[PATCH] drm/edid: Fill PAR in AVI infoframe based on CEA mode list

[Vandana Kannan]

Populate PAR in infoframe structure. If there is a user setting for PAR, then
that value is set. Else, value is taken from CEA mode list if VIC is found.
Else, PAR is calculated from resolution. If none of these conditions are
satisfied, PAR is NONE as per initialization.

As a next step, create a property that would enable a user space app to set
aspect ratio. (will be pushed as a separate patch)

Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
Cc: Jesse Barnes <jesse.barnes at intel.com>
Cc: Vijay Purushothaman <vijay.a.purushothaman at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: intel-gfx at lists.freedesktop.org
---
 drivers/gpu/drm/drm_edid.c |   34 ++++++++++++++++++++++++++++++++++
 include/drm/drm_crtc.h     |    1 +
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index d4e3f9d..3db693f 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2452,6 +2452,21 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
 }
 EXPORT_SYMBOL(drm_match_cea_mode);
 
+/**
+ * drm_get_cea_aspect_ratio - get the picture aspect ratio corresponding to
+ * the input VIC from the CEA mode list
+ *
+ * Returns picture aspect ratio
+ */
+enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code)
+{
+	/* return picture aspect ratio for video_code - 1 to access the
+	 * right array element
+	*/
+	return edid_cea_modes[video_code-1].picture_aspect_ratio;
+}
+EXPORT_SYMBOL(drm_get_cea_aspect_ratio);
+
 /*
  * Calculate the alternate clock for HDMI modes (those from the HDMI vendor
  * specific block).
@@ -3613,6 +3628,25 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
 	frame->video_code = drm_match_cea_mode(mode);
 
 	frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE;
+
+	/* Populate picture aspect ratio from either CEA mode list or
+	 *  user input
+	*/
+	if (mode->picture_aspect_ratio == HDMI_PICTURE_ASPECT_4_3 ||
+		mode->picture_aspect_ratio == HDMI_PICTURE_ASPECT_16_9)
+		frame->picture_aspect = mode->picture_aspect_ratio;
+	else if (frame->video_code > 0)
+		frame->picture_aspect = drm_get_cea_aspect_ratio(
+						frame->video_code);
+	else {
+		if (!(mode->vdisplay % 3) &&
+			(((mode->vdisplay * 4) / 3) == mode->hdisplay))
+			frame->picture_aspect = HDMI_PICTURE_ASPECT_4_3;
+		else if (!(mode->vdisplay % 9) &&
+			(((mode->vdisplay * 16) / 9) == mode->hdisplay))
+			frame->picture_aspect = HDMI_PICTURE_ASPECT_16_9;
+	}
+
 	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
 	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 27f828c..50dc55a 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -983,6 +983,7 @@ extern int drm_mode_gamma_get_ioctl(struct drm_device *dev,
 extern int drm_mode_gamma_set_ioctl(struct drm_device *dev,
 				    void *data, struct drm_file *file_priv);
 extern u8 drm_match_cea_mode(const struct drm_display_mode *to_match);
+extern enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code);
 extern bool drm_detect_hdmi_monitor(struct edid *edid);
 extern bool drm_detect_monitor_audio(struct edid *edid);
 extern bool drm_rgb_quant_range_selectable(struct edid *edid);
-- 
1.7.9.5