Hi Vinod,
(snipped)
>>> +{
>>> + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
>>> + const struct dw_edma_core_ops *ops = chan2ops(chan);
>>> + enum dma_transfer_direction dir;
>>> + unsigned long flags;
>>> + int err = 0;
>>> +
>>> + spin_lock_irqsave(&chan->vc.lock, flags);
>>> +
>>> + if (!config) {
>>> + err = -EINVAL;
>>> + goto err_config;
>>> + }
>>> +
>>> + if (chan->configured) {
>>> + dev_err(chan2dev(chan), ": channel already configured\n");
>>> + err = -EPERM;
>>> + goto err_config;
>>> + }
>>> +
>>> + dir = config->direction;
>>
>> Direction is depreciated, I have already removed the usages, so please
>> do not add new ones.
>>
>> You need to take direction for respective prep_ calls
>
> Ok, I already do that. IMHO I found it strange to have the same information
> repeated on two places. But now that you say that this is deprecated, it makes
> sense now.
>
>>
>>> + if (dir == DMA_DEV_TO_MEM && chan->dir == EDMA_DIR_WRITE) {
>>> + dev_info(chan2dev(chan),
>>> + ": direction DMA_DEV_TO_MEM (EDMA_DIR_WRITE)\n");
>>> + chan->p_addr = config->src_addr;
>>> + } else if (dir == DMA_MEM_TO_DEV && chan->dir == EDMA_DIR_READ) {
>>> + dev_info(chan2dev(chan),
>>> + ": direction DMA_MEM_TO_DEV (EDMA_DIR_READ)\n");
>>> + chan->p_addr = config->dst_addr;
>>> + } else {
>>> + dev_err(chan2dev(chan), ": invalid direction\n");
>>> + err = -EINVAL;
>>> + goto err_config;
>>> + }
>>
>> This should be removed
>
> Yeah, it was just for validation purposes. Now that direction is deprecated on
> the API, makes no sense to validate it.
>
>>
>>> +
>>> + dev_info(chan2dev(chan),
>>> + ": src_addr(physical) = 0x%.16x\n", config->src_addr);
>>> + dev_info(chan2dev(chan),
>>> + ": dst_addr(physical) = 0x%.16x\n", config->dst_addr);
>>
I've a doubt now. As you know, for a DMA transfer you need the source and
destination addresses, which in the limited can be swapped according to the
direction MEM_TO_DEV/DEV_TO_MEM case.
For the sake of simplicity, I'll just consider now the MEM_TO_DEV case, since
the other case is similar but the source and destination address are swapped.
In my code I can get some of the information that I need by using the
sg_dma_address() in the scatter-gather list (which gives me the source address).
The remaining information I got from here, using the direction to help me to
select which address I'll use later on the DMA transfer, in this case the
destination address.
Since this is deprecated how should I proceed? How can I get that information?
There is some similar function to sg_dma_address() that could give me the
destination address?
Regards,
Gustavo
