drivers/char/xillybus/xillybus_class.c

Source file repositories/reference/linux-study-clean/drivers/char/xillybus/xillybus_class.c

File Facts

System
Linux kernel
Corpus path
drivers/char/xillybus/xillybus_class.c
Extension
.c
Size
5397 bytes
Lines
257
Domain
Driver Families
Bucket
drivers/char
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

const struct file_operations *fops,
			 struct module *owner,
			 void *private_data,
			 unsigned char *idt, unsigned int len,
			 int num_nodes,
			 const char *prefix, bool enumerate)
{
	int rc;
	dev_t mdev;
	int i;
	char devname[48];

	struct device *device;
	size_t namelen;
	struct xilly_unit *unit, *u;

	unit = kzalloc_obj(*unit);

	if (!unit)
		return -ENOMEM;

	mutex_lock(&unit_mutex);

	if (!enumerate)
		snprintf(unit->name, UNITNAMELEN, "%s", prefix);

	for (i = 0; enumerate; i++) {
		snprintf(unit->name, UNITNAMELEN, "%s_%02d",
			 prefix, i);

		enumerate = false;
		list_for_each_entry(u, &unit_list, list_entry)
			if (!strcmp(unit->name, u->name)) {
				enumerate = true;
				break;
			}
	}

	rc = alloc_chrdev_region(&mdev, 0, num_nodes, unit->name);

	if (rc) {
		dev_warn(dev, "Failed to obtain major/minors");
		goto fail_obtain;
	}

	unit->major = MAJOR(mdev);
	unit->lowest_minor = MINOR(mdev);
	unit->num_nodes = num_nodes;
	unit->private_data = private_data;

	unit->cdev = cdev_alloc();
	if (!unit->cdev) {
		rc = -ENOMEM;
		goto unregister_chrdev;
	}
	unit->cdev->ops = fops;
	unit->cdev->owner = owner;

	rc = cdev_add(unit->cdev, MKDEV(unit->major, unit->lowest_minor),
		      unit->num_nodes);
	if (rc) {
		dev_err(dev, "Failed to add cdev.\n");
		/* kobject_put() is normally done by cdev_del() */
		kobject_put(&unit->cdev->kobj);
		goto unregister_chrdev;
	}

	for (i = 0; i < num_nodes; i++) {
		namelen = strnlen(idt, len);

		if (namelen == len) {
			dev_err(dev, "IDT's list of names is too short. This is exceptionally weird, because its CRC is OK\n");
			rc = -ENODEV;
			goto unroll_device_create;
		}

		snprintf(devname, sizeof(devname), "%s_%s",
			 unit->name, idt);

		len -= namelen + 1;
		idt += namelen + 1;

		device = device_create(&xillybus_class,
				       NULL,
				       MKDEV(unit->major,
					     i + unit->lowest_minor),
				       NULL,
				       "%s", devname);

		if (IS_ERR(device)) {

Annotation

Implementation Notes