1 files changed, 138 insertions, 74 deletions

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 29fa35807f09..5dce96af9c46 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -46,8 +46,14 @@
 #define EDMA_CHANS	64
 #endif /* CONFIG_ARCH_DAVINCI_DA8XX */
 
-/* Max of 16 segments per channel to conserve PaRAM slots */
-#define MAX_NR_SG		16
+/*
+ * Max of 20 segments per channel to conserve PaRAM slots
+ * Also note that MAX_NR_SG should be atleast the no.of periods
+ * that are required for ASoC, otherwise DMA prep calls will
+ * fail. Today davinci-pcm is the only user of this driver and
+ * requires atleast 17 slots, so we setup the default to 20.
+ */
+#define MAX_NR_SG		20
 #define EDMA_MAX_SLOTS		MAX_NR_SG
 #define EDMA_DESCRIPTORS	16
 
@@ -250,6 +256,117 @@ static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 	return ret;
 }
 
+/*
+ * A PaRAM set configuration abstraction used by other modes
+ * @chan: Channel who's PaRAM set we're configuring
+ * @pset: PaRAM set to initialize and setup.
+ * @src_addr: Source address of the DMA
+ * @dst_addr: Destination address of the DMA
+ * @burst: In units of dev_width, how much to send
+ * @dev_width: How much is the dev_width
+ * @dma_length: Total length of the DMA transfer
+ * @direction: Direction of the transfer
+ */
+static int edma_config_pset(struct dma_chan *chan, struct edmacc_param *pset,
+	dma_addr_t src_addr, dma_addr_t dst_addr, u32 burst,
+	enum dma_slave_buswidth dev_width, unsigned int dma_length,
+	enum dma_transfer_direction direction)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	struct device *dev = chan->device->dev;
+	int acnt, bcnt, ccnt, cidx;
+	int src_bidx, dst_bidx, src_cidx, dst_cidx;
+	int absync;
+
+	acnt = dev_width;
+	/*
+	 * If the maxburst is equal to the fifo width, use
+	 * A-synced transfers. This allows for large contiguous
+	 * buffer transfers using only one PaRAM set.
+	 */
+	if (burst == 1) {
+		/*
+		 * For the A-sync case, bcnt and ccnt are the remainder
+		 * and quotient respectively of the division of:
+		 * (dma_length / acnt) by (SZ_64K -1). This is so
+		 * that in case bcnt over flows, we have ccnt to use.
+		 * Note: In A-sync tranfer only, bcntrld is used, but it
+		 * only applies for sg_dma_len(sg) >= SZ_64K.
+		 * In this case, the best way adopted is- bccnt for the
+		 * first frame will be the remainder below. Then for
+		 * every successive frame, bcnt will be SZ_64K-1. This
+		 * is assured as bcntrld = 0xffff in end of function.
+		 */
+		absync = false;
+		ccnt = dma_length / acnt / (SZ_64K - 1);
+		bcnt = dma_length / acnt - ccnt * (SZ_64K - 1);
+		/*
+		 * If bcnt is non-zero, we have a remainder and hence an
+		 * extra frame to transfer, so increment ccnt.
+		 */
+		if (bcnt)
+			ccnt++;
+		else
+			bcnt = SZ_64K - 1;
+		cidx = acnt;
+	} else {
+		/*
+		 * If maxburst is greater than the fifo address_width,
+		 * use AB-synced transfers where A count is the fifo
+		 * address_width and B count is the maxburst. In this
+		 * case, we are limited to transfers of C count frames
+		 * of (address_width * maxburst) where C count is limited
+		 * to SZ_64K-1. This places an upper bound on the length
+		 * of an SG segment that can be handled.
+		 */
+		absync = true;
+		bcnt = burst;
+		ccnt = dma_length / (acnt * bcnt);
+		if (ccnt > (SZ_64K - 1)) {
+			dev_err(dev, "Exceeded max SG segment size\n");
+			return -EINVAL;
+		}
+		cidx = acnt * bcnt;
+	}
+
+	if (direction == DMA_MEM_TO_DEV) {
+		src_bidx = acnt;
+		src_cidx = cidx;
+		dst_bidx = 0;
+		dst_cidx = 0;
+	} else if (direction == DMA_DEV_TO_MEM)  {
+		src_bidx = 0;
+		src_cidx = 0;
+		dst_bidx = acnt;
+		dst_cidx = cidx;
+	} else {
+		dev_err(dev, "%s: direction not implemented yet\n", __func__);
+		return -EINVAL;
+	}
+
+	pset->opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
+	/* Configure A or AB synchronized transfers */
+	if (absync)
+		pset->opt |= SYNCDIM;
+
+	pset->src = src_addr;
+	pset->dst = dst_addr;
+
+	pset->src_dst_bidx = (dst_bidx << 16) | src_bidx;
+	pset->src_dst_cidx = (dst_cidx << 16) | src_cidx;
+
+	pset->a_b_cnt = bcnt << 16 | acnt;
+	pset->ccnt = ccnt;
+	/*
+	 * Only time when (bcntrld) auto reload is required is for
+	 * A-sync case, and in this case, a requirement of reload value
+	 * of SZ_64K-1 only is assured. 'link' is initially set to NULL
+	 * and then later will be populated by edma_execute.
+	 */
+	pset->link_bcntrld = 0xffffffff;
+	return absync;
+}
+
 static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 	struct dma_chan *chan, struct scatterlist *sgl,
 	unsigned int sg_len, enum dma_transfer_direction direction,
@@ -258,23 +375,21 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 	struct edma_chan *echan = to_edma_chan(chan);
 	struct device *dev = chan->device->dev;
 	struct edma_desc *edesc;
-	dma_addr_t dev_addr;
+	dma_addr_t src_addr = 0, dst_addr = 0;
 	enum dma_slave_buswidth dev_width;
 	u32 burst;
 	struct scatterlist *sg;
-	int acnt, bcnt, ccnt, src, dst, cidx;
-	int src_bidx, dst_bidx, src_cidx, dst_cidx;
-	int i, nslots;
+	int i, nslots, ret;
 
