[Intel-gfx] [PATCH 11/23] drm/i915/rkl: Add cdclk support

[Matt Roper]

Note that the 192000 clock frequencies can be achieved with different
pairs of ratio+divider, which is something we haven't encountered
before.  If any of those ratios were common with other legal cdclk
values, then it would mean we could avoid triggering full modesets if we
just needed to change the divider.  However at the moment there don't
appear to be any valid cdclks that share the same ratio so we can't take
advantage of this and it doesn't really matter which approach we use to
achieve the 192000 cdclk.  For now our driver functions that operate on
the table will just always pick the first entry (lower ratio + lower
divider).

Bspec: 49202
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/display/intel_cdclk.c | 54 +++++++++++++++++++---
 1 file changed, 48 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 979a0241fdcb..4ca87260e8ba 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1230,6 +1230,40 @@ static const struct intel_cdclk_vals icl_cdclk_table[] = {
 	{}
 };
 
+/*
+ * RKL has multiple divider+ratio pairs that can hit cdclk=192000.  Our
+ * functions to read these tables will just always pick the first one which
+ * should be fine since there's no other valid cdclk value that can be achieved
+ * via the same ratio with a different divider (i.e., no opportunity to avoid a
+ * full modeset).
+ */
+static const struct intel_cdclk_vals rkl_cdclk_table[] = {
+	{ .refclk = 19200, .cdclk = 172800, .divider = 3, .ratio = 27 },
+	{ .refclk = 19200, .cdclk = 192000, .divider = 2, .ratio = 20 },
+	{ .refclk = 19200, .cdclk = 192000, .divider = 3, .ratio = 15 },
+	{ .refclk = 19200, .cdclk = 307200, .divider = 2, .ratio = 32 },
+	{ .refclk = 19200, .cdclk = 326400, .divider = 4, .ratio = 68 },
+	{ .refclk = 19200, .cdclk = 556800, .divider = 2, .ratio = 58 },
+	{ .refclk = 19200, .cdclk = 652800, .divider = 2, .ratio = 68 },
+
+	{ .refclk = 24000, .cdclk = 176000, .divider = 3, .ratio = 22 },
+	{ .refclk = 24000, .cdclk = 192000, .divider = 2, .ratio = 16 },
+	{ .refclk = 24000, .cdclk = 192000, .divider = 3, .ratio = 24 },
+	{ .refclk = 24000, .cdclk = 312000, .divider = 2, .ratio = 26 },
+	{ .refclk = 24000, .cdclk = 324000, .divider = 4, .ratio = 54 },
+	{ .refclk = 24000, .cdclk = 552000, .divider = 2, .ratio = 45 },
+	{ .refclk = 24000, .cdclk = 648000, .divider = 2, .ratio = 54 },
+
+	{ .refclk = 38400, .cdclk = 179200, .divider = 3, .ratio = 14 },
+	{ .refclk = 38400, .cdclk = 192000, .divider = 2, .ratio = 10 },
+	{ .refclk = 38400, .cdclk = 192000, .divider = 3, .ratio = 15 },
+	{ .refclk = 38400, .cdclk = 307200, .divider = 2, .ratio = 16 },
+	{ .refclk = 38400, .cdclk = 326400, .divider = 4, .ratio = 34 },
+	{ .refclk = 38400, .cdclk = 556800, .divider = 2, .ratio = 29 },
+	{ .refclk = 38400, .cdclk = 652800, .divider = 2, .ratio = 34 },
+	{}
+};
+
 static int bxt_calc_cdclk(struct drm_i915_private *dev_priv, int min_cdclk)
 {
 	const struct intel_cdclk_vals *table = dev_priv->cdclk.table;
@@ -1405,8 +1439,8 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 		div = 2;
 		break;
 	case BXT_CDCLK_CD2X_DIV_SEL_1_5:
-		drm_WARN(&dev_priv->drm,
-			 IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10,
+		drm_WARN(&dev_priv->drm, IS_GEMINILAKE(dev_priv) ||
+			 (INTEL_GEN(dev_priv) >= 10 && !IS_ROCKETLAKE(dev_priv)),
 			 "Unsupported divider\n");
 		div = 3;
 		break;
@@ -1414,7 +1448,8 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 		div = 4;
 		break;
 	case BXT_CDCLK_CD2X_DIV_SEL_4:
-		drm_WARN(&dev_priv->drm, INTEL_GEN(dev_priv) >= 10,
+		drm_WARN(&dev_priv->drm,
+			 INTEL_GEN(dev_priv) >= 10 && !IS_ROCKETLAKE(dev_priv),
 			 "Unsupported divider\n");
 		div = 8;
 		break;
@@ -1564,7 +1599,8 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
 		break;
 	case 3:
 		drm_WARN(&dev_priv->drm,
-			 IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10,
+			 IS_GEMINILAKE(dev_priv) ||
+			 (INTEL_GEN(dev_priv) >= 10 && !IS_ROCKETLAKE(dev_priv)),
 			 "Unsupported divider\n");
 		divider = BXT_CDCLK_CD2X_DIV_SEL_1_5;
 		break;
@@ -1572,7 +1608,8 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
 		divider = BXT_CDCLK_CD2X_DIV_SEL_2;
 		break;
 	case 8:
-		drm_WARN(&dev_priv->drm, INTEL_GEN(dev_priv) >= 10,
+		drm_WARN(&dev_priv->drm,
+			 INTEL_GEN(dev_priv) >= 10 && !IS_ROCKETLAKE(dev_priv),
 			 "Unsupported divider\n");
 		divider = BXT_CDCLK_CD2X_DIV_SEL_4;
 		break;
@@ -2758,7 +2795,12 @@ u32 intel_read_rawclk(struct drm_i915_private *dev_priv)
  */
 void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
 {
-	if (INTEL_GEN(dev_priv) >= 12) {
+	if (IS_ROCKETLAKE(dev_priv)) {
+		dev_priv->display.set_cdclk = bxt_set_cdclk;
+		dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
+		dev_priv->display.calc_voltage_level = tgl_calc_voltage_level;
+		dev_priv->cdclk.table = rkl_cdclk_table;
+	} else if (INTEL_GEN(dev_priv) >= 12) {
 		dev_priv->display.set_cdclk = bxt_set_cdclk;
 		dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
 		dev_priv->display.calc_voltage_level = tgl_calc_voltage_level;
-- 
2.24.1