int extcon_dev_register()

in extcon.c [1070:1268]
167 lines of code
34 McCabe index (conditional complexity)

int extcon_dev_register(struct extcon_dev *edev)
{
	int ret, index = 0;
	static atomic_t edev_no = ATOMIC_INIT(-1);

	if (!extcon_class) {
		ret = create_extcon_class();
		if (ret < 0)
			return ret;
	}

	if (!edev || !edev->supported_cable)
		return -EINVAL;

	for (; edev->supported_cable[index] != EXTCON_NONE; index++);

	edev->max_supported = index;
	if (index > SUPPORTED_CABLE_MAX) {
		dev_err(&edev->dev,
			"exceed the maximum number of supported cables\n");
		return -EINVAL;
	}

	edev->dev.class = extcon_class;
	edev->dev.release = extcon_dev_release;

	edev->name = dev_name(edev->dev.parent);
	if (IS_ERR_OR_NULL(edev->name)) {
		dev_err(&edev->dev,
			"extcon device name is null\n");
		return -EINVAL;
	}
	dev_set_name(&edev->dev, "extcon%lu",
			(unsigned long)atomic_inc_return(&edev_no));

	if (edev->max_supported) {
		char *str;
		struct extcon_cable *cable;

		edev->cables = kcalloc(edev->max_supported,
				       sizeof(struct extcon_cable),
				       GFP_KERNEL);
		if (!edev->cables) {
			ret = -ENOMEM;
			goto err_sysfs_alloc;
		}
		for (index = 0; index < edev->max_supported; index++) {
			cable = &edev->cables[index];

			str = kasprintf(GFP_KERNEL, "cable.%d", index);
			if (!str) {
				for (index--; index >= 0; index--) {
					cable = &edev->cables[index];
					kfree(cable->attr_g.name);
				}
				ret = -ENOMEM;

				goto err_alloc_cables;
			}

			cable->edev = edev;
			cable->cable_index = index;
			cable->attrs[0] = &cable->attr_name.attr;
			cable->attrs[1] = &cable->attr_state.attr;
			cable->attrs[2] = NULL;
			cable->attr_g.name = str;
			cable->attr_g.attrs = cable->attrs;

			sysfs_attr_init(&cable->attr_name.attr);
			cable->attr_name.attr.name = "name";
			cable->attr_name.attr.mode = 0444;
			cable->attr_name.show = cable_name_show;

			sysfs_attr_init(&cable->attr_state.attr);
			cable->attr_state.attr.name = "state";
			cable->attr_state.attr.mode = 0444;
			cable->attr_state.show = cable_state_show;
		}
	}

	if (edev->max_supported && edev->mutually_exclusive) {
		char *name;

		/* Count the size of mutually_exclusive array */
		for (index = 0; edev->mutually_exclusive[index]; index++)
			;

		edev->attrs_muex = kcalloc(index + 1,
					   sizeof(struct attribute *),
					   GFP_KERNEL);
		if (!edev->attrs_muex) {
			ret = -ENOMEM;
			goto err_muex;
		}

		edev->d_attrs_muex = kcalloc(index,
					     sizeof(struct device_attribute),
					     GFP_KERNEL);
		if (!edev->d_attrs_muex) {
			ret = -ENOMEM;
			kfree(edev->attrs_muex);
			goto err_muex;
		}

		for (index = 0; edev->mutually_exclusive[index]; index++) {
			name = kasprintf(GFP_KERNEL, "0x%x",
					 edev->mutually_exclusive[index]);
			if (!name) {
				for (index--; index >= 0; index--) {
					kfree(edev->d_attrs_muex[index].attr.
					      name);
				}
				kfree(edev->d_attrs_muex);
				kfree(edev->attrs_muex);
				ret = -ENOMEM;
				goto err_muex;
			}
			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
			edev->d_attrs_muex[index].attr.name = name;
			edev->d_attrs_muex[index].attr.mode = 0000;
			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
							.attr;
		}
		edev->attr_g_muex.name = muex_name;
		edev->attr_g_muex.attrs = edev->attrs_muex;

	}

	if (edev->max_supported) {
		edev->extcon_dev_type.groups =
			kcalloc(edev->max_supported + 2,
				sizeof(struct attribute_group *),
				GFP_KERNEL);
		if (!edev->extcon_dev_type.groups) {
			ret = -ENOMEM;
			goto err_alloc_groups;
		}

		edev->extcon_dev_type.name = dev_name(&edev->dev);
		edev->extcon_dev_type.release = dummy_sysfs_dev_release;

		for (index = 0; index < edev->max_supported; index++)
			edev->extcon_dev_type.groups[index] =
				&edev->cables[index].attr_g;
		if (edev->mutually_exclusive)
			edev->extcon_dev_type.groups[index] =
				&edev->attr_g_muex;

		edev->dev.type = &edev->extcon_dev_type;
	}

	ret = device_register(&edev->dev);
	if (ret) {
		put_device(&edev->dev);
		goto err_dev;
	}

	spin_lock_init(&edev->lock);
	edev->nh = devm_kcalloc(&edev->dev, edev->max_supported,
				sizeof(*edev->nh), GFP_KERNEL);
	if (!edev->nh) {
		ret = -ENOMEM;
		device_unregister(&edev->dev);
		goto err_dev;
	}

	for (index = 0; index < edev->max_supported; index++)
		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);

	RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);

	dev_set_drvdata(&edev->dev, edev);
	edev->state = 0;

	mutex_lock(&extcon_dev_list_lock);
	list_add(&edev->entry, &extcon_dev_list);
	mutex_unlock(&extcon_dev_list_lock);

	return 0;

err_dev:
	if (edev->max_supported)
		kfree(edev->extcon_dev_type.groups);
err_alloc_groups:
	if (edev->max_supported && edev->mutually_exclusive) {
		for (index = 0; edev->mutually_exclusive[index]; index++)
			kfree(edev->d_attrs_muex[index].attr.name);
		kfree(edev->d_attrs_muex);
		kfree(edev->attrs_muex);
	}
err_muex:
	for (index = 0; index < edev->max_supported; index++)
		kfree(edev->cables[index].attr_g.name);
err_alloc_cables:
	if (edev->max_supported)
		kfree(edev->cables);
err_sysfs_alloc:
	return ret;
}