drivers/char/watchdog/advantechwdt.c - kernel/msm-4.9 - Gitiles

 /*
  *	Advantech Single Board Computer WDT driver
  *
  *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
  *
  *	Based on acquirewdt.c which is based on wdt.c.
  *	Original copyright messages:
  *
  *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
  *				http://www.redhat.com
  *
  *	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@redhat.com>
  *
  *	14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
  *	    Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
  *
  *	16-Oct-2002 Rob Radez <rob@osinvestor.com>
  *	    Clean up ioctls, clean up init + exit, add expect close support,
  *	    add wdt_start and wdt_stop as parameters.
  */

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/fs.h>
 #include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/init.h>

 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>

 #define DRV_NAME "advantechwdt"
 #define PFX DRV_NAME ": "
 #define WATCHDOG_NAME "Advantech WDT"
 #define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */

 static struct platform_device *advwdt_platform_device;	/* the watchdog platform device */
 static unsigned long advwdt_is_open;
 static char adv_expect_close;

 /*
  *	You must set these - there is no sane way to probe for this board.
  *
  *	To enable or restart, write the timeout value in seconds (1 to 63)
  *	to I/O port wdt_start.  To disable, read I/O port wdt_stop.
  *	Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
  *	check your manual (at least the PCA-6159 seems to be different -
  *	the manual says wdt_stop is 0x43, not 0x443).
  *	(0x43 is also a write-only control register for the 8254 timer!)
  */

 static int wdt_stop = 0x443;
 module_param(wdt_stop, int, 0);
 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");

 static int wdt_start = 0x443;
 module_param(wdt_start, int, 0);
 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");

 static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 module_param(timeout, int, 0);
 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");

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

 /*
  *	Watchdog Operations
  */

 static void
 advwdt_ping(void)
 {
 	/* Write a watchdog value */
 	outb_p(timeout, wdt_start);
 }

 static void
 advwdt_disable(void)
 {
 	inb_p(wdt_stop);
 }

 static int
 advwdt_set_heartbeat(int t)
 {
 	if ((t < 1) || (t > 63))
 		return -EINVAL;

 	timeout = t;
 	return 0;
 }

 /*
  *	/dev/watchdog handling
  */

 static ssize_t
 advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 {
 	if (count) {
 		if (!nowayout) {
 			size_t i;

 			adv_expect_close = 0;

 			for (i = 0; i != count; i++) {
 				char c;
 				if (get_user(c, buf+i))
 					return -EFAULT;
 				if (c == 'V')
 					adv_expect_close = 42;
 			}
 		}
 		advwdt_ping();
 	}
 	return count;
 }

 static int
 advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 	  unsigned long arg)
 {
 	int new_timeout;
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	static struct watchdog_info ident = {
 		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 		.firmware_version = 1,
 		.identity = WATCHDOG_NAME,
 	};

 	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_KEEPALIVE:
 	  advwdt_ping();
 	  break;

 	case WDIOC_SETTIMEOUT:
 	  if (get_user(new_timeout, p))
 		  return -EFAULT;
 	  if (advwdt_set_heartbeat(new_timeout))
 		  return -EINVAL;
 	  advwdt_ping();
 	  /* Fall */

 	case WDIOC_GETTIMEOUT:
 	  return put_user(timeout, p);

 	case WDIOC_SETOPTIONS:
 	{
 	  int options, retval = -EINVAL;

 	  if (get_user(options, p))
 	    return -EFAULT;

 	  if (options & WDIOS_DISABLECARD) {
 	    advwdt_disable();
 	    retval = 0;
 	  }

 	  if (options & WDIOS_ENABLECARD) {
 	    advwdt_ping();
 	    retval = 0;
 	  }

 	  return retval;
 	}

 	default:
 	  return -ENOTTY;
 	}
 	return 0;
 }

 static int
 advwdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(0, &advwdt_is_open))
 		return -EBUSY;
 	/*
 	 *	Activate
 	 */

 	advwdt_ping();
 	return nonseekable_open(inode, file);
 }

 static int
 advwdt_close(struct inode *inode, struct file *file)
 {
 	if (adv_expect_close == 42) {
 		advwdt_disable();
 	} else {
 		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 		advwdt_ping();
 	}
 	clear_bit(0, &advwdt_is_open);
 	adv_expect_close = 0;
 	return 0;
 }

 /*
  *	Kernel Interfaces
  */

 static const struct file_operations advwdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= advwdt_write,
 	.ioctl		= advwdt_ioctl,
 	.open		= advwdt_open,
 	.release	= advwdt_close,
 };

 static struct miscdevice advwdt_miscdev = {
 	.minor	= WATCHDOG_MINOR,
 	.name	= "watchdog",
 	.fops	= &advwdt_fops,
 };

