drm/i915: add PLL sharing support to handle 3 pipes

Add two new fields to the intel_crtc struct for 3 pipe support: no_pll
and use_pll_a.  The no_pll field is only set on the 3rd pipe to indicate
that it doesn't have a PLL of its own and so shouldn't try to write the
main PLL regs.  The use_pll_a field controls which PLL pipe 3 will
share, A or B.  The core code will try to share PLLs with whichever pipe
has the same timings, rejecting the mode set if none is found.  This
means that pipe 3 must always be set after one of the other pipes has
been configured with real PLL settings.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-By: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-By: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 63 insertions, 38 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 63f81416033e..c9bbf5e8fbe8 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2893,7 +2893,7 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         int pipe = intel_crtc->pipe;
-        u32 reg, temp;
+        u32 reg, temp, transc_sel;
 
         /* For PCH output, training FDI link */
         dev_priv->display.fdi_link_train(crtc);
@@ -2901,6 +2901,9 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
         intel_enable_pch_pll(dev_priv, pipe);
 
         if (HAS_PCH_CPT(dev)) {
+                transc_sel = intel_crtc->use_pll_a ? TRANSC_DPLLA_SEL :
+                        TRANSC_DPLLB_SEL;
+
                 /* Be sure PCH DPLL SEL is set */
                 temp = I915_READ(PCH_DPLL_SEL);
                 if (pipe == 0 && (temp & TRANSA_DPLL_ENABLE) == 0)
@@ -2908,7 +2911,7 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
                 else if (pipe == 1 && (temp & TRANSB_DPLL_ENABLE) == 0)
                         temp |= (TRANSB_DPLL_ENABLE | TRANSB_DPLLB_SEL);
                 else if (pipe == 2 && (temp & TRANSC_DPLL_ENABLE) == 0)
-                        temp |= (TRANSC_DPLL_ENABLE | TRANSC_DPLLB_SEL);
+                        temp |= (TRANSC_DPLL_ENABLE | transc_sel);
                 I915_WRITE(PCH_DPLL_SEL, temp);
         }
 
@@ -3080,8 +3083,8 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
                         temp &= ~(TRANSB_DPLL_ENABLE | TRANSB_DPLLB_SEL);
                         break;
                 case 2:
-                        /* FIXME: manage transcoder PLLs? */
-                        temp &= ~(TRANSC_DPLL_ENABLE | TRANSC_DPLLB_SEL);
+                        /* C shares PLL A or B */
+                        temp &= ~(TRANSC_DPLL_ENABLE | TRANSB_DPLLB_SEL);
                         break;
                 default:
                         BUG(); /* wtf */
@@ -3090,7 +3093,8 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
         }
 
         /* disable PCH DPLL */
-        intel_disable_pch_pll(dev_priv, pipe);
+        if (!intel_crtc->no_pll)
+                intel_disable_pch_pll(dev_priv, pipe);
 
         /* Switch from PCDclk to Rawclk */
         reg = FDI_RX_CTL(pipe);
@@ -5549,16 +5553,34 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
         drm_mode_debug_printmodeline(mode);
 
         /* PCH eDP needs FDI, but CPU eDP does not */
-        if (!has_edp_encoder || intel_encoder_is_pch_edp(&has_edp_encoder->base)) {
-                I915_WRITE(PCH_FP0(pipe), fp);
-                I915_WRITE(PCH_DPLL(pipe), dpll & ~DPLL_VCO_ENABLE);
-
-                POSTING_READ(PCH_DPLL(pipe));
-                udelay(150);
+        if (!intel_crtc->no_pll) {
+                if (!has_edp_encoder ||
+                    intel_encoder_is_pch_edp(&has_edp_encoder->base)) {
+                        I915_WRITE(PCH_FP0(pipe), fp);
+                        I915_WRITE(PCH_DPLL(pipe), dpll & ~DPLL_VCO_ENABLE);
+
+                        POSTING_READ(PCH_DPLL(pipe));
+                        udelay(150);
+                }
+        } else {
+                if (dpll == (I915_READ(PCH_DPLL(0)) & 0x7fffffff) &&
+                    fp == I915_READ(PCH_FP0(0))) {
+                        intel_crtc->use_pll_a = true;
+                        DRM_DEBUG_KMS("using pipe a dpll\n");
+                } else if (dpll == (I915_READ(PCH_DPLL(1)) & 0x7fffffff) &&
+                           fp == I915_READ(PCH_FP0(1))) {
+                        intel_crtc->use_pll_a = false;
+                        DRM_DEBUG_KMS("using pipe b dpll\n");
+                } else {
+                        DRM_DEBUG_KMS("no matching PLL configuration for pipe 2\n");
+                        return -EINVAL;
+                }
         }
 
