pcwd.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 1,003 行 · 第 1/2 页

	if (pcwd_private.revision == PCWD_REVISION_C) {
		spin_lock(&pcwd_private.io_lock);

		if (debug >= VERBOSE)
			printk(KERN_INFO PFX "clearing watchdog trip status\n");

		control_status = inb_p(pcwd_private.io_addr + 1);

		if (debug >= DEBUG) {
			printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
			printk(KERN_DEBUG PFX "sending: 0x%02x\n",
				(control_status & WD_REVC_R2DS));
		}

		/* clear reset status & Keep Relay 2 disable state as it is */
		outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);

		spin_unlock(&pcwd_private.io_lock);
	}
	return 0;
}

static int pcwd_get_temperature(int *temperature)
{
	/* check that port 0 gives temperature info and no command results */
	if (pcwd_private.command_mode)
		return -1;

	*temperature = 0;
	if (!pcwd_private.supports_temp)
		return -ENODEV;

	/*
	 * Convert celsius to fahrenheit, since this was
	 * the decided 'standard' for this return value.
	 */
	spin_lock(&pcwd_private.io_lock);
	*temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
	spin_unlock(&pcwd_private.io_lock);

	if (debug >= DEBUG) {
		printk(KERN_DEBUG PFX "temperature is: %d F\n",
			*temperature);
	}

	return 0;
}

/*
 *	/dev/watchdog handling
 */

static int pcwd_ioctl(struct inode *inode, struct file *file,
		      unsigned int cmd, unsigned long arg)
{
	int rv;
	int status;
	int temperature;
	int new_heartbeat;
	int __user *argp = (int __user *)arg;
	static struct watchdog_info ident = {
		.options =		WDIOF_OVERHEAT |
					WDIOF_CARDRESET |
					WDIOF_KEEPALIVEPING |
					WDIOF_SETTIMEOUT |
					WDIOF_MAGICCLOSE,
		.firmware_version =	1,
		.identity =		"PCWD",
	};

	switch(cmd) {
	default:
		return -ENOIOCTLCMD;

	case WDIOC_GETSUPPORT:
		if(copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		return 0;

	case WDIOC_GETSTATUS:
		pcwd_get_status(&status);
		return put_user(status, argp);

	case WDIOC_GETBOOTSTATUS:
		return put_user(pcwd_private.boot_status, argp);

	case WDIOC_GETTEMP:
		if (pcwd_get_temperature(&temperature))
			return -EFAULT;

		return put_user(temperature, argp);

	case WDIOC_SETOPTIONS:
		if (pcwd_private.revision == PCWD_REVISION_C)
		{
			if(copy_from_user(&rv, argp, sizeof(int)))
				return -EFAULT;

			if (rv & WDIOS_DISABLECARD)
			{
				return pcwd_stop();
			}

			if (rv & WDIOS_ENABLECARD)
			{
				return pcwd_start();
			}

			if (rv & WDIOS_TEMPPANIC)
			{
				temp_panic = 1;
			}
		}
		return -EINVAL;

	case WDIOC_KEEPALIVE:
		pcwd_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_heartbeat, argp))
			return -EFAULT;

		if (pcwd_set_heartbeat(new_heartbeat))
			return -EINVAL;

		pcwd_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(heartbeat, argp);
	}

	return 0;
}

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

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		pcwd_keepalive();
	}
	return len;
}

static int pcwd_open(struct inode *inode, struct file *file)
{
	if (!atomic_dec_and_test(&open_allowed) ) {
		if (debug >= VERBOSE)
			printk(KERN_ERR PFX "Attempt to open already opened device.\n");
		atomic_inc( &open_allowed );
		return -EBUSY;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Activate */
	pcwd_start();
	pcwd_keepalive();
	return nonseekable_open(inode, file);
}

static int pcwd_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		pcwd_stop();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		pcwd_keepalive();
	}
	expect_close = 0;
	atomic_inc( &open_allowed );
	return 0;
}

/*
 *	/dev/temperature handling
 */

static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
			 loff_t *ppos)
{
	int temperature;

	if (pcwd_get_temperature(&temperature))
		return -EFAULT;

	if (copy_to_user(buf, &temperature, 1))
		return -EFAULT;

	return 1;
}

static int pcwd_temp_open(struct inode *inode, struct file *file)
{
	if (!pcwd_private.supports_temp)
		return -ENODEV;

	return nonseekable_open(inode, file);
}

static int pcwd_temp_close(struct inode *inode, struct file *file)
{
	return 0;
}

/*
 *	Notify system
 */

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

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations pcwd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= pcwd_write,
	.ioctl		= pcwd_ioctl,
	.open		= pcwd_open,
	.release	= pcwd_close,
};

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

static struct file_operations pcwd_temp_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= pcwd_temp_read,
	.open		= pcwd_temp_open,
	.release	= pcwd_temp_close,
};

static struct miscdevice temp_miscdev = {
	.minor =	TEMP_MINOR,
	.name =		"temperature",
	.fops =		&pcwd_temp_fops,
};

static struct notifier_block pcwd_notifier = {
	.notifier_call =	pcwd_notify_sys,
};

