[PATCH v1] dma: imx-sdma: add support for sdma memory copy

Robin Gong
2014-04-17T10:01:10Z

add "device_prep_dma_memcpy" and "device_prep_dma_sg" for memory copy by sdma.

Signed-off-by: Robin Gong <b38343@freescale.com>
---
drivers/dma/imx-sdma.c | 188 +++++++++++++++++++++++++++++++++++++++++------
1 files changed, 164 insertions(+), 24 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 4e79183..2a97e03 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -229,6 +229,7 @@ struct sdma_context_data {
} __attribute__ ((packed));

#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))
+#define SDMA_BD_MAX_CNT (0xfffc) /* align with 4 bytes */

struct sdma_engine;

@@ -260,6 +261,7 @@ struct sdma_channel {
unsigned int pc_from_device, pc_to_device;
unsigned long flags;
dma_addr_t per_address;
+ unsigned int pc_to_pc;
unsigned long event_mask[2];
unsigned long watermark_level;
u32 shp_addr, per_addr;
@@ -694,6 +696,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,

sdmac->pc_from_device = 0;
sdmac->pc_to_device = 0;
+ sdmac->pc_to_pc = 0;

switch (peripheral_type) {
case IMX_DMATYPE_MEMORY:
@@ -763,6 +766,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,

sdmac->pc_from_device = per_2_emi;
sdmac->pc_to_device = emi_2_per;
+ sdmac->pc_to_pc = emi_2_emi;
}

static int sdma_load_context(struct sdma_channel *sdmac)
@@ -775,11 +779,12 @@ static int sdma_load_context(struct sdma_channel *sdmac)
int ret;
unsigned long flags;

- if (sdmac->direction == DMA_DEV_TO_MEM) {
+ if (sdmac->direction == DMA_DEV_TO_MEM)
load_address = sdmac->pc_from_device;
- } else {
+ else if (sdmac->direction == DMA_MEM_TO_MEM)
+ load_address = sdmac->pc_to_pc;
+ else
load_address = sdmac->pc_to_device;
- }

if (load_address < 0)
return load_address;
@@ -1010,16 +1015,118 @@ static void sdma_free_chan_resources(struct dma_chan *chan)
clk_disable(sdma->clk_ahb);
}

