From: Eric Long <[email protected]>
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 <[email protected]>
Signed-off-by: Baolin Wang <[email protected]>
---
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
From: Eric Long <[email protected]>
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 <[email protected]>
Signed-off-by: Baolin Wang <[email protected]>
---
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
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
Hi Vinod,
On 11 May 2018 at 19:22, Vinod Koul <[email protected]> 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
On 11-05-18, 19:44, Baolin Wang wrote:
> Hi Vinod,
>
> On 11 May 2018 at 19:22, Vinod Koul <[email protected]> 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
On 11 May 2018 at 19:53, Vinod Koul <[email protected]> wrote:
> On 11-05-18, 19:44, Baolin Wang wrote:
>> Hi Vinod,
>>
>> On 11 May 2018 at 19:22, Vinod Koul <[email protected]> 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
On 11-05-18, 19:58, Baolin Wang wrote:
> On 11 May 2018 at 19:53, Vinod Koul <[email protected]> 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
On 11 May 2018 at 20:04, Vinod Koul <[email protected]> wrote:
> On 11-05-18, 19:58, Baolin Wang wrote:
>> On 11 May 2018 at 19:53, Vinod Koul <[email protected]> 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