         /* enable transcoder DPLL */
         if (HAS_PCH_CPT(dev)) {
+                u32 transc_sel = intel_crtc->use_pll_a ? TRANSC_DPLLA_SEL :
+                        TRANSC_DPLLB_SEL;
                 temp = I915_READ(PCH_DPLL_SEL);
                 switch (pipe) {
                 case 0:
@@ -5568,8 +5590,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
                         temp |= TRANSB_DPLL_ENABLE | TRANSB_DPLLB_SEL;
                         break;
                 case 2:
-                        /* FIXME: manage transcoder PLLs? */
-                        temp |= TRANSC_DPLL_ENABLE | TRANSC_DPLLB_SEL;
+                        temp |= TRANSC_DPLL_ENABLE | transc_sel;
                         break;
                 default:
                         BUG();
@@ -5587,17 +5608,13 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
         if (is_lvds) {
                 temp = I915_READ(PCH_LVDS);
                 temp |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
-                if (pipe == 1) {
-                        if (HAS_PCH_CPT(dev))
-                                temp |= PORT_TRANS_B_SEL_CPT;
-                        else
-                                temp |= LVDS_PIPEB_SELECT;
-                } else {
-                        if (HAS_PCH_CPT(dev))
-                                temp &= ~PORT_TRANS_SEL_MASK;
-                        else
-                                temp &= ~LVDS_PIPEB_SELECT;
-                }
+                if (HAS_PCH_CPT(dev))
+                        temp |= PORT_TRANS_SEL_CPT(pipe);
+                else if (pipe == 1)
+                        temp |= LVDS_PIPEB_SELECT;
+                else
+                        temp &= ~LVDS_PIPEB_SELECT;
+
                 /* set the corresponsding LVDS_BORDER bit */
                 temp |= dev_priv->lvds_border_bits;
                 /* Set the B0-B3 data pairs corresponding to whether we're going to
@@ -5647,8 +5664,9 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
                 I915_WRITE(TRANSDPLINK_N1(pipe), 0);
         }
 
-        if (!has_edp_encoder ||
-            intel_encoder_is_pch_edp(&has_edp_encoder->base)) {
+        if (!intel_crtc->no_pll &&
+            (!has_edp_encoder ||
+             intel_encoder_is_pch_edp(&has_edp_encoder->base))) {
                 I915_WRITE(PCH_DPLL(pipe), dpll);
 
                 /* Wait for the clocks to stabilize. */
@@ -5664,18 +5682,20 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
         }
 
         intel_crtc->lowfreq_avail = false;
-        if (is_lvds && has_reduced_clock && i915_powersave) {
-                I915_WRITE(PCH_FP1(pipe), fp2);
-                intel_crtc->lowfreq_avail = true;
-                if (HAS_PIPE_CXSR(dev)) {
-                        DRM_DEBUG_KMS("enabling CxSR downclocking\n");
-                        pipeconf |= PIPECONF_CXSR_DOWNCLOCK;
-                }
-        } else {
-                I915_WRITE(PCH_FP1(pipe), fp);
-                if (HAS_PIPE_CXSR(dev)) {
-                        DRM_DEBUG_KMS("disabling CxSR downclocking\n");
-                        pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
+        if (!intel_crtc->no_pll) {
+                if (is_lvds && has_reduced_clock && i915_powersave) {
+                        I915_WRITE(PCH_FP1(pipe), fp2);
+                        intel_crtc->lowfreq_avail = true;
+                        if (HAS_PIPE_CXSR(dev)) {
+                                DRM_DEBUG_KMS("enabling CxSR downclocking\n");
+                                pipeconf |= PIPECONF_CXSR_DOWNCLOCK;
+                        }
+                } else {
+                        I915_WRITE(PCH_FP1(pipe), fp);
+                        if (HAS_PIPE_CXSR(dev)) {
+                                DRM_DEBUG_KMS("disabling CxSR downclocking\n");
+                                pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
+                        }
                 }
         }
 
@@ -7291,6 +7311,8 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
         intel_crtc->bpp = 24; /* default for pre-Ironlake */
 
         if (HAS_PCH_SPLIT(dev)) {
+                if (pipe == 2 && IS_IVYBRIDGE(dev))
+                        intel_crtc->no_pll = true;
                 intel_helper_funcs.prepare = ironlake_crtc_prepare;
                 intel_helper_funcs.commit = ironlake_crtc_commit;
         } else {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 98044d626a8d..5829854ecbf6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -171,6 +171,9 @@ struct intel_crtc {
         int16_t cursor_width, cursor_height;
         bool cursor_visible;
         unsigned int bpp;
+
+        bool no_pll; /* tertiary pipe for IVB */
+        bool use_pll_a;
 };
 
 #define to_intel_crtc(x) container_of(x, struct intel_crtc, base)