[PATCH] drm/i915/dp: allow configuring eDP panel fitting scaling mode

[Yuly Novikov]

LVDS allowed changing panel fitting scaling mode, while eDP didn't.
Copied relevant code from LVDS to eDP.
This also changes default mode on eDP to ascpect ratio preserving scaling.

Signed-off-by: Yuly Novikov <ynovikov at chromium.org>
---
 drivers/gpu/drm/i915/intel_dp.c  |   33 ++++++++++++++++++++++++++++++---
 drivers/gpu/drm/i915/intel_drv.h |    1 +
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 368ed8e..a65546e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -685,7 +685,7 @@ intel_dp_mode_fixup(struct drm_encoder *encoder,
 
 	if (is_edp(intel_dp) && intel_dp->panel_fixed_mode) {
 		intel_fixed_panel_mode(intel_dp->panel_fixed_mode, adjusted_mode);
-		intel_pch_panel_fitting(dev, DRM_MODE_SCALE_FULLSCREEN,
+		intel_pch_panel_fitting(dev, intel_dp->fitting_mode,
 					mode, adjusted_mode);
 	}
 
@@ -2358,6 +2358,22 @@ intel_dp_set_property(struct drm_connector *connector,
 		goto done;
 	}
 
+	if (is_edp(intel_dp) &&
+		property == connector->dev->mode_config.scaling_mode_property) {
+		if (val == DRM_MODE_SCALE_NONE) {
+			DRM_DEBUG_KMS("no scaling not supported\n");
+			return -EINVAL;
+		}
+
+		if (intel_dp->fitting_mode == val) {
+			/* the eDP scaling property is not changed */
+			return 0;
+		}
+		intel_dp->fitting_mode = val;
+
+		goto done;
+	}
+
 	return -EINVAL;
 
 done:
@@ -2469,10 +2485,21 @@ bool intel_dpd_is_edp(struct drm_device *dev)
 }
 
 static void
-intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector)
+intel_dp_add_properties(struct drm_device *dev,
+			struct intel_dp *intel_dp,
+			struct drm_connector *connector)
 {
 	intel_attach_force_audio_property(connector);
 	intel_attach_broadcast_rgb_property(connector);
+
+	if (is_edp(intel_dp)) {
+		drm_mode_create_scaling_mode_property(dev);
+		drm_connector_attach_property(
+			connector,
+			dev->mode_config.scaling_mode_property,
+			DRM_MODE_SCALE_ASPECT);
+		intel_dp->fitting_mode = DRM_MODE_SCALE_ASPECT;
+	}
 }
 
 void
@@ -2665,7 +2692,7 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 		intel_panel_setup_backlight(dev);
 	}
 
-	intel_dp_add_properties(intel_dp, connector);
+	intel_dp_add_properties(dev, intel_dp, connector);
 
 	/* For G4X desktop chip, PEG_BAND_GAP_DATA 3:0 must first be written
 	 * 0xd.  Failure to do so will result in spurious interrupts being
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fe71425..da50cd4 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -358,6 +358,7 @@ struct intel_dp {
 	int backlight_on_delay;
 	int backlight_off_delay;
 	struct drm_display_mode *panel_fixed_mode;  /* for eDP */
+	int fitting_mode;  /* for eDP */
 	struct delayed_work panel_vdd_work;
 	bool want_panel_vdd;
 	struct edid *edid; /* cached EDID for eDP */
-- 
1.7.7.3