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![Jean Delvare](/assets/img/avatar_default.png)
I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements. Either the device is enumerated and the driver already has a module alias (e.g. PCI, USB etc.) that will get the right driver loaded automatically. Or the device is not enumerated and loading its driver will lead to more or less intrusive hardware poking. Such hardware poking should be limited to a bare minimum, so the user should really decide which drivers should be tried and in what order. Trying them all in arbitrary order can't do any good. On top of that, loading that many drivers at once bloats the kernel log. Also many drivers will stay loaded afterward, bloating the output of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets loaded as a dependency) can't even be unloaded! If defining char-major-10-130 is needed then it should happen in user-space. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Mike Frysinger <vapier.adi@gmail.com> Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk> Cc: Jim Cromie <jim.cromie@gmail.com>
509 lines
12 KiB
C
509 lines
12 KiB
C
/*
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* Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip
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*
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* (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
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*
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* -----------------------
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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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* -----------------------
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* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
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* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
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* 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
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* 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
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* from minutes to seconds.
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* 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
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* nwwatchdog_init.
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* 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
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* remove limitiation to be used on
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* Netwinders only
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <asm/mach-types.h>
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#define WATCHDOG_VERSION "0.04"
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#define WATCHDOG_NAME "Wdt977"
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#define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */
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#define IO_DATA_PORT (IO_INDEX_PORT + 1)
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#define UNLOCK_DATA 0x87
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#define LOCK_DATA 0xAA
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#define DEVICE_REGISTER 0x07
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#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
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static int timeout = DEFAULT_TIMEOUT;
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static int timeoutM; /* timeout in minutes */
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static unsigned long timer_alive;
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static int testmode;
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static char expect_close;
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static DEFINE_SPINLOCK(spinlock);
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
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__MODULE_STRING(DEFAULT_TIMEOUT) ")");
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module_param(testmode, int, 0);
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MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/*
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* Start the watchdog
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*/
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static int wdt977_start(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* unlock the SuperIO chip */
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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/* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
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* F2 has the timeout in minutes
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* F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
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* at timeout, and to reset timer on kbd/mouse activity (not impl.)
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* F4 is used to just clear the TIMEOUT'ed state (bit 0)
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*/
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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outb_p(0xF2, IO_INDEX_PORT);
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outb_p(timeoutM, IO_DATA_PORT);
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outb_p(0xF3, IO_INDEX_PORT);
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outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for
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kbd/mouse/LED */
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outb_p(0xF4, IO_INDEX_PORT);
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outb_p(0x00, IO_DATA_PORT);
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/* At last select device Aux1 (dev=7) and set GP16 as a
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* watchdog output. In test mode watch the bit 1 on F4 to
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* indicate "triggered"
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*/
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if (!testmode) {
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x07, IO_DATA_PORT);
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outb_p(0xE6, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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}
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/* lock the SuperIO chip */
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outb_p(LOCK_DATA, IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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pr_info("activated\n");
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return 0;
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}
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/*
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* Stop the watchdog
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*/
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static int wdt977_stop(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* unlock the SuperIO chip */
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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/* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
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* F3 is reset to its default state
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* F4 can clear the TIMEOUT'ed state (bit 0) - back to default
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* We can not use GP17 as a PowerLed, as we use its usage as a RedLed
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*/
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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outb_p(0xF2, IO_INDEX_PORT);
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outb_p(0xFF, IO_DATA_PORT);
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outb_p(0xF3, IO_INDEX_PORT);
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outb_p(0x00, IO_DATA_PORT);
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outb_p(0xF4, IO_INDEX_PORT);
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outb_p(0x00, IO_DATA_PORT);
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outb_p(0xF2, IO_INDEX_PORT);
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outb_p(0x00, IO_DATA_PORT);
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/* at last select device Aux1 (dev=7) and set
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GP16 as a watchdog output */
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x07, IO_DATA_PORT);
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outb_p(0xE6, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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/* lock the SuperIO chip */
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outb_p(LOCK_DATA, IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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pr_info("shutdown\n");
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return 0;
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}
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/*
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* Send a keepalive ping to the watchdog
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* This is done by simply re-writing the timeout to reg. 0xF2
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*/
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static int wdt977_keepalive(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* unlock the SuperIO chip */
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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/* select device Aux2 (device=8) and kicks watchdog reg F2 */
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/* F2 has the timeout in minutes */
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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outb_p(0xF2, IO_INDEX_PORT);
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outb_p(timeoutM, IO_DATA_PORT);
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/* lock the SuperIO chip */
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outb_p(LOCK_DATA, IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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return 0;
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}
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/*
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* Set the watchdog timeout value
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*/
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static int wdt977_set_timeout(int t)
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{
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int tmrval;
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/* convert seconds to minutes, rounding up */
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tmrval = (t + 59) / 60;
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if (machine_is_netwinder()) {
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/* we have a hw bug somewhere, so each 977 minute is actually
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* only 30sec. This limits the max timeout to half of device
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* max of 255 minutes...