-static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
- struct dma_chan *chan, struct scatterlist *sgl,
- unsigned int sg_len, enum dma_transfer_direction direction,
- unsigned long flags, void *context)
+static struct dma_async_tx_descriptor *sdma_prep_memcpy(
+ struct dma_chan *chan, dma_addr_t dma_dst,
+ dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+ struct sdma_channel *sdmac = to_sdma_chan(chan);
+ struct sdma_engine *sdma = sdmac->sdma;
+ int channel = sdmac->channel;
+ size_t count;
+ int i = 0, param, ret;
+ struct sdma_buffer_descriptor *bd;
+
+ if (!chan || !len || sdmac->status == DMA_IN_PROGRESS)
+ return NULL;
+
+ if (len >= NUM_BD * SDMA_BD_MAX_CNT) {
+ dev_err(sdma->dev, "channel%d: maximum bytes exceeded:%d > %d\n"
+ , channel, len, NUM_BD * SDMA_BD_MAX_CNT);
+ goto err_out;
+ }
+
+ sdmac->status = DMA_IN_PROGRESS;
+
+ sdmac->buf_tail = 0;
+
+ dev_dbg(sdma->dev, "memcpy: %x->%x, len=%d, channel=%d.\n",
+ dma_src, dma_dst, len, channel);
+
+ sdmac->direction = DMA_MEM_TO_MEM;
+
+ ret = sdma_load_context(sdmac);
+ if (ret)
+ goto err_out;
+
+ sdmac->chn_count = 0;
+
+ do {
+ count = min_t(size_t, len, SDMA_BD_MAX_CNT);
+ bd = &sdmac->bd[i];
+ bd->buffer_addr = dma_src;
+ bd->ext_buffer_addr = dma_dst;
+ bd->mode.count = count;
+
+ if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) {
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ switch (sdmac->word_size) {
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ bd->mode.command = 0;
+ if (count & 3 || dma_dst & 3 || dma_src & 3)
+ return NULL;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ bd->mode.command = 2;
+ if (count & 1 || dma_dst & 1 || dma_src & 1)
+ return NULL;
+ break;
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ bd->mode.command = 1;
+ break;
+ default:
+ return NULL;
+ }
+
+ dma_src += count;
+ dma_dst += count;
+ len -= count;
+ i++;
+
+ param = BD_DONE | BD_EXTD | BD_CONT;
+ /* last bd */
+ if (!len) {
+ param |= BD_INTR;
+ param |= BD_LAST;
+ param &= ~BD_CONT;
+ }
+
+ dev_dbg(sdma->dev, "entry %d: count: %d dma: 0x%08x %s%s\n",
+ i, count, bd->buffer_addr,
+ param & BD_WRAP ? "wrap" : "",
+ param & BD_INTR ? " intr" : "");
+
+ bd->mode.status = param;
+ sdmac->chn_count += count;
+ } while (len);
+
+ sdmac->num_bd = i;
+ sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+
+ return &sdmac->desc;
+err_out:
+ sdmac->status = DMA_ERROR;
+ return NULL;
+}
+
+/*
+ * Please ensure dst_nents no smaller than src_nents , also every sg_len of
+ * dst_sg node no smaller than src_sg. To simply things, please use the same
+ * size of dst_sg as src_sg.
+ */
+static struct dma_async_tx_descriptor *sdma_prep_sg(
+ struct dma_chan *chan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ enum dma_transfer_direction direction)
{
struct sdma_channel *sdmac = to_sdma_chan(chan);
struct sdma_engine *sdma = sdmac->sdma;
int ret, i, count;
int channel = sdmac->channel;
- struct scatterlist *sg;
+ struct scatterlist *sg_src = src_sg, *sg_dst = dst_sg;

if (sdmac->status == DMA_IN_PROGRESS)
return NULL;
@@ -1030,32 +1137,38 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
sdmac->buf_tail = 0;

dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
- sg_len, channel);
+ src_nents, channel);

sdmac->direction = direction;
+
ret = sdma_load_context(sdmac);
if (ret)
goto err_out;

- if (sg_len > NUM_BD) {
+ if (src_nents > NUM_BD) {
dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
- channel, sg_len, NUM_BD);
+ channel, src_nents, NUM_BD);
ret = -EINVAL;
goto err_out;
}

sdmac->chn_count = 0;
- for_each_sg(sgl, sg, sg_len, i) {
+ for_each_sg(src_sg, sg_src, src_nents, i) {
struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
int param;

- bd->buffer_addr = sg->dma_address;
+ bd->buffer_addr = sg_src->dma_address;

- count = sg_dma_len(sg);
+ if (direction == DMA_MEM_TO_MEM) {
+ BUG_ON(!sg_dst);
+ bd->ext_buffer_addr = sg_dst->dma_address;
+ }
+
+ count = sg_dma_len(sg_src);

- if (count > 0xffff) {
+ if (count > SDMA_BD_MAX_CNT) {
dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
- channel, count, 0xffff);
+ channel, count, SDMA_BD_MAX_CNT);
ret = -EINVAL;
goto err_out;
}
@@ -1071,12 +1184,14 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
switch (sdmac->word_size) {
case DMA_SLAVE_BUSWIDTH_4_BYTES:
bd->mode.command = 0;
- if (count & 3 || sg->dma_address & 3)
+ if (count & 3 || sg_src->dma_address & 3 ||
+ (sg_dst && (sg_dst->dma_address & 3)))
return NULL;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
bd->mode.command = 2;
- if (count & 1 || sg->dma_address & 1)
+ if (count & 1 || sg_src->dma_address & 1 ||
+ (sg_dst && (sg_dst->dma_address & 1)))
return NULL;
break;
case DMA_SLAVE_BUSWIDTH_1_BYTE:
@@ -1088,21 +1203,23 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(

param = BD_DONE | BD_EXTD | BD_CONT;

