drm/i915: Move shared dpll code to a new file

Create the new file intel_dpll_mgr.c and move the shared dpll code to
it. Follow up patches that reorganize pll handling will move more code
there and tweak the interface.

No functional changes.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457451987-17466-2-git-send-email-ander.conselvan.de.oliveira@intel.com

4 files changed, 379 insertions, 346 deletions

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 0851de07bd13..5558a0312558 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -56,6 +56,7 @@ i915-y += intel_audio.o \
 	  intel_atomic_plane.o \
 	  intel_bios.o \
 	  intel_display.o \
+	  intel_dpll_mgr.o \
 	  intel_fbc.o \
 	  intel_fifo_underrun.o \
 	  intel_frontbuffer.o \
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 62d36a7b3398..1d5695d07abd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1197,34 +1197,6 @@ static void assert_dsi_pll(struct drm_i915_private *dev_priv, bool state)
 #define assert_dsi_pll_enabled(d) assert_dsi_pll(d, true)
 #define assert_dsi_pll_disabled(d) assert_dsi_pll(d, false)
 
-struct intel_shared_dpll *
-intel_crtc_to_shared_dpll(struct intel_crtc *crtc)
-{
-	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
-
-	if (crtc->config->shared_dpll < 0)
-		return NULL;
-
-	return &dev_priv->shared_dplls[crtc->config->shared_dpll];
-}
-
-/* For ILK+ */
-void assert_shared_dpll(struct drm_i915_private *dev_priv,
-			struct intel_shared_dpll *pll,
-			bool state)
-{
-	bool cur_state;
-	struct intel_dpll_hw_state hw_state;
-
-	if (WARN(!pll, "asserting DPLL %s with no DPLL\n", onoff(state)))
-		return;
-
-	cur_state = pll->get_hw_state(dev_priv, pll, &hw_state);
-	I915_STATE_WARN(cur_state != state,
-	     "%s assertion failure (expected %s, current %s)\n",
-			pll->name, onoff(state), onoff(cur_state));
-}
-
 static void assert_fdi_tx(struct drm_i915_private *dev_priv,
 			  enum pipe pipe, bool state)
 {
@@ -1461,21 +1433,8 @@ static void assert_vblank_disabled(struct drm_crtc *crtc)
 		drm_crtc_vblank_put(crtc);
 }
 
-static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
-{
-	u32 val;
-	bool enabled;
-
-	I915_STATE_WARN_ON(!(HAS_PCH_IBX(dev_priv->dev) || HAS_PCH_CPT(dev_priv->dev)));
-
-	val = I915_READ(PCH_DREF_CONTROL);
-	enabled = !!(val & (DREF_SSC_SOURCE_MASK | DREF_NONSPREAD_SOURCE_MASK |
-			    DREF_SUPERSPREAD_SOURCE_MASK));
-	I915_STATE_WARN(!enabled, "PCH refclk assertion failure, should be active but is disabled\n");
-}
-
-static void assert_pch_transcoder_disabled(struct drm_i915_private *dev_priv,
-					   enum pipe pipe)
+void assert_pch_transcoder_disabled(struct drm_i915_private *dev_priv,
+				    enum pipe pipe)
 {
 	u32 val;
 	bool enabled;
@@ -1871,100 +1830,6 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
 		     port_name(dport->port), I915_READ(dpll_reg) & port_mask, expected_mask);
 }
 
