static int create_xcdev()

in sdk/linux_kernel_drivers/xdma/xdma_cdev.c [285:388]

• 85 lines of code
• 16 McCabe index (conditional complexity)

static int create_xcdev(struct xdma_pci_dev *xpdev, struct xdma_cdev *xcdev,
			int bar, struct xdma_engine *engine,
			enum cdev_type type)
{
	int rv;
	int minor;
	struct xdma_dev *xdev = xpdev->xdev;
	dev_t dev;

	spin_lock_init(&xcdev->lock);
	/* new instance? */
	if (!xpdev->major) {
		/* allocate a dynamically allocated char device node */
		int rv = alloc_chrdev_region(&dev, XDMA_MINOR_BASE,
					XDMA_MINOR_COUNT, XDMA_NODE_NAME);

		if (rv) {
			pr_err("unable to allocate cdev region %d.\n", rv);
			return rv;
		}
		xpdev->major = MAJOR(dev);
	}

	/*
	 * do not register yet, create kobjects and name them,
	 */
	xcdev->magic = MAGIC_CHAR;
	xcdev->cdev.owner = THIS_MODULE;
	xcdev->xpdev = xpdev;
	xcdev->xdev = xdev;
	xcdev->engine = engine;
	xcdev->bar = bar;

	rv = config_kobject(xcdev, type);
	if (rv < 0)
		return rv;

	switch (type) {
	case CHAR_USER:
	case CHAR_CTRL:
		/* minor number is type index for non-SGDMA interfaces */
		minor = type;
		cdev_ctrl_init(xcdev);
		break;
	case CHAR_XVC:
		/* minor number is type index for non-SGDMA interfaces */
		minor = type;
		cdev_xvc_init(xcdev);
		break;
	case CHAR_XDMA_H2C:
		minor = 32 + engine->channel;
		cdev_sgdma_init(xcdev);
		break;
	case CHAR_XDMA_C2H:
		minor = 36 + engine->channel;
		cdev_sgdma_init(xcdev);
		break;
	case CHAR_EVENTS:
		minor = 10 + bar;
		cdev_event_init(xcdev);
		break;
	case CHAR_BYPASS_H2C:
		minor = 64 + engine->channel;
		cdev_bypass_init(xcdev);
		break;
	case CHAR_BYPASS_C2H:
		minor = 68 + engine->channel;
		cdev_bypass_init(xcdev);
		break;
	case CHAR_BYPASS:
		minor = 100;
		cdev_bypass_init(xcdev);
		break;
	default:
		pr_info("type 0x%x NOT supported.\n", type);
		return -EINVAL;
	}
	xcdev->cdevno = MKDEV(xpdev->major, minor);

	/* bring character device live */
	rv = cdev_add(&xcdev->cdev, xcdev->cdevno, 1);
	if (rv < 0) {
		pr_err("cdev_add failed %d, type 0x%x.\n", rv, type);
		goto unregister_region;
	}

	dbg_init("xcdev 0x%p, %u:%u, %s, type 0x%x.\n",
		xcdev, xpdev->major, minor, xcdev->cdev.kobj.name, type);

	/* create device on our class */
	if (g_xdma_class) {
		rv = create_sys_device(xcdev, type);
		if (rv < 0)
			goto del_cdev;
	}

	return 0;

del_cdev:
	cdev_del(&xcdev->cdev);
unregister_region:
	unregister_chrdev_region(xcdev->cdevno, XDMA_MINOR_COUNT);
	return rv;
}