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266 lines
5.3 KiB
266 lines
5.3 KiB
/* |
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* Watchdog driver for SBC-FITPC2 board |
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* |
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* Author: Denis Turischev <[email protected]> |
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* |
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* Adapted from the IXP2000 watchdog driver by Deepak Saxena. |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt |
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#include <linux/module.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/ioport.h> |
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#include <linux/delay.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include <linux/moduleparam.h> |
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#include <linux/dmi.h> |
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#include <linux/io.h> |
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#include <linux/uaccess.h> |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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static unsigned int margin = 60; /* (secs) Default is 1 minute */ |
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static unsigned long wdt_status; |
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static DEFINE_MUTEX(wdt_lock); |
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#define WDT_IN_USE 0 |
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#define WDT_OK_TO_CLOSE 1 |
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#define COMMAND_PORT 0x4c |
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#define DATA_PORT 0x48 |
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#define IFACE_ON_COMMAND 1 |
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#define REBOOT_COMMAND 2 |
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#define WATCHDOG_NAME "SBC-FITPC2 Watchdog" |
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static void wdt_send_data(unsigned char command, unsigned char data) |
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{ |
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outb(data, DATA_PORT); |
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msleep(200); |
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outb(command, COMMAND_PORT); |
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msleep(100); |
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} |
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static void wdt_enable(void) |
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{ |
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mutex_lock(&wdt_lock); |
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wdt_send_data(IFACE_ON_COMMAND, 1); |
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wdt_send_data(REBOOT_COMMAND, margin); |
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mutex_unlock(&wdt_lock); |
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} |
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static void wdt_disable(void) |
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{ |
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mutex_lock(&wdt_lock); |
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wdt_send_data(IFACE_ON_COMMAND, 0); |
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wdt_send_data(REBOOT_COMMAND, 0); |
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mutex_unlock(&wdt_lock); |
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} |
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static int fitpc2_wdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
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return -EBUSY; |
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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wdt_enable(); |
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return stream_open(inode, file); |
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} |
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static ssize_t fitpc2_wdt_write(struct file *file, const char __user *data, |
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size_t len, loff_t *ppos) |
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{ |
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size_t i; |
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if (!len) |
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return 0; |
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if (nowayout) { |
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len = 0; |
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goto out; |
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} |
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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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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set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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} |
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out: |
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wdt_enable(); |
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return len; |
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} |
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static const struct watchdog_info ident = { |
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.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | |
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WDIOF_KEEPALIVEPING, |
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.identity = WATCHDOG_NAME, |
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}; |
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static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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int ret = -ENOTTY; |
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int time; |
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switch (cmd) { |
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case WDIOC_GETSUPPORT: |
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ret = copy_to_user((struct watchdog_info __user *)arg, &ident, |
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sizeof(ident)) ? -EFAULT : 0; |
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break; |
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case WDIOC_GETSTATUS: |
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ret = put_user(0, (int __user *)arg); |
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break; |
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case WDIOC_GETBOOTSTATUS: |
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ret = put_user(0, (int __user *)arg); |
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break; |
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case WDIOC_KEEPALIVE: |
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wdt_enable(); |
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ret = 0; |
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break; |
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case WDIOC_SETTIMEOUT: |
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ret = get_user(time, (int __user *)arg); |
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if (ret) |
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break; |
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if (time < 31 || time > 255) { |
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ret = -EINVAL; |
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break; |
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} |
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margin = time; |
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wdt_enable(); |
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fallthrough; |
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case WDIOC_GETTIMEOUT: |
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ret = put_user(margin, (int __user *)arg); |
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break; |
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} |
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return ret; |
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} |
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static int fitpc2_wdt_release(struct inode *inode, struct file *file) |
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{ |
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if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { |
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wdt_disable(); |
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pr_info("Device disabled\n"); |
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} else { |
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pr_warn("Device closed unexpectedly - timer will not stop\n"); |
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wdt_enable(); |
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} |
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clear_bit(WDT_IN_USE, &wdt_status); |
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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return 0; |
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} |
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static const struct file_operations fitpc2_wdt_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = fitpc2_wdt_write, |
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.unlocked_ioctl = fitpc2_wdt_ioctl, |
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.compat_ioctl = compat_ptr_ioctl, |
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.open = fitpc2_wdt_open, |
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.release = fitpc2_wdt_release, |
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}; |
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static struct miscdevice fitpc2_wdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &fitpc2_wdt_fops, |
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}; |
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static int __init fitpc2_wdt_init(void) |
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{ |
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int err; |
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const char *brd_name; |
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brd_name = dmi_get_system_info(DMI_BOARD_NAME); |
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if (!brd_name || !strstr(brd_name, "SBC-FITPC2")) |
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return -ENODEV; |
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pr_info("%s found\n", brd_name); |
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if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) { |
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pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT); |
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return -EIO; |
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} |
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if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) { |
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pr_err("I/O address 0x%04x already in use\n", DATA_PORT); |
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err = -EIO; |
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goto err_data_port; |
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} |
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if (margin < 31 || margin > 255) { |
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pr_err("margin must be in range 31 - 255 seconds, you tried to set %d\n", |
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margin); |
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err = -EINVAL; |
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goto err_margin; |
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} |
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err = misc_register(&fitpc2_wdt_miscdev); |
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if (err) { |
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pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
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WATCHDOG_MINOR, err); |
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goto err_margin; |
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} |
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return 0; |
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err_margin: |
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release_region(DATA_PORT, 1); |
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err_data_port: |
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release_region(COMMAND_PORT, 1); |
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return err; |
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} |
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static void __exit fitpc2_wdt_exit(void) |
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{ |
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misc_deregister(&fitpc2_wdt_miscdev); |
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release_region(DATA_PORT, 1); |
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release_region(COMMAND_PORT, 1); |
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} |
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module_init(fitpc2_wdt_init); |
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module_exit(fitpc2_wdt_exit); |
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MODULE_AUTHOR("Denis Turischev <[email protected]>"); |
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MODULE_DESCRIPTION("SBC-FITPC2 Watchdog"); |
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module_param(margin, int, 0); |
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
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MODULE_LICENSE("GPL");
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