[Intel-gfx] [RFC 5/7] drm/i915/tgl: DC3CO PSR2 helper

[Anshuman Gupta]

Add dc3co helper functions to enable/disable psr2 deep sleep.
Adhere B.Specs by disallow DC3CO state before PSR2 exit.
Enable PSR2 exitline event and program the desired scanlines
to exit DC3CO in intel_psr_enable function at modeset path.

v1: moved calling of tgl_enable_psr2_transcoder_exitline() to
    intel_psr_enable(). [Imre]

Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Animesh Manna <animesh.manna at intel.com>
Cc: José Roberto de Souza <jose.souza at intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 43 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_psr.h |  2 ++
 2 files changed, 45 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 629b8b98a97f..0098465ef573 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -549,6 +549,44 @@ transcoder_has_psr2(struct drm_i915_private *dev_priv, enum transcoder trans)
 		return trans == TRANSCODER_EDP;
 }
 
+static void psr2_program_idle_frames(struct drm_i915_private *dev_priv,
+				     u32 idle_frames)
+{
+	u32 val;
+
+	idle_frames <<=  EDP_PSR2_IDLE_FRAME_SHIFT;
+	val = I915_READ(EDP_PSR2_CTL(dev_priv->psr.transcoder));
+	val &= ~EDP_PSR2_IDLE_FRAME_MASK;
+	val |= idle_frames;
+	I915_WRITE(EDP_PSR2_CTL(dev_priv->psr.transcoder), val);
+}
+
+void tgl_psr2_deep_sleep_disable(struct drm_i915_private *dev_priv)
+{
+	int idle_frames = 0;
+
+	psr2_program_idle_frames(dev_priv, idle_frames);
+}
+
+void tgl_psr2_deep_sleep_enable(struct drm_i915_private *dev_priv)
+{
+	int idle_frames;
+
+	/*
+	 * Let's use 6 as the minimum to cover all known cases including the
+	 * off-by-one issue that HW has in some cases.
+	 */
+	idle_frames = max(6, dev_priv->vbt.psr.idle_frames);
+	idle_frames = max(idle_frames, dev_priv->psr.sink_sync_latency + 1);
+	psr2_program_idle_frames(dev_priv, idle_frames);
+}
+
+static void tgl_disallow_dc3co_on_psr2_exit(struct drm_i915_private *dev_priv)
+{
+	/* Before PSR2 exit disallow dc3co*/
+	tgl_set_target_dc_state(dev_priv, DC_STATE_EN_UPTO_DC6);
+}
+
 static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 				    struct intel_crtc_state *crtc_state)
 {
@@ -809,6 +847,10 @@ void intel_psr_enable(struct intel_dp *intel_dp,
 
 	WARN_ON(dev_priv->drrs.dp);
 
+	/* Enable PSR2 transcoder exit line */
+	if (crtc_state->has_psr2)
+		tgl_enable_psr2_transcoder_exitline(crtc_state);
+
 	mutex_lock(&dev_priv->psr.lock);
 
 	if (!psr_global_enabled(dev_priv->psr.debug)) {
@@ -839,6 +881,7 @@ static void intel_psr_exit(struct drm_i915_private *dev_priv)
 	}
 
 	if (dev_priv->psr.psr2_enabled) {
+		tgl_disallow_dc3co_on_psr2_exit(dev_priv);
 		val = I915_READ(EDP_PSR2_CTL(dev_priv->psr.transcoder));
 		WARN_ON(!(val & EDP_PSR2_ENABLE));
 		val &= ~EDP_PSR2_ENABLE;
diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
index 46e4de8b8cd5..75a9862f36fd 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.h
+++ b/drivers/gpu/drm/i915/display/intel_psr.h
@@ -35,5 +35,7 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp);
 int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state,
 			    u32 *out_value);
 bool intel_psr_enabled(struct intel_dp *intel_dp);
+void tgl_psr2_deep_sleep_disable(struct drm_i915_private *dev_priv);
+void tgl_psr2_deep_sleep_enable(struct drm_i915_private *dev_priv);
 
 #endif /* __INTEL_PSR_H__ */
-- 
2.21.0