[PATCH v2 1/2] dmaengine: sprd: Optimize the sprd_dma_prep_dma_memcpy()

[PATCH v2 1/2] dmaengine: sprd: Optimize the sprd_dma_prep_dma_memcpy()

[Baolin Wang]

From: Eric Long <eric.long@spreadtrum.com>

This is one preparation patch, we can use default DMA configuration to
implement the device_prep_dma_memcpy() interface instead of issuing
sprd_dma_config().

We will implement one new sprd_dma_config() function with introducing
device_prep_slave_sg() interface in following patch. So we can remove
the obsolete sprd_dma_config() firstly.

Signed-off-by: Eric Long <eric.long@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - No updates.
---
 drivers/dma/sprd-dma.c |  154 ++++++++++--------------------------------------
 1 file changed, 32 insertions(+), 122 deletions(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index e715d07..e07e253 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -552,147 +552,57 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
 	spin_unlock_irqrestore(&schan->vc.lock, flags);
 }
 
-static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
-			   dma_addr_t dest, dma_addr_t src, size_t len)
+static struct dma_async_tx_descriptor *
+sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+			 size_t len, unsigned long flags)
 {
-	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
-	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
-	u32 datawidth, src_step, des_step, fragment_len;
-	u32 block_len, req_mode, irq_mode, transcation_len;
-	u32 fix_mode = 0, fix_en = 0;
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_desc *sdesc;
+	struct sprd_dma_chn_hw *hw;
+	enum sprd_dma_datawidth datawidth;
+	u32 step;
 
-	if (IS_ALIGNED(len, 4)) {
-		datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
-		src_step = SPRD_DMA_WORD_STEP;
-		des_step = SPRD_DMA_WORD_STEP;
-	} else if (IS_ALIGNED(len, 2)) {
-		datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
-		src_step = SPRD_DMA_SHORT_STEP;
-		des_step = SPRD_DMA_SHORT_STEP;
-	} else {
-		datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
-		src_step = SPRD_DMA_BYTE_STEP;
-		des_step = SPRD_DMA_BYTE_STEP;
-	}
+	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+	if (!sdesc)
+		return NULL;
 
-	fragment_len = SPRD_DMA_MEMCPY_MIN_SIZE;
-	if (len <= SPRD_DMA_BLK_LEN_MASK) {
-		block_len = len;
-		transcation_len = 0;
-		req_mode = SPRD_DMA_BLK_REQ;
-		irq_mode = SPRD_DMA_BLK_INT;
-	} else {
-		block_len = SPRD_DMA_MEMCPY_MIN_SIZE;
-		transcation_len = len;
-		req_mode = SPRD_DMA_TRANS_REQ;
-		irq_mode = SPRD_DMA_TRANS_INT;
-	}
+	hw = &sdesc->chn_hw;
 
 	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
+	hw->intc = SPRD_DMA_TRANS_INT | SPRD_DMA_CFG_ERR_INT_EN;
+	hw->src_addr = (u32)(src & SPRD_DMA_LOW_ADDR_MASK);
+	hw->des_addr = (u32)(dest & SPRD_DMA_LOW_ADDR_MASK);
 	hw->wrap_ptr = (u32)((src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
 			     SPRD_DMA_HIGH_ADDR_MASK);
 	hw->wrap_to = (u32)((dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
 			    SPRD_DMA_HIGH_ADDR_MASK);
 
-	hw->src_addr = (u32)(src & SPRD_DMA_LOW_ADDR_MASK);
-	hw->des_addr = (u32)(dest & SPRD_DMA_LOW_ADDR_MASK);
-
-	if ((src_step != 0 && des_step != 0) || (src_step | des_step) == 0) {
-		fix_en = 0;
+	if (IS_ALIGNED(len, 8)) {
+		datawidth = SPRD_DMA_DATAWIDTH_8_BYTES;
+		step = SPRD_DMA_DWORD_STEP;
+	} else if (IS_ALIGNED(len, 4)) {
+		datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
+		step = SPRD_DMA_WORD_STEP;
+	} else if (IS_ALIGNED(len, 2)) {
+		datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
+		step = SPRD_DMA_SHORT_STEP;
 	} else {
-		fix_en = 1;
-		if (src_step)
-			fix_mode = 1;
-		else
-			fix_mode = 0;
+		datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
+		step = SPRD_DMA_BYTE_STEP;
 	}
 
 	hw->frg_len = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
 		datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
-		req_mode << SPRD_DMA_REQ_MODE_OFFSET |
-		fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
-		fix_en << SPRD_DMA_FIX_EN_OFFSET |
-		(fragment_len & SPRD_DMA_FRG_LEN_MASK);
-	hw->blk_len = block_len & SPRD_DMA_BLK_LEN_MASK;
-
-	hw->intc = SPRD_DMA_CFG_ERR_INT_EN;
-
-	switch (irq_mode) {
-	case SPRD_DMA_NO_INT:
-		break;
-
-	case SPRD_DMA_FRAG_INT:
-		hw->intc |= SPRD_DMA_FRAG_INT_EN;
-		break;
-
-	case SPRD_DMA_BLK_INT:
-		hw->intc |= SPRD_DMA_BLK_INT_EN;
-		break;
+		SPRD_DMA_TRANS_REQ << SPRD_DMA_REQ_MODE_OFFSET |
+		(len & SPRD_DMA_FRG_LEN_MASK);
+	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
+	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
 
