drivers/watchdog/wdt977.c

Source file repositories/reference/linux-study-clean/drivers/watchdog/wdt977.c

File Facts

System
Linux kernel
Corpus path
drivers/watchdog/wdt977.c
Extension
.c
Size
11878 bytes
Lines
506
Domain
Driver Families
Bucket
drivers/watchdog
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations wdt977_fops = {
	.owner		= THIS_MODULE,
	.write		= wdt977_write,
	.unlocked_ioctl	= wdt977_ioctl,
	.compat_ioctl	= compat_ptr_ioctl,
	.open		= wdt977_open,
	.release	= wdt977_release,
};

static struct miscdevice wdt977_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &wdt977_fops,
};

static struct notifier_block wdt977_notifier = {
	.notifier_call = wdt977_notify_sys,
};

static int __init wd977_init(void)
{
	int rc;

	pr_info("driver v%s\n", WATCHDOG_VERSION);

	/* Check that the timeout value is within its range;
	   if not reset to the default */
	if (wdt977_set_timeout(timeout)) {
		wdt977_set_timeout(DEFAULT_TIMEOUT);
		pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
			DEFAULT_TIMEOUT);
	}

	/* on Netwinder the IOports are already reserved by
	 * arch/arm/mach-footbridge/netwinder-hw.c
	 */
	if (!machine_is_netwinder()) {
		if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
			pr_err("I/O address 0x%04x already in use\n",
			       IO_INDEX_PORT);
			rc = -EIO;
			goto err_out;
		}
	}

	rc = register_reboot_notifier(&wdt977_notifier);
	if (rc) {
		pr_err("cannot register reboot notifier (err=%d)\n", rc);
		goto err_out_region;
	}

	rc = misc_register(&wdt977_miscdev);
	if (rc) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       wdt977_miscdev.minor, rc);
		goto err_out_reboot;
	}

	pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
		timeout, nowayout, testmode);

	return 0;

err_out_reboot:
	unregister_reboot_notifier(&wdt977_notifier);
err_out_region:
	if (!machine_is_netwinder())
		release_region(IO_INDEX_PORT, 2);
err_out:
	return rc;
}

static void __exit wd977_exit(void)
{
	wdt977_stop();
	misc_deregister(&wdt977_miscdev);
	unregister_reboot_notifier(&wdt977_notifier);
	release_region(IO_INDEX_PORT, 2);
}

module_init(wd977_init);
module_exit(wd977_exit);

MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
MODULE_DESCRIPTION("W83977AF Watchdog driver");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes