#define  DISP_FBC_WM_DIS               (1<<15)
 #define DISP_ARB_CTL2  0x45004
 #define  DISP_DATA_PARTITION_5_6       (1<<6)
+#define DBUF_CTL       0x45008
+#define  DBUF_POWER_REQUEST            (1<<31)
+#define  DBUF_POWER_STATE              (1<<30)
 #define GEN7_MSG_CTL   0x45010
 #define  WAIT_FOR_PCH_RESET_ACK                (1<<1)
 #define  WAIT_FOR_PCH_FLR_ACK          (1<<0)
 #define   GEN6_PCODE_WRITE_D_COMP              0x11
 #define   GEN6_ENCODE_RC6_VID(mv)              (((mv) - 245) / 5)
 #define   GEN6_DECODE_RC6_VID(vids)            (((vids) * 5) + 245)
+#define   HSW_PCODE_DE_WRITE_FREQ_REQ          0x17
 #define   DISPLAY_IPS_CONTROL                  0x19
 #define          HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL  0x1A
 #define GEN6_PCODE_DATA                                0x138128
 #define  CDCLK_FREQ_675_617            (3<<26)
 #define  CDCLK_FREQ_DECIMAL_MASK       (0x7ff)
 
+#define  BXT_CDCLK_CD2X_DIV_SEL_MASK   (3<<22)
+#define  BXT_CDCLK_CD2X_DIV_SEL_1      (0<<22)
+#define  BXT_CDCLK_CD2X_DIV_SEL_1_5    (1<<22)
+#define  BXT_CDCLK_CD2X_DIV_SEL_2      (2<<22)
+#define  BXT_CDCLK_CD2X_DIV_SEL_4      (3<<22)
+#define  BXT_CDCLK_SSA_PRECHARGE_ENABLE        (1<<16)
+
 /* LCPLL_CTL */
 #define LCPLL1_CTL             0x46010
 #define LCPLL2_CTL             0x46014
 #define GET_CFG_CR1_REG(id) (DPLL1_CFGCR1 + (id - SKL_DPLL1) * 8)
 #define GET_CFG_CR2_REG(id) (DPLL1_CFGCR2 + (id - SKL_DPLL1) * 8)
 
+/* BXT display engine PLL */
+#define BXT_DE_PLL_CTL                 0x6d000
+#define   BXT_DE_PLL_RATIO(x)          (x)     /* {60,65,100} * 19.2MHz */
+#define   BXT_DE_PLL_RATIO_MASK                0xff
+
+#define BXT_DE_PLL_ENABLE              0x46070
+#define   BXT_DE_PLL_PLL_ENABLE                (1 << 31)
+#define   BXT_DE_PLL_LOCK              (1 << 30)
+
 /* Please see hsw_read_dcomp() and hsw_write_dcomp() before using this register,
  * since on HSW we can't write to it using I915_WRITE. */
 #define D_COMP_HSW                     (MCHBAR_MIRROR_BASE_SNB + 0x5F0C)
 