-	case SPRD_DMA_BLK_FRAG_INT:
-		hw->intc |= SPRD_DMA_BLK_INT_EN | SPRD_DMA_FRAG_INT_EN;
-		break;
-
-	case SPRD_DMA_TRANS_INT:
-		hw->intc |= SPRD_DMA_TRANS_INT_EN;
-		break;
-
-	case SPRD_DMA_TRANS_FRAG_INT:
-		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_FRAG_INT_EN;
-		break;
-
-	case SPRD_DMA_TRANS_BLK_INT:
-		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_BLK_INT_EN;
-		break;
-
-	case SPRD_DMA_LIST_INT:
-		hw->intc |= SPRD_DMA_LIST_INT_EN;
-		break;
-
-	case SPRD_DMA_CFGERR_INT:
-		hw->intc |= SPRD_DMA_CFG_ERR_INT_EN;
-		break;
-
-	default:
-		dev_err(sdev->dma_dev.dev, "invalid irq mode\n");
-		return -EINVAL;
-	}
-
-	if (transcation_len == 0)
-		hw->trsc_len = block_len & SPRD_DMA_TRSC_LEN_MASK;
-	else
-		hw->trsc_len = transcation_len & SPRD_DMA_TRSC_LEN_MASK;
-
-	hw->trsf_step = (des_step & SPRD_DMA_TRSF_STEP_MASK) <<
+	hw->trsf_step = (step & SPRD_DMA_TRSF_STEP_MASK) <<
 			SPRD_DMA_DEST_TRSF_STEP_OFFSET |
-			(src_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			(step & SPRD_DMA_TRSF_STEP_MASK) <<
 			SPRD_DMA_SRC_TRSF_STEP_OFFSET;
 
-	hw->frg_step = 0;
-	hw->src_blk_step = 0;
-	hw->des_blk_step = 0;
-	hw->src_blk_step = 0;
-	return 0;
-}
-
-static struct dma_async_tx_descriptor *
-sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
-			 size_t len, unsigned long flags)
-{
-	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
-	struct sprd_dma_desc *sdesc;
-	int ret;
-
-	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
-	if (!sdesc)
-		return NULL;
-
-	ret = sprd_dma_config(chan, sdesc, dest, src, len);
-	if (ret) {
-		kfree(sdesc);
-		return NULL;
-	}
-
 	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
 }
 
-- 
1.7.9.5

[PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Baolin Wang]

From: Eric Long <eric.long@spreadtrum.com>

This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces
for users to configure DMA, as well as adding one 'struct sprd_dma_config'
structure to save Spreadtrum DMA configuration for each DMA channel.

Signed-off-by: Eric Long <eric.long@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - Fix the incorrect parameter type of sprd_dma_get_step().
---
 drivers/dma/sprd-dma.c       |  215 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/dma/sprd-dma.h |    4 +
 2 files changed, 219 insertions(+)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index e07e253..26b4e01 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -100,6 +100,8 @@
 #define SPRD_DMA_DES_DATAWIDTH_OFFSET	28
 #define SPRD_DMA_SWT_MODE_OFFSET	26
 #define SPRD_DMA_REQ_MODE_OFFSET	24
+#define SPRD_DMA_WRAP_SEL_OFFSET	23
+#define SPRD_DMA_WRAP_EN_OFFSET		22
 #define SPRD_DMA_REQ_MODE_MASK		GENMASK(1, 0)
 #define SPRD_DMA_FIX_SEL_OFFSET		21
 #define SPRD_DMA_FIX_EN_OFFSET		20
@@ -154,6 +156,35 @@ struct sprd_dma_chn_hw {
 	u32 des_blk_step;
 };
 
+/*
+ * struct sprd_dma_config - DMA configuration structure
+ * @cfg: dma slave channel runtime config
+ * @src_addr: the source physical address
+ * @dst_addr: the destination physical address
+ * @block_len: specify one block transfer length
+ * @transcation_len: specify one transcation transfer length
+ * @src_step: source transfer step
+ * @dst_step: destination transfer step
+ * @wrap_ptr: wrap pointer address, once the transfer address reaches the
+ * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
+ * @wrap_to: wrap jump to address
+ * @req_mode: specify the DMA request mode
+ * @int_mode: specify the DMA interrupt type
+ */
+struct sprd_dma_config {
+	struct dma_slave_config cfg;
+	phys_addr_t src_addr;
+	phys_addr_t dst_addr;
+	u32 block_len;
+	u32 transcation_len;
+	u32 src_step;
+	u32 dst_step;
+	phys_addr_t wrap_ptr;
+	phys_addr_t wrap_to;
+	enum sprd_dma_req_mode req_mode;
+	enum sprd_dma_int_type int_mode;
+};
+
 /* dma request description */
 struct sprd_dma_desc {
 	struct virt_dma_desc	vd;
@@ -164,6 +195,7 @@ struct sprd_dma_desc {
 struct sprd_dma_chn {
 	struct virt_dma_chan	vc;
 	void __iomem		*chn_base;
+	struct sprd_dma_config	slave_cfg;
 	u32			chn_num;
 	u32			dev_id;
 	struct sprd_dma_desc	*cur_desc;
@@ -552,6 +584,121 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
 	spin_unlock_irqrestore(&schan->vc.lock, flags);
 }
 
