[Intel-gfx] [PATCH 2/3] drm/i915/display: Convert link bitrate to corresponding PLL clock

[Mika Kahola]

Compute clock during PLL readout. This prevents warn when only c20 phy
is connected during modprobe. The intel_c20pll_calc_port_clock()
function returns link bitrate which in DP2.0 and HDMI cases does not match
with the clock rate. Hence, conversion function is needed to convert
link bitrate to corresponding PLL clock rate.

while at it, update clock on C10 pll state as well.

Signed-off-by: Clint Taylor <Clinton.A.Taylor at intel.com>
Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/display/intel_cx0_phy.c | 38 ++++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_cx0_phy.h |  1 +
 drivers/gpu/drm/i915/display/intel_ddi.c     |  2 +-
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
index 2e6412fc2258..02efe2786c6a 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
@@ -1871,6 +1871,7 @@ static int intel_c10pll_calc_state(struct intel_crtc_state *crtc_state,
 }
 
 static void intel_c10pll_readout_hw_state(struct intel_encoder *encoder,
+					  struct intel_crtc_state *crtc_state,
 					  struct intel_c10pll_state *pll_state)
 {
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
@@ -1894,6 +1895,7 @@ static void intel_c10pll_readout_hw_state(struct intel_encoder *encoder,
 
 	pll_state->cmn = intel_cx0_read(i915, encoder->port, lane, PHY_C10_VDR_CMN(0));
 	pll_state->tx = intel_cx0_read(i915, encoder->port, lane, PHY_C10_VDR_TX(0));
+	pll_state->clock = crtc_state->port_clock;
 
 	intel_cx0_phy_transaction_end(encoder, wakeref);
 }
@@ -2445,12 +2447,33 @@ static void intel_program_port_clock_ctl(struct intel_encoder *encoder,
 		     XELPDP_SSC_ENABLE_PLLB, val);
 }
 
+static int intel_link_bitrate_to_clock(struct intel_encoder *encoder,
+				       struct intel_crtc_state *crtc_state,
+				       int link_bit_rate)
+{
+	const struct intel_c20pll_state * const *tables;
+	int i;
+
+	tables = intel_c20_pll_tables_get(crtc_state, encoder);
+	if (!tables)
+		return -EINVAL;
+
+	for (i = 0; tables[i]; i++) {
+		if (link_bit_rate == tables[i]->link_bit_rate)
+			return tables[i]->clock;
+	}
+
+	return -EINVAL;
+}
+
 static void intel_c20pll_readout_hw_state(struct intel_encoder *encoder,
+					  struct intel_crtc_state *crtc_state,
 					  struct intel_c20pll_state *pll_state)
 {
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
 	bool cntx;
 	intel_wakeref_t wakeref;
+	int clock;
 	int i;
 
 	wakeref = intel_cx0_phy_transaction_begin(encoder);
@@ -2500,6 +2523,13 @@ static void intel_c20pll_readout_hw_state(struct intel_encoder *encoder,
 		}
 	}
 
+	pll_state->link_bit_rate = intel_c20pll_calc_port_clock(encoder, pll_state);
+	clock = intel_link_bitrate_to_clock(encoder, crtc_state,
+					    pll_state->link_bit_rate);
+
+	if (clock >= 0)
+		pll_state->clock = clock;
+
 	intel_cx0_phy_transaction_end(encoder, wakeref);
 }
 
@@ -3053,15 +3083,16 @@ static void intel_c10pll_state_verify(const struct intel_crtc_state *state,
 }
 
 void intel_cx0pll_readout_hw_state(struct intel_encoder *encoder,
+				   struct intel_crtc_state *crtc_state,
 				   struct intel_cx0pll_state *pll_state)
 {
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
 	enum phy phy = intel_port_to_phy(i915, encoder->port);
 
 	if (intel_is_c10phy(i915, phy))
-		intel_c10pll_readout_hw_state(encoder, &pll_state->c10);
+		intel_c10pll_readout_hw_state(encoder, crtc_state, &pll_state->c10);
 	else
-		intel_c20pll_readout_hw_state(encoder, &pll_state->c20);
+		intel_c20pll_readout_hw_state(encoder, crtc_state, &pll_state->c20);
 }
 
 int intel_cx0pll_calc_port_clock(struct intel_encoder *encoder,
@@ -3145,7 +3176,8 @@ void intel_cx0pll_state_verify(struct intel_atomic_state *state,
 	if (intel_tc_port_in_tbt_alt_mode(enc_to_dig_port(encoder)))
 		return;
 
-	intel_cx0pll_readout_hw_state(encoder, &mpll_hw_state);
+	intel_cx0pll_readout_hw_state(encoder, (struct intel_crtc_state*)new_crtc_state,
+				      &mpll_hw_state);
 
 	if (intel_is_c10phy(i915, phy))
 		intel_c10pll_state_verify(new_crtc_state, crtc, encoder, &mpll_hw_state.c10);
diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.h b/drivers/gpu/drm/i915/display/intel_cx0_phy.h
index c6682677253a..eac7354e9a4e 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.h
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.h
@@ -32,6 +32,7 @@ intel_mtl_port_pll_type(struct intel_encoder *encoder,
 
 int intel_cx0pll_calc_state(struct intel_crtc_state *crtc_state, struct intel_encoder *encoder);
 void intel_cx0pll_readout_hw_state(struct intel_encoder *encoder,
+				   struct intel_crtc_state *crtc_state,
 				   struct intel_cx0pll_state *pll_state);
 int intel_cx0pll_calc_port_clock(struct intel_encoder *encoder,
 				 const struct intel_cx0pll_state *pll_state);
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 38f28c480b38..508d3363e89f 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3953,7 +3953,7 @@ static void mtl_ddi_get_config(struct intel_encoder *encoder,
 	if (intel_tc_port_in_tbt_alt_mode(dig_port)) {
 		crtc_state->port_clock = intel_mtl_tbt_calc_port_clock(encoder);
 	} else {
-		intel_cx0pll_readout_hw_state(encoder, &crtc_state->cx0pll_state);
+		intel_cx0pll_readout_hw_state(encoder, crtc_state, &crtc_state->cx0pll_state);
 		crtc_state->port_clock = intel_cx0pll_calc_port_clock(encoder, &crtc_state->cx0pll_state);
 	}
 
-- 
2.34.1