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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>
317 lines
7.3 KiB
C
317 lines
7.3 KiB
C
/*
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* MixCom Watchdog: A Simple Hardware Watchdog Device
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* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
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*
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* Author: Gergely Madarasz <gorgo@itc.hu>
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*
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* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
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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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* Version 0.1 (99/04/15):
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* - first version
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*
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* Version 0.2 (99/06/16):
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* - added kernel timer watchdog ping after close
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* since the hardware does not support watchdog shutdown
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*
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* Version 0.3 (99/06/21):
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* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
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*
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* Version 0.3.1 (99/06/22):
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* - allow module removal while internal timer is active,
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* print warning about probable reset
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*
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* Version 0.4 (99/11/15):
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* - support for one more type board
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*
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* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
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* - added nowayout module option to override
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* CONFIG_WATCHDOG_NOWAYOUT
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*
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* Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
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* - make mixcomwd_opened unsigned,
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* removed lock_kernel/unlock_kernel from mixcomwd_release,
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* modified ioctl a bit to conform to API
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#define VERSION "0.6"
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#define WATCHDOG_NAME "mixcomwd"
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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/ioport.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/timer.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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/*
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* We have two types of cards that can be probed:
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* 1) The Mixcom cards: these cards can be found at addresses
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* 0x180, 0x280, 0x380 with an additional offset of 0xc10.
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* (Or 0xd90, 0xe90, 0xf90).
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* 2) The FlashCOM cards: these cards can be set up at
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* 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
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* (Or 0x304 -> 0x37c in 0x8 jumps).
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* Each card has it's own ID.
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*/
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#define MIXCOM_ID 0x11
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#define FLASHCOM_ID 0x18
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static struct {
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int ioport;
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int id;
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} mixcomwd_io_info[] = {
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/* The Mixcom cards */
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{0x0d90, MIXCOM_ID},
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{0x0e90, MIXCOM_ID},
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{0x0f90, MIXCOM_ID},
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/* The FlashCOM cards */
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{0x0304, FLASHCOM_ID},
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{0x030c, FLASHCOM_ID},
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{0x0314, FLASHCOM_ID},
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{0x031c, FLASHCOM_ID},
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{0x0324, FLASHCOM_ID},
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{0x032c, FLASHCOM_ID},
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{0x0334, FLASHCOM_ID},
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{0x033c, FLASHCOM_ID},
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{0x0344, FLASHCOM_ID},
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{0x034c, FLASHCOM_ID},
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{0x0354, FLASHCOM_ID},
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{0x035c, FLASHCOM_ID},
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{0x0364, FLASHCOM_ID},
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{0x036c, FLASHCOM_ID},
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{0x0374, FLASHCOM_ID},
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{0x037c, FLASHCOM_ID},
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/* The end of the list */
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{0x0000, 0},
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};
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static void mixcomwd_timerfun(unsigned long d);
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static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
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static int watchdog_port;
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static int mixcomwd_timer_alive;
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static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
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static char expect_close;
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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 void mixcomwd_ping(void)
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{
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outb_p(55, watchdog_port);
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return;
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}
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static void mixcomwd_timerfun(unsigned long d)
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{
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mixcomwd_ping();
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mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
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}
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/*
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* Allow only one person to hold it open
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*/
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static int mixcomwd_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &mixcomwd_opened))
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return -EBUSY;
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mixcomwd_ping();
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if (nowayout)
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/*
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* fops_get() code via open() has already done
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* a try_module_get() so it is safe to do the
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* __module_get().
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*/
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__module_get(THIS_MODULE);
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else {
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if (mixcomwd_timer_alive) {
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del_timer(&mixcomwd_timer);
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mixcomwd_timer_alive = 0;
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}
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}
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return nonseekable_open(inode, file);
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}
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static int mixcomwd_release(struct inode *inode, struct file *file)
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{
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if (expect_close == 42) {
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if (mixcomwd_timer_alive) {
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pr_err("release called while internal timer alive\n");
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return -EBUSY;
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}
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mixcomwd_timer_alive = 1;
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mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
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} else
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pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
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clear_bit(0, &mixcomwd_opened);
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expect_close = 0;
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return 0;
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}
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static ssize_t mixcomwd_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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if (len) {
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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 != 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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mixcomwd_ping();
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}
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return len;
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}
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static long mixcomwd_ioctl(struct file *file,
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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 status;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.firmware_version = 1,
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.identity = "MixCOM watchdog",
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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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status = mixcomwd_opened;
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if (!nowayout)
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status |= mixcomwd_timer_alive;
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return put_user(status, p);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_KEEPALIVE:
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mixcomwd_ping();
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break;
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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 const struct file_operations mixcomwd_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = mixcomwd_write,
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.unlocked_ioctl = mixcomwd_ioctl,
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.open = mixcomwd_open,
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.release = mixcomwd_release,
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};
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static struct miscdevice mixcomwd_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &mixcomwd_fops,
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};
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static int __init checkcard(int port, int card_id)
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{
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int id;
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if (!request_region(port, 1, "MixCOM watchdog"))
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return 0;
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id = inb_p(port);
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if (card_id == MIXCOM_ID)
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id &= 0x3f;
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if (id != card_id) {
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release_region(port, 1);
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return 0;
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}
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return 1;
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}
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static int __init mixcomwd_init(void)
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{
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int i, ret, found = 0;
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for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
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if (checkcard(mixcomwd_io_info[i].ioport,
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mixcomwd_io_info[i].id)) {
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found = 1;
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watchdog_port = mixcomwd_io_info[i].ioport;
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}
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}
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if (!found) {
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pr_err("No card detected, or port not available\n");
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return -ENODEV;
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}
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ret = misc_register(&mixcomwd_miscdev);
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if (ret) {
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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 error_misc_register_watchdog;
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}
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pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
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VERSION, watchdog_port);
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return 0;
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error_misc_register_watchdog:
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release_region(watchdog_port, 1);
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watchdog_port = 0x0000;
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return ret;
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}
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static void __exit mixcomwd_exit(void)
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{
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if (!nowayout) {
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if (mixcomwd_timer_alive) {
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pr_warn("I quit now, hardware will probably reboot!\n");
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del_timer_sync(&mixcomwd_timer);
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mixcomwd_timer_alive = 0;
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}
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}
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misc_deregister(&mixcomwd_miscdev);
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release_region(watchdog_port, 1);
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}
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module_init(mixcomwd_init);
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module_exit(mixcomwd_exit);
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MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
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MODULE_DESCRIPTION("MixCom Watchdog driver");
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MODULE_VERSION(VERSION);
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MODULE_LICENSE("GPL");
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