+static enum sprd_dma_datawidth
+sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
+{
+	switch (buswidth) {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		return SPRD_DMA_DATAWIDTH_1_BYTE;
+
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		return SPRD_DMA_DATAWIDTH_2_BYTES;
+
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		return SPRD_DMA_DATAWIDTH_4_BYTES;
+
+	case DMA_SLAVE_BUSWIDTH_8_BYTES:
+		return SPRD_DMA_DATAWIDTH_8_BYTES;
+
+	default:
+		return SPRD_DMA_DATAWIDTH_4_BYTES;
+	}
+}
+
+static u32 sprd_dma_get_step(enum dma_slave_buswidth buswidth)
+{
+	switch (buswidth) {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		return SPRD_DMA_BYTE_STEP;
+
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		return SPRD_DMA_SHORT_STEP;
+
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		return SPRD_DMA_WORD_STEP;
+
+	case DMA_SLAVE_BUSWIDTH_8_BYTES:
+		return SPRD_DMA_DWORD_STEP;
+
+	default:
+		return SPRD_DMA_DWORD_STEP;
+	}
+}
+
+static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
+			   struct sprd_dma_config *slave_cfg)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+	u32 fix_mode = 0, fix_en = 0, wrap_en = 0, wrap_mode = 0;
+	u32 src_datawidth, dst_datawidth;
+
+	if (slave_cfg->cfg.slave_id)
+		schan->dev_id = slave_cfg->cfg.slave_id;
+
+	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
+	hw->wrap_ptr = (u32)((slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK) |
+		((slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+		 SPRD_DMA_HIGH_ADDR_MASK));
+	hw->wrap_to = (u32)((slave_cfg->wrap_to & SPRD_DMA_LOW_ADDR_MASK) |
+		((slave_cfg->dst_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+		 SPRD_DMA_HIGH_ADDR_MASK));
+
+	hw->src_addr = (u32)(slave_cfg->src_addr & SPRD_DMA_LOW_ADDR_MASK);
+	hw->des_addr = (u32)(slave_cfg->dst_addr & SPRD_DMA_LOW_ADDR_MASK);
+
+	if ((slave_cfg->src_step != 0 && slave_cfg->dst_step != 0)
+	    || (slave_cfg->src_step | slave_cfg->dst_step) == 0) {
+		fix_en = 0;
+	} else {
+		fix_en = 1;
+		if (slave_cfg->src_step)
+			fix_mode = 1;
+		else
+			fix_mode = 0;
+	}
+
+	if (slave_cfg->wrap_ptr && slave_cfg->wrap_to) {
+		wrap_en = 1;
+		if (slave_cfg->wrap_to == slave_cfg->src_addr) {
+			wrap_mode = 0;
+		} else if (slave_cfg->wrap_to == slave_cfg->dst_addr) {
+			wrap_mode = 1;
+		} else {
+			dev_err(sdev->dma_dev.dev, "invalid wrap mode\n");
+			return -EINVAL;
+		}
+	}
+
+	hw->intc = slave_cfg->int_mode | SPRD_DMA_CFG_ERR_INT_EN;
+
+	src_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.src_addr_width);
+	dst_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.dst_addr_width);
+	hw->frg_len = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
+		dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
+		slave_cfg->req_mode << SPRD_DMA_REQ_MODE_OFFSET |
+		wrap_mode << SPRD_DMA_WRAP_SEL_OFFSET |
+		wrap_en << SPRD_DMA_WRAP_EN_OFFSET |
+		fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
+		fix_en << SPRD_DMA_FIX_EN_OFFSET |
+		(slave_cfg->cfg.src_maxburst & SPRD_DMA_FRG_LEN_MASK);
+
+	hw->blk_len = slave_cfg->block_len & SPRD_DMA_BLK_LEN_MASK;
+
+	hw->trsc_len = slave_cfg->transcation_len & SPRD_DMA_TRSC_LEN_MASK;
+
+	hw->trsf_step = (slave_cfg->dst_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_DEST_TRSF_STEP_OFFSET |
+			(slave_cfg->src_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_SRC_TRSF_STEP_OFFSET;
+
+	hw->frg_step = 0;
+	hw->src_blk_step = 0;
+	hw->des_blk_step = 0;
+	return 0;
+}
+
 static struct dma_async_tx_descriptor *
 sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 			 size_t len, unsigned long flags)
@@ -606,6 +753,72 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
 	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
 }
 
