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

[Paloma Arellano <quic_parellan@xxxxxxxxxxx>]

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@xxxxxxxxxxx>
---
 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);
+}
+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