[PATCH v2 17/27] drm/connector: Add "Media" VRR display mode for QMS

[Nicolas Frattaroli]

HDMI includes a feature called "Quick Media Switching", or QMS for
short, which builds upon the existing VRR to allow for quick switching
between a select few common frame rates.

Add a new VRR display mode, "VRR_DISPLAY_MODE_MEDIA", to the
vrr_display_mode connector property, in order to expose support for
this.

Additionally, add a boolean flag to the connector's HDMI sub-struct with
which source-side support for QMS can be indicated, as well as the QMS
tfr byte to the HDMI state sub-struct.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli at collabora.com>
---
 drivers/gpu/drm/drm_connector.c |  6 ++++++
 include/drm/drm_connector.h     | 14 ++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 21222214a843..f7d619926e2d 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1456,6 +1456,7 @@ DRM_ENUM_NAME_FN(drm_get_tv_mode_name, drm_tv_mode_enum_list)
 static const struct drm_prop_enum_list drm_vrr_mode_enum_list[] = {
 	{ VRR_DISPLAY_MODE_GAME,   "Game" },
 	{ VRR_DISPLAY_MODE_OFF,    "Off" },
+	{ VRR_DISPLAY_MODE_MEDIA,  "Media" },
 };
 DRM_ENUM_NAME_FN(drm_get_vrr_mode_name, drm_vrr_mode_enum_list)
 
@@ -2593,6 +2594,11 @@ EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
  *	    - Game - set display to game mode if display supports it,
  *	      regardless of CRTC state
  *	    - Off - set display to VRR disabled mode, regardless of CRTC state
+ *	    - Media - a "media" VRR mode that only supports a select number of
+ *	      common media refresh rates as fixed targets, but does so with
+ *	      possibly better display-side processing. In the HDMI display
+ *	      protocol, this is QMS (Quick Media Switching), though the mode
+ *	      enum itself is vendor-agnostic
  *
  * VRR Limiter/Target Properties
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 4801bb2769e1..41f272afbb1e 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -829,6 +829,8 @@ enum vrr_display_mode {
 	VRR_DISPLAY_MODE_GAME = 0,
 	/** @VRR_DISPLAY_MODE_OFF: Turn off VRR on the display */
 	VRR_DISPLAY_MODE_OFF,
+	/** @VRR_DISPLAY_MODE_MEDIA: Protocol-agnostic fixed rate media mode */
+	VRR_DISPLAY_MODE_MEDIA,
 	/** @VRR_DISPLAY_MODE_COUNT: Sentinel, not a valid mode, keep last */
 	VRR_DISPLAY_MODE_COUNT
 };
@@ -1241,6 +1243,12 @@ struct drm_connector_hdmi_state {
 	 * deliberately not requested by the helper.
 	 */
 	bool scrambler_needed;
+
+	/**
+	 * @qms_tfr_byte: Target frame rate byte for HDMI QMS, or 0 if QMS is
+	 * not in use.
+	 */
+	u8 qms_tfr_byte;
 };
 
 /**
@@ -2270,6 +2278,12 @@ struct drm_connector_hdmi {
 	 */
 	bool scrambler_enabled;
 
+	/**
+	 * @qms_supported: Whether the connector supports HDMI Quick Media
+	 * Switching (QMS) on the source side, irrespective of display support.
+	 */
+	bool qms_supported;
+
 	/**
 	 * @scdc_work: Work item currently used to monitor sink-side scrambling
 	 * status and retry setup if the sink resets it.

-- 
2.56.0