/*
 *	Init & exit routines
 */

static inline int get_revision(void)
{
	int r = PCWD_REVISION_C;

	spin_lock(&pcwd_private.io_lock);
	/* REV A cards use only 2 io ports; test
	 * presumes a floating bus reads as 0xff. */
	if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
	    (inb(pcwd_private.io_addr + 3) == 0xFF))
		r=PCWD_REVISION_A;
	spin_unlock(&pcwd_private.io_lock);

	return r;
}

static int __devinit pcwatchdog_init(int base_addr)
{
	int ret;

	cards_found++;
	if (cards_found == 1)
		printk(KERN_INFO PFX "v%s Ken Hollis ([e-mail])\n", WD_VER);

	if (cards_found > 1) {
		printk(KERN_ERR PFX "This driver only supports 1 device\n");
		return -ENODEV;
	}

	if (base_addr == 0x0000) {
		printk(KERN_ERR PFX "No I/O-Address for card detected\n");
		return -ENODEV;
	}
	pcwd_private.io_addr = base_addr;

	/* Check card's revision */
	pcwd_private.revision = get_revision();

	if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			pcwd_private.io_addr);
		pcwd_private.io_addr = 0x0000;
		return -EIO;
	}

	/* Initial variables */
	pcwd_private.supports_temp = 0;
	temp_panic = 0;
	pcwd_private.boot_status = 0x0000;

	/* get the boot_status */
	pcwd_get_status(&pcwd_private.boot_status);

	/* clear the "card caused reboot" flag */
	pcwd_clear_status();

	init_timer(&pcwd_private.timer);
	pcwd_private.timer.function = pcwd_timer_ping;
	pcwd_private.timer.data = 0;

	/*  Disable the board  */
	pcwd_stop();

	/*  Check whether or not the card supports the temperature device */
	pcwd_check_temperature_support();

	/* Show info about the card itself */
	pcwd_show_card_info();

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (pcwd_set_heartbeat(heartbeat)) {
		pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
		printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
			WATCHDOG_HEARTBEAT);
	}

	ret = register_reboot_notifier(&pcwd_notifier);
	if (ret) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
		pcwd_private.io_addr = 0x0000;
		return ret;
	}

	if (pcwd_private.supports_temp) {
		ret = misc_register(&temp_miscdev);
		if (ret) {
			printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
				TEMP_MINOR, ret);
			unregister_reboot_notifier(&pcwd_notifier);
			release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
			pcwd_private.io_addr = 0x0000;
			return ret;
		}
	}

	ret = misc_register(&pcwd_miscdev);
	if (ret) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		if (pcwd_private.supports_temp)
			misc_deregister(&temp_miscdev);
		unregister_reboot_notifier(&pcwd_notifier);
		release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
		pcwd_private.io_addr = 0x0000;
		return ret;
	}

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

	return 0;
}

static void __devexit pcwatchdog_exit(void)
{
	/*  Disable the board  */
	if (!nowayout)
		pcwd_stop();

	/* Deregister */
	misc_deregister(&pcwd_miscdev);
	if (pcwd_private.supports_temp)
		misc_deregister(&temp_miscdev);
	unregister_reboot_notifier(&pcwd_notifier);
	release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
	pcwd_private.io_addr = 0x0000;
	cards_found--;
}

/*
 *  The ISA cards have a heartbeat bit in one of the registers, which
 *  register is card dependent.  The heartbeat bit is monitored, and if
 *  found, is considered proof that a Berkshire card has been found.
 *  The initial rate is once per second at board start up, then twice
 *  per second for normal operation.
 */
static int __init pcwd_checkcard(int base_addr)
{
	int port0, last_port0;	/* Reg 0, in case it's REV A */
	int port1, last_port1;	/* Register 1 for REV C cards */
	int i;
	int retval;

	if (!request_region (base_addr, 4, "PCWD")) {
		printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
		return 0;
	}

	retval = 0;

	port0 = inb_p(base_addr);	/* For REV A boards */
	port1 = inb_p(base_addr + 1);	/* For REV C boards */
	if (port0 != 0xff || port1 != 0xff) {
		/* Not an 'ff' from a floating bus, so must be a card! */
		for (i = 0; i < 4; ++i) {

			msleep(500);

			last_port0 = port0;
			last_port1 = port1;

			port0 = inb_p(base_addr);
			port1 = inb_p(base_addr + 1);

			/* Has either hearbeat bit changed?  */
			if ((port0 ^ last_port0) & WD_HRTBT ||
			    (port1 ^ last_port1) & WD_REVC_HRBT) {
				retval = 1;
				break;
			}
		}
	}
	release_region (base_addr, 4);

	return retval;
}

/*
 * These are the auto-probe addresses available.
 *
 * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 * Revision A has an address range of 2 addresses, while Revision C has 4.
 */
static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };

static int __init pcwd_init_module(void)
{
	int i, found = 0;

	spin_lock_init(&pcwd_private.io_lock);

	for (i = 0; pcwd_ioports[i] != 0; i++) {
		if (pcwd_checkcard(pcwd_ioports[i])) {
			if (!(pcwatchdog_init(pcwd_ioports[i])))
				found++;
		}
	}

	if (!found) {
		printk (KERN_INFO PFX "No card detected, or port not available\n");
		return -ENODEV;
	}

	return 0;
}

static void __exit pcwd_cleanup_module(void)
{
	if (pcwd_private.io_addr)
		pcwatchdog_exit();

	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
}

module_init(pcwd_init_module);
module_exit(pcwd_cleanup_module);

MODULE_AUTHOR("Ken Hollis <[e-mail]>");
MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);