        intel_display_set_init_power(dev_priv, false);
 }
 
+void broxton_set_cdclk(struct drm_device *dev, int frequency)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       uint32_t divider;
+       uint32_t ratio;
+       uint32_t current_freq;
+       int ret;
+
+       /* frequency = 19.2MHz * ratio / 2 / div{1,1.5,2,4} */
+       switch (frequency) {
+       case 144000:
+               divider = BXT_CDCLK_CD2X_DIV_SEL_4;
+               ratio = BXT_DE_PLL_RATIO(60);
+               break;
+       case 288000:
+               divider = BXT_CDCLK_CD2X_DIV_SEL_2;
+               ratio = BXT_DE_PLL_RATIO(60);
+               break;
+       case 384000:
+               divider = BXT_CDCLK_CD2X_DIV_SEL_1_5;
+               ratio = BXT_DE_PLL_RATIO(60);
+               break;
+       case 576000:
+               divider = BXT_CDCLK_CD2X_DIV_SEL_1;
+               ratio = BXT_DE_PLL_RATIO(60);
+               break;
+       case 624000:
+               divider = BXT_CDCLK_CD2X_DIV_SEL_1;
+               ratio = BXT_DE_PLL_RATIO(65);
+               break;
+       case 19200:
+               /*
+                * Bypass frequency with DE PLL disabled. Init ratio, divider
+                * to suppress GCC warning.
+                */
+               ratio = 0;
+               divider = 0;
+               break;
+       default:
+               DRM_ERROR("unsupported CDCLK freq %d", frequency);
+
+               return;
+       }
+
+       mutex_lock(&dev_priv->rps.hw_lock);
+       /* Inform power controller of upcoming frequency change */
+       ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
+                                     0x80000000);
+       mutex_unlock(&dev_priv->rps.hw_lock);
+
+       if (ret) {
+               DRM_ERROR("PCode CDCLK freq change notify failed (err %d, freq %d)\n",
+                         ret, frequency);
+               return;
+       }
+
+       current_freq = I915_READ(CDCLK_CTL) & CDCLK_FREQ_DECIMAL_MASK;
+       /* convert from .1 fixpoint MHz with -1MHz offset to kHz */
+       current_freq = current_freq * 500 + 1000;
+
+       /*
+        * DE PLL has to be disabled when
+        * - setting to 19.2MHz (bypass, PLL isn't used)
+        * - before setting to 624MHz (PLL needs toggling)
+        * - before setting to any frequency from 624MHz (PLL needs toggling)
+        */
+       if (frequency == 19200 || frequency == 624000 ||
+           current_freq == 624000) {
+               I915_WRITE(BXT_DE_PLL_ENABLE, ~BXT_DE_PLL_PLL_ENABLE);
+               /* Timeout 200us */
+               if (wait_for(!(I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK),
+                            1))
+                       DRM_ERROR("timout waiting for DE PLL unlock\n");
+       }
+
+       if (frequency != 19200) {
+               uint32_t val;
+
+               val = I915_READ(BXT_DE_PLL_CTL);
+               val &= ~BXT_DE_PLL_RATIO_MASK;
+               val |= ratio;
+               I915_WRITE(BXT_DE_PLL_CTL, val);
+
+               I915_WRITE(BXT_DE_PLL_ENABLE, BXT_DE_PLL_PLL_ENABLE);
+               /* Timeout 200us */
+               if (wait_for(I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK, 1))
+                       DRM_ERROR("timeout waiting for DE PLL lock\n");
+
+               val = I915_READ(CDCLK_CTL);
+               val &= ~BXT_CDCLK_CD2X_DIV_SEL_MASK;
+               val |= divider;
+               /*
+                * Disable SSA Precharge when CD clock frequency < 500 MHz,
+                * enable otherwise.
+                */
+               val &= ~BXT_CDCLK_SSA_PRECHARGE_ENABLE;
+               if (frequency >= 500000)
+                       val |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;
+
+               val &= ~CDCLK_FREQ_DECIMAL_MASK;
+               /* convert from kHz to .1 fixpoint MHz with -1MHz offset */
+               val |= (frequency - 1000) / 500;
+               I915_WRITE(CDCLK_CTL, val);
+       }
+
+       mutex_lock(&dev_priv->rps.hw_lock);
+       ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
+                                     DIV_ROUND_UP(frequency, 25000));
+       mutex_unlock(&dev_priv->rps.hw_lock);
+
+       if (ret) {
+               DRM_ERROR("PCode CDCLK freq set failed, (err %d, freq %d)\n",
+                         ret, frequency);
+               return;
+       }
+
+       dev_priv->cdclk_freq = frequency;
+}
+
+void broxton_init_cdclk(struct drm_device *dev)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       uint32_t val;
+
+       /*
+        * NDE_RSTWRN_OPT RST PCH Handshake En must always be 0b on BXT
+        * or else the reset will hang because there is no PCH to respond.
+        * Move the handshake programming to initialization sequence.
+        * Previously was left up to BIOS.
+        */
+       val = I915_READ(HSW_NDE_RSTWRN_OPT);
+       val &= ~RESET_PCH_HANDSHAKE_ENABLE;
+       I915_WRITE(HSW_NDE_RSTWRN_OPT, val);
+
+       /* Enable PG1 for cdclk */
+       intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
+
+       /* check if cd clock is enabled */
+       if (I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_PLL_ENABLE) {
+               DRM_DEBUG_KMS("Display already initialized\n");
+               return;
+       }
+
+       /*
+        * FIXME:
+        * - The initial CDCLK needs to be read from VBT.
+        *   Need to make this change after VBT has changes for BXT.
+        * - check if setting the max (or any) cdclk freq is really necessary
+        *   here, it belongs to modeset time
+        */
+       broxton_set_cdclk(dev, 624000);
+
+       I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) | DBUF_POWER_REQUEST);
+       udelay(10);
+
+       if (!(I915_READ(DBUF_CTL) & DBUF_POWER_STATE))
+               DRM_ERROR("DBuf power enable timeout!\n");
+}
+
+void broxton_uninit_cdclk(struct drm_device *dev)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+
+       I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) & ~DBUF_POWER_REQUEST);
+       udelay(10);
+
+       if (I915_READ(DBUF_CTL) & DBUF_POWER_STATE)
+               DRM_ERROR("DBuf power disable timeout!\n");
+
+       /* Set minimum (bypass) frequency, in effect turning off the DE PLL */
+       broxton_set_cdclk(dev, 19200);
+
+       intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+}
+
 /* returns HPLL frequency in kHz */
 static int valleyview_get_vco(struct drm_i915_private *dev_priv)
 {
                return 200000;
 }
 