-static void intel_prepare_shared_dpll(struct intel_crtc *crtc)
-{
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
-
-	if (WARN_ON(pll == NULL))
-		return;
-
-	WARN_ON(!pll->config.crtc_mask);
-	if (pll->active == 0) {
-		DRM_DEBUG_DRIVER("setting up %s\n", pll->name);
-		WARN_ON(pll->on);
-		assert_shared_dpll_disabled(dev_priv, pll);
-
-		pll->mode_set(dev_priv, pll);
-	}
-}
-
-/**
- * intel_enable_shared_dpll - enable PCH PLL
- * @dev_priv: i915 private structure
- * @pipe: pipe PLL to enable
- *
- * The PCH PLL needs to be enabled before the PCH transcoder, since it
- * drives the transcoder clock.
- */
-static void intel_enable_shared_dpll(struct intel_crtc *crtc)
-{
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
-
-	if (WARN_ON(pll == NULL))
-		return;
-
-	if (WARN_ON(pll->config.crtc_mask == 0))
-		return;
-
-	DRM_DEBUG_KMS("enable %s (active %d, on? %d) for crtc %d\n",
-		      pll->name, pll->active, pll->on,
-		      crtc->base.base.id);
-
-	if (pll->active++) {
-		WARN_ON(!pll->on);
-		assert_shared_dpll_enabled(dev_priv, pll);
-		return;
-	}
-	WARN_ON(pll->on);
-
-	intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
-
-	DRM_DEBUG_KMS("enabling %s\n", pll->name);
-	pll->enable(dev_priv, pll);
-	pll->on = true;
-}
-
-static void intel_disable_shared_dpll(struct intel_crtc *crtc)
-{
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
-
-	/* PCH only available on ILK+ */
-	if (INTEL_INFO(dev)->gen < 5)
-		return;
-
-	if (pll == NULL)
-		return;
-
-	if (WARN_ON(!(pll->config.crtc_mask & (1 << drm_crtc_index(&crtc->base)))))
-		return;
-
-	DRM_DEBUG_KMS("disable %s (active %d, on? %d) for crtc %d\n",
-		      pll->name, pll->active, pll->on,
-		      crtc->base.base.id);
-
-	if (WARN_ON(pll->active == 0)) {
-		assert_shared_dpll_disabled(dev_priv, pll);
-		return;
-	}
-
-	assert_shared_dpll_enabled(dev_priv, pll);
-	WARN_ON(!pll->on);
-	if (--pll->active)
-		return;
-
-	DRM_DEBUG_KMS("disabling %s\n", pll->name);
-	pll->disable(dev_priv, pll);
-	pll->on = false;
-
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
-}
-
 static void ironlake_enable_pch_transcoder(struct drm_i915_private *dev_priv,
 					   enum pipe pipe)
 {
@@ -4361,113 +4226,6 @@ static void lpt_pch_enable(struct drm_crtc *crtc)
 	lpt_enable_pch_transcoder(dev_priv, cpu_transcoder);
 }
 
-struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc,
-						struct intel_crtc_state *crtc_state)
-{
-	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
-	struct intel_shared_dpll *pll;
-	struct intel_shared_dpll_config *shared_dpll;
-	enum intel_dpll_id i;
-	int max = dev_priv->num_shared_dpll;
-
-	shared_dpll = intel_atomic_get_shared_dpll_state(crtc_state->base.state);
-
-	if (HAS_PCH_IBX(dev_priv->dev)) {
-		/* Ironlake PCH has a fixed PLL->PCH pipe mapping. */
-		i = (enum intel_dpll_id) crtc->pipe;
-		pll = &dev_priv->shared_dplls[i];
-
-		DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
-			      crtc->base.base.id, pll->name);
-
-		WARN_ON(shared_dpll[i].crtc_mask);
-
-		goto found;
-	}
-
-	if (IS_BROXTON(dev_priv->dev)) {
-		/* PLL is attached to port in bxt */
-		struct intel_encoder *encoder;
-		struct intel_digital_port *intel_dig_port;
-
-		encoder = intel_ddi_get_crtc_new_encoder(crtc_state);
-		if (WARN_ON(!encoder))
-			return NULL;
-
-		intel_dig_port = enc_to_dig_port(&encoder->base);
-		/* 1:1 mapping between ports and PLLs */
-		i = (enum intel_dpll_id)intel_dig_port->port;
-		pll = &dev_priv->shared_dplls[i];
-		DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
-			crtc->base.base.id, pll->name);
-		WARN_ON(shared_dpll[i].crtc_mask);
-
-		goto found;
-	} else if (INTEL_INFO(dev_priv)->gen < 9 && HAS_DDI(dev_priv))
-		/* Do not consider SPLL */
-		max = 2;
-
-	for (i = 0; i < max; i++) {
-		pll = &dev_priv->shared_dplls[i];
-
-		/* Only want to check enabled timings first */
-		if (shared_dpll[i].crtc_mask == 0)
-			continue;
-
-		if (memcmp(&crtc_state->dpll_hw_state,
-			   &shared_dpll[i].hw_state,
-			   sizeof(crtc_state->dpll_hw_state)) == 0) {
-			DRM_DEBUG_KMS("CRTC:%d sharing existing %s (crtc mask 0x%08x, ative %d)\n",
-				      crtc->base.base.id, pll->name,
-				      shared_dpll[i].crtc_mask,
-				      pll->active);
-			goto found;
-		}
-	}
-
-	/* Ok no matching timings, maybe there's a free one? */
-	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
-		pll = &dev_priv->shared_dplls[i];
-		if (shared_dpll[i].crtc_mask == 0) {
-			DRM_DEBUG_KMS("CRTC:%d allocated %s\n",
-				      crtc->base.base.id, pll->name);
-			goto found;
-		}
-	}
-
-	return NULL;
-
-found:
-	if (shared_dpll[i].crtc_mask == 0)
-		shared_dpll[i].hw_state =
-			crtc_state->dpll_hw_state;
-
-	crtc_state->shared_dpll = i;
-	DRM_DEBUG_DRIVER("using %s for pipe %c\n", pll->name,
-			 pipe_name(crtc->pipe));
-
-	shared_dpll[i].crtc_mask |= 1 << crtc->pipe;
-
-	return pll;
-}
-
-static void intel_shared_dpll_commit(struct drm_atomic_state *state)
-{
-	struct drm_i915_private *dev_priv = to_i915(state->dev);
-	struct intel_shared_dpll_config *shared_dpll;
-	struct intel_shared_dpll *pll;
-	enum intel_dpll_id i;
-
-	if (!to_intel_atomic_state(state)->dpll_set)
-		return;
-
-	shared_dpll = to_intel_atomic_state(state)->shared_dpll;
-	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
-		pll = &dev_priv->shared_dplls[i];
-		pll->config = shared_dpll[i];
-	}
-}
-
 static void cpt_verify_modeset(struct drm_device *dev, int pipe)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -13887,108 +13645,6 @@ static const struct drm_crtc_funcs intel_crtc_funcs = {
 	.atomic_destroy_state = intel_crtc_destroy_state,
 };
 
