[PATCH v7 3/8] drm/bridge: mhdp8546: Add minimal format negotiation

[Neil Armstrong]

On 06/06/2023 10:21, Aradhya Bhatia wrote:
> From: Nikhil Devshatwar <nikhil.nd at ti.com>
> 
> With new connector model, mhdp bridge will not create the connector and
> SoC driver will rely on format negotiation to setup the encoder format.
> 
> Support minimal format negotiations hooks in the drm_bridge_funcs.
> Complete format negotiation can be added based on EDID data.
> This patch adds the minimal required support to avoid failure
> after moving to new connector model.
> 
> Signed-off-by: Nikhil Devshatwar <nikhil.nd at ti.com>
> [a-bhatia1: Drop the output_fmt check condition]
> Signed-off-by: Aradhya Bhatia <a-bhatia1 at ti.com>
> ---
> 
> Notes:
> 
>      changes from v1:
>      * cosmetic fixes, commit message update.
> 
>      changes from v5:
>      * drop the default_bus_format variable and directly assigned
>        MEDIA_BUS_FMT_RGB121212_1X36 to input_fmts.
> 
>      changes from v6:
>      * Drop the output_fmt check condition and hence drop Tomi
>        Valkeinen's R-b tag.
> 
>   .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 22 +++++++++++++++++++
>   1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> index f6822dfa3805..afd4e353f37a 100644
> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> @@ -2146,6 +2146,27 @@ cdns_mhdp_bridge_atomic_reset(struct drm_bridge *bridge)
>   	return &cdns_mhdp_state->base;
>   }
>   
> +static u32 *cdns_mhdp_get_input_bus_fmts(struct drm_bridge *bridge,
> +					 struct drm_bridge_state *bridge_state,
> +					 struct drm_crtc_state *crtc_state,
> +					 struct drm_connector_state *conn_state,
> +					 u32 output_fmt,
> +					 unsigned int *num_input_fmts)
> +{
> +	u32 *input_fmts;
> +
> +	*num_input_fmts = 0;
> +
> +	input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	*num_input_fmts = 1;
> +	input_fmts[0] = MEDIA_BUS_FMT_RGB121212_1X36;
> +
> +	return input_fmts;
> +}
> +
>   static int cdns_mhdp_atomic_check(struct drm_bridge *bridge,
>   				  struct drm_bridge_state *bridge_state,
>   				  struct drm_crtc_state *crtc_state,
> @@ -2210,6 +2231,7 @@ static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
>   	.atomic_duplicate_state = cdns_mhdp_bridge_atomic_duplicate_state,
>   	.atomic_destroy_state = cdns_mhdp_bridge_atomic_destroy_state,
>   	.atomic_reset = cdns_mhdp_bridge_atomic_reset,
> +	.atomic_get_input_bus_fmts = cdns_mhdp_get_input_bus_fmts,
>   	.detect = cdns_mhdp_bridge_detect,
>   	.get_edid = cdns_mhdp_bridge_get_edid,
>   	.hpd_enable = cdns_mhdp_bridge_hpd_enable,

Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>