 /*
  *	Init & exit routines
  */

 static int __devinit
 advwdt_probe(struct platform_device *dev)
 {
 	int ret;

 	if (wdt_stop != wdt_start) {
 		if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
 			printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 				wdt_stop);
 			ret = -EIO;
 			goto out;
 		}
 	}

 	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
 		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 			wdt_start);
 		ret = -EIO;
 		goto unreg_stop;
 	}

 	/* Check that the heartbeat value is within it's range ; if not reset to the default */
 	if (advwdt_set_heartbeat(timeout)) {
 		advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
 		printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
 			timeout);
 	}

 	ret = misc_register(&advwdt_miscdev);
 	if (ret != 0) {
 		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 			WATCHDOG_MINOR, ret);
 		goto unreg_regions;
 	}

 	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
 		timeout, nowayout);

 out:
 	return ret;
 unreg_regions:
 	release_region(wdt_start, 1);
 unreg_stop:
 	if (wdt_stop != wdt_start)
 		release_region(wdt_stop, 1);
 	goto out;
 }

 static int __devexit
 advwdt_remove(struct platform_device *dev)
 {
 	misc_deregister(&advwdt_miscdev);
 	release_region(wdt_start,1);
 	if(wdt_stop != wdt_start)
 		release_region(wdt_stop,1);

 	return 0;
 }

 static void
 advwdt_shutdown(struct platform_device *dev)
 {
 	/* Turn the WDT off if we have a soft shutdown */
 	advwdt_disable();
 }

 static struct platform_driver advwdt_driver = {
 	.probe		= advwdt_probe,
 	.remove		= __devexit_p(advwdt_remove),
 	.shutdown	= advwdt_shutdown,
 	.driver		= {
 		.owner	= THIS_MODULE,
 		.name	= DRV_NAME,
 	},
 };

 static int __init
 advwdt_init(void)
 {
 	int err;

 	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");

 	err = platform_driver_register(&advwdt_driver);
 	if (err)
 		return err;

 	advwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0);
 	if (IS_ERR(advwdt_platform_device)) {
 		err = PTR_ERR(advwdt_platform_device);
 		goto unreg_platform_driver;
 	}

 	return 0;

 unreg_platform_driver:
 	platform_driver_unregister(&advwdt_driver);
 	return err;
 }

 static void __exit
 advwdt_exit(void)
 {
 	platform_device_unregister(advwdt_platform_device);
 	platform_driver_unregister(&advwdt_driver);
 	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
 }

 module_init(advwdt_init);
 module_exit(advwdt_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	/*
	* Advantech Single Board Computer WDT driver
	*
	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	*
	* Based on acquirewdt.c which is based on wdt.c.
	* Original copyright messages:
	*
	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	* http://www.redhat.com
	*
	* 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@redhat.com>
	*
	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	*
	* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
	* Clean up ioctls, clean up init + exit, add expect close support,
	* add wdt_start and wdt_stop as parameters.
	*/

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/types.h>
	#include <linux/miscdevice.h>
	#include <linux/watchdog.h>
	#include <linux/fs.h>
	#include <linux/ioport.h>
	#include <linux/platform_device.h>
	#include <linux/init.h>

	#include <asm/io.h>
	#include <asm/uaccess.h>
	#include <asm/system.h>

	#define DRV_NAME "advantechwdt"
	#define PFX DRV_NAME ": "
	#define WATCHDOG_NAME "Advantech WDT"
	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */

	static struct platform_device advwdt_platform_device; / the watchdog platform device */
	static unsigned long advwdt_is_open;
	static char adv_expect_close;

	/*
	* You must set these - there is no sane way to probe for this board.
	*
	* To enable or restart, write the timeout value in seconds (1 to 63)
	* to I/O port wdt_start. To disable, read I/O port wdt_stop.
	* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
	* check your manual (at least the PCA-6159 seems to be different -
	* the manual says wdt_stop is 0x43, not 0x443).
	* (0x43 is also a write-only control register for the 8254 timer!)
	*/

	static int wdt_stop = 0x443;
	module_param(wdt_stop, int, 0);
	MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");

	static int wdt_start = 0x443;
	module_param(wdt_start, int, 0);
	MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");

	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	module_param(timeout, int, 0);
	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");