-static bool ibx_pch_dpll_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_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
-		return false;
-
-	val = I915_READ(PCH_DPLL(pll->id));
-	hw_state->dpll = val;
-	hw_state->fp0 = I915_READ(PCH_FP0(pll->id));
-	hw_state->fp1 = I915_READ(PCH_FP1(pll->id));
-
-	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
-
-	return val & DPLL_VCO_ENABLE;
-}
-
-static void ibx_pch_dpll_mode_set(struct drm_i915_private *dev_priv,
-				  struct intel_shared_dpll *pll)
-{
-	I915_WRITE(PCH_FP0(pll->id), pll->config.hw_state.fp0);
-	I915_WRITE(PCH_FP1(pll->id), pll->config.hw_state.fp1);
-}
-
-static void ibx_pch_dpll_enable(struct drm_i915_private *dev_priv,
-				struct intel_shared_dpll *pll)
-{
-	/* PCH refclock must be enabled first */
-	ibx_assert_pch_refclk_enabled(dev_priv);
-
-	I915_WRITE(PCH_DPLL(pll->id), pll->config.hw_state.dpll);
-
-	/* Wait for the clocks to stabilize. */
-	POSTING_READ(PCH_DPLL(pll->id));
-	udelay(150);
-
-	/* The pixel multiplier can only be updated once the
-	 * DPLL is enabled and the clocks are stable.
-	 *
-	 * So write it again.
-	 */
-	I915_WRITE(PCH_DPLL(pll->id), pll->config.hw_state.dpll);
-	POSTING_READ(PCH_DPLL(pll->id));
-	udelay(200);
-}
-
-static void ibx_pch_dpll_disable(struct drm_i915_private *dev_priv,
-				 struct intel_shared_dpll *pll)
-{
-	struct drm_device *dev = dev_priv->dev;
-	struct intel_crtc *crtc;
-
-	/* Make sure no transcoder isn't still depending on us. */
-	for_each_intel_crtc(dev, crtc) {
-		if (intel_crtc_to_shared_dpll(crtc) == pll)
-			assert_pch_transcoder_disabled(dev_priv, crtc->pipe);
-	}
-
-	I915_WRITE(PCH_DPLL(pll->id), 0);
-	POSTING_READ(PCH_DPLL(pll->id));
-	udelay(200);
-}
-
-static char *ibx_pch_dpll_names[] = {
-	"PCH DPLL A",
-	"PCH DPLL B",
-};
-
-static void ibx_pch_dpll_init(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	int i;
-
-	dev_priv->num_shared_dpll = 2;
-
-	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
-		dev_priv->shared_dplls[i].id = i;
-		dev_priv->shared_dplls[i].name = ibx_pch_dpll_names[i];
-		dev_priv->shared_dplls[i].mode_set = ibx_pch_dpll_mode_set;
-		dev_priv->shared_dplls[i].enable = ibx_pch_dpll_enable;
-		dev_priv->shared_dplls[i].disable = ibx_pch_dpll_disable;
-		dev_priv->shared_dplls[i].get_hw_state =
-			ibx_pch_dpll_get_hw_state;
-	}
-}
-
-static void intel_shared_dpll_init(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	if (HAS_DDI(dev))
-		intel_ddi_pll_init(dev);
-	else if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
-		ibx_pch_dpll_init(dev);
-	else
-		dev_priv->num_shared_dpll = 0;
-
-	BUG_ON(dev_priv->num_shared_dpll > I915_NUM_PLLS);
-}
-
 /**
  * intel_prepare_plane_fb - Prepare fb for usage on plane
  * @plane: drm plane to prepare for
diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
new file mode 100644
index 000000000000..d7ebac6619a3
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -0,0 +1,368 @@
+/*
+ * Copyright © 2006-2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "intel_drv.h"
+
+struct intel_shared_dpll *
+intel_crtc_to_shared_dpll(struct intel_crtc *crtc)
+{
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+
+	if (crtc->config->shared_dpll < 0)
+		return NULL;
+
