On 13/05/20 11:41 pm, Angelo Dureghello wrote:
> Some controller as the ColdFire eshdc may require an endianness
> byte swap, becouse DMA read endianness is not configurable.
>
> Signed-off-by: Angelo Dureghello <angelo.dureghello@xxxxxxxxxxx>
> ---
> Changes for v3:
> - add post request callback
> Changes for v4:
> none
> ---
> drivers/mmc/host/sdhci.c | 7 +++++++
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 9 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 3f716466fcfd..d3bfbb6e11d5 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -637,6 +637,13 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host,
> sg_copy_to_buffer(data->sg, data->sg_len,
> host->bounce_buffer,
> length);
> +
> + /*
> + * Endianness can't be swapped in the sg list,
> + * since the sg list is processed again later on.
> + */
The data in the sg list must not be changed because we don't know how
else it might be being used. Maybe leave out the comment.
> + if (host->ops->pre_dma_transfer)
> + host->ops->pre_dma_transfer(host, data);
Let's make this slightly more generic i.e.
if (host->ops->copy_to_bounce_buffer) {
host->ops->copy_to_bounce_buffer(host, data);
} else {
sg_copy_to_buffer(data->sg, data->sg_len,
host->bounce_buffer,
length);
}
> }
> /* Switch ownership to the DMA */
> dma_sync_single_for_device(host->mmc->parent,
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 79dffbb731d3..076054308423 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -653,6 +653,8 @@ struct sdhci_ops {
> void (*voltage_switch)(struct sdhci_host *host);
> void (*adma_write_desc)(struct sdhci_host *host, void **desc,
> dma_addr_t addr, int len, unsigned int cmd);
> + void (*pre_dma_transfer)(struct sdhci_host *host,
> + struct mmc_data *data);
> void (*request_done)(struct sdhci_host *host,
> struct mmc_request *mrq);
> };
>
