[PATCH v3 4/6] dmaengine: dw-edma: Don't rely on the deprecated "direction" member

[Frank Li <Frank.Li@nxp.com>]

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The "direction" member of the "dma_slave_config" structure is deprecated.
The clients no longer use this field to specify the direction of the slave
channel. But in the eDMA core, this field is used to differentiate between the
Root complex (remote) and Endpoint (local) DMA accesses.

Nevertheless, we can't differentiate between local and remote accesses without
a dedicated flag. So let's get rid of the old check and add a new check for
verifying the DMA operation between local and remote memory instead.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
Resend added dmaengine@vger.kernel.org

Change from v1 to v3
 - direct pick up from Manivannan

 drivers/dma/dw-edma/dw-edma-core.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 3636c48f5df15..0635157d260c1 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -341,22 +341,9 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 	if (!chan->configured)
 		return NULL;
 
-	switch (chan->config.direction) {
-	case DMA_DEV_TO_MEM: /* local DMA */
-		if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_READ)
-			break;
-		return NULL;
-	case DMA_MEM_TO_DEV: /* local DMA */
-		if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_WRITE)
-			break;
+	/* eDMA supports only read and write between local and remote memory */
+	if (dir != DMA_DEV_TO_MEM && dir != DMA_MEM_TO_DEV)
 		return NULL;
-	default: /* remote DMA */
-		if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_READ)
-			break;
-		if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_WRITE)
-			break;
-		return NULL;
-	}
 
 	if (xfer->type == EDMA_XFER_CYCLIC) {
 		if (!xfer->xfer.cyclic.len || !xfer->xfer.cyclic.cnt)
-- 
2.24.0.rc1