drm/i915: Shovel hw setup code out of ilk_crtc_mode_set

Again this code just transforms sw state from the pipe config into
hardware state, so we can just move it around. Unfortunately again a
few forward declarations since intel_display.c is becoming a bit of a
mess.

Note that both for i9xx and ironlake code the only things remaining in
the ->crtc_mode_set hook is now the clock state computation and
sharing code. That needs to be moved into the compute config stage so
that we can catch impossible configurations earlier.

Also note that some of the DPLL hw setup code is still run from within
->crtc_mode_set, namele the pll->mode_set callback. We need to move
that first before we can do fancy things like enable runtime PM for
dpms off.

v2: Make it compile again after the rebase, bisectability issue
reported by Wu Fengguang.
Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -61,6 +61,9 @@ static int intel_framebuffer_init(struct drm_device *dev,
 static void intel_dp_set_m_n(struct intel_crtc *crtc);
 static void i9xx_set_pipeconf(struct intel_crtc *intel_crtc);
 static void intel_set_pipe_timings(struct intel_crtc *intel_crtc);
+static void intel_cpu_transcoder_set_m_n(struct intel_crtc *crtc,
+					 struct intel_link_m_n *m_n);
+static void ironlake_set_pipeconf(struct drm_crtc *crtc);
 
 typedef struct {
 	int	min, max;
@@ -3911,12 +3914,32 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	struct intel_encoder *encoder;
 	int pipe = intel_crtc->pipe;
+	enum plane plane = intel_crtc->plane;
 
 	WARN_ON(!crtc->enabled);
 
 	if (intel_crtc->active)
 		return;
 
+	if (intel_crtc->config.has_dp_encoder)
+		intel_dp_set_m_n(intel_crtc);
+
+	intel_set_pipe_timings(intel_crtc);
+
+	if (intel_crtc->config.has_pch_encoder) {
+		intel_cpu_transcoder_set_m_n(intel_crtc,
+					     &intel_crtc->config.fdi_m_n);
+	}
+
+	ironlake_set_pipeconf(crtc);
+
+	/* Set up the display plane register */
+	I915_WRITE(DSPCNTR(plane), DISPPLANE_GAMMA_ENABLE);
+	POSTING_READ(DSPCNTR(plane));
+
+	dev_priv->display.update_primary_plane(crtc, crtc->primary->fb,
+					       crtc->x, crtc->y);
+
 	intel_crtc->active = true;
 
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, true);
@@ -6824,10 +6847,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 				  struct drm_framebuffer *fb)
 {
 	struct drm_device *dev = crtc->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-	int pipe = intel_crtc->pipe;
-	int plane = intel_crtc->plane;
 	int num_connectors = 0;
 	intel_clock_t clock, reduced_clock;
 	u32 dpll = 0, fp = 0, fp2 = 0;
@@ -6884,7 +6904,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 		pll = intel_get_shared_dpll(intel_crtc);
 		if (pll == NULL) {
 			DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
-					 pipe_name(pipe));
+					 pipe_name(intel_crtc->pipe));
 			return -EINVAL;
 		}
 	} else
@@ -6895,24 +6915,6 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 	else
 		intel_crtc->lowfreq_avail = false;
 
-	if (intel_crtc->config.has_dp_encoder)
-		intel_dp_set_m_n(intel_crtc);
-
-	intel_set_pipe_timings(intel_crtc);
-
-	if (intel_crtc->config.has_pch_encoder) {
-		intel_cpu_transcoder_set_m_n(intel_crtc,
-					     &intel_crtc->config.fdi_m_n);
-	}
-
-	ironlake_set_pipeconf(crtc);
-
-	/* Set up the display plane register */
-	I915_WRITE(DSPCNTR(plane), DISPPLANE_GAMMA_ENABLE);
-	POSTING_READ(DSPCNTR(plane));
-
-	dev_priv->display.update_primary_plane(crtc, fb, x, y);
-
 	return 0;
 }