[Intel-gfx] [PATCH 5/8] drm/i915/bdw: Add support for DRRS to switch RR

[Vandana Kannan]

For Broadwell, there is one instance of Transcoder MN values per transcoder.
For dynamic switching between multiple refreshr rates, M/N values may be
reprogrammed on the fly. Link N programming triggers update of all data and
link M & N registers and the new M/N values will be used in the next frame
that is output.

Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
Signed-off-by: Pradeep Bhat <pradeep.bhat at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |  9 +++------
 drivers/gpu/drm/i915/intel_dp.c      | 15 ++++++++++++++-
 drivers/gpu/drm/i915/intel_drv.h     |  3 +++
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a4a565c..411d34e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -88,9 +88,6 @@ static int intel_framebuffer_init(struct drm_device *dev,
 				  struct drm_i915_gem_object *obj);
 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,
-					 struct intel_link_m_n *m2_n2);
 static void ironlake_set_pipeconf(struct drm_crtc *crtc);
 static void haswell_set_pipeconf(struct drm_crtc *crtc);
 static void intel_set_pipe_csc(struct drm_crtc *crtc);
@@ -5795,9 +5792,9 @@ static void intel_pch_transcoder_set_m_n(struct intel_crtc *crtc,
 	I915_WRITE(PCH_TRANS_LINK_N1(pipe), m_n->link_n);
 }
 
-static void intel_cpu_transcoder_set_m_n(struct intel_crtc *crtc,
-					 struct intel_link_m_n *m_n,
-					 struct intel_link_m_n *m2_n2)
+void intel_cpu_transcoder_set_m_n(struct intel_crtc *crtc,
+				 struct intel_link_m_n *m_n,
+				 struct intel_link_m_n *m2_n2)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index bc17900..38d61f2 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4802,7 +4802,20 @@ static void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
 		return;
 	}
 
-	if (INTEL_INFO(dev)->gen > 6 && INTEL_INFO(dev)->gen < 8) {
+	if (INTEL_INFO(dev)->gen >= 8) {
+		switch(index) {
+		case DRRS_HIGH_RR:
+			intel_dp_set_m_n(intel_crtc);
+			break;
+		case DRRS_LOW_RR:
+			intel_cpu_transcoder_set_m_n(intel_crtc,
+					&intel_crtc->config.dp_m2_n2, NULL);
+			break;
+		case DRRS_MAX_RR:
+		default:
+			break;
+		}
+	} else if (INTEL_INFO(dev)->gen > 6) {
 		reg = PIPECONF(intel_crtc->config.cpu_transcoder);
 		val = I915_READ(reg);
 		if (index > DRRS_HIGH_RR) {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 763c097..bdfdea8 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -952,6 +952,9 @@ void hsw_disable_pc8(struct drm_i915_private *dev_priv);
 void intel_dp_get_m_n(struct intel_crtc *crtc,
 		      struct intel_crtc_config *pipe_config);
 void intel_dp_set_m_n(struct intel_crtc *crtc);
+void intel_cpu_transcoder_set_m_n(struct intel_crtc *crtc,
+				 struct intel_link_m_n *m_n,
+				 struct intel_link_m_n *m2_n2);
 int intel_dotclock_calculate(int link_freq, const struct intel_link_m_n *m_n);
 void
 ironlake_check_encoder_dotclock(const struct intel_crtc_config *pipe_config,
-- 
2.0.1