drm/edid: Add function to parse EDID descriptors for monitor range

Adaptive Sync is a VESA feature so add a DRM core helper to parse
the EDID's detailed descritors to obtain the adaptive sync monitor range.
Store this info as part fo drm_display_info so it can be used
across all drivers.
This part of the code is stripped out of amdgpu's function
amdgpu_dm_update_freesync_caps() to make it generic and be used
across all DRM drivers

v6:
* Call it monitor_range (Ville)
v5:
* Use the renamed flags
v4:
* Use is_display_descriptor() (Ville)
* Name the monitor range flags (Ville)
v3:
* Remove the edid parsing restriction for just DP (Nicholas)
* Use drm_for_each_detailed_block (Ville)
* Make the drm_get_adaptive_sync_range function static (Harry, Jani)
v2:
* Change vmin and vmax to use u8 (Ville)
* Dont store pixel clock since that is just a max dotclock
and not related to VRR mode (Manasi)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Clinton A Taylor <clinton.a.taylor@intel.com>
Cc: Kazlauskas Nicholas <Nicholas.Kazlauskas@amd.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310231651.13841-2-manasi.d.navare@intel.com

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ad41764..b269cd7 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4938,6 +4938,47 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
        }
 }
 
+static
+void get_monitor_range(struct detailed_timing *timing,
+                      void *info_monitor_range)
+{
+       struct drm_monitor_range_info *monitor_range = info_monitor_range;
+       const struct detailed_non_pixel *data = &timing->data.other_data;
+       const struct detailed_data_monitor_range *range = &data->data.range;
+
+       if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE))
+               return;
+
+       /*
+        * Check for flag range limits only. If flag == 1 then
+        * no additional timing information provided.
+        * Default GTF, GTF Secondary curve and CVT are not
+        * supported
+        */
+       if (range->flags != DRM_EDID_RANGE_LIMITS_ONLY_FLAG)
+               return;
+
+       monitor_range->min_vfreq = range->min_vfreq;
+       monitor_range->max_vfreq = range->max_vfreq;
+}
+
+static
+void drm_get_monitor_range(struct drm_connector *connector,
+                          const struct edid *edid)
+{
+       struct drm_display_info *info = &connector->display_info;
+
+       if (!version_greater(edid, 1, 1))
+               return;
+
+       drm_for_each_detailed_block((u8 *)edid, get_monitor_range,
+                                   &info->monitor_range);
+
+       DRM_DEBUG_KMS("Supported Monitor Refresh rate range is %d Hz - %d Hz\n",
+                     info->monitor_range.min_vfreq,
+                     info->monitor_range.max_vfreq);
+}
+
 /* A connector has no EDID information, so we've got no EDID to compute quirks from. Reset
  * all of the values which would have been set from EDID
  */
@@ -4960,6 +5001,7 @@ drm_reset_display_info(struct drm_connector *connector)
        memset(&info->hdmi, 0, sizeof(info->hdmi));
 
        info->non_desktop = 0;
+       memset(&info->monitor_range, 0, sizeof(info->monitor_range));
 }
 
 u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid)
@@ -4975,6 +5017,8 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi
 
        info->non_desktop = !!(quirks & EDID_QUIRK_NON_DESKTOP);
 
+       drm_get_monitor_range(connector, edid);
+
        DRM_DEBUG_KMS("non_desktop set to %d\n", info->non_desktop);
 
        if (edid->revision < 3)

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 0df7a95..19ae6bb 100644 (file)
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -254,6 +254,23 @@ enum drm_panel_orientation {
        DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
 };
 
+/**
+ * struct drm_monitor_range_info - Panel's Monitor range in EDID for
+ * &drm_display_info
+ *
+ * This struct is used to store a frequency range supported by panel
+ * as parsed from EDID's detailed monitor range descriptor block.
+ *
+ * @min_vfreq: This is the min supported refresh rate in Hz from
+ *             EDID's detailed monitor range.
+ * @max_vfreq: This is the max supported refresh rate in Hz from
+ *             EDID's detailed monitor range
+ */
+struct drm_monitor_range_info {
+       u8 min_vfreq;
+       u8 max_vfreq;
+};
+
 /*
  * This is a consolidated colorimetry list supported by HDMI and
  * DP protocol standard. The respective connectors will register
@@ -473,6 +490,11 @@ struct drm_display_info {
         * @non_desktop: Non desktop display (HMD).
         */
        bool non_desktop;
+
+       /**
+        * @monitor_range: Frequency range supported by monitor range descriptor
+        */
+       struct drm_monitor_range_info monitor_range;
 };
 
 int drm_display_info_set_bus_formats(struct drm_display_info *info,