This patch parses HFVSDB fields for VRR capabilities of an
HDMI2.1 sink and stores the VRR caps in a new structure in
drm_hdmi_info.

Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
---
 drivers/gpu/drm/drm_edid.c  | 26 ++++++++++++++++++++++++--
 include/drm/drm_connector.h | 27 +++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 47465b9765f1..bb1f7d899580 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5823,6 +5823,21 @@ static void drm_parse_ycbcr420_deep_color_info(struct 
drm_connector *connector,
        hdmi->y420_dc_modes = dc_mask;
 }
 
+static void drm_parse_vrr_info(struct drm_hdmi_vrr_cap *hdmi_vrr,
+                              const u8 *hf_scds)
+{
+       if (hf_scds[8] & DRM_EDID_CNMVRR)
+               hdmi_vrr->cnm_vrr = true;
+       if (hf_scds[8] & DRM_EDID_CINEMA_VRR)
+               hdmi_vrr->cinema_vrr = true;
+       if (hf_scds[8] & DRM_EDID_MDELTA)
+               hdmi_vrr->m_delta = true;
+
+       hdmi_vrr->vrr_min = hf_scds[9] & DRM_EDID_VRR_MIN_MASK;
+       hdmi_vrr->vrr_max = (hf_scds[9] & DRM_EDID_VRR_MAX_UPPER_MASK) << 2;
+       hdmi_vrr->vrr_max |= hf_scds[10] & DRM_EDID_VRR_MAX_LOWER_MASK;
+}
+
 static void drm_parse_dsc_info(struct drm_hdmi_dsc_cap *hdmi_dsc,
                               const u8 *hf_scds)
 {
@@ -5901,9 +5916,11 @@ static void drm_parse_hdmi_forum_scds(struct 
drm_connector *connector,
        struct drm_display_info *display = &connector->display_info;
        struct drm_hdmi_info *hdmi = &display->hdmi;
        struct drm_hdmi_dsc_cap *hdmi_dsc = &hdmi->dsc_cap;
+       struct drm_hdmi_vrr_cap *hdmi_vrr = &hdmi->vrr_cap;
        int max_tmds_clock = 0;
        u8 max_frl_rate = 0;
        bool dsc_support = false;
+       bool vrr_support = false;
 
        display->has_hdmi_infoframe = true;
 
@@ -5949,14 +5966,19 @@ static void drm_parse_hdmi_forum_scds(struct 
drm_connector *connector,
 
        drm_parse_ycbcr420_deep_color_info(connector, hf_scds);
 
+       if (cea_db_payload_len(hf_scds) >= 8 && hf_scds[8]) {
+               drm_parse_vrr_info(hdmi_vrr, hf_scds);
+               vrr_support = true;
+       }
+
        if (cea_db_payload_len(hf_scds) >= 11 && hf_scds[11]) {
                drm_parse_dsc_info(hdmi_dsc, hf_scds);
                dsc_support = true;
        }
 
        drm_dbg_kms(connector->dev,
-                   "HF-VSDB: max TMDS clock: %d KHz, HDMI 2.1 support: %s, DSC 
1.2 support: %s\n",
-                   max_tmds_clock, str_yes_no(max_frl_rate), 
str_yes_no(dsc_support));
+                   "HF-VSDB: max TMDS clock: %d KHz, HDMI 2.1 support: %s, VRR 
support: %s, DSC 1.2 support: %s\n",
+                   max_tmds_clock, str_yes_no(max_frl_rate), 
str_yes_no(vrr_support), str_yes_no(dsc_support));
 }
 
 static void drm_parse_hdmi_deep_color_info(struct drm_connector *connector,
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index b1b2df48d42c..ec6ef71ab5cd 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -219,6 +219,30 @@ struct drm_hdmi_dsc_cap {
        u8 total_chunk_kbytes;
 };
 
+
+/**
+ * struct drm_hdmi_vrr_cap - VRR capabilities of HDMI sink
+ * Describes the VRR support provided by HDMI 2.1 sink.
+ * The information is fetched fom additional HFVSDB blocks defined
+ * for HDMI 2.1.
+ */
+struct drm_hdmi_vrr_cap {
+       /** @cnm_vrr: sink supports negative Mvrr values*/
+       bool cnm_vrr;
+
+       /** @cinema_vrr: sink supports fractional and integer media rates < 
VRRmin*/
+       bool cinema_vrr;
+
+       /** @m_delta: sink can anticipate and compensate for frame-to-frame 
variation in Mvrr */
+       bool m_delta;
+
+       /** @vrr_min: VRRmin - lowest framerate in Hz that sink can support in 
VRR */
+       u8 vrr_min;
+
+       /** @vrr_max: VRRmax - highest framerate in Hz that sink can support in 
VRR */
+       u16 vrr_max;
+};
+
 /**
  * struct drm_hdmi_info - runtime information about the connected HDMI sink
  *
@@ -259,6 +283,9 @@ struct drm_hdmi_info {
 
        /** @dsc_cap: DSC capabilities of the sink */
        struct drm_hdmi_dsc_cap dsc_cap;
+
+       /** @vrr_cap: VRR capabilities of the sink */
+       struct drm_hdmi_vrr_cap vrr_cap;
 };
 
 /**
-- 
2.25.1

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