 	if (unlikely(!echan || !sgl || !sg_len))
 		return NULL;
 
 	if (direction == DMA_DEV_TO_MEM) {
-		dev_addr = echan->cfg.src_addr;
+		src_addr = echan->cfg.src_addr;
 		dev_width = echan->cfg.src_addr_width;
 		burst = echan->cfg.src_maxburst;
 	} else if (direction == DMA_MEM_TO_DEV) {
-		dev_addr = echan->cfg.dst_addr;
+		dst_addr = echan->cfg.dst_addr;
 		dev_width = echan->cfg.dst_addr_width;
 		burst = echan->cfg.dst_maxburst;
 	} else {
@@ -305,7 +420,9 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 				edma_alloc_slot(EDMA_CTLR(echan->ch_num),
 						EDMA_SLOT_ANY);
 			if (echan->slot[i] < 0) {
+				kfree(edesc);
 				dev_err(dev, "Failed to allocate slot\n");
+				kfree(edesc);
 				return NULL;
 			}
 		}
@@ -313,63 +430,21 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 
 	/* Configure PaRAM sets for each SG */
 	for_each_sg(sgl, sg, sg_len, i) {
-
-		acnt = dev_width;
-
-		/*
-		 * If the maxburst is equal to the fifo width, use
-		 * A-synced transfers. This allows for large contiguous
-		 * buffer transfers using only one PaRAM set.
-		 */
-		if (burst == 1) {
-			edesc->absync = false;
-			ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
-			bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
-			if (bcnt)
-				ccnt++;
-			else
-				bcnt = SZ_64K - 1;
-			cidx = acnt;
-		/*
-		 * If maxburst is greater than the fifo address_width,
-		 * use AB-synced transfers where A count is the fifo
-		 * address_width and B count is the maxburst. In this
-		 * case, we are limited to transfers of C count frames
-		 * of (address_width * maxburst) where C count is limited
-		 * to SZ_64K-1. This places an upper bound on the length
-		 * of an SG segment that can be handled.
-		 */
-		} else {
-			edesc->absync = true;
-			bcnt = burst;
-			ccnt = sg_dma_len(sg) / (acnt * bcnt);
-			if (ccnt > (SZ_64K - 1)) {
-				dev_err(dev, "Exceeded max SG segment size\n");
-				return NULL;
-			}
-			cidx = acnt * bcnt;
+		/* Get address for each SG */
+		if (direction == DMA_DEV_TO_MEM)
+			dst_addr = sg_dma_address(sg);
+		else
+			src_addr = sg_dma_address(sg);
+
+		ret = edma_config_pset(chan, &edesc->pset[i], src_addr,
+				       dst_addr, burst, dev_width,
+				       sg_dma_len(sg), direction);
+		if (ret < 0) {
+			kfree(edesc);
+			return NULL;
 		}
 
-		if (direction == DMA_MEM_TO_DEV) {
-			src = sg_dma_address(sg);
-			dst = dev_addr;
-			src_bidx = acnt;
-			src_cidx = cidx;
-			dst_bidx = 0;
-			dst_cidx = 0;
-		} else {
-			src = dev_addr;
-			dst = sg_dma_address(sg);
-			src_bidx = 0;
-			src_cidx = 0;
-			dst_bidx = acnt;
-			dst_cidx = cidx;
-		}
-
-		edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
-		/* Configure A or AB synchronized transfers */
-		if (edesc->absync)
-			edesc->pset[i].opt |= SYNCDIM;
+		edesc->absync = ret;
 
 		/* If this is the last in a current SG set of transactions,
 		   enable interrupts so that next set is processed */
@@ -379,17 +454,6 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
 		/* If this is the last set, enable completion interrupt flag */
 		if (i == sg_len - 1)
 			edesc->pset[i].opt |= TCINTEN;
-
-		edesc->pset[i].src = src;
-		edesc->pset[i].dst = dst;
-
-		edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx;
-		edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx;
-
-		edesc->pset[i].a_b_cnt = bcnt << 16 | acnt;
-		edesc->pset[i].ccnt = ccnt;
-		edesc->pset[i].link_bcntrld = 0xffffffff;
-
 	}
 
 	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);