drm/i915: manage PCH PLLs separately from pipes

PCH PLLs aren't required for outputs on the CPU, so we shouldn't just
treat them as part of the pipe.

So split the code out and manage PCH PLLs separately, allocating them
when needed or trying to re-use existing PCH PLL setups when the timings
match.

v2: add num_pch_pll field to dev_priv (Daniel)
    don't NULL the pch_pll pointer in disable or DPMS will fail (Jesse)
    put register offsets in pll struct (Chris)

v3: Decouple enable/disable of PLLs from get/put.
v4: Track temporary PLL disabling during modeset
v5: Tidy PLL initialisation by only checking for num_pch_pll == 0 (Eugeni)
v6: Avoid mishandling allocation failure by embedding the small array of
    PLLs into the device struct

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44309
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> (up to v2)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v3+)
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -377,18 +377,23 @@ void intel_detect_pch(struct drm_device *dev)
 
 			if (id == INTEL_PCH_IBX_DEVICE_ID_TYPE) {
 				dev_priv->pch_type = PCH_IBX;
+				dev_priv->num_pch_pll = 2;
 				DRM_DEBUG_KMS("Found Ibex Peak PCH\n");
 			} else if (id == INTEL_PCH_CPT_DEVICE_ID_TYPE) {
 				dev_priv->pch_type = PCH_CPT;
+				dev_priv->num_pch_pll = 2;
 				DRM_DEBUG_KMS("Found CougarPoint PCH\n");
 			} else if (id == INTEL_PCH_PPT_DEVICE_ID_TYPE) {
 				/* PantherPoint is CPT compatible */
 				dev_priv->pch_type = PCH_CPT;
+				dev_priv->num_pch_pll = 2;
 				DRM_DEBUG_KMS("Found PatherPoint PCH\n");
 			} else if (id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
 				dev_priv->pch_type = PCH_LPT;
+				dev_priv->num_pch_pll = 0;
 				DRM_DEBUG_KMS("Found LynxPoint PCH\n");
 			}
+			BUG_ON(dev_priv->num_pch_pll > I915_NUM_PLLS);
 		}
 		pci_dev_put(pch);
 	}

drivers/gpu/drm/i915/i915_drv.h

@@ -78,6 +78,16 @@ enum port {
 
 #define for_each_pipe(p) for ((p) = 0; (p) < dev_priv->num_pipe; (p)++)
 
+struct intel_pch_pll {
+	int refcount; /* count of number of CRTCs sharing this PLL */
+	int active; /* count of number of active CRTCs (i.e. DPMS on) */
+	bool on; /* is the PLL actually active? Disabled during modeset */
+	int pll_reg;
+	int fp0_reg;
+	int fp1_reg;
+};
+#define I915_NUM_PLLS 2
+
 /* Interface history:
  *
  * 1.1: Original.
@@ -233,6 +243,7 @@ struct drm_i915_display_funcs {
 			     struct drm_display_mode *adjusted_mode,
 			     int x, int y,
 			     struct drm_framebuffer *old_fb);
+	void (*off)(struct drm_crtc *crtc);
 	void (*write_eld)(struct drm_connector *connector,
 			  struct drm_crtc *crtc);
 	void (*fdi_link_train)(struct drm_crtc *crtc);
@@ -391,6 +402,7 @@ typedef struct drm_i915_private {
 	unsigned int sr01, adpa, ppcr, dvob, dvoc, lvds;
 	int vblank_pipe;
 	int num_pipe;
+	int num_pch_pll;
 
 	/* For hangcheck timer */
 #define DRM_I915_HANGCHECK_PERIOD 1500 /* in ms */
@@ -753,6 +765,8 @@ typedef struct drm_i915_private {
 	wait_queue_head_t pending_flip_queue;
 	bool flip_pending_is_done;
 
+	struct intel_pch_pll pch_plls[I915_NUM_PLLS];
+
 	/* Reclocking support */
 	bool render_reclock_avail;
 	bool lvds_downclock_avail;

drivers/gpu/drm/i915/i915_reg.h

@@ -3402,15 +3402,15 @@
 
 #define _PCH_DPLL_A              0xc6014
 #define _PCH_DPLL_B              0xc6018
-#define PCH_DPLL(pipe) (pipe == 0 ?  _PCH_DPLL_A : _PCH_DPLL_B)
+#define _PCH_DPLL(pll) (pll == 0 ? _PCH_DPLL_A : _PCH_DPLL_B)
 
 #define _PCH_FPA0                0xc6040
 #define  FP_CB_TUNE		(0x3<<22)
 #define _PCH_FPA1                0xc6044
 #define _PCH_FPB0                0xc6048
 #define _PCH_FPB1                0xc604c
-#define PCH_FP0(pipe) (pipe == 0 ? _PCH_FPA0 : _PCH_FPB0)
-#define PCH_FP1(pipe) (pipe == 0 ? _PCH_FPA1 : _PCH_FPB1)
+#define _PCH_FP0(pll) (pll == 0 ? _PCH_FPA0 : _PCH_FPB0)
+#define _PCH_FP1(pll) (pll == 0 ? _PCH_FPA1 : _PCH_FPB1)
 
 #define PCH_DPLL_TEST           0xc606c
 

drivers/gpu/drm/i915/i915_suspend.c

@@ -40,7 +40,7 @@ static bool i915_pipe_enabled(struct drm_device *dev, enum pipe pipe)
 		return false;
 
 	if (HAS_PCH_SPLIT(dev))
-		dpll_reg = PCH_DPLL(pipe);
+		dpll_reg = _PCH_DPLL(pipe);
 	else
 		dpll_reg = (pipe == PIPE_A) ? _DPLL_A : _DPLL_B;