Re: [PATCH 1/2] dmaengine: Add QCOM ADM DMA driver

+static int adm_slave_config(struct adm_chan *achan,
+		struct dma_slave_config *cfg)
+{
+	int ret = 0;
+	u32 burst;
+	struct adm_device *adev = achan->adev;
+
+	memcpy(&achan->slave, cfg, sizeof(*cfg));
+
+	/* set channel CRCI burst, if applicable */
+	if (achan->crci) {
+		burst = max_t(u32, cfg->src_maxburst, cfg->dst_maxburst);
+
+		switch (burst) {
+		case 16:
+			achan->blk_size = 0;
+			break;
+		case 32:
+			achan->blk_size = 1;
+			break;
+		case 64:
+			achan->blk_size = 2;
+			break;
+		case 128:
+			achan->blk_size = 3;
+			break;
+		case 192:
+			achan->blk_size = 4;
+			break;
+		case 256:
+			achan->blk_size = 5;
+			break;
+		default:
+			achan->slave.src_maxburst = 0;
+			achan->slave.dst_maxburst = 0;

+			ret = -EINVAL;
+			break;
+		}
+
+		if (!ret)
+			writel(achan->blk_size,
+				adev->regs + HI_CRCI_CTL(achan->id, adev->ee));

+static enum dma_status adm_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+	struct dma_tx_state *txstate)
+{
+	struct adm_chan *achan = to_adm_chan(chan);
+	struct virt_dma_desc *vd;
+	enum dma_status ret;
+	unsigned long flags;
+	size_t residue = 0;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+

+	spin_lock_irqsave(&achan->vc.lock, flags);
+
+	vd = vchan_find_desc(&achan->vc, cookie);
+	if (vd)
+		residue = container_of(vd, struct adm_async_desc, vd)->length;
+	else if (achan->curr_txd && achan->curr_txd->vd.tx.cookie == cookie)
+		residue = achan->curr_txd->length;

+
+	spin_unlock_irqrestore(&achan->vc.lock, flags);
+
+	dma_set_residue(txstate, residue);
+
+	if (achan->error)
+		return DMA_ERROR;
+
+	return ret;