drm/i915: Track pipe gamma enable/disable in crtc state

Track whether pipe gamma is enabled or disabled. For now we
stick to the current behaviour of always enabling gamma. But
we do get working state readout for this now. On SKL+ we use
the pipe bottom color as our hardware state. On pre-SKL we
read the state back from the primary plane control register.
That only really correct for g4x+, as older platforms never
gamma correct pipe bottom color. But doing the readout the
same way on all platforms is fine, and there is no other way
to do it really.

v2: Initialize val at declaration (Uma)
    Drop the bogus skl scaler comment change (Uma)
    Rebase
v3: Allow fastboot with gamma_enable changes (Maarten)
v4: Drop the PIPE_BOTTOM_COLOR write from
    intel_update_pipe_config() again. It snuck back in
    during the rebase

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190207203913.5529-1-ville.syrjala@linux.intel.com

1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
index 86915125d17c..746138d7bcbc 100644
--- a/drivers/gpu/drm/i915/intel_color.c
+++ b/drivers/gpu/drm/i915/intel_color.c
@@ -387,6 +387,28 @@ static void hsw_color_commit(const struct intel_crtc_state *crtc_state)
 	ilk_load_csc_matrix(crtc_state);
 }
 
+static void skl_color_commit(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	u32 val = 0;
+
+	/*
+	 * We don't (yet) allow userspace to control the pipe background color,
+	 * so force it to black, but apply pipe gamma and CSC appropriately
+	 * so that its handling will match how we program our planes.
+	 */
+	if (crtc_state->gamma_enable)
+		val |= SKL_BOTTOM_COLOR_GAMMA_ENABLE;
+	val |= SKL_BOTTOM_COLOR_CSC_ENABLE;
+	I915_WRITE(SKL_BOTTOM_COLOR(pipe), val);
+
+	I915_WRITE(GAMMA_MODE(crtc->pipe), crtc_state->gamma_mode);
+
+	ilk_load_csc_matrix(crtc_state);
+}
+
 static void bdw_load_degamma_lut(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
@@ -644,6 +666,8 @@ int intel_color_check(struct intel_crtc_state *crtc_state)
 	degamma_tests = INTEL_INFO(dev_priv)->color.degamma_lut_tests;
 	gamma_tests = INTEL_INFO(dev_priv)->color.gamma_lut_tests;
 
+	crtc_state->gamma_enable = true;
+
 	/* Always allow legacy gamma LUT with no further checking. */
 	if (crtc_state_is_legacy_gamma(crtc_state)) {
 		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
@@ -689,7 +713,9 @@ void intel_color_init(struct intel_crtc *crtc)
 		else
 			dev_priv->display.load_luts = i9xx_load_luts;
 
-		if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv))
+		if (INTEL_GEN(dev_priv) >= 9)
+			dev_priv->display.color_commit = skl_color_commit;
+		else if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
 			dev_priv->display.color_commit = hsw_color_commit;
 		else
 			dev_priv->display.color_commit = ilk_color_commit;