[PATCH 1/3] DMA: PL330: Infer transfer direction from transfer request instead of platform data

[Thomas Abraham]

Hi Boojin,

On 24 August 2011 06:51, Boojin Kim <boojin.kim at samsung.com> wrote:
> Thomas Abraham wrote:
>> Sent: Tuesday, August 23, 2011 7:00 AM
>> To: linux-arm-kernel at lists.infradead.org
>> Cc: linux-samsung-soc at vger.kernel.org; kgene.kim at samsung.com;
>> vinod.koul at intel.com; Jassi Brar; Boojin Kim
>> Subject: [PATCH 1/3] DMA: PL330: Infer transfer direction from
>> transfer request instead of platform data
>>
>> The transfer direction for a channel can be inferred from the transfer
>> request and the need for specifying transfer direction in platfrom
>> data
>> can be eliminated. So the structure definition 'struct dma_pl330_peri'
>> is no longer required.
>>
>> With the 'struct dma_pl330_peri' removed, the dma controller transfer
>> capabilities cannot be inferred any longer. Hence, the dma controller
>> capabilities is specified using platforme data.
>>
>> Cc: Jassi Brar <jassisinghbrar at gmail.com>
>> Cc: Boojin Kim <boojin.kim at samsung.com>
>> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
>> ---
>>  drivers/dma/pl330.c        |   56 ++++++++------------------------------
>> ------
>>  include/linux/amba/pl330.h |   14 +++--------
>>  2 files changed, 14 insertions(+), 56 deletions(-)
>>

[...]

>>       for (i = 0; i < num_chan; i++) {
>>               pch = &pdmac->peripherals[i];
>> -             if (pdat) {
>> -                     struct dma_pl330_peri *peri = &pdat->peri[i];
>> -
>> -                     switch (peri->rqtype) {
>> -                     case MEMTOMEM:
>> -                             dma_cap_set(DMA_MEMCPY, pd->cap_mask);
>> -                             break;
>> -                     case MEMTODEV:
>> -                     case DEVTOMEM:
>> -                             dma_cap_set(DMA_SLAVE, pd->cap_mask);
>> -                             dma_cap_set(DMA_CYCLIC, pd->cap_mask);
>> -                             break;
> If remove capabilities setting, dmaengine() doesn't search the channel that
> client requests with specific capability.
> So, I think dma_request_channel() would fail.

The capabilities is now supplied using platform data. There is a new
member 'cap_mask' added to the pl330 driver platform data structure.
The capabilities for a pl330 controller can be specified using
cap_mask. For exynos4, the capabilities is set up in the
exynos4_dma_init function. These changes are part of the third patch
in this patchset.

Thanks for your review.

Regards,
Thomas.

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