drm/i915/alpm: Move alpm related code to a new file

Move ALPM feature related code as it will be used for
non-psr panel also thorugh LOBF feature.

v1: Initial version.
v2: Correct ordering in makefile. [Jani]

Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240529200742.1694401-3-animesh.manna@intel.com

1 files changed, 295 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
new file mode 100644
index 000000000000..7307e02277d6
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2024, Intel Corporation.
+ */
+
+#include "intel_alpm.h"
+#include "intel_crtc.h"
+#include "intel_de.h"
+#include "intel_display_types.h"
+#include "intel_dp.h"
+#include "intel_dp_aux.h"
+#include "intel_psr_regs.h"
+
+/*
+ * See Bspec: 71632 for the table
+ *
+ * Silence_period = tSilence,Min + ((tSilence,Max - tSilence,Min) / 2)
+ *
+ * Half cycle duration:
+ *
+ * Link rates 1.62 - 4.32 and tLFPS_Cycle = 70 ns
+ * FLOOR( (Link Rate * tLFPS_Cycle) / (2 * 10) )
+ *
+ * Link rates 5.4 - 8.1
+ * PORT_ALPM_LFPS_CTL[ LFPS Cycle Count ] = 10
+ * LFPS Period chosen is the mid-point of the min:max values from the table
+ * FLOOR( LFPS Period in Symbol clocks /
+ * (2 * PORT_ALPM_LFPS_CTL[ LFPS Cycle Count ]) )
+ */
+static bool _lnl_get_silence_period_and_lfps_half_cycle(int link_rate,
+							int *silence_period,
+							int *lfps_half_cycle)
+{
+	switch (link_rate) {
+	case 162000:
+		*silence_period = 20;
+		*lfps_half_cycle = 5;
+		break;
+	case 216000:
+		*silence_period = 27;
+		*lfps_half_cycle = 7;
+		break;
+	case 243000:
+		*silence_period = 31;
+		*lfps_half_cycle = 8;
+		break;
+	case 270000:
+		*silence_period = 34;
+		*lfps_half_cycle = 9;
+		break;
+	case 324000:
+		*silence_period = 41;
+		*lfps_half_cycle = 11;
+		break;
+	case 432000:
+		*silence_period = 56;
+		*lfps_half_cycle = 15;
+		break;
+	case 540000:
+		*silence_period = 69;
+		*lfps_half_cycle = 12;
+		break;
+	case 648000:
+		*silence_period = 84;
+		*lfps_half_cycle = 15;
+		break;
+	case 675000:
+		*silence_period = 87;
+		*lfps_half_cycle = 15;
+		break;
+	case 810000:
+		*silence_period = 104;
+		*lfps_half_cycle = 19;
+		break;
+	default:
+		*silence_period = *lfps_half_cycle = -1;
+		return false;
+	}
+	return true;
+}
+
+/*
+ * AUX-Less Wake Time = CEILING( ((PHY P2 to P0) + tLFPS_Period, Max+
+ * tSilence, Max+ tPHY Establishment + tCDS) / tline)
+ * For the "PHY P2 to P0" latency see the PHY Power Control page
+ * (PHY P2 to P0) : https://gfxspecs.intel.com/Predator/Home/Index/68965
+ * : 12 us
+ * The tLFPS_Period, Max term is 800ns
+ * The tSilence, Max term is 180ns
+ * The tPHY Establishment (a.k.a. t1) term is 50us
+ * The tCDS term is 1 or 2 times t2
+ * t2 = Number ML_PHY_LOCK * tML_PHY_LOCK
+ * Number ML_PHY_LOCK = ( 7 + CEILING( 6.5us / tML_PHY_LOCK ) + 1)
+ * Rounding up the 6.5us padding to the next ML_PHY_LOCK boundary and
+ * adding the "+ 1" term ensures all ML_PHY_LOCK sequences that start
+ * within the CDS period complete within the CDS period regardless of
+ * entry into the period
+ * tML_PHY_LOCK = TPS4 Length * ( 10 / (Link Rate in MHz) )
+ * TPS4 Length = 252 Symbols
+ */
+static int _lnl_compute_aux_less_wake_time(int port_clock)
+{
+	int tphy2_p2_to_p0 = 12 * 1000;
+	int tlfps_period_max = 800;
+	int tsilence_max = 180;
+	int t1 = 50 * 1000;
+	int tps4 = 252;
+	int tml_phy_lock = 1000 * 1000 * tps4 * 10 / port_clock;
+	int num_ml_phy_lock = 7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1;
+	int t2 = num_ml_phy_lock * tml_phy_lock;
+	int tcds = 1 * t2;
+
+	return DIV_ROUND_UP(tphy2_p2_to_p0 + tlfps_period_max + tsilence_max +
+			    t1 + tcds, 1000);
+}
+
+static int _lnl_compute_aux_less_alpm_params(struct intel_dp *intel_dp,
+					     struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	int aux_less_wake_time, aux_less_wake_lines, silence_period,
+		lfps_half_cycle;
+
+	aux_less_wake_time =
+		_lnl_compute_aux_less_wake_time(crtc_state->port_clock);
+	aux_less_wake_lines = intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode,
+						       aux_less_wake_time);
+
+	if (!_lnl_get_silence_period_and_lfps_half_cycle(crtc_state->port_clock,
+							 &silence_period,
+							 &lfps_half_cycle))
+		return false;
+
+	if (aux_less_wake_lines > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK ||
+	    silence_period > PORT_ALPM_CTL_SILENCE_PERIOD_MASK ||
+	    lfps_half_cycle > PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION_MASK)
