Re: [PATCH 10/19] dma: imx-sdma: Add multi fifo support

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Mar 17, 2022 at 05:08:55PM +0800, Shengjiu Wang wrote:
>    On Thu, Mar 17, 2022 at 4:28 PM Sascha Hauer <[1]s.hauer@pengutronix.de>
>    wrote:
> 
>      +struct sdma_peripheral_config {
>      +       int n_fifos_src;
>      +       int n_fifos_dst;
>      +       bool sw_done;
>      +};
>      +
>       #endif
> 
>    Hi Sascha
>    This is our internal definition for this sdma_peripheral_config.
>    Could you please adopt this?

This structure is completely internal to the kernel and can be adjusted
when we need it. I don't see a reason to add unused fields to it just to
be compatible with a downstream kernel.

Sascha

>    /**
>     * struct sdma_audio_config - special sdma config for audio case
>     * @src_fifo_num: source fifo number for mcu_2_sai/sai_2_mcu script
>     *                For example, if there are 4 fifos, sdma will fetch
>     *                fifos one by one and roll back to the first fifo after
>     *                the 4th fifo fetch.
>     * @dst_fifo_num: similar as src_fifo_num, but dest fifo instead.
>     * @src_fifo_off: source fifo offset, 0 means all fifos are continuous, 1
>     *                means 1 word offset between fifos. All offset between
>     *                fifos should be same.
>     * @dst_fifo_off: dst fifo offset, similar as @src_fifo_off.
>     * @words_per_fifo: numbers of words per fifo fetch/fill, 0 means
>     *                  one channel per fifo, 1 means 2 channels per fifo..
>     *                  If 'src_fifo_num =  4' and 'chans_per_fifo = 1', it
>     *                  means the first two words(channels) fetch from fifo1
>     *                  and then jump to fifo2 for next two words, and so on
>     *                  after the last fifo4 fetched, roll back to fifo1.
>     * @sw_done_sel: software done selector, PDM need enable software done
>    feature
>     *               in mcu_2_sai/sai_2_mcu script.
>     *               Bit31: sw_done eanbled or not
>     *               Bit16~Bit0: selector
>     *               For example: 0x80000000 means sw_done enabled for done0
>     *                            sector which is for PDM on i.mx8mm.
>     */
>    struct sdma_audio_config {
>            u8 src_fifo_num;
>            u8 dst_fifo_num;
>            u8 src_fifo_off;
>            u8 dst_fifo_off;
>            u8 words_per_fifo;
>            u32 sw_done_sel;
>    };
>    best regards
>    wang shengjiu
>     
> 
> References
> 
>    Visible links
>    1. mailto:s.hauer@pengutronix.de
>    2. mailto:s.hauer@pengutronix.de

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