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313 lines
7.1 KiB
313 lines
7.1 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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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 <[email protected]> |
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* |
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* Copyright (c) 1999 ITConsult-Pro Co. <[email protected]> |
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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 <[email protected]> |
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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 <[email protected]> |
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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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#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(struct timer_list *unused); |
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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); |
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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(struct timer_list *unused) |
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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 stream_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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.compat_ioctl = compat_ptr_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 <[email protected]>"); |
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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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