drm/i915/mtl: C20 port clock calculation

Calculate port clock with C20 phy.

BSpec: 64568
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230428095433.4109054-5-mika.kahola@intel.com

drivers/gpu/drm/i915/display/intel_cx0_phy.c

@@ -2283,6 +2283,51 @@ int intel_c10pll_calc_port_clock(struct intel_encoder *encoder,
 	return tmpclk;
 }
 
+int intel_c20pll_calc_port_clock(struct intel_encoder *encoder,
+				 const struct intel_c20pll_state *pll_state)
+{
+	unsigned int frac, frac_en, frac_quot, frac_rem, frac_den;
+	unsigned int multiplier, refclk = 38400;
+	unsigned int tx_clk_div;
+	unsigned int ref_clk_mpllb_div;
+	unsigned int fb_clk_div4_en;
+	unsigned int ref, vco;
+	unsigned int tx_rate_mult;
+	unsigned int tx_rate = REG_FIELD_GET(C20_PHY_TX_RATE, pll_state->tx[0]);
+
+	if (pll_state->tx[0] & C20_PHY_USE_MPLLB) {
+		tx_rate_mult = 1;
+		frac_en = REG_FIELD_GET(C20_MPLLB_FRACEN, pll_state->mpllb[6]);
+		frac_quot = pll_state->mpllb[8];
+		frac_rem =  pll_state->mpllb[9];
+		frac_den =  pll_state->mpllb[7];
+		multiplier = REG_FIELD_GET(C20_MULTIPLIER_MASK, pll_state->mpllb[0]);
+		tx_clk_div = REG_FIELD_GET(C20_MPLLB_TX_CLK_DIV_MASK, pll_state->mpllb[0]);
+		ref_clk_mpllb_div = REG_FIELD_GET(C20_REF_CLK_MPLLB_DIV_MASK, pll_state->mpllb[6]);
+		fb_clk_div4_en = 0;
+	} else {
+		tx_rate_mult = 2;
+		frac_en = REG_FIELD_GET(C20_MPLLA_FRACEN, pll_state->mplla[6]);
+		frac_quot = pll_state->mplla[8];
+		frac_rem =  pll_state->mplla[9];
+		frac_den =  pll_state->mplla[7];
+		multiplier = REG_FIELD_GET(C20_MULTIPLIER_MASK, pll_state->mplla[0]);
+		tx_clk_div = REG_FIELD_GET(C20_MPLLA_TX_CLK_DIV_MASK, pll_state->mplla[1]);
+		ref_clk_mpllb_div = REG_FIELD_GET(C20_REF_CLK_MPLLB_DIV_MASK, pll_state->mplla[6]);
+		fb_clk_div4_en = REG_FIELD_GET(C20_FB_CLK_DIV4_EN, pll_state->mplla[0]);
+	}
+
+	if (frac_en)
+		frac = frac_quot + DIV_ROUND_CLOSEST(frac_rem, frac_den);
+	else
+		frac = 0;
+
+	ref = DIV_ROUND_CLOSEST(refclk * (1 << (1 + fb_clk_div4_en)), 1 << ref_clk_mpllb_div);
+	vco = DIV_ROUND_CLOSEST_ULL(mul_u32_u32(ref, (multiplier << (17 - 2)) + frac) >> 17, 10);
+
+	return vco << tx_rate_mult >> tx_clk_div >> tx_rate;
+}
+
 static void intel_program_port_clock_ctl(struct intel_encoder *encoder,
 					 const struct intel_crtc_state *crtc_state,
 					 bool lane_reversal)

drivers/gpu/drm/i915/display/intel_cx0_phy.h

@@ -34,6 +34,8 @@ void intel_c20pll_readout_hw_state(struct intel_encoder *encoder,
 				   struct intel_c20pll_state *pll_state);
 void intel_c20pll_dump_hw_state(struct drm_i915_private *i915,
 				const struct intel_c20pll_state *hw_state);
+int intel_c20pll_calc_port_clock(struct intel_encoder *encoder,
+				 const struct intel_c20pll_state *pll_state);
 void intel_cx0_phy_set_signal_levels(struct intel_encoder *encoder,
 				     const struct intel_crtc_state *crtc_state);
 int intel_cx0_phy_check_hdmi_link_rate(struct intel_hdmi *hdmi, int clock);

drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h

@@ -196,16 +196,19 @@
 #define   PHY_C20_CUSTOM_WIDTH(val)	REG_FIELD_PREP8(PHY_C20_CUSTOM_WIDTH_MASK, val)
 #define PHY_C20_A_TX_CNTX_CFG(idx)	(0xCF2E - (idx))
 #define PHY_C20_B_TX_CNTX_CFG(idx)	(0xCF2A - (idx))
+#define   C20_PHY_TX_RATE		REG_GENMASK(2, 0)
 #define PHY_C20_A_CMN_CNTX_CFG(idx)	(0xCDAA - (idx))
 #define PHY_C20_B_CMN_CNTX_CFG(idx)	(0xCDA5 - (idx))
 #define PHY_C20_A_MPLLA_CNTX_CFG(idx)	(0xCCF0 - (idx))
 #define PHY_C20_B_MPLLA_CNTX_CFG(idx)	(0xCCE5 - (idx))
 #define   C20_MPLLA_FRACEN		REG_BIT(14)
+#define   C20_FB_CLK_DIV4_EN		REG_BIT(13)
 #define   C20_MPLLA_TX_CLK_DIV_MASK	REG_GENMASK(10, 8)
 #define PHY_C20_A_MPLLB_CNTX_CFG(idx)	(0xCB5A - (idx))
 #define PHY_C20_B_MPLLB_CNTX_CFG(idx)	(0xCB4E - (idx))
 #define   C20_MPLLB_TX_CLK_DIV_MASK	REG_GENMASK(15, 13)
 #define   C20_MPLLB_FRACEN		REG_BIT(13)
+#define   C20_REF_CLK_MPLLB_DIV_MASK	REG_GENMASK(12, 10)
 #define   C20_MULTIPLIER_MASK		REG_GENMASK(11, 0)
 #define   C20_PHY_USE_MPLLB		REG_BIT(7)
 

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -3856,13 +3856,13 @@ static void mtl_ddi_get_config(struct intel_encoder *encoder,
 	if (intel_is_c10phy(i915, phy)) {
 		intel_c10pll_readout_hw_state(encoder, &crtc_state->cx0pll_state.c10);
 		intel_c10pll_dump_hw_state(i915, &crtc_state->cx0pll_state.c10);
+		crtc_state->port_clock = intel_c10pll_calc_port_clock(encoder, &crtc_state->cx0pll_state.c10);
 	} else {
 		intel_c20pll_readout_hw_state(encoder, &crtc_state->cx0pll_state.c20);
 		intel_c20pll_dump_hw_state(i915, &crtc_state->cx0pll_state.c20);
+		crtc_state->port_clock = intel_c20pll_calc_port_clock(encoder, &crtc_state->cx0pll_state.c20);
 	}
 
-	crtc_state->port_clock = intel_c10pll_calc_port_clock(encoder, &crtc_state->cx0pll_state.c10);
-
 	intel_ddi_get_config(encoder, crtc_state);
 }
 

drivers/gpu/drm/i915/display/intel_dpll.c

@@ -1014,6 +1014,8 @@ static int mtl_crtc_compute_clock(struct intel_atomic_state *state,
 	/* TODO: Do the readback via intel_compute_shared_dplls() */
 	if (intel_is_c10phy(i915, phy))
 		crtc_state->port_clock = intel_c10pll_calc_port_clock(encoder, &crtc_state->cx0pll_state.c10);
+	else
+		crtc_state->port_clock = intel_c20pll_calc_port_clock(encoder, &crtc_state->cx0pll_state.c20);
 
 	crtc_state->hw.adjusted_mode.crtc_clock = intel_crtc_dotclock(crtc_state);