Re: [PATCH 1/2] soc: qcom: geni-se: Add interfaces geni_se_tx_init_dma() and geni_se_rx_init_dma()

[Doug Anderson <dianders@xxxxxxxxxxxx>]

Hi,

On Fri, May 12, 2023 at 10:07 AM Vijaya Krishna Nivarthi
<quic_vnivarth@xxxxxxxxxxx> wrote:
>
> The geni_se_xx_dma_prep() interfaces necessarily do DMA mapping before
> initiating DMA transfers. This is not suitable for spi where framework
> is expected to handle map/unmap.
>
> Expose new interfaces geni_se_xx_init_dma() which do only DMA transfer.
>
> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
> ---
>  drivers/soc/qcom/qcom-geni-se.c  | 67 +++++++++++++++++++++++++++++-----------
>  include/linux/soc/qcom/geni-se.h |  4 +++
>  2 files changed, 53 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
> index 795a2e1..adfcd6e 100644
> --- a/drivers/soc/qcom/qcom-geni-se.c
> +++ b/drivers/soc/qcom/qcom-geni-se.c
> @@ -682,6 +682,30 @@ EXPORT_SYMBOL(geni_se_clk_freq_match);
>  #define GENI_SE_DMA_EOT_EN BIT(1)
>  #define GENI_SE_DMA_AHB_ERR_EN BIT(2)
>  #define GENI_SE_DMA_EOT_BUF BIT(0)
> +
> +/**
> + * geni_se_tx_init_dma() - Initiate TX DMA transfer on the serial engine
> + * @se:                        Pointer to the concerned serial engine.
> + * @iova:              Pointer to store the mapped DMA address.

We're not returning the "iova" from this function, so it shouldn't say
"Pointer to store".


> + * @len:               Length of the TX buffer.
> + *
> + * This function is used to initiate DMA TX transfer.
> + */
> +void geni_se_tx_init_dma(struct geni_se *se, dma_addr_t *iova, size_t len)

There is no reason to pass iova as a pointer, right? Change it to just
"dma_addr_t"


Same comments on the RX side of things.


-Doug