On the JHB100, there is only one channel available for DMA transfer.
In flash access scenarios, it operates in half-duplex mode, so we
can request this DMA channel for the direction that transfers a
larger amount of data. Different transfer directions need to share
a single DMA channel in a time-multiplexed manner. Therefore, it is
necessary to request the DMA channel at runtime based on the current
transfer direction, and release the DMA channel after use.

This series has already been tested on the JHB100 EVB1.

Changhuang Liang (2):
  spi: dw: Request DMA channels at runtime instead of probe
  spi: dw: Add DMA support for enhanced memory operations

 drivers/spi/spi-dw-core.c | 154 ++++++++++++++------
 drivers/spi/spi-dw-dma.c  | 289 +++++++++++++++++++++++++++++++++++++-
 drivers/spi/spi-dw-mmio.c |   2 +
 drivers/spi/spi-dw.h      |  10 ++
 4 files changed, 404 insertions(+), 51 deletions(-)

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2.25.1