static int virtinput_probe()

in virtio_input.c [218:337]

• 102 lines of code
• 13 McCabe index (conditional complexity)

static int virtinput_probe(struct virtio_device *vdev)
{
	struct virtio_input *vi;
	unsigned long flags;
	size_t size;
	int abs, err, nslots;

	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
		return -ENODEV;

	vi = kzalloc(sizeof(*vi), GFP_KERNEL);
	if (!vi)
		return -ENOMEM;

	vdev->priv = vi;
	vi->vdev = vdev;
	spin_lock_init(&vi->lock);

	err = virtinput_init_vqs(vi);
	if (err)
		goto err_init_vq;

	vi->idev = input_allocate_device();
	if (!vi->idev) {
		err = -ENOMEM;
		goto err_input_alloc;
	}
	input_set_drvdata(vi->idev, vi);

	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);
	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
					      u.string),
			   vi->name, min(size, sizeof(vi->name)));
	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);
	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
					      u.string),
			   vi->serial, min(size, sizeof(vi->serial)));
	snprintf(vi->phys, sizeof(vi->phys),
		 "virtio%d/input0", vdev->index);
	vi->idev->name = vi->name;
	vi->idev->phys = vi->phys;
	vi->idev->uniq = vi->serial;

	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);
	if (size >= sizeof(struct virtio_input_devids)) {
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.bustype, &vi->idev->id.bustype);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.vendor, &vi->idev->id.vendor);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.product, &vi->idev->id.product);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.version, &vi->idev->id.version);
	} else {
		vi->idev->id.bustype = BUS_VIRTUAL;
	}

	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,
			   vi->idev->propbit, INPUT_PROP_CNT);
	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);
	if (size)
		__set_bit(EV_REP, vi->idev->evbit);

	vi->idev->dev.parent = &vdev->dev;
	vi->idev->event = virtinput_status;

	/* device -> kernel */
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,
			   vi->idev->keybit, KEY_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,
			   vi->idev->relbit, REL_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,
			   vi->idev->absbit, ABS_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,
			   vi->idev->mscbit, MSC_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,
			   vi->idev->swbit,  SW_CNT);

	/* kernel -> device */
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,
			   vi->idev->ledbit, LED_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,
			   vi->idev->sndbit, SND_CNT);

	if (test_bit(EV_ABS, vi->idev->evbit)) {
		for (abs = 0; abs < ABS_CNT; abs++) {
			if (!test_bit(abs, vi->idev->absbit))
				continue;
			virtinput_cfg_abs(vi, abs);
		}

		if (test_bit(ABS_MT_SLOT, vi->idev->absbit)) {
			nslots = input_abs_get_max(vi->idev, ABS_MT_SLOT) + 1;
			err = input_mt_init_slots(vi->idev, nslots, 0);
			if (err)
				goto err_mt_init_slots;
		}
	}

	virtio_device_ready(vdev);
	vi->ready = true;
	err = input_register_device(vi->idev);
	if (err)
		goto err_input_register;

	virtinput_fill_evt(vi);
	return 0;

err_input_register:
	spin_lock_irqsave(&vi->lock, flags);
	vi->ready = false;
	spin_unlock_irqrestore(&vi->lock, flags);
err_mt_init_slots:
	input_free_device(vi->idev);
err_input_alloc:
	vdev->config->del_vqs(vdev);
err_init_vq:
	kfree(vi);
	return err;
}