pcwd_pci.c

linux-2.6.15.6

/*
 *	/dev/watchdog handling
 */

static ssize_t pcipcwd_write(struct file *file, const char __user *data,
			     size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the magic character
			 * five months ago... */
			expect_release = 0;

			/* scan to see whether or not we got the magic character */
			for (i = 0; i != len; i++) {
				char c;
				if(get_user(c, data+i))
					return -EFAULT;
				if (c == 'V')
					expect_release = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		pcipcwd_keepalive();
	}
	return len;
}

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

	switch (cmd) {
		case WDIOC_GETSUPPORT:
			return copy_to_user(argp, &ident,
				sizeof (ident)) ? -EFAULT : 0;

		case WDIOC_GETSTATUS:
		{
			int status;

			pcipcwd_get_status(&status);

			return put_user(status, p);
		}

		case WDIOC_GETBOOTSTATUS:
			return put_user(pcipcwd_private.boot_status, p);

		case WDIOC_GETTEMP:
		{
			int temperature;

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

			return put_user(temperature, p);
		}

		case WDIOC_KEEPALIVE:
			pcipcwd_keepalive();
			return 0;

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

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

			if (new_options & WDIOS_DISABLECARD) {
				if (pcipcwd_stop())
					return -EIO;
				retval = 0;
			}

			if (new_options & WDIOS_ENABLECARD) {
				if (pcipcwd_start())
					return -EIO;
				retval = 0;
			}

			if (new_options & WDIOS_TEMPPANIC) {
				temp_panic = 1;
				retval = 0;
			}

			return retval;
		}

		case WDIOC_SETTIMEOUT:
		{
			int new_heartbeat;

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

			if (pcipcwd_set_heartbeat(new_heartbeat))
			    return -EINVAL;

			pcipcwd_keepalive();
			/* Fall */
		}

		case WDIOC_GETTIMEOUT:
			return put_user(heartbeat, p);

		default:
			return -ENOIOCTLCMD;
	}
}

static int pcipcwd_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &is_active)) {
		if (debug >= VERBOSE)
			printk(KERN_ERR PFX "Attempt to open already opened device.\n");
		return -EBUSY;
	}

	/* Activate */
	pcipcwd_start();
	pcipcwd_keepalive();
	return nonseekable_open(inode, file);
}

static int pcipcwd_release(struct inode *inode, struct file *file)
{
	/*
	 *      Shut off the timer.
	 */
	if (expect_release == 42) {
		pcipcwd_stop();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		pcipcwd_keepalive();
	}
	expect_release = 0;
	clear_bit(0, &is_active);
	return 0;
}

/*
 *	/dev/temperature handling
 */

static ssize_t pcipcwd_temp_read(struct file *file, char __user *data,
				size_t len, loff_t *ppos)
{
	int temperature;

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

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

	return 1;
}

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

	return nonseekable_open(inode, file);
}

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

/*
 *	Notify system
 */

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

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations pcipcwd_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.write =	pcipcwd_write,
	.ioctl =	pcipcwd_ioctl,
	.open =		pcipcwd_open,
	.release =	pcipcwd_release,
};

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

static struct file_operations pcipcwd_temp_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.read =		pcipcwd_temp_read,
	.open =		pcipcwd_temp_open,
	.release =	pcipcwd_temp_release,
};

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

static struct notifier_block pcipcwd_notifier = {
	.notifier_call =	pcipcwd_notify_sys,
};

/*
 *	Init & exit routines
 */

static int __devinit pcipcwd_card_init(struct pci_dev *pdev,
		const struct pci_device_id *ent)
{
	int ret = -EIO;

	cards_found++;
	if (cards_found == 1)
		printk(KERN_INFO PFX DRIVER_VERSION);

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

	if (pci_enable_device(pdev)) {
		printk(KERN_ERR PFX "Not possible to enable PCI Device\n");
		return -ENODEV;
	}

	if (pci_resource_start(pdev, 0) == 0x0000) {
		printk(KERN_ERR PFX "No I/O-Address for card detected\n");
		ret = -ENODEV;
		goto err_out_disable_device;
	}

	pcipcwd_private.pdev = pdev;
	pcipcwd_private.io_addr = pci_resource_start(pdev, 0);

	if (pci_request_regions(pdev, WATCHDOG_NAME)) {
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			(int) pcipcwd_private.io_addr);
		ret = -EIO;
		goto err_out_disable_device;
	}

	/* get the boot_status */
	pcipcwd_get_status(&pcipcwd_private.boot_status);

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

	/* disable card */
	pcipcwd_stop();

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

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

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (pcipcwd_set_heartbeat(heartbeat)) {
		pcipcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
		printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
			WATCHDOG_HEARTBEAT);
	}

	ret = register_reboot_notifier(&pcipcwd_notifier);
	if (ret != 0) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		goto err_out_release_region;
	}

	if (pcipcwd_private.supports_temp) {
		ret = misc_register(&pcipcwd_temp_miscdev);
		if (ret != 0) {
			printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
				TEMP_MINOR, ret);
			goto err_out_unregister_reboot;
		}
	}

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

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

	return 0;

err_out_misc_deregister:
	if (pcipcwd_private.supports_temp)
		misc_deregister(&pcipcwd_temp_miscdev);
err_out_unregister_reboot:
	unregister_reboot_notifier(&pcipcwd_notifier);
err_out_release_region:
	pci_release_regions(pdev);
err_out_disable_device:
	pci_disable_device(pdev);
	return ret;
}

static void __devexit pcipcwd_card_exit(struct pci_dev *pdev)
{
	/* Stop the timer before we leave */
	if (!nowayout)
		pcipcwd_stop();

	/* Deregister */
	misc_deregister(&pcipcwd_miscdev);
	if (pcipcwd_private.supports_temp)
		misc_deregister(&pcipcwd_temp_miscdev);
	unregister_reboot_notifier(&pcipcwd_notifier);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
	cards_found--;
}

static struct pci_device_id pcipcwd_pci_tbl[] = {
	{ PCI_VENDOR_ID_QUICKLOGIC, PCI_DEVICE_ID_WATCHDOG_PCIPCWD,
		PCI_ANY_ID, PCI_ANY_ID, },
	{ 0 },			/* End of list */
};
MODULE_DEVICE_TABLE(pci, pcipcwd_pci_tbl);

static struct pci_driver pcipcwd_driver = {
	.name		= WATCHDOG_NAME,
	.id_table	= pcipcwd_pci_tbl,
	.probe		= pcipcwd_card_init,
	.remove		= __devexit_p(pcipcwd_card_exit),
};

static int __init pcipcwd_init_module(void)
{
	spin_lock_init(&pcipcwd_private.io_lock);

	return pci_register_driver(&pcipcwd_driver);
}

static void __exit pcipcwd_cleanup_module(void)
{
	pci_unregister_driver(&pcipcwd_driver);
}

module_init(pcipcwd_init_module);
module_exit(pcipcwd_cleanup_module);

MODULE_AUTHOR("Wim Van Sebroeck <[e-mail]>");
MODULE_DESCRIPTION("Berkshire PCI-PC Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);