Re: [PATCH 14/17] spi: dw: Add DMA support to the DW SPI MMIO driver

[Andy Shevchenko]

On Fri, May 08, 2020 at 04:29:39PM +0300, Serge Semin wrote:
> Since the common code in the spi-dw-dma.c driver is ready to be used
> by the MMIO driver, we just need to initialize the DW SPI private data
> fields with Tx/Rx DMA channel handlers and setup the DW SPI DMA
> callbacks. This commit introduces such alterations to the DW SPI
> DMA/MMIO code. A dedicated DW SPI MMIO DMA initializer performs the
> DMA channels request from the parental device (which is supposed to be
> a DW SPI platform device). Then it checks whether the retrieved DW DMA
> channels support LLP. If they don't currently we print a warning, that
> further DMA usage may be finished with DW SPI inbound FIFO overflow
> (nothing else we can do about it at the moment). Finally the DW SPI
> MMIO DMA initializer sets the DMA-inited flag.
> 
> Currently the DMA will be initialized only for a generic DW SPI MMIO
> device declared with "snps,dw-apb-ssi" compatible string if SPI_DW_DMA
> kernel config is enabled.

Already in spi/for-next (see for generic suffix in spi-dw-mid.c).

-- 
With Best Regards,
Andy Shevchenko