cregit-Linux how code gets into the kernel

Release 4.10 drivers/watchdog/wafer5823wdt.c

Directory: drivers/watchdog
/*
 *      ICP Wafer 5823 Single Board Computer WDT driver
 *      http://www.icpamerica.com/wafer_5823.php
 *      May also work on other similar models
 *
 *      (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
 *
 *      Release 0.02
 *
 *      Based on advantechwdt.c which is based on wdt.c.
 *      Original copyright messages:
 *
 *      (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
 *                                              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.
 *
 *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *      warranty for any of this software. This material is provided
 *      "AS-IS" and at no charge.
 *
 *      (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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


#define WATCHDOG_NAME "Wafer 5823 WDT"

#define PFX WATCHDOG_NAME ": "

#define WD_TIMO 60			
/* 60 sec default timeout */


static unsigned long wafwdt_is_open;

static char expect_close;
static DEFINE_SPINLOCK(wafwdt_lock);

/*
 *      You must set these - there is no sane way to probe for this board.
 *
 *      To enable, write the timeout value in seconds (1 to 255) to I/O
 *      port WDT_START, then read the port to start the watchdog. To pat
 *      the dog, read port WDT_STOP to stop the timer, then read WDT_START
 *      to restart it again.
 */


static int wdt_stop = 0x843;

static int wdt_start = 0x443;


static int timeout = WD_TIMO;  
/* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
				__MODULE_STRING(WD_TIMO) ".");


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) ")");


static void wafwdt_ping(void) { /* pat watchdog */ spin_lock(&wafwdt_lock); inb_p(wdt_stop); inb_p(wdt_start); spin_unlock(&wafwdt_lock); }

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dave jonesdave jones2993.55%150.00%
wim van sebroeckwim van sebroeck26.45%150.00%
Total31100.00%2100.00%


static void wafwdt_start(void) { /* start up watchdog */ outb_p(timeout, wdt_start); inb_p(wdt_start); }

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dave jonesdave jones1885.71%150.00%
wim van sebroeckwim van sebroeck314.29%150.00%
Total21100.00%2100.00%


static void wafwdt_stop(void) { /* stop watchdog */ inb_p(wdt_stop); }

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dave jonesdave jones1392.86%150.00%
wim van sebroeckwim van sebroeck17.14%150.00%
Total14100.00%2100.00%


static ssize_t wafwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { /* See if we got the magic character 'V' and reload the timer */ if (count) { if (!nowayout) { size_t i; /* In case it was set long ago */ expect_close = 0; /* scan to see whether or not we got the magic character */ for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } /* Well, anyhow someone wrote to us, we should return that favour */ wafwdt_ping(); } return count; }

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dave jonesdave jones9193.81%240.00%
wim van sebroeckwim van sebroeck33.09%120.00%
alan coxalan cox22.06%120.00%
al viroal viro11.03%120.00%
Total97100.00%5100.00%


static long wafwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int new_timeout; void __user *argp = (void __user *)arg; int __user *p = argp; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "Wafer 5823 WDT", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_SETOPTIONS: { int options, retval = -EINVAL; if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { wafwdt_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { wafwdt_start(); retval = 0; } return retval; } case WDIOC_KEEPALIVE: wafwdt_ping(); break; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, p)) return -EFAULT; if ((new_timeout < 1) || (new_timeout > 255)) return -EINVAL; timeout = new_timeout; wafwdt_stop(); wafwdt_start(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(timeout, p); default: return -ENOTTY; } return 0; }

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dave jonesdave jones14158.51%222.22%
wim van sebroeckwim van sebroeck7229.88%333.33%
al viroal viro239.54%111.11%
axel linaxel lin20.83%111.11%
alan coxalan cox20.83%111.11%
samuel tardieusamuel tardieu10.41%111.11%
Total241100.00%9100.00%


static int wafwdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &wafwdt_is_open)) return -EBUSY; /* * Activate */ wafwdt_start(); return nonseekable_open(inode, file); }

