[PATCH v4] dmaengine: Add MOXA ART DMA engine driver

Jonas Jensen jonas.jensen at gmail.com
Fri Aug 2 08:28:28 EDT 2013


Hi Arnd,

Thanks for the replies. I think what you mention should now be fixed.

Except one thing where I still have questions:

On 29 July 2013 18:35, Arnd Bergmann <arnd at arndb.de> wrote:
> You must not override the "dest_req_no" and "dest_req_no" in moxart_slave_config
> since they are already set by the ->xlate() function and the driver calling
> slave_config generally has no knowledge of what the slave id is.

MMC now has a device tree node:

mmc: mmc at 98e00000 {
compatible = "moxa,moxart-mmc";
reg = <0x98e00000 0x5C>;
interrupts = <5 0>;
clocks = <&coreclk>;
dmas = <&dma 0>,
            <&dma 1>;
dma-names = "tx", "rx";
};

.. where the driver requests channel 0-1 and sets cfg.slave_id =
APB_DMA_SD_REQ_NO for both.

Perhaps this is not how slave_id is intended to be used?

Maybe it would be more appropriate to have two DMA cells?

APB_DMA_SD_REQ_NO can then be moved from driver code to DT.

Best regards,
Jonas



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