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

	/*
	* Watchdog Operations
	*/

	static void
	advwdt_ping(void)
	{
	/* Write a watchdog value */
	outb_p(timeout, wdt_start);
	}

	static void
	advwdt_disable(void)
	{
	inb_p(wdt_stop);
	}

	static int
	advwdt_set_heartbeat(int t)
	{
	if ((t < 1) \|\| (t > 63))
	return -EINVAL;

	timeout = t;
	return 0;
	}

	/*
	* /dev/watchdog handling
	*/

	static ssize_t
	advwdt_write(struct file file, const char __user buf, size_t count, loff_t *ppos)
	{
	if (count) {
	if (!nowayout) {
	size_t i;

	adv_expect_close = 0;

	for (i = 0; i != count; i++) {
	char c;
	if (get_user(c, buf+i))
	return -EFAULT;
	if (c == 'V')
	adv_expect_close = 42;
	}
	}
	advwdt_ping();
	}
	return count;
	}

	static int
	advwdt_ioctl(struct inode inode, struct file file, unsigned int cmd,
	unsigned long arg)
	{
	int new_timeout;
	void __user argp = (void __user )arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	.firmware_version = 1,
	.identity = WATCHDOG_NAME,
	};

	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_KEEPALIVE:
	advwdt_ping();
	break;

	case WDIOC_SETTIMEOUT:
	if (get_user(new_timeout, p))
	return -EFAULT;
	if (advwdt_set_heartbeat(new_timeout))
	return -EINVAL;
	advwdt_ping();
	/* Fall */

	case WDIOC_GETTIMEOUT:
	return put_user(timeout, p);

	case WDIOC_SETOPTIONS:
	{
	int options, retval = -EINVAL;

	if (get_user(options, p))
	return -EFAULT;

	if (options & WDIOS_DISABLECARD) {
	advwdt_disable();
	retval = 0;
	}

	if (options & WDIOS_ENABLECARD) {
	advwdt_ping();
	retval = 0;
	}

	return retval;
	}

	default:
	return -ENOTTY;
	}
	return 0;
	}

	static int
	advwdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(0, &advwdt_is_open))
	return -EBUSY;
	/*
	* Activate
	*/

	advwdt_ping();
	return nonseekable_open(inode, file);
	}

	static int
	advwdt_close(struct inode inode, struct file file)
	{
	if (adv_expect_close == 42) {
	advwdt_disable();
	} else {
	printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
	advwdt_ping();
	}
	clear_bit(0, &advwdt_is_open);
	adv_expect_close = 0;
	return 0;
	}

	/*
	* Kernel Interfaces
	*/

	static const struct file_operations advwdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = advwdt_write,
	.ioctl = advwdt_ioctl,
	.open = advwdt_open,
	.release = advwdt_close,
	};

	static struct miscdevice advwdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &advwdt_fops,
	};

	/*
	* Init & exit routines
	*/

	static int __devinit
	advwdt_probe(struct platform_device *dev)
	{
	int ret;

	if (wdt_stop != wdt_start) {
	if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
	printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
	wdt_stop);
	ret = -EIO;
	goto out;
	}
	}

	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
	printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
	wdt_start);
	ret = -EIO;
	goto unreg_stop;
	}

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (advwdt_set_heartbeat(timeout)) {
	advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
	printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
	timeout);
	}

	ret = misc_register(&advwdt_miscdev);
	if (ret != 0) {
	printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
	WATCHDOG_MINOR, ret);
	goto unreg_regions;
	}

	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
	timeout, nowayout);

	out:
	return ret;
	unreg_regions:
	release_region(wdt_start, 1);
	unreg_stop:
	if (wdt_stop != wdt_start)
	release_region(wdt_stop, 1);
	goto out;
	}

	static int __devexit
	advwdt_remove(struct platform_device *dev)
	{
	misc_deregister(&advwdt_miscdev);
	release_region(wdt_start,1);
	if(wdt_stop != wdt_start)
	release_region(wdt_stop,1);

	return 0;
	}

	static void
	advwdt_shutdown(struct platform_device *dev)
	{
	/* Turn the WDT off if we have a soft shutdown */
	advwdt_disable();
	}

	static struct platform_driver advwdt_driver = {
	.probe = advwdt_probe,
	.remove = __devexit_p(advwdt_remove),
	.shutdown = advwdt_shutdown,
	.driver = {
	.owner = THIS_MODULE,
	.name = DRV_NAME,
	},
	};

	static int __init
	advwdt_init(void)
	{
	int err;

	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");

	err = platform_driver_register(&advwdt_driver);
	if (err)
	return err;

	advwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0);
	if (IS_ERR(advwdt_platform_device)) {
	err = PTR_ERR(advwdt_platform_device);
	goto unreg_platform_driver;
	}

	return 0;

	unreg_platform_driver:
	platform_driver_unregister(&advwdt_driver);
	return err;
	}

	static void __exit
	advwdt_exit(void)
	{
	platform_device_unregister(advwdt_platform_device);
	platform_driver_unregister(&advwdt_driver);
	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
	}

	module_init(advwdt_init);
	module_exit(advwdt_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
	MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);