+	return &dev_priv->shared_dplls[crtc->config->shared_dpll];
+}
+
+/* For ILK+ */
+void assert_shared_dpll(struct drm_i915_private *dev_priv,
+			struct intel_shared_dpll *pll,
+			bool state)
+{
+	bool cur_state;
+	struct intel_dpll_hw_state hw_state;
+
+	if (WARN(!pll, "asserting DPLL %s with no DPLL\n", onoff(state)))
+		return;
+
+	cur_state = pll->get_hw_state(dev_priv, pll, &hw_state);
+	I915_STATE_WARN(cur_state != state,
+	     "%s assertion failure (expected %s, current %s)\n",
+			pll->name, onoff(state), onoff(cur_state));
+}
+
+void intel_prepare_shared_dpll(struct intel_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
+
+	if (WARN_ON(pll == NULL))
+		return;
+
+	WARN_ON(!pll->config.crtc_mask);
+	if (pll->active == 0) {
+		DRM_DEBUG_DRIVER("setting up %s\n", pll->name);
+		WARN_ON(pll->on);
+		assert_shared_dpll_disabled(dev_priv, pll);
+
+		pll->mode_set(dev_priv, pll);
+	}
+}
+
+/**
+ * intel_enable_shared_dpll - enable PCH PLL
+ * @dev_priv: i915 private structure
+ * @pipe: pipe PLL to enable
+ *
+ * The PCH PLL needs to be enabled before the PCH transcoder, since it
+ * drives the transcoder clock.
+ */
+void intel_enable_shared_dpll(struct intel_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
+
+	if (WARN_ON(pll == NULL))
+		return;
+
+	if (WARN_ON(pll->config.crtc_mask == 0))
+		return;
+
+	DRM_DEBUG_KMS("enable %s (active %d, on? %d) for crtc %d\n",
+		      pll->name, pll->active, pll->on,
+		      crtc->base.base.id);
+
+	if (pll->active++) {
+		WARN_ON(!pll->on);
+		assert_shared_dpll_enabled(dev_priv, pll);
+		return;
+	}
+	WARN_ON(pll->on);
+
+	intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
+
+	DRM_DEBUG_KMS("enabling %s\n", pll->name);
+	pll->enable(dev_priv, pll);
+	pll->on = true;
+}
+
+void intel_disable_shared_dpll(struct intel_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
+
+	/* PCH only available on ILK+ */
+	if (INTEL_INFO(dev)->gen < 5)
+		return;
+
+	if (pll == NULL)
+		return;
+
+	if (WARN_ON(!(pll->config.crtc_mask & (1 << drm_crtc_index(&crtc->base)))))
+		return;
+
+	DRM_DEBUG_KMS("disable %s (active %d, on? %d) for crtc %d\n",
+		      pll->name, pll->active, pll->on,
+		      crtc->base.base.id);
+
+	if (WARN_ON(pll->active == 0)) {
+		assert_shared_dpll_disabled(dev_priv, pll);
+		return;
+	}
+
+	assert_shared_dpll_enabled(dev_priv, pll);
+	WARN_ON(!pll->on);
+	if (--pll->active)
+		return;
+
+	DRM_DEBUG_KMS("disabling %s\n", pll->name);
+	pll->disable(dev_priv, pll);
+	pll->on = false;
+
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+}
+
+struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc,
+						struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct intel_shared_dpll *pll;
+	struct intel_shared_dpll_config *shared_dpll;
+	enum intel_dpll_id i;
+	int max = dev_priv->num_shared_dpll;
+
+	shared_dpll = intel_atomic_get_shared_dpll_state(crtc_state->base.state);
+
+	if (HAS_PCH_IBX(dev_priv->dev)) {
+		/* Ironlake PCH has a fixed PLL->PCH pipe mapping. */
+		i = (enum intel_dpll_id) crtc->pipe;
+		pll = &dev_priv->shared_dplls[i];
+
+		DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
+			      crtc->base.base.id, pll->name);
+
+		WARN_ON(shared_dpll[i].crtc_mask);
+
+		goto found;
+	}
+
+	if (IS_BROXTON(dev_priv->dev)) {