+static struct dma_async_tx_descriptor *
+sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+		       unsigned int sglen, enum dma_transfer_direction dir,
+		       unsigned long flags, void *context)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
+	struct sprd_dma_desc *sdesc;
+	struct scatterlist *sg;
+	int ret, i;
+
+	/* TODO: now we only support one sg for each DMA configuration. */
+	if (!is_slave_direction(dir) || sglen > 1)
+		return NULL;
+
+	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+	if (!sdesc)
+		return NULL;
+
+	for_each_sg(sgl, sg, sglen, i) {
+		if (dir == DMA_MEM_TO_DEV) {
+			slave_cfg->src_addr = sg_dma_address(sg);
+			slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
+			slave_cfg->src_step =
+			sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
+			slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
+		} else {
+			slave_cfg->src_addr = slave_cfg->cfg.src_addr;
+			slave_cfg->dst_addr = sg_dma_address(sg);
+			slave_cfg->src_step = SPRD_DMA_NONE_STEP;
+			slave_cfg->dst_step =
+			sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);
+		}
+
+		slave_cfg->block_len = sg_dma_len(sg);
+		slave_cfg->transcation_len = sg_dma_len(sg);
+	}
+
+	slave_cfg->req_mode =
+		(flags >> SPRD_DMA_REQ_SHIFT) & SPRD_DMA_REQ_MODE_MASK;
+	slave_cfg->int_mode = flags & SPRD_DMA_INT_MASK;
+
+	ret = sprd_dma_config(chan, sdesc, slave_cfg);
+	if (ret) {
+		kfree(sdesc);
+		return NULL;
+	}
+
+	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
+}
+
+static int sprd_dma_slave_config(struct dma_chan *chan,
+				 struct dma_slave_config *config)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
+
+	if (!is_slave_direction(config->direction))
+		return -EINVAL;
+
+	memset(slave_cfg, 0, sizeof(*slave_cfg));
+	memcpy(&slave_cfg->cfg, config, sizeof(*config));
+
+	return 0;
+}
+
 static int sprd_dma_pause(struct dma_chan *chan)
 {
 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
@@ -732,6 +945,8 @@ static int sprd_dma_probe(struct platform_device *pdev)
 	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
 	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
 	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
+	sdev->dma_dev.device_prep_slave_sg = sprd_dma_prep_slave_sg;
+	sdev->dma_dev.device_config = sprd_dma_slave_config;
 	sdev->dma_dev.device_pause = sprd_dma_pause;
 	sdev->dma_dev.device_resume = sprd_dma_resume;
 	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;
diff --git a/include/linux/dma/sprd-dma.h b/include/linux/dma/sprd-dma.h
index c545162..b0115e3 100644
--- a/include/linux/dma/sprd-dma.h
+++ b/include/linux/dma/sprd-dma.h
@@ -3,6 +3,10 @@
 #ifndef _SPRD_DMA_H_
 #define _SPRD_DMA_H_
 
+#define SPRD_DMA_REQ_SHIFT 16
+#define SPRD_DMA_FLAGS(req_mode, int_type) \
+	((req_mode) << SPRD_DMA_REQ_SHIFT | (int_type))
+
 /*
  * enum sprd_dma_req_mode: define the DMA request mode
  * @SPRD_DMA_FRAG_REQ: fragment request mode
-- 
1.7.9.5

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Vinod Koul]

On 09-05-18, 19:12, Baolin Wang wrote:

> +/*
> + * struct sprd_dma_config - DMA configuration structure
> + * @cfg: dma slave channel runtime config
> + * @src_addr: the source physical address
> + * @dst_addr: the destination physical address
> + * @block_len: specify one block transfer length
> + * @transcation_len: specify one transcation transfer length
> + * @src_step: source transfer step
> + * @dst_step: destination transfer step
> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
> + * @wrap_to: wrap jump to address
> + * @req_mode: specify the DMA request mode
> + * @int_mode: specify the DMA interrupt type
> + */
> +struct sprd_dma_config {
> +	struct dma_slave_config cfg;
> +	phys_addr_t src_addr;
> +	phys_addr_t dst_addr;

these are already in cfg so why duplicate, same for few more here.

> +static enum sprd_dma_datawidth
> +sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
> +{
> +	switch (buswidth) {
> +	case DMA_SLAVE_BUSWIDTH_1_BYTE:
> +		return SPRD_DMA_DATAWIDTH_1_BYTE;
> +
> +	case DMA_SLAVE_BUSWIDTH_2_BYTES:
> +		return SPRD_DMA_DATAWIDTH_2_BYTES;
> +
> +	case DMA_SLAVE_BUSWIDTH_4_BYTES:
> +		return SPRD_DMA_DATAWIDTH_4_BYTES;
> +
> +	case DMA_SLAVE_BUSWIDTH_8_BYTES:
> +		return SPRD_DMA_DATAWIDTH_8_BYTES;
> +
> +	default:
> +		return SPRD_DMA_DATAWIDTH_4_BYTES;

what is the logic of translation here, sometime you might be able to do that
with logical operators, see other drivers..

> +	}
> +}
> +
> +static u32 sprd_dma_get_step(enum dma_slave_buswidth buswidth)
> +{
> +	switch (buswidth) {
> +	case DMA_SLAVE_BUSWIDTH_1_BYTE:
> +		return SPRD_DMA_BYTE_STEP;
> +
> +	case DMA_SLAVE_BUSWIDTH_2_BYTES:
> +		return SPRD_DMA_SHORT_STEP;
> +
> +	case DMA_SLAVE_BUSWIDTH_4_BYTES:
> +		return SPRD_DMA_WORD_STEP;
> +
> +	case DMA_SLAVE_BUSWIDTH_8_BYTES:
> +		return SPRD_DMA_DWORD_STEP;
> +
> +	default:
> +		return SPRD_DMA_DWORD_STEP;
> +	}

here as well

> +}
> +
> +static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
> +			   struct sprd_dma_config *slave_cfg)
> +{
> +	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
> +	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
> +	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
> +	u32 fix_mode = 0, fix_en = 0, wrap_en = 0, wrap_mode = 0;
> +	u32 src_datawidth, dst_datawidth;
> +
> +	if (slave_cfg->cfg.slave_id)
> +		schan->dev_id = slave_cfg->cfg.slave_id;
> +
> +	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
> +	hw->wrap_ptr = (u32)((slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK) |

why cast?

> +		((slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
> +		 SPRD_DMA_HIGH_ADDR_MASK));

more readable would be:

        temp = slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK;
        temp |= slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET;
        temp &= SPRD_DMA_HIGH_ADDR_MASK;

and then assign... could help readability in few places...

