[PATCH v2 02/19] drm/msm/dp: add an API to indicate if sink supports VSC SDP

[Dmitry Baryshkov]

On Sat, 10 Feb 2024 at 03:53, Paloma Arellano <quic_parellan at quicinc.com> wrote:
>
> YUV420 format is supported only in the VSC SDP packet and not through
> MSA. Hence add an API which indicates the sink support which can be used
> by the rest of the DP programming.
>
> Changes in v2:
>         - Move VSC SDP support check API from dp_panel.c to
>           drm_dp_helper.c
>
> Signed-off-by: Paloma Arellano <quic_parellan at quicinc.com>
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 21 +++++++++++++++++++++
>  include/drm/display/drm_dp_helper.h     |  1 +
>  2 files changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
> index d72b6f9a352c1..c6ee0f9ab5f8f 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -2917,6 +2917,27 @@ void drm_dp_vsc_sdp_log(const char *level, struct device *dev,
>  }
>  EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
>
> +/**
> + * drm_dp_vsc_sdp_supported() - check if vsc sdp is supported
> + * @aux: DisplayPort AUX channel
> + * @dpcd: DisplayPort configuration data
> + *
> + * Returns true if vsc sdp is supported, else returns false
> + */
> +bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> +       u8 rx_feature;
> +
> +       if (drm_dp_dpcd_readb(aux, DP_DPRX_FEATURE_ENUMERATION_LIST, &rx_feature) != 1) {
> +               drm_dbg_dp(aux->drm_dev, "failed to read DP_DPRX_FEATURE_ENUMERATION_LIST\n");
> +               return false;
> +       }
> +
> +       return (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_13) &&
> +               !!(rx_feature & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED);

Nit: we don't even need  the `!!` here. I'll probably drop it while applying.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>


> +}
> +EXPORT_SYMBOL(drm_dp_vsc_sdp_supported);
> +
>  /**
>   * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON
>   * @dpcd: DisplayPort configuration data
> diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
> index 863b2e7add29e..948381b2b0b1b 100644
> --- a/include/drm/display/drm_dp_helper.h
> +++ b/include/drm/display/drm_dp_helper.h
> @@ -100,6 +100,7 @@ struct drm_dp_vsc_sdp {
>
>  void drm_dp_vsc_sdp_log(const char *level, struct device *dev,
>                         const struct drm_dp_vsc_sdp *vsc);
> +bool drm_dp_vsc_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
>
>  int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
>
> --
> 2.39.2
>


-- 
With best wishes
Dmitry