+		/* PLL is attached to port in bxt */
+		struct intel_encoder *encoder;
+		struct intel_digital_port *intel_dig_port;
+
+		encoder = intel_ddi_get_crtc_new_encoder(crtc_state);
+		if (WARN_ON(!encoder))
+			return NULL;
+
+		intel_dig_port = enc_to_dig_port(&encoder->base);
+		/* 1:1 mapping between ports and PLLs */
+		i = (enum intel_dpll_id)intel_dig_port->port;
+		pll = &dev_priv->shared_dplls[i];
+		DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
+			crtc->base.base.id, pll->name);
+		WARN_ON(shared_dpll[i].crtc_mask);
+
+		goto found;
+	} else if (INTEL_INFO(dev_priv)->gen < 9 && HAS_DDI(dev_priv))
+		/* Do not consider SPLL */
+		max = 2;
+
+	for (i = 0; i < max; i++) {
+		pll = &dev_priv->shared_dplls[i];
+
+		/* Only want to check enabled timings first */
+		if (shared_dpll[i].crtc_mask == 0)
+			continue;
+
+		if (memcmp(&crtc_state->dpll_hw_state,
+			   &shared_dpll[i].hw_state,
+			   sizeof(crtc_state->dpll_hw_state)) == 0) {
+			DRM_DEBUG_KMS("CRTC:%d sharing existing %s (crtc mask 0x%08x, ative %d)\n",
+				      crtc->base.base.id, pll->name,
+				      shared_dpll[i].crtc_mask,
+				      pll->active);
+			goto found;
+		}
+	}
+
+	/* Ok no matching timings, maybe there's a free one? */
+	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
+		pll = &dev_priv->shared_dplls[i];
+		if (shared_dpll[i].crtc_mask == 0) {
+			DRM_DEBUG_KMS("CRTC:%d allocated %s\n",
+				      crtc->base.base.id, pll->name);
+			goto found;
+		}
+	}
+
+	return NULL;
+
+found:
+	if (shared_dpll[i].crtc_mask == 0)
+		shared_dpll[i].hw_state =
+			crtc_state->dpll_hw_state;
+
+	crtc_state->shared_dpll = i;
+	DRM_DEBUG_DRIVER("using %s for pipe %c\n", pll->name,
+			 pipe_name(crtc->pipe));
+
+	shared_dpll[i].crtc_mask |= 1 << crtc->pipe;
+
+	return pll;
+}
+
+void intel_shared_dpll_commit(struct drm_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->dev);
+	struct intel_shared_dpll_config *shared_dpll;
+	struct intel_shared_dpll *pll;
+	enum intel_dpll_id i;
+
+	if (!to_intel_atomic_state(state)->dpll_set)
+		return;
+
+	shared_dpll = to_intel_atomic_state(state)->shared_dpll;
+	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
+		pll = &dev_priv->shared_dplls[i];
+		pll->config = shared_dpll[i];
+	}
+}
+
+static bool ibx_pch_dpll_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_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
+		return false;
+
+	val = I915_READ(PCH_DPLL(pll->id));
+	hw_state->dpll = val;
+	hw_state->fp0 = I915_READ(PCH_FP0(pll->id));
+	hw_state->fp1 = I915_READ(PCH_FP1(pll->id));
+
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
+	return val & DPLL_VCO_ENABLE;
+}
+
+static void ibx_pch_dpll_mode_set(struct drm_i915_private *dev_priv,
+				  struct intel_shared_dpll *pll)
+{
+	I915_WRITE(PCH_FP0(pll->id), pll->config.hw_state.fp0);
+	I915_WRITE(PCH_FP1(pll->id), pll->config.hw_state.fp1);
+}
+
+static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
+{
+	u32 val;
+	bool enabled;
+
+	I915_STATE_WARN_ON(!(HAS_PCH_IBX(dev_priv->dev) || HAS_PCH_CPT(dev_priv->dev)));
+
+	val = I915_READ(PCH_DREF_CONTROL);
+	enabled = !!(val & (DREF_SSC_SOURCE_MASK | DREF_NONSPREAD_SOURCE_MASK |
+			    DREF_SUPERSPREAD_SOURCE_MASK));
+	I915_STATE_WARN(!enabled, "PCH refclk assertion failure, should be active but is disabled\n");
