drm: xilinx: plane: Use IS_ERR() for of_dma_request_slave_channel()

of_dma_request_slave_channel() returns an error pointer in case of
error, so use IS_ERR() and PTR_ERR() to check and return the correct
error code.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
drm: xilinx: plane: Use the inteleaved dmaengine API

The VDMA driver is modified to implement the interleaved dmaengine API.
Use the updated interface of VDMA driver.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
drm: xilinx: plane: Change the dma name from 'vdma' to 'dma'

As a part of removing direct dependency on VDMA, change the dma name
from 'vdma' to 'dma'.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
drm: xilinx: plane: Use 'dma' for the DMA channel name

As VDMA dependency is being removed, make the dma channel name
more generic, and use 'dma' instead of 'vdma'. Update the documentation
with a new dma-name string.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
drm: xilinx: plane: Remove the vdma reset call

Resetting the VDMA IP shouldn't be needed in the client driver.
This introduces the direct dependency on the VDMA driver as well.
Thus, remove the VDMA reset call in the plane driver.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
media: xilinx: dma: Use the interleaved dmaengine API

The Xilinx VDMA driver is implemented based on the interleaved dmaengine
API, so the Xilinx V4L2 is updated accordingly.

Signed-off-by: Hyun Kwon <hyunk@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>