drm/i915: panel fitter hw state readout&check support

Pfit state readout is a bit ugly on gen2/3 due to the intermingling
with the lvds state, but alas.

Also note that since state is always cleared to zero we can
unconditonally compare all the state and completely neglect the actual
platform we're running on.

v2: Properly check for the pfit power domain on haswell.

v3: Don't check pgm_ratios on gen4+, they're auto-computed by the hw.

v4: Properly clear the lvds border bits, upset the state checker a
bit.

v5: Unconditionally read out panel dither settings on gen2/3.
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -4976,6 +4976,36 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc,
 	return ret;
 }
 
+static void i9xx_get_pfit_config(struct intel_crtc *crtc,
+				 struct intel_crtc_config *pipe_config)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t tmp;
+
+	tmp = I915_READ(PFIT_CONTROL);
+
+	if (INTEL_INFO(dev)->gen < 4) {
+		if (crtc->pipe != PIPE_B)
+			return;
+
+		/* gen2/3 store dither state in pfit control, needs to match */
+		pipe_config->gmch_pfit.control = tmp & PANEL_8TO6_DITHER_ENABLE;
+	} else {
+		if ((tmp & PFIT_PIPE_MASK) != (crtc->pipe << PFIT_PIPE_SHIFT))
+			return;
+	}
+
+	if (!(tmp & PFIT_ENABLE))
+		return;
+
+	pipe_config->gmch_pfit.control = I915_READ(PFIT_CONTROL);
+	pipe_config->gmch_pfit.pgm_ratios = I915_READ(PFIT_PGM_RATIOS);
+	if (INTEL_INFO(dev)->gen < 5)
+		pipe_config->gmch_pfit.lvds_border_bits =
+			I915_READ(LVDS) & LVDS_BORDER_ENABLE;
+}
+
 static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 				 struct intel_crtc_config *pipe_config)
 {
@@ -4989,6 +5019,8 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 
 	intel_get_pipe_timings(crtc, pipe_config);
 
+	i9xx_get_pfit_config(crtc, pipe_config);
+
 	return true;
 }
 
@@ -5820,6 +5852,21 @@ static void ironlake_get_fdi_m_n_config(struct intel_crtc *crtc,
 				   & TU_SIZE_MASK) >> TU_SIZE_SHIFT) + 1;
 }
 
+static void ironlake_get_pfit_config(struct intel_crtc *crtc,
+				     struct intel_crtc_config *pipe_config)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t tmp;
+
+	tmp = I915_READ(PF_CTL(crtc->pipe));
+
+	if (tmp & PF_ENABLE) {
+		pipe_config->pch_pfit.pos = I915_READ(PF_WIN_POS(crtc->pipe));
+		pipe_config->pch_pfit.size = I915_READ(PF_WIN_SZ(crtc->pipe));
+	}
+}
+
 static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 				     struct intel_crtc_config *pipe_config)
 {
@@ -5843,6 +5890,8 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 
 	intel_get_pipe_timings(crtc, pipe_config);
 
+	ironlake_get_pfit_config(crtc, pipe_config);
+
 	return true;
 }
 
@@ -5962,6 +6011,7 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	enum transcoder cpu_transcoder = crtc->config.cpu_transcoder;
+	enum intel_display_power_domain pfit_domain;
 	uint32_t tmp;
 
 	if (!intel_display_power_enabled(dev,
@@ -5991,6 +6041,10 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 
 	intel_get_pipe_timings(crtc, pipe_config);
 
+	pfit_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
+	if (intel_display_power_enabled(dev, pfit_domain))
+		ironlake_get_pfit_config(crtc, pipe_config);
+
 	return true;
 }
 
@@ -7956,7 +8010,8 @@ intel_modeset_update_state(struct drm_device *dev, unsigned prepare_pipes)
 		if (mask & (1 <<(intel_crtc)->pipe))
 
 static bool
-intel_pipe_config_compare(struct intel_crtc_config *current_config,
+intel_pipe_config_compare(struct drm_device *dev,
+			  struct intel_crtc_config *current_config,
 			  struct intel_crtc_config *pipe_config)
 {
 #define PIPE_CONF_CHECK_I(name)	\
@@ -8005,6 +8060,14 @@ intel_pipe_config_compare(struct intel_crtc_config *current_config,
 	PIPE_CONF_CHECK_I(requested_mode.hdisplay);
 	PIPE_CONF_CHECK_I(requested_mode.vdisplay);
 
+	PIPE_CONF_CHECK_I(gmch_pfit.control);
+	/* pfit ratios are autocomputed by the hw on gen4+ */
+	if (INTEL_INFO(dev)->gen < 4)
+		PIPE_CONF_CHECK_I(gmch_pfit.pgm_ratios);
+	PIPE_CONF_CHECK_I(gmch_pfit.lvds_border_bits);
+	PIPE_CONF_CHECK_I(pch_pfit.pos);
+	PIPE_CONF_CHECK_I(pch_pfit.size);
+
 #undef PIPE_CONF_CHECK_I
 #undef PIPE_CONF_CHECK_FLAGS
 
@@ -8116,7 +8179,7 @@ intel_modeset_check_state(struct drm_device *dev)
 		     "(expected %i, found %i)\n", crtc->active, active);
 
 		WARN(active &&
-		     !intel_pipe_config_compare(&crtc->config, &pipe_config),
+		     !intel_pipe_config_compare(dev, &crtc->config, &pipe_config),
 		     "pipe state doesn't match!\n");
 	}
 }

drivers/gpu/drm/i915/intel_lvds.c

@@ -116,6 +116,7 @@ static void intel_pre_pll_enable_lvds(struct intel_encoder *encoder)
 	}
 
 	/* set the corresponsding LVDS_BORDER bit */
+	temp &= ~LVDS_BORDER_ENABLE;
 	temp |= intel_crtc->config.gmch_pfit.lvds_border_bits;
 	/* Set the B0-B3 data pairs corresponding to whether we're going to
 	 * set the DPLLs for dual-channel mode or not.