+}
+
+static void ibx_pch_dpll_enable(struct drm_i915_private *dev_priv,
+				struct intel_shared_dpll *pll)
+{
+	/* PCH refclock must be enabled first */
+	ibx_assert_pch_refclk_enabled(dev_priv);
+
+	I915_WRITE(PCH_DPLL(pll->id), pll->config.hw_state.dpll);
+
+	/* Wait for the clocks to stabilize. */
+	POSTING_READ(PCH_DPLL(pll->id));
+	udelay(150);
+
+	/* The pixel multiplier can only be updated once the
+	 * DPLL is enabled and the clocks are stable.
+	 *
+	 * So write it again.
+	 */
+	I915_WRITE(PCH_DPLL(pll->id), pll->config.hw_state.dpll);
+	POSTING_READ(PCH_DPLL(pll->id));
+	udelay(200);
+}
+
+static void ibx_pch_dpll_disable(struct drm_i915_private *dev_priv,
+				 struct intel_shared_dpll *pll)
+{
+	struct drm_device *dev = dev_priv->dev;
+	struct intel_crtc *crtc;
+
+	/* Make sure no transcoder isn't still depending on us. */
+	for_each_intel_crtc(dev, crtc) {
+		if (intel_crtc_to_shared_dpll(crtc) == pll)
+			assert_pch_transcoder_disabled(dev_priv, crtc->pipe);
+	}
+
+	I915_WRITE(PCH_DPLL(pll->id), 0);
+	POSTING_READ(PCH_DPLL(pll->id));
+	udelay(200);
+}
+
+static char *ibx_pch_dpll_names[] = {
+	"PCH DPLL A",
+	"PCH DPLL B",
+};
+
+static void ibx_pch_dpll_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	dev_priv->num_shared_dpll = 2;
+
+	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
+		dev_priv->shared_dplls[i].id = i;
+		dev_priv->shared_dplls[i].name = ibx_pch_dpll_names[i];
+		dev_priv->shared_dplls[i].mode_set = ibx_pch_dpll_mode_set;
+		dev_priv->shared_dplls[i].enable = ibx_pch_dpll_enable;
+		dev_priv->shared_dplls[i].disable = ibx_pch_dpll_disable;
+		dev_priv->shared_dplls[i].get_hw_state =
+			ibx_pch_dpll_get_hw_state;
+	}
+}
+
+void intel_shared_dpll_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (HAS_DDI(dev))
+		intel_ddi_pll_init(dev);
+	else if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
+		ibx_pch_dpll_init(dev);
+	else
+		dev_priv->num_shared_dpll = 0;
+
+	BUG_ON(dev_priv->num_shared_dpll > I915_NUM_PLLS);
+}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 7b2d66d8dd7f..63b36b56c913 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1201,6 +1201,9 @@ intel_rotation_90_or_270(unsigned int rotation)
 void intel_create_rotation_property(struct drm_device *dev,
 					struct intel_plane *plane);
 
+void assert_pch_transcoder_disabled(struct drm_i915_private *dev_priv,
+				    enum pipe pipe);
+
 /* shared dpll functions */
 struct intel_shared_dpll *intel_crtc_to_shared_dpll(struct intel_crtc *crtc);
 void assert_shared_dpll(struct drm_i915_private *dev_priv,
@@ -1210,6 +1213,11 @@ void assert_shared_dpll(struct drm_i915_private *dev_priv,
 #define assert_shared_dpll_disabled(d, p) assert_shared_dpll(d, p, false)
 struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc,
 						struct intel_crtc_state *state);
+void intel_prepare_shared_dpll(struct intel_crtc *crtc);
+void intel_enable_shared_dpll(struct intel_crtc *crtc);
+void intel_disable_shared_dpll(struct intel_crtc *crtc);
+void intel_shared_dpll_commit(struct drm_atomic_state *state);
+void intel_shared_dpll_init(struct drm_device *dev);
 
 int vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
 		     const struct dpll *dpll);