[PATCH v3 2/6] drm/bridge: tfp410: Support format negotiation hooks

[Laurent Pinchart]

Hi Nikhil,

Thank you for the patch.

On Thu, Nov 19, 2020 at 09:31:30PM +0530, Nikhil Devshatwar wrote:
> With new connector model, tfp410 will not create the connector and
> SoC driver will rely on format negotiation to setup the encoder format.
> 
> Support format negotiations hooks in the drm_bridge_funcs.
> Use helper functions for state management.
> 
> Output format is expected to be MEDIA_BUS_FMT_FIXED
> Input format is the one selected by the bridge from DT properties.
> 
> Signed-off-by: Nikhil Devshatwar <nikhil.nd at ti.com>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen at ti.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
> 
> Notes:
>     changes from v1:
>     * Use only MEDIA_BUS_FMT_FIXED for output
> 
>  drivers/gpu/drm/bridge/ti-tfp410.c | 33 ++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
> index ba3fa2a9b8a4..3def9acba86b 100644
> --- a/drivers/gpu/drm/bridge/ti-tfp410.c
> +++ b/drivers/gpu/drm/bridge/ti-tfp410.c
> @@ -204,12 +204,45 @@ static enum drm_mode_status tfp410_mode_valid(struct drm_bridge *bridge,
>  	return MODE_OK;
>  }
>  
> +static u32 *tfp410_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)
> +{
> +	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
> +	u32 *input_fmts;
> +
> +	*num_input_fmts = 0;
> +
> +	/*
> +	 * Output of tfp410 is DVI, which is TMDS.
> +	 * There is no media format defined for this.
> +	 * Using MEDIA_BUS_FMT_FIXED for now.
> +	 */
> +	if (output_fmt != MEDIA_BUS_FMT_FIXED)
> +		return NULL;
> +
> +	input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	*num_input_fmts = 1;
> +	input_fmts[0] = dvi->bus_format;
> +	return input_fmts;
> +}
> +
>  static const struct drm_bridge_funcs tfp410_bridge_funcs = {
>  	.attach		= tfp410_attach,
>  	.detach		= tfp410_detach,
>  	.enable		= tfp410_enable,
>  	.disable	= tfp410_disable,
>  	.mode_valid	= tfp410_mode_valid,
> +	.atomic_reset = drm_atomic_helper_bridge_reset,
> +	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +	.atomic_get_input_bus_fmts = tfp410_get_input_bus_fmts,
>  };
>  
>  static const struct drm_bridge_timings tfp410_default_timings = {

-- 
Regards,

Laurent Pinchart