+static int broxton_calc_cdclk(struct drm_i915_private *dev_priv,
+                             int max_pixclk)
+{
+       /*
+        * FIXME:
+        * - remove the guardband, it's not needed on BXT
+        * - set 19.2MHz bypass frequency if there are no active pipes
+        */
+       if (max_pixclk > 576000*9/10)
+               return 624000;
+       else if (max_pixclk > 384000*9/10)
+               return 576000;
+       else if (max_pixclk > 288000*9/10)
+               return 384000;
+       else if (max_pixclk > 144000*9/10)
+               return 288000;
+       else
+               return 144000;
+}
+
 /* compute the max pixel clock for new configuration */
 static int intel_mode_max_pixclk(struct drm_atomic_state *state)
 {
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_crtc *intel_crtc;
        int max_pixclk = intel_mode_max_pixclk(state);
+       int cdclk;
 
        if (max_pixclk < 0)
                return max_pixclk;
 
-       if (valleyview_calc_cdclk(dev_priv, max_pixclk) ==
-           dev_priv->cdclk_freq)
+       if (IS_VALLEYVIEW(dev_priv))
+               cdclk = valleyview_calc_cdclk(dev_priv, max_pixclk);
+       else
+               cdclk = broxton_calc_cdclk(dev_priv, max_pixclk);
+
+       if (cdclk == dev_priv->cdclk_freq)
                return 0;
 
        /* disable/enable all currently active pipes while we change cdclk */
        intel_prepare_ddi(dev);
 }
 
+static void broxton_modeset_global_resources(struct drm_atomic_state *state)
+{
+       struct drm_device *dev = state->dev;
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       int max_pixclk = intel_mode_max_pixclk(state);
+       int req_cdclk;
+
+       /* see the comment in valleyview_modeset_global_resources */
+       if (WARN_ON(max_pixclk < 0))
+               return;
+
+       req_cdclk = broxton_calc_cdclk(dev_priv, max_pixclk);
+
+       if (req_cdclk != dev_priv->cdclk_freq)
+               broxton_set_cdclk(dev, req_cdclk);
+}
+
 static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
                                      struct intel_crtc_state *crtc_state)
 {
         * mode set on this crtc.  For other crtcs we need to use the
         * adjusted_mode bits in the crtc directly.
         */
-       if (IS_VALLEYVIEW(dev)) {
+       if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev)) {
                ret = valleyview_modeset_global_pipes(state, &prepare_pipes);
                if (ret)
                        goto done;
        } else if (IS_VALLEYVIEW(dev)) {
                dev_priv->display.modeset_global_resources =
                        valleyview_modeset_global_resources;
+       } else if (IS_BROXTON(dev)) {
+               dev_priv->display.modeset_global_resources =
+                       broxton_modeset_global_resources;
        }
 
        switch (INTEL_INFO(dev)->gen) {