drm/i915: switch crtc->shared_dpll from a pointer to an enum

Dealing with discrete enum values is simpler for hw state readout and
pipe config computations than pointers - having neat names instead of
chasing pointers should look better in the code.

This isn't a that good reason for pch plls, but on haswell we actually
have 3 different types of plls: WRPLL, SPLL and the DP clocks. Having
explicit names should help there.

Since this also adds the intel_crtc_to_shared_dpll helper to further
abstract away the crtc -> dpll relationship this will also help to
make the next patch simpler, which moves the shared dpll into the pipe
configuration.

Also note that for uniformity we have two special dpll ids: NONE for
pipes which need a shared pll but don't have one (yet) and private for
when there's a non-shared pll (e.g. per-pipe or per-port pll).

I've thought whether we should also add a 2nd enum for the type of the
pll we want (for really generic pll selection code) but thrown that
idea out again - likely there's too much platform craziness going on
to be able to share the pll selection logic much.

Since this touched all the shared_pll functions a bit I've also done
an s/intel_crtc/crtc/ replacement on a few of them.

v2: Kill DPLL_ID_NONE. It's probably better to call it DPLL_ID_INVALID and use
it to check that the compute config stage assigns a dpll to every pipe.
But since that code isn't ready yet until we move the dpll selection out
of the ->mode_set callback, there's no use for it.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -140,6 +140,13 @@ struct intel_shared_dpll {
 	int fp0_reg;
 	int fp1_reg;
 };
+
+enum intel_dpll_id {
+	DPLL_ID_PRIVATE = -1, /* non-shared dpll in use */
+	/* real shared dpll ids must be >= 0 */
+	DPLL_ID_PCH_PLL_A,
+	DPLL_ID_PCH_PLL_B,
+};
 #define I915_NUM_PLLS 2
 
 /* Used by dp and fdi links */

drivers/gpu/drm/i915/intel_display.c

@@ -909,6 +909,17 @@ static void assert_pll(struct drm_i915_private *dev_priv,
 #define assert_pll_enabled(d, p) assert_pll(d, p, true)
 #define assert_pll_disabled(d, p) assert_pll(d, p, false)
 
+static 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->shared_dpll < 0)
+		return NULL;
+
+	return &dev_priv->shared_dplls[crtc->shared_dpll];
+}
+
 /* For ILK+ */
 static void assert_shared_dpll(struct drm_i915_private *dev_priv,
 			       struct intel_shared_dpll *pll,
@@ -1404,16 +1415,15 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv, int port)
  * The PCH PLL needs to be enabled before the PCH transcoder, since it
  * drives the transcoder clock.
  */
-static void ironlake_enable_shared_dpll(struct intel_crtc *intel_crtc)
+static void ironlake_enable_shared_dpll(struct intel_crtc *crtc)
 {
-	struct drm_i915_private *dev_priv = intel_crtc->base.dev->dev_private;
-	struct intel_shared_dpll *pll;
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
 	int reg;
 	u32 val;
 
 	/* PCH PLLs only available on ILK, SNB and IVB */
 	BUG_ON(dev_priv->info->gen < 5);
-	pll = intel_crtc->shared_dpll;
 	if (pll == NULL)
 		return;
 
@@ -1422,7 +1432,7 @@ static void ironlake_enable_shared_dpll(struct intel_crtc *intel_crtc)
 
 	DRM_DEBUG_KMS("enable PCH PLL %x (active %d, on? %d)for crtc %d\n",
 		      pll->pll_reg, pll->active, pll->on,
-		      intel_crtc->base.base.id);
+		      crtc->base.base.id);
 
 	/* PCH refclock must be enabled first */
 	assert_pch_refclk_enabled(dev_priv);
@@ -1446,10 +1456,10 @@ static void ironlake_enable_shared_dpll(struct intel_crtc *intel_crtc)
 	pll->on = true;
 }
 
-static void intel_disable_shared_dpll(struct intel_crtc *intel_crtc)
+static void intel_disable_shared_dpll(struct intel_crtc *crtc)
 {
-	struct drm_i915_private *dev_priv = intel_crtc->base.dev->dev_private;
-	struct intel_shared_dpll *pll = intel_crtc->shared_dpll;
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
 	int reg;
 	u32 val;
 
@@ -1463,7 +1473,7 @@ static void intel_disable_shared_dpll(struct intel_crtc *intel_crtc)
 
