drm/i915/dp: use single point of truth for PPS divisor register

Set pp_div field of struct pps_registers to INVALID_MMIO_REG when the
register isn't there, and use i915_mmio_reg_valid() instead of repeating
the condition all over the place.

Use INVALID_MMIO_REG explicitly for documentation purposes, even if the
value is unchanged from 0.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190305135215.29862-2-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -949,8 +949,12 @@ static void intel_pps_get_registers(struct intel_dp *intel_dp,
 	regs->pp_stat = PP_STATUS(pps_idx);
 	regs->pp_on = PP_ON_DELAYS(pps_idx);
 	regs->pp_off = PP_OFF_DELAYS(pps_idx);
-	if (!IS_GEN9_LP(dev_priv) && !HAS_PCH_CNP(dev_priv) &&
-	    !HAS_PCH_ICP(dev_priv))
+
+	/* Cycle delay moved from PP_DIVISOR to PP_CONTROL */
+	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
+	    HAS_PCH_ICP(dev_priv))
+		regs->pp_div = INVALID_MMIO_REG;
+	else
 		regs->pp_div = PP_DIVISOR(pps_idx);
 }
 
@@ -6420,7 +6424,7 @@ static void
 intel_pps_readout_hw_state(struct intel_dp *intel_dp, struct edp_power_seq *seq)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	u32 pp_on, pp_off, pp_div = 0, pp_ctl = 0;
+	u32 pp_on, pp_off, pp_ctl;
 	struct pps_registers regs;
 
 	intel_pps_get_registers(intel_dp, &regs);
@@ -6433,10 +6437,6 @@ intel_pps_readout_hw_state(struct intel_dp *intel_dp, struct edp_power_seq *seq)
 
 	pp_on = I915_READ(regs.pp_on);
 	pp_off = I915_READ(regs.pp_off);
-	if (!IS_GEN9_LP(dev_priv) && !HAS_PCH_CNP(dev_priv) &&
-	    !HAS_PCH_ICP(dev_priv)) {
-		pp_div = I915_READ(regs.pp_div);
-	}
 
 	/* Pull timing values out of registers */
 	seq->t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
@@ -6451,13 +6451,17 @@ intel_pps_readout_hw_state(struct intel_dp *intel_dp, struct edp_power_seq *seq)
 	seq->t10 = (pp_off & PANEL_POWER_DOWN_DELAY_MASK) >>
 		   PANEL_POWER_DOWN_DELAY_SHIFT;
 
-	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
-	    HAS_PCH_ICP(dev_priv)) {
+	if (i915_mmio_reg_valid(regs.pp_div)) {
+		u32 pp_div;
+
+		pp_div = I915_READ(regs.pp_div);
+
+		seq->t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
+				PANEL_POWER_CYCLE_DELAY_SHIFT) * 1000;
+
+	} else {
 		seq->t11_t12 = ((pp_ctl & BXT_POWER_CYCLE_DELAY_MASK) >>
 				BXT_POWER_CYCLE_DELAY_SHIFT) * 1000;
-	} else {
-		seq->t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
-		       PANEL_POWER_CYCLE_DELAY_SHIFT) * 1000;
 	}
 }
 
@@ -6582,7 +6586,7 @@ intel_dp_init_panel_power_sequencer_registers(struct intel_dp *intel_dp,
 					      bool force_disable_vdd)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	u32 pp_on, pp_off, pp_div, port_sel = 0;
+	u32 pp_on, pp_off, port_sel = 0;
 	int div = dev_priv->rawclk_freq / 1000;
 	struct pps_registers regs;
 	enum port port = dp_to_dig_port(intel_dp)->base.port;
@@ -6621,19 +6625,6 @@ intel_dp_init_panel_power_sequencer_registers(struct intel_dp *intel_dp,
 		(seq->t8 << PANEL_LIGHT_ON_DELAY_SHIFT);
 	pp_off = (seq->t9 << PANEL_LIGHT_OFF_DELAY_SHIFT) |
 		 (seq->t10 << PANEL_POWER_DOWN_DELAY_SHIFT);
-	/* Compute the divisor for the pp clock, simply match the Bspec
-	 * formula. */
-	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
-	    HAS_PCH_ICP(dev_priv)) {
-		pp_div = I915_READ(regs.pp_ctrl);
-		pp_div &= ~BXT_POWER_CYCLE_DELAY_MASK;
-		pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000)
-				<< BXT_POWER_CYCLE_DELAY_SHIFT);
-	} else {
-		pp_div = ((100 * div)/2 - 1) << PP_REFERENCE_DIVIDER_SHIFT;
-		pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000)
-				<< PANEL_POWER_CYCLE_DELAY_SHIFT);
-	}
 
 	/* Haswell doesn't have any port selection bits for the panel
 	 * power sequencer any more. */
@@ -6660,19 +6651,33 @@ intel_dp_init_panel_power_sequencer_registers(struct intel_dp *intel_dp,
 
 	I915_WRITE(regs.pp_on, pp_on);
 	I915_WRITE(regs.pp_off, pp_off);
-	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
-	    HAS_PCH_ICP(dev_priv))
-		I915_WRITE(regs.pp_ctrl, pp_div);
-	else
+
+	/*
+	 * Compute the divisor for the pp clock, simply match the Bspec formula.
+	 */
+	if (i915_mmio_reg_valid(regs.pp_div)) {
+		u32 pp_div;
+
+		pp_div = ((100 * div) / 2 - 1) << PP_REFERENCE_DIVIDER_SHIFT;
+		pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000) <<
+			   PANEL_POWER_CYCLE_DELAY_SHIFT);
 		I915_WRITE(regs.pp_div, pp_div);
+	} else {
+		u32 pp_ctl;
+
+		pp_ctl = I915_READ(regs.pp_ctrl);
+		pp_ctl &= ~BXT_POWER_CYCLE_DELAY_MASK;
+		pp_ctl |= (DIV_ROUND_UP(seq->t11_t12, 1000) <<
+			   BXT_POWER_CYCLE_DELAY_SHIFT);
+		I915_WRITE(regs.pp_ctrl, pp_ctl);
+	}
 
 	DRM_DEBUG_KMS("panel power sequencer register settings: PP_ON %#x, PP_OFF %#x, PP_DIV %#x\n",
 		      I915_READ(regs.pp_on),
 		      I915_READ(regs.pp_off),
-		      (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv)  ||
-		       HAS_PCH_ICP(dev_priv)) ?
-		      (I915_READ(regs.pp_ctrl) & BXT_POWER_CYCLE_DELAY_MASK) :
-		      I915_READ(regs.pp_div));
+		      i915_mmio_reg_valid(regs.pp_div) ?
+		      I915_READ(regs.pp_div) :
+		      (I915_READ(regs.pp_ctrl) & BXT_POWER_CYCLE_DELAY_MASK));
 }
 
 static void intel_dp_pps_init(struct intel_dp *intel_dp)