[PATCH] remove redundant queue structure for Mediatek Command-Queue DMA controller

[shun-chih.yu]

This patchset introduces support for MediaTek Command-Queue DMA controller in dt-bindings, and simplifies the controller by removing redundant structures.

Main changes to the initial version:
- remove redundant queue structure in mtk_cqdma_pchan
- remove redundant completion management
- remove redundant tasklet management
- fix wrong residue assignment in mtk_cqdma_tx_status
- fix typos

The result of dmatest shown below:
dmatest: dma0chan0-copy2: summary 5000 tests, 0 failures 3500 iops 28037 KB/s
dmatest: dma0chan0-copy4: summary 5000 tests, 0 failures 3494 iops 27612 KB/s
dmatest: dma0chan0-copy1: summary 5000 tests, 0 failures 3491 iops 27749 KB/s
dmatest: dma0chan0-copy7: summary 5000 tests, 0 failures 3673 iops 29092 KB/s 
dmatest: dma0chan0-copy6: summary 5000 tests, 0 failures 3763 iops 30237 KB/s 
dmatest: dma0chan0-copy0: summary 5000 tests, 0 failures 3730 iops 30131 KB/s
dmatest: dma0chan0-copy3: summary 5000 tests, 0 failures 3717 iops 29569 KB/s
dmatest: dma0chan0-copy5: summary 5000 tests, 0 failures 3699 iops 29302 KB/s

Shun-Chih Yu (2):
  dt-bindings: dmaengine: Add MediaTek Command-Queue DMA controller
    bindings
  dmaengine: mediatek-cqdma: remove redundant queue structure

 .../devicetree/bindings/dma/mtk-cqdma.txt          |   31 ++
 drivers/dma/mediatek/mtk-cqdma.c                   |  399 +++++---------------
 2 files changed, 129 insertions(+), 301 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/mtk-cqdma.txt