 	DRM_DEBUG_KMS("disable PCH PLL %x (active %d, on? %d) for crtc %d\n",
 		      pll->pll_reg, pll->active, pll->on,
-		      intel_crtc->base.base.id);
+		      crtc->base.base.id);
 
 	if (WARN_ON(pll->active == 0)) {
 		assert_shared_dpll_disabled(dev_priv, pll, NULL);
@@ -1478,7 +1488,7 @@ static void intel_disable_shared_dpll(struct intel_crtc *intel_crtc)
 	DRM_DEBUG_KMS("disabling PCH PLL %x\n", pll->pll_reg);
 
 	/* Make sure transcoder isn't still depending on us */
-	assert_pch_transcoder_disabled(dev_priv, intel_crtc->pipe);
+	assert_pch_transcoder_disabled(dev_priv, crtc->pipe);
 
 	reg = pll->pll_reg;
 	val = I915_READ(reg);
@@ -1495,6 +1505,7 @@ static void ironlake_enable_pch_transcoder(struct drm_i915_private *dev_priv,
 {
 	struct drm_device *dev = dev_priv->dev;
 	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	uint32_t reg, val, pipeconf_val;
 
 	/* PCH only available on ILK+ */
@@ -1502,8 +1513,8 @@ static void ironlake_enable_pch_transcoder(struct drm_i915_private *dev_priv,
 
 	/* Make sure PCH DPLL is enabled */
 	assert_shared_dpll_enabled(dev_priv,
-				   to_intel_crtc(crtc)->shared_dpll,
-				   to_intel_crtc(crtc));
+				   intel_crtc_to_shared_dpll(intel_crtc),
+				   intel_crtc);
 
 	/* FDI must be feeding us bits for PCH ports */
 	assert_fdi_tx_enabled(dev_priv, pipe);
@@ -2990,7 +3001,7 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
 			sel = TRANSC_DPLLB_SEL;
 			break;
 		}
-		if (intel_crtc->shared_dpll->pll_reg == _PCH_DPLL_B)
+		if (intel_crtc->shared_dpll == DPLL_ID_PCH_PLL_B)
 			temp |= sel;
 		else
 			temp &= ~sel;
@@ -3059,9 +3070,9 @@ static void lpt_pch_enable(struct drm_crtc *crtc)
 	lpt_enable_pch_transcoder(dev_priv, cpu_transcoder);
 }
 
-static void intel_put_shared_dpll(struct intel_crtc *intel_crtc)
+static void intel_put_shared_dpll(struct intel_crtc *crtc)
 {
-	struct intel_shared_dpll *pll = intel_crtc->shared_dpll;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
 
 	if (pll == NULL)
 		return;
@@ -3076,29 +3087,28 @@ static void intel_put_shared_dpll(struct intel_crtc *intel_crtc)
 		WARN_ON(pll->active);
 	}
 
-	intel_crtc->shared_dpll = NULL;
+	crtc->shared_dpll = DPLL_ID_PRIVATE;
 }
 
-static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *intel_crtc, u32 dpll, u32 fp)
+static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc, u32 dpll, u32 fp)
 {
-	struct drm_i915_private *dev_priv = intel_crtc->base.dev->dev_private;
-	struct intel_shared_dpll *pll;
-	int i;
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct intel_shared_dpll *pll = intel_crtc_to_shared_dpll(crtc);
+	enum intel_dpll_id i;
 
-	pll = intel_crtc->shared_dpll;
 	if (pll) {
 		DRM_DEBUG_KMS("CRTC:%d dropping existing PCH PLL %x\n",
-			      intel_crtc->base.base.id, pll->pll_reg);
-		intel_put_shared_dpll(intel_crtc);
+			      crtc->base.base.id, pll->pll_reg);
+		intel_put_shared_dpll(crtc);
 	}
 
 	if (HAS_PCH_IBX(dev_priv->dev)) {
 		/* Ironlake PCH has a fixed PLL->PCH pipe mapping. */
-		i = intel_crtc->pipe;
+		i = crtc->pipe;
 		pll = &dev_priv->shared_dplls[i];
 
