int mhi_register_controller()

in mhi/core/init.c [877:1019]
115 lines of code
25 McCabe index (conditional complexity)

int mhi_register_controller(struct mhi_controller *mhi_cntrl,
			    const struct mhi_controller_config *config)
{
	struct mhi_event *mhi_event;
	struct mhi_chan *mhi_chan;
	struct mhi_cmd *mhi_cmd;
	struct mhi_device *mhi_dev;
	u32 soc_info;
	int ret, i;

	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs ||
	    !mhi_cntrl->irq || !mhi_cntrl->reg_len)
		return -EINVAL;

	ret = parse_config(mhi_cntrl, config);
	if (ret)
		return -EINVAL;

	mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
				     sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
	if (!mhi_cntrl->mhi_cmd) {
		ret = -ENOMEM;
		goto err_free_event;
	}

	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
	mutex_init(&mhi_cntrl->pm_mutex);
	rwlock_init(&mhi_cntrl->pm_lock);
	spin_lock_init(&mhi_cntrl->transition_lock);
	spin_lock_init(&mhi_cntrl->wlock);
	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
	init_waitqueue_head(&mhi_cntrl->state_event);

	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI);
	if (!mhi_cntrl->hiprio_wq) {
		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
		ret = -ENOMEM;
		goto err_free_cmd;
	}

	mhi_cmd = mhi_cntrl->mhi_cmd;
	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
		spin_lock_init(&mhi_cmd->lock);

	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		/* Skip for offload events */
		if (mhi_event->offload_ev)
			continue;

		mhi_event->mhi_cntrl = mhi_cntrl;
		spin_lock_init(&mhi_event->lock);
		if (mhi_event->data_type == MHI_ER_CTRL)
			tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
				     (ulong)mhi_event);
		else
			tasklet_init(&mhi_event->task, mhi_ev_task,
				     (ulong)mhi_event);
	}

	mhi_chan = mhi_cntrl->mhi_chan;
	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
		mutex_init(&mhi_chan->mutex);
		init_completion(&mhi_chan->completion);
		rwlock_init(&mhi_chan->lock);

		/* used in setting bei field of TRE */
		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
		mhi_chan->intmod = mhi_event->intmod;
	}

	if (mhi_cntrl->bounce_buf) {
		mhi_cntrl->map_single = mhi_map_single_use_bb;
		mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
	} else {
		mhi_cntrl->map_single = mhi_map_single_no_bb;
		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
	}

	/* Read the MHI device info */
	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
			   SOC_HW_VERSION_OFFS, &soc_info);
	if (ret)
		goto err_destroy_wq;

	mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
					SOC_HW_VERSION_FAM_NUM_SHFT;
	mhi_cntrl->device_number = (soc_info & SOC_HW_VERSION_DEV_NUM_BMSK) >>
					SOC_HW_VERSION_DEV_NUM_SHFT;
	mhi_cntrl->major_version = (soc_info & SOC_HW_VERSION_MAJOR_VER_BMSK) >>
					SOC_HW_VERSION_MAJOR_VER_SHFT;
	mhi_cntrl->minor_version = (soc_info & SOC_HW_VERSION_MINOR_VER_BMSK) >>
					SOC_HW_VERSION_MINOR_VER_SHFT;

	mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
	if (mhi_cntrl->index < 0) {
		ret = mhi_cntrl->index;
		goto err_destroy_wq;
	}

	/* Register controller with MHI bus */
	mhi_dev = mhi_alloc_device(mhi_cntrl);
	if (IS_ERR(mhi_dev)) {
		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
		ret = PTR_ERR(mhi_dev);
		goto err_ida_free;
	}

	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
	mhi_dev->mhi_cntrl = mhi_cntrl;
	dev_set_name(&mhi_dev->dev, "mhi%d", mhi_cntrl->index);
	mhi_dev->name = dev_name(&mhi_dev->dev);

	/* Init wakeup source */
	device_init_wakeup(&mhi_dev->dev, true);

	ret = device_add(&mhi_dev->dev);
	if (ret)
		goto err_release_dev;

	mhi_cntrl->mhi_dev = mhi_dev;

	mhi_create_debugfs(mhi_cntrl);

	return 0;

err_release_dev:
	put_device(&mhi_dev->dev);
err_ida_free:
	ida_free(&mhi_controller_ida, mhi_cntrl->index);
err_destroy_wq:
	destroy_workqueue(mhi_cntrl->hiprio_wq);
err_free_cmd:
	kfree(mhi_cntrl->mhi_cmd);
err_free_event:
	kfree(mhi_cntrl->mhi_event);
	vfree(mhi_cntrl->mhi_chan);

	return ret;
}