[Intel-gfx] [PATCH 6/8] drm/i915: Use cdclk_state->voltage on BXT/GLK

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Track the system agent voltage we request from pcode in the cdclk state
on BXT/GLK. Annoyingly we can't actually read out the current value since
there's no pcode command to do that, so we'll have to just assume that
it worked.

Cc: Mika Kahola <mika.kahola at intel.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_cdclk.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 6f7b5abe6e3f..1b4dcd9689da 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1166,6 +1166,11 @@ static int glk_calc_cdclk(int min_cdclk)
 		return 79200;
 }
 
+static u8 bxt_calc_voltage(int cdclk)
+{
+	return DIV_ROUND_UP(cdclk, 25000);
+}
+
 static int bxt_de_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
 {
 	int ratio;
@@ -1242,7 +1247,7 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 	cdclk_state->cdclk = cdclk_state->ref;
 
 	if (cdclk_state->vco == 0)
-		return;
+		goto out;
 
 	divider = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK;
 
@@ -1266,6 +1271,13 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
 	}
 
 	cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div);
+
+ out:
+	/*
+	 * Can't read this out :( Let's assume it's
+	 * at least what the CDCLK frequency requires.
+	 */
+	cdclk_state->voltage = bxt_calc_voltage(cdclk_state->cdclk);
 }
 
 static void bxt_de_pll_disable(struct drm_i915_private *dev_priv)
@@ -1368,7 +1380,7 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
 
 	mutex_lock(&dev_priv->pcu_lock);
 	ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
-				      DIV_ROUND_UP(cdclk, 25000));
+				      cdclk_state->voltage);
 	mutex_unlock(&dev_priv->pcu_lock);
 
 	if (ret) {
@@ -1460,6 +1472,7 @@ void bxt_init_cdclk(struct drm_i915_private *dev_priv)
 		cdclk_state.cdclk = bxt_calc_cdclk(0);
 		cdclk_state.vco = bxt_de_pll_vco(dev_priv, cdclk_state.cdclk);
 	}
+	cdclk_state.voltage = bxt_calc_voltage(cdclk_state.cdclk);
 
 	bxt_set_cdclk(dev_priv, &cdclk_state);
 }
@@ -1477,6 +1490,7 @@ void bxt_uninit_cdclk(struct drm_i915_private *dev_priv)
 
 	cdclk_state.cdclk = cdclk_state.ref;
 	cdclk_state.vco = 0;
+	cdclk_state.voltage = bxt_calc_voltage(cdclk_state.cdclk);
 
 	bxt_set_cdclk(dev_priv, &cdclk_state);
 }
@@ -2030,6 +2044,7 @@ static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
 
 	intel_state->cdclk.logical.vco = vco;
 	intel_state->cdclk.logical.cdclk = cdclk;
+	intel_state->cdclk.logical.voltage = bxt_calc_voltage(cdclk);
 
 	if (!intel_state->active_crtcs) {
 		if (IS_GEMINILAKE(dev_priv)) {
@@ -2042,6 +2057,7 @@ static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
 
 		intel_state->cdclk.actual.vco = vco;
 		intel_state->cdclk.actual.cdclk = cdclk;
+		intel_state->cdclk.actual.voltage = bxt_calc_voltage(cdclk);
 	} else {
 		intel_state->cdclk.actual =
 			intel_state->cdclk.logical;
-- 
2.13.6