[...]
>>> struct variant_data {
>>> unsigned int clkreg;
>>> @@ -348,6 +350,8 @@ struct variant_data {
>>> unsigned int irq_pio_mask;
>>> u32 start_err;
>>> u32 opendrain;
>>> + bool dma_lli;
>>> + u32 stm32_idmabsize_mask;
>>
>>
>> What are these?
>
>
> This property is specific for sdmmc variants:
> sdmmc has a Internal DMA and the number bytes per buffer
> could be different between sdmmc variants
> (depend of SDMMC_IDMABSIZER register).
Okay. Thanks for clarifying.
Could you please add some information about this in the changelog as well?
[...]
>>> +
>>> +static int _sdmmc_idma_prep_data(struct mmci_host *host,
>>> + struct mmc_data *data)
>>> +{
>>> + int n_elem;
>>> +
>>> + n_elem = dma_map_sg(mmc_dev(host->mmc),
>>> + data->sg,
>>> + data->sg_len,
>>> + mmc_get_dma_dir(data));
>>> +
>>> + if (!n_elem) {
>>> + dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int sdmmc_idma_prep_data(struct mmci_host *host,
>>> + struct mmc_data *data, bool next)
>>> +{
>>> + /* Check if job is already prepared. */
>>> + if (!next && data->host_cookie == host->next_cookie)
>>> + return 0;
>>> +
>>> + return _sdmmc_idma_prep_data(host, data);
>>> +}
>>> +
>>> +static void sdmmc_idma_unprep_data(struct mmci_host *host,
>>> + struct mmc_data *data, int err)
>>> +{
>>> + dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
>>> + mmc_get_dma_dir(data));
>>> +}
>>
>>
>> The sdmmc_idma_prep_data() and sdmmc_idma_unprep_data(), seems very
>> similar to what the mmci core driver needs to do in this regards.
>>
>> Can we perhaps avoid adding these callbacks altogether, but rather
>> rely on common code in the mmci core driver?
>
>
> Actually, these callbacks allow to manage prepare/unprepare of
> dmaengine interface for mmci variant, (not needed for sdmmc which uses an
> internal dma).
>
> For Sdmmc, today there are no special case, just dma_map/unmap.
> But in the future, I hope manage the lli list in these callback.
>
> Only dma_map/unmap could be common, but the error management may
> be complicated (in mmci variant).
>
> Personally, I prefer keep prep_data/unprep_data mmci_host_ops
> interfaces.
> What do you suggest ?
Okay, let's keep them for now. We can always change things on top, in
case we see later that those callbacks can be removed.
[...]
Kind regards
Uffe
