On 10/14/2015 09:11 AM, Roger Quadros wrote:
> On 14/10/15 16:26, Franklin S Cooper Jr. wrote:
>>
>> On 10/14/2015 06:52 AM, Roger Quadros wrote:
>>> Franklin,
>>>
>>> On 14/10/15 14:36, Roger Quadros wrote:
>>>> On 13/10/15 04:38, Franklin S Cooper Jr wrote:
>>>>> Switch from dma_request_channel to allow passing dma channel
>>>>> information from DT rather than hardcoding a value.
>>>>>
>>>>> Signed-off-by: Franklin S Cooper Jr <fcooper@xxxxxx>
>>>> Acked-by: Roger Quadros <rogerq@xxxxxx>
>>>>
>>>>> ---
>>>>> drivers/mtd/nand/omap2.c | 4 +++-
>>>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
>>>>> index d0f2620..957c32f 100644
>>>>> --- a/drivers/mtd/nand/omap2.c
>>>>> +++ b/drivers/mtd/nand/omap2.c
>>>>> @@ -1866,7 +1866,9 @@ static int omap_nand_probe(struct platform_device *pdev)
>>>>> dma_cap_zero(mask);
>>>>> dma_cap_set(DMA_SLAVE, mask);
>>>>> sig = OMAP24XX_DMA_GPMC;
>>>>> - info->dma = dma_request_channel(mask, omap_dma_filter_fn, &sig);
>>>>> + info->dma = dma_request_slave_channel_compat(mask,
>>>>> + omap_dma_filter_fn, &sig, pdev->dev.parent, "rxtx");
>>>>> +
>>> Just discovered that you are using the parent device node.
>>>
>>> How about moving the dma bindings to the nand node instead and using
>>> pdev->dev here?
>> Roger,
>>
>> From what I can tell the interrupt number and the dma channel will always be
>> the same no matter what. Doesn't matter if you have multiple nands or a
>> combination of nands and nors. Since that is the case I think it just makes
>> sense to leave it in the gpmc parent node and define it once.
> Is prefetch/writepost dma used for NOR or any other GPMC peripheral
> or only for NAND?
The dma seems tied to the prefetch. From what I can tell the prefetch is only
used by nand.
>
> Let's also get Tony's inputs on this.
Sure.
>
>>>>> if (!info->dma) {
>>>>> dev_err(&pdev->dev, "DMA engine request failed\n");
>>>>> err = -ENXIO;
>>>>>
> --
> cheers,
> -roger
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