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dave jonesdave jones3583.33%133.33%
linus torvaldslinus torvalds614.29%133.33%
wim van sebroeckwim van sebroeck12.38%133.33%
Total42100.00%3100.00%


static int wafwdt_close(struct inode *inode, struct file *file) { if (expect_close == 42) wafwdt_stop(); else { pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); wafwdt_ping(); } clear_bit(0, &wafwdt_is_open); expect_close = 0; return 0; }

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dave jonesdave jones3262.75%250.00%
wim van sebroeckwim van sebroeck1733.33%125.00%
joe perchesjoe perches23.92%125.00%
Total51100.00%4100.00%

/* * Notifier for system down */
static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) wafwdt_stop(); return NOTIFY_DONE; }

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dave jonesdave jones35100.00%1100.00%
Total35100.00%1100.00%

/* * Kernel Interfaces */ static const struct file_operations wafwdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = wafwdt_write, .unlocked_ioctl = wafwdt_ioctl, .open = wafwdt_open, .release = wafwdt_close, }; static struct miscdevice wafwdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wafwdt_fops, }; /* * The WDT needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block wafwdt_notifier = { .notifier_call = wafwdt_notify_sys, };
static int __init wafwdt_init(void) { int ret; pr_info("WDT driver for Wafer 5823 single board computer initialising\n"); if (timeout < 1 || timeout > 255) { timeout = WD_TIMO; pr_info("timeout value must be 1 <= x <= 255, using %d\n", timeout); } if (wdt_stop != wdt_start) { if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { pr_err("I/O address 0x%04x already in use\n", wdt_stop); ret = -EIO; goto error; } } if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) { pr_err("I/O address 0x%04x already in use\n", wdt_start); ret = -EIO; goto error2; } ret = register_reboot_notifier(&wafwdt_notifier); if (ret != 0) { pr_err("cannot register reboot notifier (err=%d)\n", ret); goto error3; } ret = misc_register(&wafwdt_miscdev); if (ret != 0) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto error4; } pr_info("initialized. timeout=%d sec (nowayout=%d)\n", timeout, nowayout); return ret; error4: unregister_reboot_notifier(&wafwdt_notifier); error3: release_region(wdt_start, 1); error2: if (wdt_stop != wdt_start) release_region(wdt_stop, 1); error: return ret; }

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wim van sebroeckwim van sebroeck11153.11%240.00%
dave jonesdave jones7535.89%120.00%
joe perchesjoe perches2210.53%120.00%
alan coxalan cox10.48%120.00%
Total209100.00%5100.00%


static void __exit wafwdt_exit(void) { misc_deregister(&wafwdt_miscdev); unregister_reboot_notifier(&wafwdt_notifier); if (wdt_stop != wdt_start) release_region(wdt_stop, 1); release_region(wdt_start, 1); }

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dave jonesdave jones3380.49%150.00%
wim van sebroeckwim van sebroeck819.51%150.00%
Total41100.00%2100.00%

module_init(wafwdt_init); module_exit(wafwdt_exit); MODULE_AUTHOR("Justin Cormack"); MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); MODULE_LICENSE("GPL"); /* end of wafer5823wdt.c */

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PersonTokensPropCommitsCommitProp
dave jonesdave jones64863.28%416.67%
wim van sebroeckwim van sebroeck28728.03%833.33%
joe perchesjoe perches313.03%14.17%
al viroal viro242.34%14.17%
alan coxalan cox100.98%28.33%
andrew mortonandrew morton90.88%28.33%
linus torvaldslinus torvalds60.59%14.17%
alexey dobriyanalexey dobriyan40.39%14.17%
axel linaxel lin20.20%14.17%
arjan van de venarjan van de ven10.10%14.17%
samuel tardieusamuel tardieu10.10%14.17%
andrey paninandrey panin10.10%14.17%
Total1024100.00%24100.00%
Directory: drivers/watchdog
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