[PATCH v3 2/2] DMAEngine: Add DMAEngine driver based on old MSM DMA APIs

[Linus Walleij]

On Wed, Mar 14, 2012 at 4:05 PM, Daniel Walker <dwalker at fifo99.com> wrote:
> On Tue, Mar 13, 2012 at 06:16:39PM +0530, Ravi Kumar V wrote:
>>
>> There is a MSM DMA driver in arch/arm/mach-msm/ which is not in
>> dmaengine framework standards, but that driver is been used by
>> client drivers nand, eMMC and serial drivers. Now if we implement
>> the whole dma driver using dmaengine framework then nand, eMMC like
>> drivers will be failed as they are using old dma driver API's, so
>> instead of implementing new driver from scratch we are keeping the
>> old dma API's as it is and using those API's in new dmaengine
>> framework.So that we can convert clients drivers to use dma engine
>> framework.
>
> Did you investigate converting the drivers (nand, eMMC, serial) ? It
> seems like there would be a 1:1 mapping between the API's , so it might
> only be a find->replace operation.

The eMMC i.e. drivers/mmc/host/msm_sdcc.c should preferably
not be converted, instead switch the platforms over to using
drivers/mmc/host/mmci.c which is already very well enabled for
DMA engine.

Augment it with Qualcomm silicon differences as needed, I do
not think they will be major.

Yours,
Linus Walleij