[Intel-gfx] [PATCH 04/17] drm/i915/cnl: Allow dynamic cdclk changes on CNL

[Rodrigo Vivi]

All the low level cdclk bits are present, so let's add the required
hooks to reconfigure cdclk on the fly.

v2: Rebase due to cnl_sanitize_cdclk()
v3: Rebased by Rodrigo on top of Ville's cdclk rework.
v4: Rebase moving cnl_calc_cdclk up to follow same order
    as previous platforms.
v2: Squash drm/i915/cnl: Adjust min pixel rate. to address
    the current limitation where CDCLK cannot be set to 168MHz
    if audio is used with 96MHz. (Imre)

Cc: Imre Deak <imre.deak at intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

Cannonlake also needs to adjust the minimal pixel rate
as gen9 platforms. Specially for the Azalia audio case.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Sanyog Kale <sanyog.r.kale at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_cdclk.c | 56 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 35a1432..1d7cfc5 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1400,6 +1400,16 @@ void bxt_uninit_cdclk(struct drm_i915_private *dev_priv)
 	bxt_set_cdclk(dev_priv, &cdclk_state);
 }
 
+static int cnl_calc_cdclk(int max_pixclk)
+{
+	if (max_pixclk > 336000)
+		return 528000;
+	else if (max_pixclk > 168000)
+		return 336000;
+	else
+		return 168000;
+}
+
 static void cnl_cdclk_pll_update(struct drm_i915_private *dev_priv,
 				 struct intel_cdclk_state *cdclk_state)
 {
@@ -1641,7 +1651,7 @@ void cnl_init_cdclk(struct drm_i915_private *dev_priv)
 
 	cdclk_state = dev_priv->cdclk.hw;
 
-	cdclk_state.cdclk = 168000;
+	cdclk_state.cdclk = cnl_calc_cdclk(0);
 	cdclk_state.vco = cnl_cdclk_pll_vco(dev_priv, cdclk_state.cdclk);
 
 	cnl_set_cdclk(dev_priv, &cdclk_state);
@@ -1768,7 +1778,7 @@ static int intel_max_pixel_rate(struct drm_atomic_state *state)
 
 		pixel_rate = crtc_state->pixel_rate;
 
-		if (IS_BROADWELL(dev_priv) || IS_GEN9(dev_priv))
+		if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
 			pixel_rate =
 				bdw_adjust_min_pipe_pixel_rate(crtc_state,
 							       pixel_rate);
@@ -1929,6 +1939,40 @@ static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
 	return 0;
 }
 
+static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->dev);
+	struct intel_atomic_state *intel_state =
+		to_intel_atomic_state(state);
+	int max_pixclk = intel_max_pixel_rate(state);
+	int cdclk, vco;
+
+	cdclk = cnl_calc_cdclk(max_pixclk);
+	vco = cnl_cdclk_pll_vco(dev_priv, cdclk);
+
+	if (cdclk > dev_priv->max_cdclk_freq) {
+		DRM_DEBUG_KMS("requested cdclk (%d kHz) exceeds max (%d kHz)\n",
+			      cdclk, dev_priv->max_cdclk_freq);
+		return -EINVAL;
+	}
+
+	intel_state->cdclk.logical.vco = vco;
+	intel_state->cdclk.logical.cdclk = cdclk;
+
+	if (!intel_state->active_crtcs) {
+		cdclk = cnl_calc_cdclk(0);
+		vco = cnl_cdclk_pll_vco(dev_priv, cdclk);
+
+		intel_state->cdclk.actual.vco = vco;
+		intel_state->cdclk.actual.cdclk = cdclk;
+	} else {
+		intel_state->cdclk.actual =
+			intel_state->cdclk.logical;
+	}
+
+	return 0;
+}
+
 static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv)
 {
 	int max_cdclk_freq = dev_priv->max_cdclk_freq;
@@ -1960,7 +2004,9 @@ static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv)
  */
 void intel_update_max_cdclk(struct drm_i915_private *dev_priv)
 {
-	if (IS_GEN9_BC(dev_priv)) {
+	if (IS_CANNONLAKE(dev_priv)) {
+		dev_priv->max_cdclk_freq = 528000;
+	} else if (IS_GEN9_BC(dev_priv)) {
 		u32 limit = I915_READ(SKL_DFSM) & SKL_DFSM_CDCLK_LIMIT_MASK;
 		int max_cdclk, vco;
 
@@ -2157,6 +2203,10 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
 		dev_priv->display.set_cdclk = skl_set_cdclk;
 		dev_priv->display.modeset_calc_cdclk =
 			skl_modeset_calc_cdclk;
+	} else if (IS_CANNONLAKE(dev_priv)) {
+		dev_priv->display.set_cdclk = cnl_set_cdclk;
+		dev_priv->display.modeset_calc_cdclk =
+			cnl_modeset_calc_cdclk;
 	}
 
 	if (IS_CANNONLAKE(dev_priv))
-- 
1.9.1