[PATCH v2] dmaengine: add CSR SiRFprimaII DMAC driver

Jassi Brar jaswinder.singh at linaro.org
Tue Sep 20 00:40:11 EDT 2011


On 19 September 2011 16:55, Barry Song <21cnbao at gmail.com> wrote:
> 2011/9/19 Vinod Koul <vinod.koul at intel.com>:
>> On Mon, 2011-09-19 at 09:56 +0000, Barry Song wrote:
>>> > > > Not sure why you support this, there seem to be no DMA_SLAVE
>>> support in
>>> > > > this version ate least
>>> > >
>>> > > Not. I support dma_slave. But I have no prep_slave_sg function
>>> since I can
>>> > use the gen xfer to replace it.
>>> > Yes thats okay...
>>> >
>>> > Then I have questions on genxfer function...
>>> > where are you copying either src or dstn_start address, you seem to
>>> > completely ignore them?
>>>
>>> Since I only support memory->device or device ->memory, and channel
>>> number is fixed to every device. Then I actually don't care device
>>> address at all. Either src or dst is fixed to the device's address.
>> peripheral address can be fixed, not the memory, where do you copy the
>> memory address?
>
> +static int sirfsoc_dma_slave_config(struct sirfsoc_dma_chan *schan,
> +       struct dma_slave_config *config)
> +{
> +       u32 addr, direction;
> +       unsigned long flags;
> +
> +       switch (config->direction) {
> +       case DMA_FROM_DEVICE:
> +               direction = 0;
> +               addr = config->dst_addr;
> +               break;
> +
> +       case DMA_TO_DEVICE:
> +               direction = 1;
> +               addr = config->src_addr;
> +               break;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +  ...
I repeat
{
Pass addresses using dmaxfer_template.src_start and dmaxfer_template.dst_start
instead of dma_slave_config.dst_addr and dma_slave_config.src_addr
}



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