[PATCH v9 17/17] drm/i915/vrr: Enable DC Balance

[Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>]

Enable DC Balance from vrr compute config and related hw flag.
Also to add pipe restrictions along with this.

--v2:
- Use dc balance check instead of source restriction.
--v3:
- Club pipe restriction check with dc balance enablement. (Ankit)

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
---
 drivers/gpu/drm/i915/display/intel_vrr.c | 29 +++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index ec2e5a94a99e..425bd83aebfc 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -352,14 +352,28 @@ int intel_vrr_compute_vmax(struct intel_connector *connector,
 	return vmax;
 }
 
+static bool intel_vrr_dc_balance_possible(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_display *display = to_intel_display(crtc_state);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	enum pipe pipe = crtc->pipe;
+
+	/*
+	 * FIXME: Currently Firmware supports DC Balancing on PIPE A
+	 * and PIPE B. Account those limitation while computing DC
+	 * Balance parameters.
+	 */
+	return (HAS_VRR_DC_BALANCE(display) &&
+		((pipe == PIPE_A) || (pipe == PIPE_B)));
+}
+
 static void
 intel_vrr_dc_balance_compute_config(struct intel_crtc_state *crtc_state)
 {
 	int guardband_usec, adjustment_usec;
-	struct intel_display *display = to_intel_display(crtc_state);
 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
 
-	if (!(HAS_VRR_DC_BALANCE(display) && crtc_state->vrr.enable))
+	if (!(intel_vrr_dc_balance_possible(crtc_state) && crtc_state->vrr.enable))
 		return;
 
 	crtc_state->vrr.dc_balance.vmax = crtc_state->vrr.vmax;
@@ -385,6 +399,7 @@ intel_vrr_dc_balance_compute_config(struct intel_crtc_state *crtc_state)
 	crtc_state->vrr.dc_balance.vblank_target =
 		DIV_ROUND_UP((crtc_state->vrr.vmax - crtc_state->vrr.vmin) *
 			     DCB_BLANK_TARGET, 100);
+	crtc_state->vrr.dc_balance.enable = true;
 }
 
 void
@@ -775,6 +790,7 @@ intel_vrr_enable_dc_balancing(const struct intel_crtc_state *crtc_state)
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	enum pipe pipe = crtc->pipe;
+	u32 vrr_ctl = intel_de_read(display, TRANS_VRR_CTL(display, cpu_transcoder));
 
 	if (!crtc_state->vrr.dc_balance.enable)
 		return;
@@ -813,6 +829,9 @@ intel_vrr_enable_dc_balancing(const struct intel_crtc_state *crtc_state)
 	intel_de_write(display, TRANS_ADAPTIVE_SYNC_DCB_CTL(cpu_transcoder),
 		       ADAPTIVE_SYNC_COUNTER_EN);
 	intel_pipedmc_dcb_enable(NULL, crtc);
+
+	vrr_ctl |= VRR_CTL_DCB_ADJ_ENABLE;
+	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder), vrr_ctl);
 }
 
 static void
@@ -822,6 +841,7 @@ intel_vrr_disable_dc_balancing(const struct intel_crtc_state *old_crtc_state)
 	enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
 	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
 	enum pipe pipe = crtc->pipe;
+	u32 vrr_ctl = intel_de_read(display, TRANS_VRR_CTL(display, cpu_transcoder));
 
 	if (!old_crtc_state->vrr.dc_balance.enable)
 		return;
@@ -844,6 +864,9 @@ intel_vrr_disable_dc_balancing(const struct intel_crtc_state *old_crtc_state)
 	intel_de_write(display, TRANS_VRR_DCB_ADJ_FLIPLINE_CFG(cpu_transcoder), 0);
 	intel_de_write(display, TRANS_VRR_DCB_VMAX(cpu_transcoder), 0);
 	intel_de_write(display, TRANS_VRR_DCB_FLIPLINE(cpu_transcoder), 0);
+
+	vrr_ctl &= ~VRR_CTL_DCB_ADJ_ENABLE;
+	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder), vrr_ctl);
 }
 
 static void intel_vrr_tg_enable(const struct intel_crtc_state *crtc_state,
@@ -949,7 +972,7 @@ void intel_vrr_get_dc_balance_config(struct intel_crtc_state *crtc_state)
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	enum pipe pipe = crtc->pipe;
 
-	if (!HAS_VRR_DC_BALANCE(display))
+	if (!intel_vrr_dc_balance_possible(crtc_state))
 		return;
 
 	reg_val = intel_de_read(display, PIPEDMC_DCB_VMIN(pipe));
-- 
2.48.1