forked from Minki/linux
487722cf2d
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>
461 lines
9.7 KiB
C
461 lines
9.7 KiB
C
/*
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* w83697hf/hg WDT driver
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*
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* (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
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* (c) Copyright 2006 Marcus Junker <junker@anduras.de>
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*
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* Based on w83627hf_wdt.c which is based on advantechwdt.c
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* which is based on wdt.c.
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* Original copyright messages:
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*
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* (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
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*
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* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
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*
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* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
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* All Rights Reserved.
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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 Marcus Junker nor ANDURAS AG 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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#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/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 <linux/spinlock.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#define WATCHDOG_NAME "w83697hf/hg WDT"
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#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
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#define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */
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static unsigned long wdt_is_open;
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static char expect_close;
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static DEFINE_SPINLOCK(io_lock);
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/* You must set this - there is no sane way to probe for this board. */
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static int wdt_io = 0x2e;
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module_param(wdt_io, int, 0);
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MODULE_PARM_DESC(wdt_io,
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"w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
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static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. 1<= timeout <=255 (default="
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__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
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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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static int early_disable = WATCHDOG_EARLY_DISABLE;
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module_param(early_disable, int, 0);
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MODULE_PARM_DESC(early_disable,
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"Watchdog gets disabled at boot time (default="
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__MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")");
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/*
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* Kernel methods.
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*/
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#define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */
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#define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register
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(same as EFER) */
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#define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */
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static inline void w83697hf_unlock(void)
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{
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outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
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outb_p(0x87, W83697HF_EFER); /* Again according to manual */
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}
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static inline void w83697hf_lock(void)
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{
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outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
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}
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/*
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* The three functions w83697hf_get_reg(), w83697hf_set_reg() and
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* w83697hf_write_timeout() must be called with the device unlocked.
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*/
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static unsigned char w83697hf_get_reg(unsigned char reg)
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{
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outb_p(reg, W83697HF_EFIR);
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return inb_p(W83697HF_EFDR);
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}
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static void w83697hf_set_reg(unsigned char reg, unsigned char data)
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{
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outb_p(reg, W83697HF_EFIR);
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outb_p(data, W83697HF_EFDR);
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}
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static void w83697hf_write_timeout(int timeout)
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{
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/* Write Timeout counter to CRF4 */
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w83697hf_set_reg(0xF4, timeout);
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}
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static void w83697hf_select_wdt(void)
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{
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w83697hf_unlock();
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w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
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}
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static inline void w83697hf_deselect_wdt(void)
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{
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w83697hf_lock();
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}
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static void w83697hf_init(void)
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{
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unsigned char bbuf;
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w83697hf_select_wdt();
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bbuf = w83697hf_get_reg(0x29);
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bbuf &= ~0x60;
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bbuf |= 0x20;
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/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
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w83697hf_set_reg(0x29, bbuf);
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bbuf = w83697hf_get_reg(0xF3);
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bbuf &= ~0x04;
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w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
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w83697hf_deselect_wdt();
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}
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static void wdt_ping(void)
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{
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spin_lock(&io_lock);
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w83697hf_select_wdt();
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w83697hf_write_timeout(timeout);
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w83697hf_deselect_wdt();
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spin_unlock(&io_lock);
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}
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static void wdt_enable(void)
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{
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spin_lock(&io_lock);
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w83697hf_select_wdt();
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w83697hf_write_timeout(timeout);
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w83697hf_set_reg(0x30, 1); /* Enable timer */
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w83697hf_deselect_wdt();
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spin_unlock(&io_lock);
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}
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static void wdt_disable(void)
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{
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spin_lock(&io_lock);
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w83697hf_select_wdt();
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w83697hf_set_reg(0x30, 0); /* Disable timer */
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w83697hf_write_timeout(0);
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w83697hf_deselect_wdt();
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spin_unlock(&io_lock);
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}
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static unsigned char wdt_running(void)
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{
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unsigned char t;
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spin_lock(&io_lock);
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w83697hf_select_wdt();
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t = w83697hf_get_reg(0xF4); /* Read timer */
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w83697hf_deselect_wdt();
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spin_unlock(&io_lock);
