[PATCH v4 4/5] drm/i915/psr: Enable ALPM for eDP Panel replay

From: "Jouni Högander" <jouni.hogander@intel.com>
To: intel-gfx@lists.freedesktop.org
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>,
	"Animesh Manna" <animesh.manna@intel.com>,
	"Arun R Murthy" <arun.r.murthy@intel.com>,
	"Jouni Högander" <jouni.hogander@intel.com>
Subject: [PATCH v4 4/5] drm/i915/psr: Enable ALPM for eDP Panel replay
Date: Fri, 15 Mar 2024 10:02:21 +0200	[thread overview]
Message-ID: <20240315080222.72838-5-jouni.hogander@intel.com> (raw)
In-Reply-To: <20240315080222.72838-1-jouni.hogander@intel.com>

Enable ALPM AUX-Less for Panel Replay eDP. Also write all calculated
AUX-Less configuration values accordingly.

Bspec: 71477

v4:
  - add comment explaining why AUX less is enabled on eDP panel replay
    without any extra checks
v3:
  - do not use alpm_ctl as uninitialized variable
v2:
  - do not set AUX-Wake related bits for AUX-Less case
  - drop switch to active latency
  - add SLEEP_HOLD_TIME_50_SYMBOLS
  - add PORT_ALPM_CTL_MAX_PHY_SWING_HOLD

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 47 ++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 9429c5002986..05b30dc63b3d 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1721,14 +1721,43 @@ static void lnl_alpm_configure(struct intel_dp *intel_dp)
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
 	struct intel_psr *psr = &intel_dp->psr;
+	u32 alpm_ctl;
 
 	if (DISPLAY_VER(dev_priv) < 20)
 		return;
 
-	intel_de_write(dev_priv, ALPM_CTL(cpu_transcoder),
-		       ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
-		       ALPM_CTL_ALPM_ENTRY_CHECK(psr->alpm_parameters.check_entry_lines) |
-		       ALPM_CTL_EXTENDED_FAST_WAKE_TIME(psr->alpm_parameters.fast_wake_lines));
+	/*
+	 * Panel Replay on eDP is always using ALPM aux less. I.e. no need to
+	 * check panel support at this point.
+	 */
+	if (intel_dp->psr.panel_replay_enabled && intel_dp_is_edp(intel_dp)) {
+		alpm_ctl = ALPM_CTL_ALPM_ENABLE |
+			ALPM_CTL_ALPM_AUX_LESS_ENABLE |
+			ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS;
+
+		intel_de_write(dev_priv, PORT_ALPM_CTL(cpu_transcoder),
+			       PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
+			       PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
+			       PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
+			       PORT_ALPM_CTL_SILENCE_PERIOD(
+				       psr->alpm_parameters.silence_period_sym_clocks));
+
+		intel_de_write(dev_priv, PORT_ALPM_LFPS_CTL(cpu_transcoder),
+			       PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
+			       PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
+				       psr->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			       PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
+				       psr->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			       PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
+				       psr->alpm_parameters.lfps_half_cycle_num_of_syms));
+	} else {
+		alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
+			ALPM_CTL_EXTENDED_FAST_WAKE_TIME(psr->alpm_parameters.fast_wake_lines);
+	}
+
+	alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(psr->alpm_parameters.check_entry_lines);
+
+	intel_de_write(dev_priv, ALPM_CTL(cpu_transcoder), alpm_ctl);
 }
 
 static void intel_psr_enable_source(struct intel_dp *intel_dp,
@@ -1999,6 +2028,16 @@ static void intel_psr_disable_locked(struct intel_dp *intel_dp)
 
 	intel_snps_phy_update_psr_power_state(dev_priv, phy, false);
 
+	/* Panel Replay on eDP is always using ALPM aux less. */
+	if (intel_dp->psr.panel_replay_enabled && intel_dp_is_edp(intel_dp)) {
+		intel_de_rmw(dev_priv, ALPM_CTL(cpu_transcoder),
+			     ALPM_CTL_ALPM_ENABLE |
+			     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
+
+		intel_de_rmw(dev_priv, PORT_ALPM_CTL(cpu_transcoder),
+			     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
+	}
+
 	/* Disable PSR on Sink */
 	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
 
-- 
2.34.1

