cregit-Linux how code gets into the kernel

Release 4.14 drivers/watchdog/sbc_epx_c3.c

Directory: drivers/watchdog
/*
 *      SBC EPX C3 0.1  A Hardware Watchdog Device for the Winsystems EPX-C3
 *      single board computer
 *
 *      (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights
 *      Reserved.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *      based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/uaccess.h>
#include <linux/io.h>


static int epx_c3_alive;


#define WATCHDOG_TIMEOUT 1		
/* 1 sec default timeout */


static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
					__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


#define EPXC3_WATCHDOG_CTL_REG 0x1ee 
/* write 1 to enable, 0 to disable */

#define EPXC3_WATCHDOG_PET_REG 0x1ef 
/* write anything to pet once enabled */


static void epx_c3_start(void) { outb(1, EPXC3_WATCHDOG_CTL_REG); }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu15100.00%1100.00%
Total15100.00%1100.00%


static void epx_c3_stop(void) { outb(0, EPXC3_WATCHDOG_CTL_REG); pr_info("Stopped watchdog timer\n"); }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu1785.00%150.00%
Joe Perches315.00%150.00%
Total20100.00%2100.00%


static void epx_c3_pet(void) { outb(1, EPXC3_WATCHDOG_PET_REG); }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu15100.00%1100.00%
Total15100.00%1100.00%

/* * Allow only one person to hold it open */
static int epx_c3_open(struct inode *inode, struct file *file) { if (epx_c3_alive) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate timer */ epx_c3_start(); epx_c3_pet(); epx_c3_alive = 1; pr_info("Started watchdog timer\n"); return nonseekable_open(inode, file); }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu5596.49%150.00%
Joe Perches23.51%150.00%
Total57100.00%2100.00%


static int epx_c3_release(struct inode *inode, struct file *file) { /* Shut off the timer. * Lock it in if it's a module and we defined ...NOWAYOUT */ if (!nowayout) epx_c3_stop(); /* Turn the WDT off */ epx_c3_alive = 0; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu33100.00%1100.00%
Total33100.00%1100.00%


static ssize_t epx_c3_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { /* Refresh the timer. */ if (len) epx_c3_pet(); return len; }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu3497.14%150.00%
Al Viro12.86%150.00%
Total35100.00%2100.00%


static long epx_c3_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int options, retval = -EINVAL; int __user *argp = (void __user *)arg; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING, .firmware_version = 0, .identity = "Winsystems EPX-C3 H/W Watchdog", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; return 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, argp); case WDIOC_SETOPTIONS: if (get_user(options, argp)) return -EFAULT; if (options & WDIOS_DISABLECARD) { epx_c3_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { epx_c3_start(); retval = 0; } return retval; case WDIOC_KEEPALIVE: epx_c3_pet(); return 0; case WDIOC_GETTIMEOUT: return put_user(WATCHDOG_TIMEOUT, argp); default: return -ENOTTY; } }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu14379.01%120.00%
Wim Van Sebroeck2011.05%120.00%
Al Viro158.29%120.00%
Alan Cox21.10%120.00%
Samuel Tardieu10.55%120.00%
Total181100.00%5100.00%


static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) epx_c3_stop(); /* Turn the WDT off */ return NOTIFY_DONE; }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu36100.00%1100.00%
Total36100.00%1100.00%

static const struct file_operations epx_c3_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = epx_c3_write, .unlocked_ioctl = epx_c3_ioctl, .open = epx_c3_open, .release = epx_c3_release, }; static struct miscdevice epx_c3_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &epx_c3_fops, }; static struct notifier_block epx_c3_notifier = { .notifier_call = epx_c3_notify_sys, };
static int __init watchdog_init(void) { int ret; if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog")) return -EBUSY; ret = register_reboot_notifier(&epx_c3_notifier); if (ret) { pr_err("cannot register reboot notifier (err=%d)\n", ret); goto out; } ret = misc_register(&epx_c3_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); unregister_reboot_notifier(&epx_c3_notifier); goto out; } pr_info("Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n"); return 0; out: release_region(EPXC3_WATCHDOG_CTL_REG, 2); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu5956.73%133.33%
Alan Cox3432.69%133.33%
Joe Perches1110.58%133.33%
Total104100.00%3100.00%


static void __exit watchdog_exit(void) { misc_deregister(&epx_c3_miscdev); unregister_reboot_notifier(&epx_c3_notifier); release_region(EPXC3_WATCHDOG_CTL_REG, 2); }

Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu2175.00%150.00%
Alan Cox725.00%150.00%
Total28100.00%2100.00%

module_init(watchdog_init); module_exit(watchdog_exit); MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>"); MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. " "Note that there is no way to probe for this device -- " "so only use it if you are *sure* you are running on this specific " "SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Calin A. Culianu59982.96%17.69%
Alan Cox506.93%323.08%
Wim Van Sebroeck314.29%430.77%
Joe Perches233.19%17.69%
Al Viro162.22%17.69%
Samuel Tardieu10.14%17.69%
Arjan van de Ven10.14%17.69%
Justin P. Mattock10.14%17.69%
Total722100.00%13100.00%
Directory: drivers/watchdog
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.