Re: [PATCH v7 10/15] drm/imx: dc-ed: Support getting source selection

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Hi,

thanks for the patch and adding me.

Am Montag, 26. Oktober 2026, 11:05:15 Mitteleuropäische Normalzeit schrieb Liu Ying:
> Add a helper to get ExtDst source selection.  This is needed by
> disabling CRTC at boot in an upcoming commit which tries to get
> the source selection.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Acked-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> --
> v7:
> - Collect Maxime's A-b tag.
> - Check regmap_read()'s return valure.  (Sashiko AI bot)
> 
> v2:
> - Collect Frank's R-b tag.
> ---
>  drivers/gpu/drm/imx/dc/dc-ed.c | 29 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/imx/dc/dc-pe.h |  1 +
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/gpu/drm/imx/dc/dc-ed.c b/drivers/gpu/drm/imx/dc/dc-ed.c
> index de1b71315eab..67163dca1363 100644
> --- a/drivers/gpu/drm/imx/dc/dc-ed.c
> +++ b/drivers/gpu/drm/imx/dc/dc-ed.c
> @@ -149,6 +149,35 @@ void dc_ed_pec_src_sel(struct dc_ed *ed, enum dc_link_id src)
>  	}
>  }
>  
> +int dc_ed_pec_src_sel_get(struct dc_ed *ed, enum dc_link_id *src)
> +{
> +	u32 val;
> +	int ret;
> +
> +	ret = regmap_read(ed->reg_pec, PIXENGCFG_DYNAMIC, &val);
> +	if (ret)
> +		return -EINVAL;

Shouldn't you return ret here instead? With that fixed:
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>

Best regards
Alexander

> +
> +	switch (val) {
> +	case LINK_ID_NONE:
> +	case LINK_ID_CONSTFRAME0:
> +	case LINK_ID_CONSTFRAME4:
> +	case LINK_ID_CONSTFRAME1:
> +	case LINK_ID_CONSTFRAME5:
> +	case LINK_ID_FETCHWARP2:
> +	case LINK_ID_FETCHLAYER0:
> +	case LINK_ID_LAYERBLEND0:
> +	case LINK_ID_LAYERBLEND1:
> +	case LINK_ID_LAYERBLEND2:
> +	case LINK_ID_LAYERBLEND3:
> +		*src = val;
> +		dev_dbg(ed->dev, "get source selection: 0x%02x\n", val);
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
>  void dc_ed_pec_sync_trigger(struct dc_ed *ed)
>  {
>  	regmap_write(ed->reg_pec, PIXENGCFG_TRIGGER, SYNC_TRIGGER);
> diff --git a/drivers/gpu/drm/imx/dc/dc-pe.h b/drivers/gpu/drm/imx/dc/dc-pe.h
> index f5e01a6eb9e9..0b81dc6b251c 100644
> --- a/drivers/gpu/drm/imx/dc/dc-pe.h
> +++ b/drivers/gpu/drm/imx/dc/dc-pe.h
> @@ -85,6 +85,7 @@ void dc_cf_init(struct dc_cf *cf);
>  
>  /* External Destination Unit */
>  void dc_ed_pec_src_sel(struct dc_ed *ed, enum dc_link_id src);
> +int dc_ed_pec_src_sel_get(struct dc_ed *ed, enum dc_link_id *src);
>  void dc_ed_pec_sync_trigger(struct dc_ed *ed);
>  void dc_ed_init(struct dc_ed *ed);
>  
> 
> 


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