- if (i + 1 == sg_len) {
+ if (i + 1 == src_nents) {
param |= BD_INTR;
param |= BD_LAST;
param &= ~BD_CONT;
}

- dev_dbg(sdma->dev, "entry %d: count: %d dma: %#llx %s%s\n",
- i, count, (u64)sg->dma_address,
+ dev_dbg(sdma->dev, "entry %d: count: %d dma: 0x%08x %s%s\n",
+ i, count, sg_src->dma_address,
param & BD_WRAP ? "wrap" : "",
param & BD_INTR ? " intr" : "");

bd->mode.status = param;
+ if (direction == DMA_MEM_TO_MEM)
+ sg_dst = sg_next(sg_dst);
}

- sdmac->num_bd = sg_len;
+ sdmac->num_bd = src_nents;
sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

return &sdmac->desc;
@@ -1111,6 +1228,24 @@ err_out:
return NULL;
}

+static struct dma_async_tx_descriptor *sdma_prep_memcpy_sg(
+ struct dma_chan *chan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ unsigned long flags)
+{
+ return sdma_prep_sg(chan, dst_sg, dst_nents, src_sg, src_nents,
+ DMA_MEM_TO_MEM);
+}
+
+static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ return sdma_prep_sg(chan, NULL, 0, sgl, sg_len, direction);
+}
+
static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
@@ -1143,9 +1278,9 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
goto err_out;
}

- if (period_len > 0xffff) {
+ if (period_len > SDMA_BD_MAX_CNT) {
dev_err(sdma->dev, "SDMA channel %d: maximum period size exceeded: %d > %d\n",
- channel, period_len, 0xffff);
+ channel, period_len, SDMA_BD_MAX_CNT);
goto err_out;
}

@@ -1206,6 +1341,8 @@ static int sdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
sdmac->watermark_level = dmaengine_cfg->src_maxburst *
dmaengine_cfg->src_addr_width;
sdmac->word_size = dmaengine_cfg->src_addr_width;
+ } else if (dmaengine_cfg->direction == DMA_MEM_TO_MEM) {
+ sdmac->word_size = dmaengine_cfg->dst_addr_width;
} else {
sdmac->per_address = dmaengine_cfg->dst_addr;
sdmac->watermark_level = dmaengine_cfg->dst_maxburst *
@@ -1516,6 +1653,7 @@ static int __init sdma_probe(struct platform_device *pdev)

dma_cap_set(DMA_SLAVE, sdma->dma_device.cap_mask);
dma_cap_set(DMA_CYCLIC, sdma->dma_device.cap_mask);
+ dma_cap_set(DMA_MEMCPY, sdma->dma_device.cap_mask);

INIT_LIST_HEAD(&sdma->dma_device.channels);
/* Initialize channel parameters */
@@ -1578,6 +1716,8 @@ static int __init sdma_probe(struct platform_device *pdev)
sdma->dma_device.device_tx_status = sdma_tx_status;
sdma->dma_device.device_prep_slave_sg = sdma_prep_slave_sg;
sdma->dma_device.device_prep_dma_cyclic = sdma_prep_dma_cyclic;
+ sdma->dma_device.device_prep_dma_memcpy = sdma_prep_memcpy;
+ sdma->dma_device.device_prep_dma_sg = sdma_prep_memcpy_sg;
sdma->dma_device.device_control = sdma_control;
sdma->dma_device.device_issue_pending = sdma_issue_pending;
sdma->dma_device.dev->dma_parms = &sdma->dma_parms;
--
1.7.5.4