drm/i915: enable intel_lvds->pre_pll_enable for ilk+, too

Only two things needed adjustment:
- pipe select for PCH_CPT
- There's no dithering bit on ilk+ in the lvds ctl reg
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -5322,7 +5322,6 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 	bool ok, has_reduced_clock = false;
 	bool is_lvds = false, is_dp = false, is_cpu_edp = false;
 	struct intel_encoder *encoder;
-	u32 temp;
 	int ret;
 	bool dither, fdi_config_ok;
 
@@ -5386,45 +5385,6 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 	} else
 		intel_put_pch_pll(intel_crtc);
 
-	/* The LVDS pin pair needs to be on before the DPLLs are enabled.
-	 * This is an exception to the general rule that mode_set doesn't turn
-	 * things on.
-	 */
-	if (is_lvds) {
-		temp = I915_READ(PCH_LVDS);
-		temp |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
-		if (HAS_PCH_CPT(dev)) {
-			temp &= ~PORT_TRANS_SEL_MASK;
-			temp |= PORT_TRANS_SEL_CPT(pipe);
-		} else {
-			if (pipe == 1)
-				temp |= LVDS_PIPEB_SELECT;
-			else
-				temp &= ~LVDS_PIPEB_SELECT;
-		}
-
-		/* set the corresponsding LVDS_BORDER bit */
-		temp |= dev_priv->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.
-		 */
-		if (clock.p2 == 7)
-			temp |= LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP;
-		else
-			temp &= ~(LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP);
-
-		/* It would be nice to set 24 vs 18-bit mode (LVDS_A3_POWER_UP)
-		 * appropriately here, but we need to look more thoroughly into how
-		 * panels behave in the two modes.
-		 */
-		temp &= ~(LVDS_HSYNC_POLARITY | LVDS_VSYNC_POLARITY);
-		if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
-			temp |= LVDS_HSYNC_POLARITY;
-		if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC)
-			temp |= LVDS_VSYNC_POLARITY;
-		I915_WRITE(PCH_LVDS, temp);
-	}
-
 	if (is_dp && !is_cpu_edp) {
 		intel_dp_set_m_n(crtc, mode, adjusted_mode);
 	} else {

drivers/gpu/drm/i915/intel_lvds.c

@@ -104,17 +104,20 @@ static void intel_pre_pll_enable_lvds(struct intel_encoder *encoder)
 	int pipe = intel_crtc->pipe;
 	u32 temp;
 
-	/* pch split platforms are not yet converted. */
-	if (HAS_PCH_SPLIT(dev))
-		return;
-
 	temp = I915_READ(lvds_encoder->reg);
 	temp |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
-	if (pipe == 1) {
-		temp |= LVDS_PIPEB_SELECT;
+
+	if (HAS_PCH_CPT(dev)) {
+		temp &= ~PORT_TRANS_SEL_MASK;
+		temp |= PORT_TRANS_SEL_CPT(pipe);
 	} else {
-		temp &= ~LVDS_PIPEB_SELECT;
+		if (pipe == 1) {
+			temp |= LVDS_PIPEB_SELECT;
+		} else {
+			temp &= ~LVDS_PIPEB_SELECT;
+		}
 	}
+
 	/* set the corresponsding LVDS_BORDER bit */
 	temp |= dev_priv->lvds_border_bits;
 	/* Set the B0-B3 data pairs corresponding to whether we're going to
@@ -129,8 +132,11 @@ static void intel_pre_pll_enable_lvds(struct intel_encoder *encoder)
 	 * appropriately here, but we need to look more thoroughly into how
 	 * panels behave in the two modes.
 	 */
-	/* set the dithering flag on LVDS as needed */
-	if (INTEL_INFO(dev)->gen >= 4) {
+
+	/* Set the dithering flag on LVDS as needed, note that there is no
+	 * special lvds dither control bit on pch-split platforms, dithering is
+	 * only controlled through the PIPECONF reg. */
+	if (INTEL_INFO(dev)->gen == 4) {
 		if (dev_priv->lvds_dither)
 			temp |= LVDS_ENABLE_DITHER;
 		else