drivers/watchdog/smsc37b787_wdt.c

Source file repositories/reference/linux-study-clean/drivers/watchdog/smsc37b787_wdt.c

File Facts

System
Linux kernel
Corpus path
drivers/watchdog/smsc37b787_wdt.c
Extension
.c
Size
15273 bytes
Lines
615
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 wb_smsc_wdt_fops = {
	.owner	  = THIS_MODULE,
	.write		= wb_smsc_wdt_write,
	.unlocked_ioctl	= wb_smsc_wdt_ioctl,
	.compat_ioctl	= compat_ptr_ioctl,
	.open		= wb_smsc_wdt_open,
	.release	= wb_smsc_wdt_release,
};

static struct notifier_block wb_smsc_wdt_notifier = {
	.notifier_call  = wb_smsc_wdt_notify_sys,
};

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

/* -- Module init functions -------------------------------------*/

/* module's "constructor" */

static int __init wb_smsc_wdt_init(void)
{
	int ret;

	pr_info("SMsC 37B787 watchdog component driver "
		VERSION " initialising...\n");

	if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
		pr_err("Unable to register IO port %#x\n", IOPORT);
		ret = -EBUSY;
		goto out_pnp;
	}

	/* set new maximum, if it's too big */
	if (timeout > MAX_TIMEOUT)
		timeout = MAX_TIMEOUT;

	/* init the watchdog timer */
	wb_smsc_wdt_initialize();

	ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
	if (ret) {
		pr_err("Unable to register reboot notifier err = %d\n", ret);
		goto out_io;
	}

	ret = misc_register(&wb_smsc_wdt_miscdev);
	if (ret) {
		pr_err("Unable to register miscdev on minor %d\n",
		       WATCHDOG_MINOR);
		goto out_rbt;
	}

	/* output info */
	pr_info("Timeout set to %d %s\n",
		timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
	pr_info("Watchdog initialized and sleeping (nowayout=%d)...\n",
		nowayout);
out_clean:
	return ret;

out_rbt:
	unregister_reboot_notifier(&wb_smsc_wdt_notifier);

out_io:
	release_region(IOPORT, IOPORT_SIZE);

out_pnp:
	goto out_clean;
}

/* module's "destructor" */

static void __exit wb_smsc_wdt_exit(void)
{
	/* Stop the timer before we leave */
	if (!nowayout) {
		wb_smsc_wdt_shutdown();
		pr_info("Watchdog disabled\n");
	}

	misc_deregister(&wb_smsc_wdt_miscdev);
	unregister_reboot_notifier(&wb_smsc_wdt_notifier);
	release_region(IOPORT, IOPORT_SIZE);

	pr_info("SMsC 37B787 watchdog component driver removed\n");
}

Annotation

Implementation Notes