+		return false;
+
+	if (i915->display.params.psr_safest_params)
+		aux_less_wake_lines = ALPM_CTL_AUX_LESS_WAKE_TIME_MASK;
+
+	intel_dp->alpm_parameters.fast_wake_lines = aux_less_wake_lines;
+	intel_dp->alpm_parameters.silence_period_sym_clocks = silence_period;
+	intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms = lfps_half_cycle;
+
+	return true;
+}
+
+static bool _lnl_compute_alpm_params(struct intel_dp *intel_dp,
+				     struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	int check_entry_lines;
+
+	if (DISPLAY_VER(i915) < 20)
+		return true;
+
+	/* ALPM Entry Check = 2 + CEILING( 5us /tline ) */
+	check_entry_lines = 2 +
+		intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode, 5);
+
+	if (check_entry_lines > 15)
+		return false;
+
+	if (!_lnl_compute_aux_less_alpm_params(intel_dp, crtc_state))
+		return false;
+
+	if (i915->display.params.psr_safest_params)
+		check_entry_lines = 15;
+
+	intel_dp->alpm_parameters.check_entry_lines = check_entry_lines;
+
+	return true;
+}
+
+/*
+ * IO wake time for DISPLAY_VER < 12 is not directly mentioned in Bspec. There
+ * are 50 us io wake time and 32 us fast wake time. Clearly preharge pulses are
+ * not (improperly) included in 32 us fast wake time. 50 us - 32 us = 18 us.
+ */
+static int skl_io_buffer_wake_time(void)
+{
+	return 18;
+}
+
+static int tgl_io_buffer_wake_time(void)
+{
+	return 10;
+}
+
+static int io_buffer_wake_time(const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+
+	if (DISPLAY_VER(i915) >= 12)
+		return tgl_io_buffer_wake_time();
+	else
+		return skl_io_buffer_wake_time();
+}
+
+bool intel_alpm_compute_params(struct intel_dp *intel_dp,
+				      struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	int io_wake_lines, io_wake_time, fast_wake_lines, fast_wake_time;
+	int tfw_exit_latency = 20; /* eDP spec */
+	int phy_wake = 4;	   /* eDP spec */
+	int preamble = 8;	   /* eDP spec */
+	int precharge = intel_dp_aux_fw_sync_len() - preamble;
+	u8 max_wake_lines;
+
+	io_wake_time = max(precharge, io_buffer_wake_time(crtc_state)) +
+		preamble + phy_wake + tfw_exit_latency;
+	fast_wake_time = precharge + preamble + phy_wake +
+		tfw_exit_latency;
+
+	if (DISPLAY_VER(i915) >= 20)
+		max_wake_lines = 68;
+	else if (DISPLAY_VER(i915) >= 12)
+		max_wake_lines = 12;
+	else
+		max_wake_lines = 8;
+
+	io_wake_lines = intel_usecs_to_scanlines(
+		&crtc_state->hw.adjusted_mode, io_wake_time);
+	fast_wake_lines = intel_usecs_to_scanlines(
+		&crtc_state->hw.adjusted_mode, fast_wake_time);
+
+	if (io_wake_lines > max_wake_lines ||
+	    fast_wake_lines > max_wake_lines)
+		return false;
+
+	if (!_lnl_compute_alpm_params(intel_dp, crtc_state))
+		return false;
+
+	if (i915->display.params.psr_safest_params)
+		io_wake_lines = fast_wake_lines = max_wake_lines;
+
+	/* According to Bspec lower limit should be set as 7 lines. */
+	intel_dp->alpm_parameters.io_wake_lines = max(io_wake_lines, 7);
+	intel_dp->alpm_parameters.fast_wake_lines = max(fast_wake_lines, 7);
+
+	return true;
+}
+
+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;
+	u32 alpm_ctl;
+
+	if (DISPLAY_VER(dev_priv) < 20 || (!intel_dp->psr.sel_update_enabled &&
+					   !intel_dp_is_edp(intel_dp)))
+		return;
+
+	/*
+	 * 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(dev_priv, 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(
+				       intel_dp->alpm_parameters.silence_period_sym_clocks));
+
+		intel_de_write(dev_priv,
+			       PORT_ALPM_LFPS_CTL(dev_priv, cpu_transcoder),
+			       PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
+			       PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
+				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			       PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
+				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
+			       PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
+				       intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms));
+	} else {
+		alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
+			ALPM_CTL_EXTENDED_FAST_WAKE_TIME(intel_dp->alpm_parameters.fast_wake_lines);
+	}
+
+	alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(intel_dp->alpm_parameters.check_entry_lines);
+
+	intel_de_write(dev_priv, ALPM_CTL(dev_priv, cpu_transcoder), alpm_ctl);
+}
+
+void intel_alpm_configure(struct intel_dp *intel_dp)
+{
+	lnl_alpm_configure(intel_dp);
+}