> +	hw->wrap_to = (u32)((slave_cfg->wrap_to & SPRD_DMA_LOW_ADDR_MASK) |
> +		((slave_cfg->dst_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
> +		 SPRD_DMA_HIGH_ADDR_MASK));
> +
> +	hw->src_addr = (u32)(slave_cfg->src_addr & SPRD_DMA_LOW_ADDR_MASK);
> +	hw->des_addr = (u32)(slave_cfg->dst_addr & SPRD_DMA_LOW_ADDR_MASK);
> +
> +	if ((slave_cfg->src_step != 0 && slave_cfg->dst_step != 0)
> +	    || (slave_cfg->src_step | slave_cfg->dst_step) == 0) {
> +		fix_en = 0;
> +	} else {
> +		fix_en = 1;
> +		if (slave_cfg->src_step)
> +			fix_mode = 1;
> +		else
> +			fix_mode = 0;
> +	}
> +
> +	if (slave_cfg->wrap_ptr && slave_cfg->wrap_to) {
> +		wrap_en = 1;
> +		if (slave_cfg->wrap_to == slave_cfg->src_addr) {
> +			wrap_mode = 0;
> +		} else if (slave_cfg->wrap_to == slave_cfg->dst_addr) {
> +			wrap_mode = 1;
> +		} else {
> +			dev_err(sdev->dma_dev.dev, "invalid wrap mode\n");
> +			return -EINVAL;
> +		}
> +	}
> +
> +	hw->intc = slave_cfg->int_mode | SPRD_DMA_CFG_ERR_INT_EN;
> +
> +	src_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.src_addr_width);
> +	dst_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.dst_addr_width);
> +	hw->frg_len = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
> +		dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
> +		slave_cfg->req_mode << SPRD_DMA_REQ_MODE_OFFSET |
> +		wrap_mode << SPRD_DMA_WRAP_SEL_OFFSET |
> +		wrap_en << SPRD_DMA_WRAP_EN_OFFSET |
> +		fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
> +		fix_en << SPRD_DMA_FIX_EN_OFFSET |
> +		(slave_cfg->cfg.src_maxburst & SPRD_DMA_FRG_LEN_MASK);

sorry this is not at all readable...

> +static struct dma_async_tx_descriptor *
> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> +		       unsigned int sglen, enum dma_transfer_direction dir,
> +		       unsigned long flags, void *context)
> +{
> +	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
> +	struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
> +	struct sprd_dma_desc *sdesc;
> +	struct scatterlist *sg;
> +	int ret, i;
> +
> +	/* TODO: now we only support one sg for each DMA configuration. */

thats a SW limit right and you will fix it later?

> +	if (!is_slave_direction(dir) || sglen > 1)
> +		return NULL;
> +
> +	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
> +	if (!sdesc)
> +		return NULL;
> +
> +	for_each_sg(sgl, sg, sglen, i) {
> +		if (dir == DMA_MEM_TO_DEV) {
> +			slave_cfg->src_addr = sg_dma_address(sg);
> +			slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
> +			slave_cfg->src_step =
> +			sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
> +			slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
> +		} else {
> +			slave_cfg->src_addr = slave_cfg->cfg.src_addr;
> +			slave_cfg->dst_addr = sg_dma_address(sg);
> +			slave_cfg->src_step = SPRD_DMA_NONE_STEP;
> +			slave_cfg->dst_step =
> +			sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);

use a helper for filling this and passing right values for each case?

-- 
~Vinod

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Baolin Wang]

Hi Vinod,

On 11 May 2018 at 19:22, Vinod Koul <vkoul@kernel.org> wrote:
> On 09-05-18, 19:12, Baolin Wang wrote:
>
>> +/*
>> + * struct sprd_dma_config - DMA configuration structure
>> + * @cfg: dma slave channel runtime config
>> + * @src_addr: the source physical address
>> + * @dst_addr: the destination physical address
>> + * @block_len: specify one block transfer length
>> + * @transcation_len: specify one transcation transfer length
>> + * @src_step: source transfer step
>> + * @dst_step: destination transfer step
>> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
>> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
>> + * @wrap_to: wrap jump to address
>> + * @req_mode: specify the DMA request mode
>> + * @int_mode: specify the DMA interrupt type
>> + */
>> +struct sprd_dma_config {
>> +     struct dma_slave_config cfg;
>> +     phys_addr_t src_addr;
>> +     phys_addr_t dst_addr;
>
> these are already in cfg so why duplicate, same for few more here.

We save them in 'struct sprd_dma_config' as one parameter for
sprd_dma_config(), otherwise we need add 2 more parameters (src and
dst) for sprd_dma_config().

>
>> +static enum sprd_dma_datawidth
>> +sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
>> +{
>> +     switch (buswidth) {
>> +     case DMA_SLAVE_BUSWIDTH_1_BYTE:
>> +             return SPRD_DMA_DATAWIDTH_1_BYTE;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_2_BYTES:
>> +             return SPRD_DMA_DATAWIDTH_2_BYTES;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_4_BYTES:
>> +             return SPRD_DMA_DATAWIDTH_4_BYTES;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_8_BYTES:
>> +             return SPRD_DMA_DATAWIDTH_8_BYTES;
>> +
>> +     default:
>> +             return SPRD_DMA_DATAWIDTH_4_BYTES;
>
> what is the logic of translation here, sometime you might be able to do that
> with logical operators, see other drivers..

OK. I will change to logical operators.

