[PATCH 2/2] dmaengine: i.MX: Add support for interleaved transfers.

From: Javier Martin
Date: Fri Feb 03 2012 - 11:11:34 EST


i.MX2 and i.MX1 chips have the possibility to do
interleaved transfers with one constraint: only one
chunk can be used (i.e. only 2D transfers are allowed).

Signed-off-by: Javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>
---
drivers/dma/imx-dma.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index 9aa6e85..366a248 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -359,6 +359,57 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
return &imxdmac->desc;
}

+static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
+ struct dma_chan *chan, struct dma_interleaved_template *xt,
+ unsigned long flags)
+{
+ struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+ struct imxdma_engine *imxdma = imxdmac->imxdma;
+ unsigned int src_config, dst_config;
+ unsigned int x, y, w;
+ int ret;
+
+ dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%x dst_start=0x%x\n"
+ " src_sgl=%s dst_sgl=%s numf=%d frame_size=%d\n", __func__,
+ imxdmac->channel, xt->src_start, xt->dst_start,
+ xt->src_sgl ? "true" : "false", xt->dst_sgl ? "true" : "false",
+ xt->numf, xt->frame_size);
+
+ if (imxdmac->status == DMA_IN_PROGRESS)
+ return NULL;
+ imxdmac->status = DMA_IN_PROGRESS;
+
+
+ if (xt->frame_size != 1 || xt->numf <= 0 || xt->dir != DMA_MEM_TO_MEM)
+ return NULL;
+
+ y = xt->numf;
+ x = xt->sgl[0].size;
+ w = xt->sgl[0].icg + x;
+ ret = imx_dma_config_2d(imxdmac->imxdma_channel, x, y, w);
+ if (ret)
+ return NULL;
+
+ src_config = IMX_DMA_MEMSIZE_32;
+ dst_config = IMX_DMA_MEMSIZE_32;
+ if (xt->src_sgl)
+ src_config |= IMX_DMA_TYPE_2D;
+ if (xt->dst_sgl)
+ dst_config |= IMX_DMA_TYPE_2D;
+
+ ret = imx_dma_config_channel(imxdmac->imxdma_channel,
+ dst_config, src_config, 0, 0);
+ if (ret)
+ return NULL;
+
+ ret = imx_dma_setup_single(imxdmac->imxdma_channel, xt->src_start,
+ x * y, xt->dst_start, DMA_MODE_WRITE);
+ if (ret)
+ return NULL;
+
+ return &imxdmac->desc;
+}
+
static void imxdma_issue_pending(struct dma_chan *chan)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
@@ -381,6 +432,7 @@ static int __init imxdma_probe(struct platform_device *pdev)
dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
dma_cap_set(DMA_MEMCPY, imxdma->dma_device.cap_mask);
+ dma_cap_set(DMA_INTERLEAVE, imxdma->dma_device.cap_mask);

/* Initialize channel parameters */
for (i = 0; i < MAX_DMA_CHANNELS; i++) {
@@ -415,6 +467,7 @@ static int __init imxdma_probe(struct platform_device *pdev)
imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
imxdma->dma_device.device_prep_dma_memcpy = imxdma_prep_dma_memcpy;
+ imxdma->dma_device.device_prep_interleaved_dma = imxdma_prep_dma_interleaved;
imxdma->dma_device.device_control = imxdma_control;
imxdma->dma_device.device_issue_pending = imxdma_issue_pending;

--
1.7.0.4

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