static int parse_ch_cfg()

in mhi/core/init.c [722:838]

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

static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
			const struct mhi_controller_config *config)
{
	const struct mhi_channel_config *ch_cfg;
	struct device *dev = mhi_cntrl->cntrl_dev;
	int i;
	u32 chan;

	mhi_cntrl->max_chan = config->max_channels;

	/*
	 * The allocation of MHI channels can exceed 32KB in some scenarios,
	 * so to avoid any memory possible allocation failures, vzalloc is
	 * used here
	 */
	mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
				      sizeof(*mhi_cntrl->mhi_chan));
	if (!mhi_cntrl->mhi_chan)
		return -ENOMEM;

	INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);

	/* Populate channel configurations */
	for (i = 0; i < config->num_channels; i++) {
		struct mhi_chan *mhi_chan;

		ch_cfg = &config->ch_cfg[i];

		chan = ch_cfg->num;
		if (chan >= mhi_cntrl->max_chan) {
			dev_err(dev, "Channel %d not available\n", chan);
			goto error_chan_cfg;
		}

		mhi_chan = &mhi_cntrl->mhi_chan[chan];
		mhi_chan->name = ch_cfg->name;
		mhi_chan->chan = chan;

		mhi_chan->tre_ring.elements = ch_cfg->num_elements;
		if (!mhi_chan->tre_ring.elements)
			goto error_chan_cfg;

		/*
		 * For some channels, local ring length should be bigger than
		 * the transfer ring length due to internal logical channels
		 * in device. So host can queue much more buffers than transfer
		 * ring length. Example, RSC channels should have a larger local
		 * channel length than transfer ring length.
		 */
		mhi_chan->buf_ring.elements = ch_cfg->local_elements;
		if (!mhi_chan->buf_ring.elements)
			mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
		mhi_chan->er_index = ch_cfg->event_ring;
		mhi_chan->dir = ch_cfg->dir;

		/*
		 * For most channels, chtype is identical to channel directions.
		 * So, if it is not defined then assign channel direction to
		 * chtype
		 */
		mhi_chan->type = ch_cfg->type;
		if (!mhi_chan->type)
			mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;

		mhi_chan->ee_mask = ch_cfg->ee_mask;
		mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
		mhi_chan->lpm_notify = ch_cfg->lpm_notify;
		mhi_chan->offload_ch = ch_cfg->offload_channel;
		mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
		mhi_chan->pre_alloc = ch_cfg->auto_queue;
		mhi_chan->wake_capable = ch_cfg->wake_capable;

		/*
		 * If MHI host allocates buffers, then the channel direction
		 * should be DMA_FROM_DEVICE
		 */
		if (mhi_chan->pre_alloc && mhi_chan->dir != DMA_FROM_DEVICE) {
			dev_err(dev, "Invalid channel configuration\n");
			goto error_chan_cfg;
		}

		/*
		 * Bi-directional and direction less channel must be an
		 * offload channel
		 */
		if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
		     mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
			dev_err(dev, "Invalid channel configuration\n");
			goto error_chan_cfg;
		}

		if (!mhi_chan->offload_ch) {
			mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
			if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
				dev_err(dev, "Invalid Door bell mode\n");
				goto error_chan_cfg;
			}
		}

		if (mhi_chan->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
			mhi_chan->db_cfg.process_db = mhi_db_brstmode;
		else
			mhi_chan->db_cfg.process_db = mhi_db_brstmode_disable;

		mhi_chan->configured = true;

		if (mhi_chan->lpm_notify)
			list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
	}

	return 0;

error_chan_cfg:
	vfree(mhi_cntrl->mhi_chan);

	return -EINVAL;
}