[PATCH v2 08/10] drm/i915/alpm: Enable MAC Transmitting LFPS for LT phy

[Animesh Manna <animesh.manna@intel.com>]

Enable LT phy for transmitting LFPS during aux-less alpm.

Cc: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c      |  5 ++-
 drivers/gpu/drm/i915/display/intel_lt_phy.c   | 35 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_lt_phy.h   |  2 ++
 .../gpu/drm/i915/display/intel_lt_phy_regs.h  |  3 ++
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 733ef4559131..f6450ebea2a8 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3781,7 +3781,10 @@ static void mtl_ddi_prepare_link_retrain(struct intel_dp *intel_dp,
 	 *     ii. Enable MAC Transmits LFPS in the "PHY Common Control 0" PIPE
 	 *         register
 	 */
-	intel_lnl_mac_transmit_lfps(encoder, crtc_state);
+	if (HAS_LT_PHY(display))
+		intel_xe3plpd_mac_transmit_lfps(encoder, crtc_state);
+	else
+		intel_lnl_mac_transmit_lfps(encoder, crtc_state);
 }
 
 static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy.c b/drivers/gpu/drm/i915/display/intel_lt_phy.c
index af48d6cde226..87659a9d9847 100644
--- a/drivers/gpu/drm/i915/display/intel_lt_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_lt_phy.c
@@ -7,6 +7,7 @@
 
 #include "i915_reg.h"
 #include "i915_utils.h"
+#include "intel_alpm.h"
 #include "intel_cx0_phy.h"
 #include "intel_cx0_phy_regs.h"
 #include "intel_ddi.h"
@@ -1998,3 +1999,37 @@ void intel_xe3plpd_pll_disable(struct intel_encoder *encoder)
 		intel_lt_phy_pll_disable(encoder);
 
 }
+
+/*
+ * According to HAS we need to enable MAC Transmitting LFPS in the "PHY Common
+ * Control 0" PIPE register in case of AUX Less ALPM is going to be used. This
+ * function is doing that and is called by link retrain sequence.
+ */
+void intel_xe3plpd_mac_transmit_lfps(struct intel_encoder *encoder,
+				     const struct intel_crtc_state *crtc_state)
+{
+	intel_wakeref_t wakeref;
+	int i;
+	u8 owned_lane_mask;
+
+	if (!intel_alpm_is_alpm_aux_less(enc_to_intel_dp(encoder), crtc_state))
+		return;
+
+	owned_lane_mask = intel_lt_phy_get_owned_lane_mask(encoder);
+
+	wakeref = intel_lt_phy_transaction_begin(encoder);
+
+	for (i = 0; i < 4; i++) {
+		int tx = i % 2 + 1;
+		u8 lane_mask = i < 2 ? INTEL_LT_PHY_LANE0 : INTEL_LT_PHY_LANE1;
+
+		if (!(owned_lane_mask & lane_mask))
+			continue;
+
+		intel_lt_phy_rmw(encoder, lane_mask, LT_PHY_CMN_CTL(tx, 0),
+				 LT_PHY_CMN_LFPS_ENABLE,
+				 LT_PHY_CMN_LFPS_ENABLE, MB_WRITE_COMMITTED);
+	}
+
+	intel_lt_phy_transaction_end(encoder, wakeref);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy.h b/drivers/gpu/drm/i915/display/intel_lt_phy.h
index a538d4c69210..7391dd7252d7 100644
--- a/drivers/gpu/drm/i915/display/intel_lt_phy.h
+++ b/drivers/gpu/drm/i915/display/intel_lt_phy.h
@@ -38,6 +38,8 @@ void intel_lt_phy_pll_state_verify(struct intel_atomic_state *state,
 void intel_xe3plpd_pll_enable(struct intel_encoder *encoder,
 			      const struct intel_crtc_state *crtc_state);
 void intel_xe3plpd_pll_disable(struct intel_encoder *encoder);
+void intel_xe3plpd_mac_transmit_lfps(struct intel_encoder *encoder,
+				     const struct intel_crtc_state *crtc_state);
 
 #define HAS_LT_PHY(display) (DISPLAY_VER(display) >= 35)
 
diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy_regs.h b/drivers/gpu/drm/i915/display/intel_lt_phy_regs.h
index 9223487d764e..8a19b7cb59dc 100644
--- a/drivers/gpu/drm/i915/display/intel_lt_phy_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_lt_phy_regs.h
@@ -36,6 +36,9 @@
 #define LT_PHY_TXY_CTL10_MAC(idx)	_MMIO(LT_PHY_TXY_CTL10(idx))
 #define  LT_PHY_TX_LANE_ENABLE		REG_BIT8(0)
 
+#define LT_PHY_CMN_CTL(idx, control)	(0x800 + (0x200 * ((idx) - 1)) + (control))
+#define  LT_PHY_CMN_LFPS_ENABLE		REG_BIT8(1)
+
 /* LT Phy Vendor Register */
 #define LT_PHY_VDR_0_CONFIG	0xC02
 #define  LT_PHY_VDR_DP_PLL_ENABLE	REG_BIT(7)
-- 
2.29.0