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return t;
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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 > 255)
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return -EINVAL;
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timeout = t;
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return 0;
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}
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static ssize_t wdt_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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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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static long wdt_ioctl(struct file *file, unsigned int cmd, 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_timeout;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
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| WDIOF_MAGICCLOSE,
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.firmware_version = 1,
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.identity = "W83697HF WDT",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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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, p))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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wdt_disable();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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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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wdt_ping();
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break;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, p))
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return -EFAULT;
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if (wdt_set_heartbeat(new_timeout))
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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(timeout, p);
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default:
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return -ENOTTY;
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}
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return 0;
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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_enable();
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return nonseekable_open(inode, file);
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}
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static int wdt_close(struct inode *inode, struct file *file)
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{
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if (expect_close == 42)
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wdt_disable();
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else {
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pr_crit("Unexpected close, not stopping watchdog!\n");
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wdt_ping();
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}
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expect_close = 0;
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clear_bit(0, &wdt_is_open);
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return 0;
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}
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/*
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* Notifier for system down
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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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wdt_disable(); /* Turn the WDT off */
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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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.unlocked_ioctl = wdt_ioctl,
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.open = wdt_open,
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.release = wdt_close,
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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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/*
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* The WDT 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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static int w83697hf_check_wdt(void)
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{
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if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
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pr_err("I/O address 0x%x already in use\n", wdt_io);
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return -EIO;
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}
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pr_debug("Looking for watchdog at address 0x%x\n", wdt_io);
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w83697hf_unlock();
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if (w83697hf_get_reg(0x20) == 0x60) {
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pr_info("watchdog found at address 0x%x\n", wdt_io);
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w83697hf_lock();
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return 0;
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}
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/* Reprotect in case it was a compatible device */
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w83697hf_lock();
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pr_info("watchdog not found at address 0x%x\n", wdt_io);
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release_region(wdt_io, 2);
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return -EIO;
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}
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static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
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static int __init wdt_init(void)
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{
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int ret, i, found = 0;
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pr_info("WDT driver for W83697HF/HG initializing\n");
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if (wdt_io == 0) {
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/* we will autodetect the W83697HF/HG watchdog */
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for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
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wdt_io = w83697hf_ioports[i];
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if (!w83697hf_check_wdt())
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found++;
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}
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} else {
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if (!w83697hf_check_wdt())
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found++;
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}
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if (!found) {
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pr_err("No W83697HF/HG could be found\n");
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ret = -EIO;
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goto out;
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}
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w83697hf_init();
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if (early_disable) {
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if (wdt_running())
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pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
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wdt_disable();
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}
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if (wdt_set_heartbeat(timeout)) {
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wdt_set_heartbeat(WATCHDOG_TIMEOUT);
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pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
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WATCHDOG_TIMEOUT);
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}
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ret = register_reboot_notifier(&wdt_notifier);
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if (ret != 0) {
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pr_err("cannot register reboot notifier (err=%d)\n", ret);
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goto unreg_regions;
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}
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ret = misc_register(&wdt_miscdev);
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if (ret != 0) {
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pr_err("cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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goto unreg_reboot;
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}
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pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
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timeout, nowayout);
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out:
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return ret;
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unreg_reboot:
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unregister_reboot_notifier(&wdt_notifier);
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unreg_regions:
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release_region(wdt_io, 2);
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goto out;
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}
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static void __exit wdt_exit(void)
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{
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misc_deregister(&wdt_miscdev);
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unregister_reboot_notifier(&wdt_notifier);
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release_region(wdt_io, 2);
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}
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module_init(wdt_init);
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module_exit(wdt_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, "
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"Samuel Tardieu <sam@rfc1149.net>");
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MODULE_DESCRIPTION("w83697hf/hg WDT driver");
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