>
>> +     }
>> +}
>> +
>> +static u32 sprd_dma_get_step(enum dma_slave_buswidth buswidth)
>> +{
>> +     switch (buswidth) {
>> +     case DMA_SLAVE_BUSWIDTH_1_BYTE:
>> +             return SPRD_DMA_BYTE_STEP;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_2_BYTES:
>> +             return SPRD_DMA_SHORT_STEP;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_4_BYTES:
>> +             return SPRD_DMA_WORD_STEP;
>> +
>> +     case DMA_SLAVE_BUSWIDTH_8_BYTES:
>> +             return SPRD_DMA_DWORD_STEP;
>> +
>> +     default:
>> +             return SPRD_DMA_DWORD_STEP;
>> +     }
>
> here as well

Will do.

>
>> +}
>> +
>> +static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
>> +                        struct sprd_dma_config *slave_cfg)
>> +{
>> +     struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
>> +     struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
>> +     struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
>> +     u32 fix_mode = 0, fix_en = 0, wrap_en = 0, wrap_mode = 0;
>> +     u32 src_datawidth, dst_datawidth;
>> +
>> +     if (slave_cfg->cfg.slave_id)
>> +             schan->dev_id = slave_cfg->cfg.slave_id;
>> +
>> +     hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
>> +     hw->wrap_ptr = (u32)((slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK) |
>
> why cast?

Since the wrap_ptr register is always 32bit.

>
>> +             ((slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
>> +              SPRD_DMA_HIGH_ADDR_MASK));
>
> more readable would be:
>
>         temp = slave_cfg->wrap_ptr & SPRD_DMA_LOW_ADDR_MASK;
>         temp |= slave_cfg->src_addr >> SPRD_DMA_HIGH_ADDR_OFFSET;
>         temp &= SPRD_DMA_HIGH_ADDR_MASK;
>
> and then assign... could help readability in few places...

OK.

>
>> +     hw->wrap_to = (u32)((slave_cfg->wrap_to & SPRD_DMA_LOW_ADDR_MASK) |
>> +             ((slave_cfg->dst_addr >> SPRD_DMA_HIGH_ADDR_OFFSET) &
>> +              SPRD_DMA_HIGH_ADDR_MASK));
>> +
>> +     hw->src_addr = (u32)(slave_cfg->src_addr & SPRD_DMA_LOW_ADDR_MASK);
>> +     hw->des_addr = (u32)(slave_cfg->dst_addr & SPRD_DMA_LOW_ADDR_MASK);
>> +
>> +     if ((slave_cfg->src_step != 0 && slave_cfg->dst_step != 0)
>> +         || (slave_cfg->src_step | slave_cfg->dst_step) == 0) {
>> +             fix_en = 0;
>> +     } else {
>> +             fix_en = 1;
>> +             if (slave_cfg->src_step)
>> +                     fix_mode = 1;
>> +             else
>> +                     fix_mode = 0;
>> +     }
>> +
>> +     if (slave_cfg->wrap_ptr && slave_cfg->wrap_to) {
>> +             wrap_en = 1;
>> +             if (slave_cfg->wrap_to == slave_cfg->src_addr) {
>> +                     wrap_mode = 0;
>> +             } else if (slave_cfg->wrap_to == slave_cfg->dst_addr) {
>> +                     wrap_mode = 1;
>> +             } else {
>> +                     dev_err(sdev->dma_dev.dev, "invalid wrap mode\n");
>> +                     return -EINVAL;
>> +             }
>> +     }
>> +
>> +     hw->intc = slave_cfg->int_mode | SPRD_DMA_CFG_ERR_INT_EN;
>> +
>> +     src_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.src_addr_width);
>> +     dst_datawidth = sprd_dma_get_datawidth(slave_cfg->cfg.dst_addr_width);
>> +     hw->frg_len = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
>> +             dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
>> +             slave_cfg->req_mode << SPRD_DMA_REQ_MODE_OFFSET |
>> +             wrap_mode << SPRD_DMA_WRAP_SEL_OFFSET |
>> +             wrap_en << SPRD_DMA_WRAP_EN_OFFSET |
>> +             fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
>> +             fix_en << SPRD_DMA_FIX_EN_OFFSET |
>> +             (slave_cfg->cfg.src_maxburst & SPRD_DMA_FRG_LEN_MASK);
>
> sorry this is not at all readable...

Will fix in next version.

>
>> +static struct dma_async_tx_descriptor *
>> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>> +                    unsigned int sglen, enum dma_transfer_direction dir,
>> +                    unsigned long flags, void *context)
>> +{
>> +     struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
>> +     struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
>> +     struct sprd_dma_desc *sdesc;
>> +     struct scatterlist *sg;
>> +     int ret, i;
>> +
>> +     /* TODO: now we only support one sg for each DMA configuration. */
>
> thats a SW limit right and you will fix it later?

We will add new features to fix it in future.

>
>> +     if (!is_slave_direction(dir) || sglen > 1)
>> +             return NULL;
>> +
>> +     sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
>> +     if (!sdesc)
>> +             return NULL;
>> +
>> +     for_each_sg(sgl, sg, sglen, i) {
>> +             if (dir == DMA_MEM_TO_DEV) {
>> +                     slave_cfg->src_addr = sg_dma_address(sg);
>> +                     slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
>> +                     slave_cfg->src_step =
>> +                     sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
>> +                     slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
>> +             } else {
>> +                     slave_cfg->src_addr = slave_cfg->cfg.src_addr;
>> +                     slave_cfg->dst_addr = sg_dma_address(sg);
>> +                     slave_cfg->src_step = SPRD_DMA_NONE_STEP;
>> +                     slave_cfg->dst_step =
>> +                     sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);
>
> use a helper for filling this and passing right values for each case?

