[PATCH v5 6/9] dmaengine: dw-edma: Don't rely on the deprecated "direction" member

Frank Li
2022-03-10T19:25:47Z

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>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
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 924f220007362..156255ce7744e 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