drm/i915/bdw: Broadwell also has the "power down well"

Just like Haswell, but with the small twist that the panel fitter for pipe A is
now also in the always-on power well.

v2: Use the new HAS_POWER_WELL macro.

v3: Rebase on top of intel_using_power_well patches.

v4: This time actually update the PFIT check correctly so that the
pipe A pfit is in the always-on domain.

v5: Rebase on top of the VGA power domain addition.

v6: Rebase on top of the new power domain infrastructure. Also pimp the commit
message a bit while at it.

v7: Use IS_BROADWELL instead of IS_GEN8 (Ville).

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
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

@@ -117,6 +117,10 @@ enum intel_display_power_domain {
 #define HSW_ALWAYS_ON_POWER_DOMAINS (		\
 	BIT(POWER_DOMAIN_PIPE_A) |		\
 	BIT(POWER_DOMAIN_TRANSCODER_EDP))
+#define BDW_ALWAYS_ON_POWER_DOMAINS (		\
+	BIT(POWER_DOMAIN_PIPE_A) |		\
+	BIT(POWER_DOMAIN_TRANSCODER_EDP) |	\
+	BIT(POWER_DOMAIN_PIPE_A_PANEL_FITTER))
 
 enum hpd_pin {
 	HPD_NONE = 0,
@@ -1804,7 +1808,7 @@ struct drm_i915_file_private {
 #define HAS_IPS(dev)		(IS_ULT(dev))
 
 #define HAS_DDI(dev)		(INTEL_INFO(dev)->has_ddi)
-#define HAS_POWER_WELL(dev)	(IS_HASWELL(dev))
+#define HAS_POWER_WELL(dev)	(IS_HASWELL(dev) || IS_BROADWELL(dev))
 #define HAS_FPGA_DBG_UNCLAIMED(dev)	(INTEL_INFO(dev)->has_fpga_dbg)
 #define HAS_PSR(dev)		(IS_HASWELL(dev))
 

drivers/gpu/drm/i915/intel_pm.c

@@ -5520,7 +5520,9 @@ static bool is_always_on_power_domain(struct drm_device *dev,
 
 	BUG_ON(BIT(domain) & ~POWER_DOMAIN_MASK);
 
-	if (IS_HASWELL(dev)) {
+	if (IS_BROADWELL(dev)) {
+		always_on_domains = BDW_ALWAYS_ON_POWER_DOMAINS;
+	} else if (IS_HASWELL(dev)) {
 		always_on_domains = HSW_ALWAYS_ON_POWER_DOMAINS;
 	} else {
 		WARN_ON(1);
@@ -6006,4 +6008,3 @@ void intel_pm_init(struct drm_device *dev)
 	INIT_DELAYED_WORK(&dev_priv->rps.delayed_resume_work,
 			  intel_gen6_powersave_work);
 }
-