[PATCH v6 1/3] dmaengine: sun6i: Simplify lli setting

[Jean-Francois Moine]

Checking the DMA config before setting the lli list avoids to do tests
inside the setting loop.

Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
---
 drivers/dma/sun6i-dma.c | 102 ++++++++++++++++++++++--------------------------
 1 file changed, 47 insertions(+), 55 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 3579ee7..b08245e 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -276,45 +276,6 @@ static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
 	return next;
 }
 
-static inline int sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli,
-				    dma_addr_t src,
-				    dma_addr_t dst, u32 len,
-				    struct dma_slave_config *config)
-{
-	s8 src_width, dst_width, src_burst, dst_burst;
-
-	if (!config)
-		return -EINVAL;
-
-	src_burst = convert_burst(config->src_maxburst);
-	if (src_burst < 0)
-		return src_burst;
-
-	dst_burst = convert_burst(config->dst_maxburst);
-	if (dst_burst < 0)
-		return dst_burst;
-
-	src_width = convert_buswidth(config->src_addr_width);
-	if (src_width < 0)
-		return src_width;
-
-	dst_width = convert_buswidth(config->dst_addr_width);
-	if (dst_width < 0)
-		return dst_width;
-
-	lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
-		DMA_CHAN_CFG_SRC_WIDTH(src_width) |
-		DMA_CHAN_CFG_DST_BURST(dst_burst) |
-		DMA_CHAN_CFG_DST_WIDTH(dst_width);
-
-	lli->src = src;
-	lli->dst = dst;
-	lli->len = len;
-	lli->para = NORMAL_WAIT;
-
-	return 0;
-}
-
 static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
 				      struct sun6i_dma_lli *lli)
 {
@@ -502,6 +463,35 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
 	return ret;
 }
 
+static int set_config(struct sun6i_dma_dev *sdev,
+			struct dma_slave_config *sconfig,
+			enum dma_transfer_direction direction,
+			u32 *p_cfg)
+{
+	s8 src_width, dst_width, src_burst, dst_burst;
+
+	src_burst = convert_burst(sconfig->src_maxburst);
+	src_width = convert_buswidth(sconfig->src_addr_width);
+	dst_burst = convert_burst(sconfig->dst_maxburst);
+	dst_width = convert_buswidth(sconfig->dst_addr_width);
+
+	if (src_burst < 0)
+		return src_burst;
+	if (src_width < 0)
+		return src_width;
+	if (dst_burst < 0)
+		return dst_burst;
+	if (dst_width < 0)
+		return dst_width;
+
+	*p_cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
+		DMA_CHAN_CFG_SRC_WIDTH(src_width) |
+		DMA_CHAN_CFG_DST_BURST(dst_burst) |
+		DMA_CHAN_CFG_DST_WIDTH(dst_width);
+
+	return 0;
+}
+
 static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
 		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		size_t len, unsigned long flags)
@@ -569,6 +559,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 	struct sun6i_desc *txd;
 	struct scatterlist *sg;
 	dma_addr_t p_lli;
+	u32 lli_cfg;
 	int i, ret;
 
 	if (!sgl)
@@ -579,6 +570,12 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 		return NULL;
 	}
 
+	ret = set_config(sdev, sconfig, dir, &lli_cfg);
+	if (ret) {
+		dev_err(chan2dev(chan), "Invalid DMA configuration\n");
+		return NULL;
+	}
+
 	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 	if (!txd)
 		return NULL;
@@ -588,14 +585,14 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 		if (!v_lli)
 			goto err_lli_free;
 
-		if (dir == DMA_MEM_TO_DEV) {
-			ret = sun6i_dma_cfg_lli(v_lli, sg_dma_address(sg),
-						sconfig->dst_addr, sg_dma_len(sg),
-						sconfig);
-			if (ret)
-				goto err_cur_lli_free;
+		v_lli->len = sg_dma_len(sg);
+		v_lli->para = NORMAL_WAIT;
 
-			v_lli->cfg |= DMA_CHAN_CFG_DST_IO_MODE |
+		if (dir == DMA_MEM_TO_DEV) {
+			v_lli->src = sg_dma_address(sg);
+			v_lli->dst = sconfig->dst_addr;
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_IO_MODE |
 				DMA_CHAN_CFG_SRC_LINEAR_MODE |
 				DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
 				DMA_CHAN_CFG_DST_DRQ(vchan->port);
@@ -607,13 +604,10 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 				sg_dma_len(sg), flags);
 
 		} else {
-			ret = sun6i_dma_cfg_lli(v_lli, sconfig->src_addr,
-						sg_dma_address(sg), sg_dma_len(sg),
-						sconfig);
-			if (ret)
-				goto err_cur_lli_free;
-
-			v_lli->cfg |= DMA_CHAN_CFG_DST_LINEAR_MODE |
+			v_lli->src = sconfig->src_addr;
+			v_lli->dst = sg_dma_address(sg);
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_LINEAR_MODE |
 				DMA_CHAN_CFG_SRC_IO_MODE |
 				DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
 				DMA_CHAN_CFG_SRC_DRQ(vchan->port);
@@ -634,8 +628,6 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 
 	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 
-err_cur_lli_free:
-	dma_pool_free(sdev->pool, v_lli, p_lli);
 err_lli_free:
 	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
 		dma_pool_free(sdev->pool, prev, virt_to_phys(prev));
-- 
2.8.1