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*/
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tmrval += tmrval;
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}
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if (tmrval < 1 || tmrval > 255)
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return -EINVAL;
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/* timeout is the timeout in seconds, timeoutM is
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the timeout in minutes) */
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timeout = t;
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timeoutM = tmrval;
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return 0;
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}
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/*
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* Get the watchdog status
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*/
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static int wdt977_get_status(int *status)
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{
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int new_status;
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unsigned long flags;
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spin_lock_irqsave(&spinlock, flags);
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/* unlock the SuperIO chip */
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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outb_p(UNLOCK_DATA, IO_INDEX_PORT);
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/* select device Aux2 (device=8) and read watchdog reg F4 */
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outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
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outb_p(0x08, IO_DATA_PORT);
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outb_p(0xF4, IO_INDEX_PORT);
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new_status = inb_p(IO_DATA_PORT);
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/* lock the SuperIO chip */
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outb_p(LOCK_DATA, IO_INDEX_PORT);
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spin_unlock_irqrestore(&spinlock, flags);
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*status = 0;
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if (new_status & 1)
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*status |= WDIOF_CARDRESET;
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return 0;
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}
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/*
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* /dev/watchdog handling
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*/
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static int wdt977_open(struct inode *inode, struct file *file)
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{
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/* If the watchdog is alive we don't need to start it again */
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if (test_and_set_bit(0, &timer_alive))
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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wdt977_start();
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return nonseekable_open(inode, file);
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}
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static int wdt977_release(struct inode *inode, struct file *file)
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{
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/*
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* Shut off the timer.
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* Lock it in if it's a module and we set nowayout
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*/
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if (expect_close == 42) {
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wdt977_stop();
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clear_bit(0, &timer_alive);
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} else {
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wdt977_keepalive();
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pr_crit("Unexpected close, not stopping watchdog!\n");
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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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/*
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* wdt977_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 wdt977_write(struct file *file, const char __user *buf,
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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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/* someone wrote to us, we should restart timer */
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wdt977_keepalive();
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}
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return count;
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}
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static const 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 = WATCHDOG_NAME,
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};
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/*
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* wdt977_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.
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*/
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static long wdt977_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int status;
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int new_options, retval = -EINVAL;
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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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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,
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sizeof(ident)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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wdt977_get_status(&status);
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return put_user(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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if (get_user(new_options, uarg.i))
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return -EFAULT;
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if (new_options & WDIOS_DISABLECARD) {
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wdt977_stop();
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retval = 0;
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}
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if (new_options & WDIOS_ENABLECARD) {
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wdt977_start();
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retval = 0;
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}
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return retval;
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case WDIOC_KEEPALIVE:
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wdt977_keepalive();
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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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if (wdt977_set_timeout(new_timeout))
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return -EINVAL;
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wdt977_keepalive();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(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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static int wdt977_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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wdt977_stop();
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return NOTIFY_DONE;
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}
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static const struct file_operations wdt977_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdt977_write,
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.unlocked_ioctl = wdt977_ioctl,
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.open = wdt977_open,
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.release = wdt977_release,
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};
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static struct miscdevice wdt977_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdt977_fops,
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};
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static struct notifier_block wdt977_notifier = {
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.notifier_call = wdt977_notify_sys,
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};
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static int __init wd977_init(void)
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{
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int rc;
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pr_info("driver v%s\n", WATCHDOG_VERSION);
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/* Check that the timeout value is within its range;
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if not reset to the default */
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if (wdt977_set_timeout(timeout)) {
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wdt977_set_timeout(DEFAULT_TIMEOUT);
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pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
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DEFAULT_TIMEOUT);
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}
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/* on Netwinder the IOports are already reserved by
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* arch/arm/mach-footbridge/netwinder-hw.c
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*/
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if (!machine_is_netwinder()) {
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if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
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pr_err("I/O address 0x%04x already in use\n",
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IO_INDEX_PORT);
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rc = -EIO;
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goto err_out;
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}
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}
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rc = register_reboot_notifier(&wdt977_notifier);
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if (rc) {
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pr_err("cannot register reboot notifier (err=%d)\n", rc);
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goto err_out_region;
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}
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rc = misc_register(&wdt977_miscdev);
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if (rc) {
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pr_err("cannot register miscdev on minor=%d (err=%d)\n",
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wdt977_miscdev.minor, rc);
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goto err_out_reboot;
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}
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pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
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timeout, nowayout, testmode);
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return 0;
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err_out_reboot:
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unregister_reboot_notifier(&wdt977_notifier);
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err_out_region:
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if (!machine_is_netwinder())
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release_region(IO_INDEX_PORT, 2);
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err_out:
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return rc;
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}
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static void __exit wd977_exit(void)
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{
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wdt977_stop();
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misc_deregister(&wdt977_miscdev);
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unregister_reboot_notifier(&wdt977_notifier);
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release_region(IO_INDEX_PORT, 2);
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}
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module_init(wd977_init);
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module_exit(wd977_exit);
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MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
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MODULE_DESCRIPTION("W83977AF Watchdog driver");
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MODULE_LICENSE("GPL");
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