We need pass many values to this helper, but will try. Thanks.

-- 
Baolin.wang
Best Regards

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Vinod Koul]

On 11-05-18, 19:44, Baolin Wang wrote:
> Hi Vinod,
> 
> On 11 May 2018 at 19:22, Vinod Koul <vkoul@kernel.org> wrote:
> > On 09-05-18, 19:12, Baolin Wang wrote:
> >
> >> +/*
> >> + * struct sprd_dma_config - DMA configuration structure
> >> + * @cfg: dma slave channel runtime config
> >> + * @src_addr: the source physical address
> >> + * @dst_addr: the destination physical address
> >> + * @block_len: specify one block transfer length
> >> + * @transcation_len: specify one transcation transfer length
> >> + * @src_step: source transfer step
> >> + * @dst_step: destination transfer step
> >> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
> >> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
> >> + * @wrap_to: wrap jump to address
> >> + * @req_mode: specify the DMA request mode
> >> + * @int_mode: specify the DMA interrupt type
> >> + */
> >> +struct sprd_dma_config {
> >> +     struct dma_slave_config cfg;
> >> +     phys_addr_t src_addr;
> >> +     phys_addr_t dst_addr;
> >
> > these are already in cfg so why duplicate, same for few more here.
> 
> We save them in 'struct sprd_dma_config' as one parameter for
> sprd_dma_config(), otherwise we need add 2 more parameters (src and
> dst) for sprd_dma_config().

I am not sure I follow...

I meant you can use sprd_dma_config.cfg->src_addr/dst_addr and remove src_addr &
dst_addr in the sprd_dma_config. It duplicate..

Same for few more params...

> >> +     if (!is_slave_direction(dir) || sglen > 1)
> >> +             return NULL;
> >> +
> >> +     sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
> >> +     if (!sdesc)
> >> +             return NULL;
> >> +
> >> +     for_each_sg(sgl, sg, sglen, i) {
> >> +             if (dir == DMA_MEM_TO_DEV) {
> >> +                     slave_cfg->src_addr = sg_dma_address(sg);
> >> +                     slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
> >> +                     slave_cfg->src_step =
> >> +                     sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
> >> +                     slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
> >> +             } else {
> >> +                     slave_cfg->src_addr = slave_cfg->cfg.src_addr;
> >> +                     slave_cfg->dst_addr = sg_dma_address(sg);
> >> +                     slave_cfg->src_step = SPRD_DMA_NONE_STEP;
> >> +                     slave_cfg->dst_step =
> >> +                     sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);
> >
> > use a helper for filling this and passing right values for each case?
> 
> We need pass many values to this helper, but will try. Thanks.

I think 5 and that may help to look it better :)

-- 
~Vinod

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Baolin Wang]

On 11 May 2018 at 19:53, Vinod Koul <vkoul@kernel.org> wrote:
> On 11-05-18, 19:44, Baolin Wang wrote:
>> Hi Vinod,
>>
>> On 11 May 2018 at 19:22, Vinod Koul <vkoul@kernel.org> wrote:
>> > On 09-05-18, 19:12, Baolin Wang wrote:
>> >
>> >> +/*
>> >> + * struct sprd_dma_config - DMA configuration structure
>> >> + * @cfg: dma slave channel runtime config
>> >> + * @src_addr: the source physical address
>> >> + * @dst_addr: the destination physical address
>> >> + * @block_len: specify one block transfer length
>> >> + * @transcation_len: specify one transcation transfer length
>> >> + * @src_step: source transfer step
>> >> + * @dst_step: destination transfer step
>> >> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
>> >> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
>> >> + * @wrap_to: wrap jump to address
>> >> + * @req_mode: specify the DMA request mode
>> >> + * @int_mode: specify the DMA interrupt type
>> >> + */
>> >> +struct sprd_dma_config {
>> >> +     struct dma_slave_config cfg;
>> >> +     phys_addr_t src_addr;
>> >> +     phys_addr_t dst_addr;
>> >
>> > these are already in cfg so why duplicate, same for few more here.
>>
>> We save them in 'struct sprd_dma_config' as one parameter for
>> sprd_dma_config(), otherwise we need add 2 more parameters (src and
>> dst) for sprd_dma_config().
>
> I am not sure I follow...
>
> I meant you can use sprd_dma_config.cfg->src_addr/dst_addr and remove src_addr &
> dst_addr in the sprd_dma_config. It duplicate..

But we can not set values if dir == DMA_MEM_TO_DEV, since they
represent the device address, right?
sprd_dma_config.cfg->src_addr = sg_dma_address(sg);

>
> Same for few more params...
>
>> >> +     if (!is_slave_direction(dir) || sglen > 1)
>> >> +             return NULL;
>> >> +
>> >> +     sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
>> >> +     if (!sdesc)
>> >> +             return NULL;
>> >> +
>> >> +     for_each_sg(sgl, sg, sglen, i) {
>> >> +             if (dir == DMA_MEM_TO_DEV) {
>> >> +                     slave_cfg->src_addr = sg_dma_address(sg);
>> >> +                     slave_cfg->dst_addr = slave_cfg->cfg.dst_addr;
>> >> +                     slave_cfg->src_step =
>> >> +                     sprd_dma_get_step(slave_cfg->cfg.src_addr_width);
>> >> +                     slave_cfg->dst_step = SPRD_DMA_NONE_STEP;
>> >> +             } else {
>> >> +                     slave_cfg->src_addr = slave_cfg->cfg.src_addr;
>> >> +                     slave_cfg->dst_addr = sg_dma_address(sg);
>> >> +                     slave_cfg->src_step = SPRD_DMA_NONE_STEP;
>> >> +                     slave_cfg->dst_step =
>> >> +                     sprd_dma_get_step(slave_cfg->cfg.dst_addr_width);
>> >
>> > use a helper for filling this and passing right values for each case?
>>
>> We need pass many values to this helper, but will try. Thanks.
>
> I think 5 and that may help to look it better :)

OK.

