drm/i915: Consider SPLL as another shared pll, v2.

When diagnosing a unrelated bug for someone on irc, it would seem the hardware can
be brought up by the BIOS with the embedded displayport using the SPLL for spread spectrum.

Right now this is not handled well in i915, and it calculates the crtc needs to
be reprogrammed on the first modeset without SSC, but  the SPLL itself was kept
active. Fix this by exposing SPLL as a shared pll that will not be returned
by intel_get_shared_dpll; you have to know it exists to use it.

Changes since v1:
- Create a separate dpll_hw_state.spll for spll, and use
  separate pll functions for spll.

Tested-by: Emil Renner Berthing <kernel@esmil.dk>
Tested-by: Gabriel Feceoru <gabriel.feceoru@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447681332-6318-1-git-send-email-maarten.lankhorst@linux.intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 65 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index b25e99a..a6752a6 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1286,6 +1286,18 @@ hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
 		}
 
 		crtc_state->ddi_pll_sel = PORT_CLK_SEL_WRPLL(pll->id);
+	} else if (crtc_state->ddi_pll_sel == PORT_CLK_SEL_SPLL) {
+		struct drm_atomic_state *state = crtc_state->base.state;
+		struct intel_shared_dpll_config *spll =
+			&intel_atomic_get_shared_dpll_state(state)[DPLL_ID_SPLL];
+
+		if (spll->crtc_mask &&
+		    WARN_ON(spll->hw_state.spll != crtc_state->dpll_hw_state.spll))
+			return false;
+
+		crtc_state->shared_dpll = DPLL_ID_SPLL;
+		spll->hw_state.spll = crtc_state->dpll_hw_state.spll;
+		spll->crtc_mask |= 1 << intel_crtc->pipe;
 	}
 
 	return true;
@@ -2437,7 +2449,7 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder)
 	}
 }
 
-static void hsw_ddi_pll_enable(struct drm_i915_private *dev_priv,
+static void hsw_ddi_wrpll_enable(struct drm_i915_private *dev_priv,
 			       struct intel_shared_dpll *pll)
 {
 	I915_WRITE(WRPLL_CTL(pll->id), pll->config.hw_state.wrpll);
@@ -2445,9 +2457,17 @@ static void hsw_ddi_pll_enable(struct drm_i915_private *dev_priv,
 	udelay(20);
 }
 
-static void hsw_ddi_pll_disable(struct drm_i915_private *dev_priv,
+static void hsw_ddi_spll_enable(struct drm_i915_private *dev_priv,
 				struct intel_shared_dpll *pll)
 {
+	I915_WRITE(SPLL_CTL, pll->config.hw_state.spll);
+	POSTING_READ(SPLL_CTL);
+	udelay(20);
+}
+
+static void hsw_ddi_wrpll_disable(struct drm_i915_private *dev_priv,
+				  struct intel_shared_dpll *pll)
+{
 	uint32_t val;
 
 	val = I915_READ(WRPLL_CTL(pll->id));
@@ -2455,9 +2475,19 @@ static void hsw_ddi_pll_disable(struct drm_i915_private *dev_priv,
 	POSTING_READ(WRPLL_CTL(pll->id));
 }
 
-static bool hsw_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
-				     struct intel_shared_dpll *pll,
-				     struct intel_dpll_hw_state *hw_state)
+static void hsw_ddi_spll_disable(struct drm_i915_private *dev_priv,
+				 struct intel_shared_dpll *pll)
+{
+	uint32_t val;
+
+	val = I915_READ(SPLL_CTL);
+	I915_WRITE(SPLL_CTL, val & ~SPLL_PLL_ENABLE);
+	POSTING_READ(SPLL_CTL);
+}
+
+static bool hsw_ddi_wrpll_get_hw_state(struct drm_i915_private *dev_priv,
+				       struct intel_shared_dpll *pll,
+				       struct intel_dpll_hw_state *hw_state)
 {
 	uint32_t val;
 
@@ -2470,25 +2500,50 @@ static bool hsw_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	return val & WRPLL_PLL_ENABLE;
 }
 
+static bool hsw_ddi_spll_get_hw_state(struct drm_i915_private *dev_priv,
+				      struct intel_shared_dpll *pll,
+				      struct intel_dpll_hw_state *hw_state)
+{
+	uint32_t val;
+
+	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+		return false;
+
+	val = I915_READ(SPLL_CTL);
+	hw_state->spll = val;
+
+	return val & SPLL_PLL_ENABLE;
+}
+
+
 static const char * const hsw_ddi_pll_names[] = {
 	"WRPLL 1",
 	"WRPLL 2",
+	"SPLL"
 };
 
 static void hsw_shared_dplls_init(struct drm_i915_private *dev_priv)
 {
 	int i;
 
-	dev_priv->num_shared_dpll = 2;
+	dev_priv->num_shared_dpll = 3;
 
-	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
+	for (i = 0; i < 2; i++) {
 		dev_priv->shared_dplls[i].id = i;
 		dev_priv->shared_dplls[i].name = hsw_ddi_pll_names[i];
-		dev_priv->shared_dplls[i].disable = hsw_ddi_pll_disable;
-		dev_priv->shared_dplls[i].enable = hsw_ddi_pll_enable;
+		dev_priv->shared_dplls[i].disable = hsw_ddi_wrpll_disable;
+		dev_priv->shared_dplls[i].enable = hsw_ddi_wrpll_enable;
 		dev_priv->shared_dplls[i].get_hw_state =
-			hsw_ddi_pll_get_hw_state;
+			hsw_ddi_wrpll_get_hw_state;
 	}
+
+	/* SPLL is special, but needs to be initialized anyway.. */
+	dev_priv->shared_dplls[i].id = i;
+	dev_priv->shared_dplls[i].name = hsw_ddi_pll_names[i];
+	dev_priv->shared_dplls[i].disable = hsw_ddi_spll_disable;
+	dev_priv->shared_dplls[i].enable = hsw_ddi_spll_enable;
+	dev_priv->shared_dplls[i].get_hw_state = hsw_ddi_spll_get_hw_state;
+
 }
 
 static const char * const skl_ddi_pll_names[] = {