drm/i915: hw state readout support for pipe timings

This does duplicate the logic in intel_crtc_mode_get a bit, but the
issue is that we also should handle interlace modes and other insanity
correctly.

Hence I've opted for a sligthly more elaborate route where we first
read out the crtc timings for the adjusted mode, and then optionally
(not sure if we really need it) compute the modeline from that.

v2: Also read out the pipe source dimensions into the requested mode.

v3: Rebase on top of the moved cpu_transcoder.

v4: Simplify CHECK_FLAGS logic as suggested by Chris Wilson. Also
properly #undef that macro again.

Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> (v3)
[danvet: Use the existing mask for interlaced bits, spotted by Mika.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -2842,6 +2842,7 @@
 #define   PIPECONF_INTERLACED_ILK		(3 << 21)
 #define   PIPECONF_INTERLACED_DBL_ILK		(4 << 21) /* ilk/snb only */
 #define   PIPECONF_PFIT_PF_INTERLACED_DBL_ILK	(5 << 21) /* ilk/snb only */
+#define   PIPECONF_INTERLACE_MODE_MASK		(7 << 21)
 #define   PIPECONF_CXSR_DOWNCLOCK	(1<<16)
 #define   PIPECONF_COLOR_RANGE_SELECT	(1 << 13)
 #define   PIPECONF_BPC_MASK	(0x7 << 5)

drivers/gpu/drm/i915/intel_display.c

@@ -4721,6 +4721,45 @@ static void intel_set_pipe_timings(struct intel_crtc *intel_crtc,
 		   ((mode->hdisplay - 1) << 16) | (mode->vdisplay - 1));
 }
 
+static void intel_get_pipe_timings(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;
+	enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
+	uint32_t tmp;
+
+	tmp = I915_READ(HTOTAL(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_hdisplay = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_htotal = ((tmp >> 16) & 0xffff) + 1;
+	tmp = I915_READ(HBLANK(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_hblank_start = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_hblank_end = ((tmp >> 16) & 0xffff) + 1;
+	tmp = I915_READ(HSYNC(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_hsync_start = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_hsync_end = ((tmp >> 16) & 0xffff) + 1;
+
+	tmp = I915_READ(VTOTAL(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_vdisplay = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_vtotal = ((tmp >> 16) & 0xffff) + 1;
+	tmp = I915_READ(VBLANK(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_vblank_start = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_vblank_end = ((tmp >> 16) & 0xffff) + 1;
+	tmp = I915_READ(VSYNC(cpu_transcoder));
+	pipe_config->adjusted_mode.crtc_vsync_start = (tmp & 0xffff) + 1;
+	pipe_config->adjusted_mode.crtc_vsync_end = ((tmp >> 16) & 0xffff) + 1;
+
+	if (I915_READ(PIPECONF(cpu_transcoder)) & PIPECONF_INTERLACE_MASK) {
+		pipe_config->adjusted_mode.flags |= DRM_MODE_FLAG_INTERLACE;
+		pipe_config->adjusted_mode.crtc_vtotal += 1;
+		pipe_config->adjusted_mode.crtc_vblank_end += 1;
+	}
+
+	tmp = I915_READ(PIPESRC(crtc->pipe));
+	pipe_config->requested_mode.vdisplay = (tmp & 0xffff) + 1;
+	pipe_config->requested_mode.hdisplay = ((tmp >> 16) & 0xffff) + 1;
+}
+
 static void i9xx_set_pipeconf(struct intel_crtc *intel_crtc)
 {
 	struct drm_device *dev = intel_crtc->base.dev;
@@ -4937,6 +4976,8 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 	if (!(tmp & PIPECONF_ENABLE))
 		return false;
 
+	intel_get_pipe_timings(crtc, pipe_config);
+
 	return true;
 }
 
@@ -5854,6 +5895,8 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 		ironlake_get_fdi_m_n_config(crtc, pipe_config);
 	}
 
+	intel_get_pipe_timings(crtc, pipe_config);
+
 	return true;
 }
 
@@ -6001,6 +6044,8 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 		ironlake_get_fdi_m_n_config(crtc, pipe_config);
 	}
 
+	intel_get_pipe_timings(crtc, pipe_config);
+
 	return true;
 }
 
@@ -7978,6 +8023,15 @@ intel_pipe_config_compare(struct intel_crtc_config *current_config,
 		return false; \
 	}
 
+#define PIPE_CONF_CHECK_FLAGS(name, mask)	\
+	if ((current_config->name ^ pipe_config->name) & (mask)) { \
+		DRM_ERROR("mismatch in " #name " " \
+			  "(expected %i, found %i)\n", \
+			  current_config->name & (mask), \
+			  pipe_config->name & (mask)); \
+		return false; \
+	}
+
 	PIPE_CONF_CHECK_I(has_pch_encoder);
 	PIPE_CONF_CHECK_I(fdi_lanes);
 	PIPE_CONF_CHECK_I(fdi_m_n.gmch_m);
@@ -7986,7 +8040,28 @@ intel_pipe_config_compare(struct intel_crtc_config *current_config,
 	PIPE_CONF_CHECK_I(fdi_m_n.link_n);
 	PIPE_CONF_CHECK_I(fdi_m_n.tu);
 
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_hdisplay);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_htotal);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_hblank_start);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_hblank_end);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_hsync_start);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_hsync_end);
+
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vdisplay);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vtotal);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vblank_start);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vblank_end);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vsync_start);
+	PIPE_CONF_CHECK_I(adjusted_mode.crtc_vsync_end);
+
+	PIPE_CONF_CHECK_FLAGS(adjusted_mode.flags,
+			      DRM_MODE_FLAG_INTERLACE);
+
+	PIPE_CONF_CHECK_I(requested_mode.hdisplay);
+	PIPE_CONF_CHECK_I(requested_mode.vdisplay);
+
 #undef PIPE_CONF_CHECK_I
+#undef PIPE_CONF_CHECK_FLAGS
 
 	return true;
 }