uarg.i);
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case WDIOC_SETOPTIONS:
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{
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int options, retval = -EINVAL;
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if (get_user(options, uarg.i))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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wb_smsc_wdt_disable();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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wb_smsc_wdt_enable();
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retval = 0;
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}
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return retval;
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}
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case WDIOC_KEEPALIVE:
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wb_smsc_wdt_reset_timer();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, uarg.i))
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return -EFAULT;
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/* the API states this is given in secs */
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if (unit == UNIT_MINUTE)
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new_timeout /= 60;
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if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
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return -EINVAL;
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timeout = new_timeout;
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wb_smsc_wdt_set_timeout(timeout);
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/* fall through and return the new timeout... */
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case WDIOC_GETTIMEOUT:
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new_timeout = timeout;
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if (unit == UNIT_MINUTE)
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new_timeout *= 60;
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return put_user(new_timeout, uarg.i);
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default:
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return -ENOTTY;
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}
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}
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/* -- Notifier funtions -----------------------------------------*/
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static int wb_smsc_wdt_notify_sys(struct notifier_block *this,
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unsigned long code, void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT) {
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/* set timeout to 0, to avoid possible race-condition */
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timeout = 0;
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wb_smsc_wdt_disable();
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}
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return NOTIFY_DONE;
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}
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/* -- Module's structures ---------------------------------------*/
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static const struct file_operations wb_smsc_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wb_smsc_wdt_write,
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.unlocked_ioctl = wb_smsc_wdt_ioctl,
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.open = wb_smsc_wdt_open,
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.release = wb_smsc_wdt_release,
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};
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static struct notifier_block wb_smsc_wdt_notifier = {
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.notifier_call = wb_smsc_wdt_notify_sys,
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};
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static struct miscdevice wb_smsc_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wb_smsc_wdt_fops,
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};
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/* -- Module init functions -------------------------------------*/
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/* module's "constructor" */
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static int __init wb_smsc_wdt_init(void)
|
|
{
|
|
int ret;
|
|
|
|
printk(KERN_INFO "SMsC 37B787 watchdog component driver "
|
|
VERSION " initialising...\n");
|
|
|
|
if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
|
|
printk(KERN_ERR MODNAME "Unable to register IO port %#x\n",
|
|
IOPORT);
|
|
ret = -EBUSY;
|
|
goto out_pnp;
|
|
}
|
|
|
|
/* set new maximum, if it's too big */
|
|
if (timeout > MAX_TIMEOUT)
|
|
timeout = MAX_TIMEOUT;
|
|
|
|
/* init the watchdog timer */
|
|
wb_smsc_wdt_initialize();
|
|
|
|
ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
if (ret) {
|
|
printk(KERN_ERR MODNAME
|
|
"Unable to register reboot notifier err = %d\n", ret);
|
|
goto out_io;
|
|
}
|
|
|
|
ret = misc_register(&wb_smsc_wdt_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR MODNAME
|
|
"Unable to register miscdev on minor %d\n",
|
|
WATCHDOG_MINOR);
|
|
goto out_rbt;
|
|
}
|
|
|
|
/* output info */
|
|
printk(KERN_INFO MODNAME "Timeout set to %d %s.\n",
|
|
timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
|
|
printk(KERN_INFO MODNAME
|
|
"Watchdog initialized and sleeping (nowayout=%d)...\n",
|
|
nowayout);
|
|
out_clean:
|
|
return ret;
|
|
|
|
out_rbt:
|
|
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
|
|
out_io:
|
|
release_region(IOPORT, IOPORT_SIZE);
|
|
|
|
out_pnp:
|
|
goto out_clean;
|
|
}
|
|
|
|
/* module's "destructor" */
|
|
|
|
static void __exit wb_smsc_wdt_exit(void)
|
|
{
|
|
/* Stop the timer before we leave */
|
|
if (!nowayout) {
|
|
wb_smsc_wdt_shutdown();
|
|
printk(KERN_INFO MODNAME "Watchdog disabled.\n");
|
|
}
|
|
|
|
misc_deregister(&wb_smsc_wdt_miscdev);
|
|
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
|
|
release_region(IOPORT, IOPORT_SIZE);
|
|
|
|
printk(KERN_INFO "SMsC 37B787 watchdog component driver removed.\n");
|
|
}
|
|
|
|
module_init(wb_smsc_wdt_init);
|
|
module_exit(wb_smsc_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
|
|
MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version "
|
|
VERSION ")");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
|
|
#ifdef SMSC_SUPPORT_MINUTES
|
|
module_param(unit, int, 0);
|
|
MODULE_PARM_DESC(unit,
|
|
"set unit to use, 0=seconds or 1=minutes, default is 0");
|
|
#endif
|
|
|
|
module_param(timeout, int, 0);
|
|
MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");
|
|
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|