 		DRM_DEBUG_KMS("CRTC:%d using pre-allocated PCH PLL %x\n",
-			      intel_crtc->base.base.id, pll->pll_reg);
+			      crtc->base.base.id, pll->pll_reg);
 
 		goto found;
 	}
@@ -3113,7 +3123,7 @@ static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *intel_
 		if (dpll == (I915_READ(pll->pll_reg) & 0x7fffffff) &&
 		    fp == I915_READ(pll->fp0_reg)) {
 			DRM_DEBUG_KMS("CRTC:%d sharing existing PCH PLL %x (refcount %d, ative %d)\n",
-				      intel_crtc->base.base.id,
+				      crtc->base.base.id,
 				      pll->pll_reg, pll->refcount, pll->active);
 
 			goto found;
@@ -3125,7 +3135,7 @@ static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *intel_
 		pll = &dev_priv->shared_dplls[i];
 		if (pll->refcount == 0) {
 			DRM_DEBUG_KMS("CRTC:%d allocated PCH PLL %x\n",
-				      intel_crtc->base.base.id, pll->pll_reg);
+				      crtc->base.base.id, pll->pll_reg);
 			goto found;
 		}
 	}
@@ -3133,8 +3143,8 @@ static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *intel_
 	return NULL;
 
 found:
-	intel_crtc->shared_dpll = pll;
-	DRM_DEBUG_DRIVER("using pll %d for pipe %c\n", i, pipe_name(intel_crtc->pipe));
+	crtc->shared_dpll = i;
+	DRM_DEBUG_DRIVER("using pll %d for pipe %c\n", i, pipe_name(crtc->pipe));
 	if (pll->active == 0) {
 		DRM_DEBUG_DRIVER("setting up pll %d\n", i);
 		WARN_ON(pll->on);
@@ -5730,6 +5740,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 	bool ok, has_reduced_clock = false;
 	bool is_lvds = false;
 	struct intel_encoder *encoder;
+	struct intel_shared_dpll *pll;
 	int ret;
 
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
@@ -5765,8 +5776,6 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 
 	/* CPU eDP is the only output that doesn't need a PCH PLL of its own. */
 	if (intel_crtc->config.has_pch_encoder) {
-		struct intel_shared_dpll *pll;
-
 		fp = i9xx_dpll_compute_fp(&intel_crtc->config.dpll);
 		if (has_reduced_clock)
 			fp2 = i9xx_dpll_compute_fp(&reduced_clock);
@@ -5791,11 +5800,15 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 		if (encoder->pre_pll_enable)
 			encoder->pre_pll_enable(encoder);
 
-	if (intel_crtc->shared_dpll) {
-		I915_WRITE(intel_crtc->shared_dpll->pll_reg, dpll);
+	intel_crtc->lowfreq_avail = false;
+
+	if (intel_crtc->config.has_pch_encoder) {
+		pll = intel_crtc_to_shared_dpll(intel_crtc);
+
+		I915_WRITE(pll->pll_reg, dpll);
 
 		/* Wait for the clocks to stabilize. */
-		POSTING_READ(intel_crtc->shared_dpll->pll_reg);
+		POSTING_READ(pll->pll_reg);
 		udelay(150);
 
 		/* The pixel multiplier can only be updated once the
@@ -5803,16 +5816,13 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 		 *
 		 * So write it again.
 		 */
-		I915_WRITE(intel_crtc->shared_dpll->pll_reg, dpll);
-	}
+		I915_WRITE(pll->pll_reg, dpll);
 
-	intel_crtc->lowfreq_avail = false;
-	if (intel_crtc->shared_dpll) {
 		if (is_lvds && has_reduced_clock && i915_powersave) {
-			I915_WRITE(intel_crtc->shared_dpll->fp1_reg, fp2);
+			I915_WRITE(pll->fp1_reg, fp2);
 			intel_crtc->lowfreq_avail = true;
 		} else {
-			I915_WRITE(intel_crtc->shared_dpll->fp1_reg, fp);
+			I915_WRITE(pll->fp1_reg, fp);
 		}
 	}
 

drivers/gpu/drm/i915/intel_drv.h

@@ -317,7 +317,7 @@ struct intel_crtc {
 	struct intel_crtc_config config;
 
 	/* We can share PLLs across outputs if the timings match */
-	struct intel_shared_dpll *shared_dpll;
+	enum intel_dpll_id shared_dpll;
 	uint32_t ddi_pll_sel;
 
 	/* reset counter value when the last flip was submitted */