[Intel-gfx] [PATCH 32/42] drm/i915/lnl: Introduce MDCLK

[Lucas De Marchi]

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

In Lunar Lake we now separate MDCLK from CDLCK, which used to be before
always 2 times CDCLK.  Now we might afford lower CDCLK, while having
higher memory clock, so improving bandwidth and power consumption at the
same time.  This is prep work required to enable that.

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 | 30 ++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_cdclk.h |  2 +-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index fdd8d04fe12c..3e566f45996d 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1223,6 +1223,7 @@ static void skl_cdclk_uninit_hw(struct drm_i915_private *dev_priv)
 
 struct intel_cdclk_vals {
 	u32 cdclk;
+	u32 mdclk;
 	u16 refclk;
 	u16 waveform;
 	u8 divider;	/* CD2X divider * 2 */
@@ -1524,6 +1525,8 @@ static void bxt_de_pll_readout(struct drm_i915_private *dev_priv,
 static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 			  struct intel_cdclk_config *cdclk_config)
 {
+	const struct intel_cdclk_vals *table = dev_priv->display.cdclk.table;
+	int i, ratio, tbl_waveform = 0;
 	u32 squash_ctl = 0;
 	u32 divider;
 	int div;
@@ -1574,10 +1577,36 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 
 		cdclk_config->cdclk = DIV_ROUND_CLOSEST(hweight16(waveform) *
 							cdclk_config->vco, size * div);
+		tbl_waveform = squash_ctl & CDCLK_SQUASH_WAVEFORM_MASK;
 	} else {
 		cdclk_config->cdclk = DIV_ROUND_CLOSEST(cdclk_config->vco, div);
 	}
 
+	ratio = cdclk_config->vco / cdclk_config->ref;
+
+	for (i = 0; table[i].refclk; i++) {
+		if (table[i].refclk != cdclk_config->ref)
+			continue;
+
+		if (table[i].divider != div)
+			continue;
+
+		if (table[i].waveform != tbl_waveform)
+			continue;
+
+		if (table[i].ratio != ratio)
+			continue;
+
+		/*
+		 * Supported from LunarLake HW onwards, however considering that
+		 * besides this the whole procedure is the same, we keep this
+		 * for all the platforms.
+		 */
+		cdclk_config->mdclk = table[i].mdclk;
+
+		break;
+	}
+
  out:
 	/*
 	 * Can't read this out :( Let's assume it's
@@ -2191,6 +2220,7 @@ bool intel_cdclk_needs_modeset(const struct intel_cdclk_config *a,
 			       const struct intel_cdclk_config *b)
 {
 	return a->cdclk != b->cdclk ||
+		a->mdclk != b->mdclk ||
 		a->vco != b->vco ||
 		a->ref != b->ref;
 }
diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.h b/drivers/gpu/drm/i915/display/intel_cdclk.h
index 48fd7d39e0cd..3e7eabd4d7b6 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.h
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.h
@@ -16,7 +16,7 @@ struct intel_atomic_state;
 struct intel_crtc_state;
 
 struct intel_cdclk_config {
-	unsigned int cdclk, vco, ref, bypass;
+	unsigned int cdclk, mdclk, vco, ref, bypass;
 	u8 voltage_level;
 };
 
-- 
2.40.1