[Intel-gfx] [PATCH 34/42] drm/i915/lnl: Start using CDCLK through PLL

[Lucas De Marchi]

From: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>

Introduce correspondent definitions and for choosing between CD2X CDCLK
and PLL CDCLK as a source.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/display/intel_cdclk.c | 14 ++++++++++++--
 drivers/gpu/drm/i915/i915_reg.h            |  3 +++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index ed45a2cf5c9a..04937aaabcee 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1932,8 +1932,7 @@ static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
 		dg2_cdclk_squash_program(dev_priv, waveform);
 
 	val = bxt_cdclk_cd2x_div_sel(dev_priv, clock, vco) |
-		bxt_cdclk_cd2x_pipe(dev_priv, pipe) |
-		skl_cdclk_decimal(cdclk);
+		bxt_cdclk_cd2x_pipe(dev_priv, pipe);
 
 	/*
 	 * Disable SSA Precharge when CD clock frequency < 500 MHz,
@@ -1942,6 +1941,17 @@ static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
 	if ((IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv)) &&
 	    cdclk >= 500000)
 		val |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;
+
+	if (DISPLAY_VER(dev_priv) >= 20)
+		/*
+		 * Using CDCLK through PLL seems to be always better option when
+		 * its supported, both in terms of performance and power
+		 * consumption.
+		 */
+		val |= CDCLK_SOURCE_SEL_CDCLK_PLL;
+	else
+		val |= skl_cdclk_decimal(cdclk);
+
 	intel_de_write(dev_priv, CDCLK_CTL, val);
 
 	if (pipe != INVALID_PIPE)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index fa85530afac3..d5850761a75a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5933,6 +5933,9 @@ enum skl_power_gate {
 #define  CDCLK_FREQ_540		REG_FIELD_PREP(CDCLK_FREQ_SEL_MASK, 1)
 #define  CDCLK_FREQ_337_308		REG_FIELD_PREP(CDCLK_FREQ_SEL_MASK, 2)
 #define  CDCLK_FREQ_675_617		REG_FIELD_PREP(CDCLK_FREQ_SEL_MASK, 3)
+#define  CDCLK_SOURCE_SEL_MASK		REG_BIT(25)
+#define  CDCLK_SOURCE_SEL_CD2X		REG_FIELD_PREP(CDCLK_SOURCE_SEL_MASK, 0)
+#define  CDCLK_SOURCE_SEL_CDCLK_PLL	REG_FIELD_PREP(CDCLK_SOURCE_SEL_MASK, 1)
 #define  BXT_CDCLK_CD2X_DIV_SEL_MASK	REG_GENMASK(23, 22)
 #define  BXT_CDCLK_CD2X_DIV_SEL_1	REG_FIELD_PREP(BXT_CDCLK_CD2X_DIV_SEL_MASK, 0)
 #define  BXT_CDCLK_CD2X_DIV_SEL_1_5	REG_FIELD_PREP(BXT_CDCLK_CD2X_DIV_SEL_MASK, 1)
-- 
2.40.1