-- 
Baolin.wang
Best Regards

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Vinod Koul]

On 11-05-18, 19:58, Baolin Wang wrote:
> On 11 May 2018 at 19:53, Vinod Koul <vkoul@kernel.org> wrote:
> >> >
> >> >> +/*
> >> >> + * struct sprd_dma_config - DMA configuration structure
> >> >> + * @cfg: dma slave channel runtime config
> >> >> + * @src_addr: the source physical address
> >> >> + * @dst_addr: the destination physical address
> >> >> + * @block_len: specify one block transfer length
> >> >> + * @transcation_len: specify one transcation transfer length
> >> >> + * @src_step: source transfer step
> >> >> + * @dst_step: destination transfer step
> >> >> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
> >> >> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
> >> >> + * @wrap_to: wrap jump to address
> >> >> + * @req_mode: specify the DMA request mode
> >> >> + * @int_mode: specify the DMA interrupt type
> >> >> + */
> >> >> +struct sprd_dma_config {
> >> >> +     struct dma_slave_config cfg;
> >> >> +     phys_addr_t src_addr;
> >> >> +     phys_addr_t dst_addr;
> >> >
> >> > these are already in cfg so why duplicate, same for few more here.
> >>
> >> We save them in 'struct sprd_dma_config' as one parameter for
> >> sprd_dma_config(), otherwise we need add 2 more parameters (src and
> >> dst) for sprd_dma_config().
> >
> > I am not sure I follow...
> >
> > I meant you can use sprd_dma_config.cfg->src_addr/dst_addr and remove src_addr &
> > dst_addr in the sprd_dma_config. It duplicate..
> 
> But we can not set values if dir == DMA_MEM_TO_DEV, since they
> represent the device address, right?
> sprd_dma_config.cfg->src_addr = sg_dma_address(sg);

Ah right and that is another issue to fix then :) we should not store addresses
you get for prep_ calls. They are supposed to be stored in the descriptor.
Current approach is not correct.

You can get different prepare calls  (i think fixing this will remove 1 sg
limitation).. and use the argument values and store in respective descriptors.
Pls do see the other driver examples..

-- 
~Vinod

Re: [PATCH v2 2/2] dmaengine: sprd: Add Spreadtrum DMA configuration

[Baolin Wang]

On 11 May 2018 at 20:04, Vinod Koul <vinod.koul@linaro.org> wrote:
> On 11-05-18, 19:58, Baolin Wang wrote:
>> On 11 May 2018 at 19:53, Vinod Koul <vkoul@kernel.org> wrote:
>> >> >
>> >> >> +/*
>> >> >> + * struct sprd_dma_config - DMA configuration structure
>> >> >> + * @cfg: dma slave channel runtime config
>> >> >> + * @src_addr: the source physical address
>> >> >> + * @dst_addr: the destination physical address
>> >> >> + * @block_len: specify one block transfer length
>> >> >> + * @transcation_len: specify one transcation transfer length
>> >> >> + * @src_step: source transfer step
>> >> >> + * @dst_step: destination transfer step
>> >> >> + * @wrap_ptr: wrap pointer address, once the transfer address reaches the
>> >> >> + * 'wrap_ptr', the next transfer address will jump to the 'wrap_to' address.
>> >> >> + * @wrap_to: wrap jump to address
>> >> >> + * @req_mode: specify the DMA request mode
>> >> >> + * @int_mode: specify the DMA interrupt type
>> >> >> + */
>> >> >> +struct sprd_dma_config {
>> >> >> +     struct dma_slave_config cfg;
>> >> >> +     phys_addr_t src_addr;
>> >> >> +     phys_addr_t dst_addr;
>> >> >
>> >> > these are already in cfg so why duplicate, same for few more here.
>> >>
>> >> We save them in 'struct sprd_dma_config' as one parameter for
>> >> sprd_dma_config(), otherwise we need add 2 more parameters (src and
>> >> dst) for sprd_dma_config().
>> >
>> > I am not sure I follow...
>> >
>> > I meant you can use sprd_dma_config.cfg->src_addr/dst_addr and remove src_addr &
>> > dst_addr in the sprd_dma_config. It duplicate..
>>
>> But we can not set values if dir == DMA_MEM_TO_DEV, since they
>> represent the device address, right?
>> sprd_dma_config.cfg->src_addr = sg_dma_address(sg);
>
> Ah right and that is another issue to fix then :) we should not store addresses
> you get for prep_ calls. They are supposed to be stored in the descriptor.
> Current approach is not correct.

OK. But we do not want to touch the descriptor structure, so we plan
to add 2 more parameters for sprd_dma_config().
And remove these 2 values from struct sprd_dma_config.

>
> You can get different prepare calls  (i think fixing this will remove 1 sg
> limitation).. and use the argument values and store in respective descriptors.
> Pls do see the other driver examples..
>
> --
> ~Vinod



-- 
Baolin.wang
Best Regards