drm/i915: Introduce a gmbus power domain

Currently the gmbus code uses intel_aux_display_runtime_get/put in an
effort to make sure the hardware is powered up sufficiently for gmbus.
That function only takes the runtime PM reference which on VLV/CHV/BXT
is not enough. We need the disp2d/pipe-a well on VLV/CHV and power well
2 on BXT. So add a new power domnain for gmbus and kill off the now
unused intel_aux_display_runtime_get/put. And change
intel_hdmi_set_edid() to use the gmbus power domain too since that's all
we need there.

Also toss in a BUILD_BUG_ON() to catch problems if we run out of
bits for power domains. We're already really close to the limit...

[Patrik: Add gmbus string to debugfs output]

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
[Cherry-picked from drm-intel-next-queued f0ab43e6 (Imre)]
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448643329-18675-3-git-send-email-imre.deak@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 4 insertions, 30 deletions

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index d89c1d0aa1b7..7e23d65c9b24 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -362,6 +362,7 @@ static void hsw_set_power_well(struct drm_i915_private *dev_priv,
 	BIT(POWER_DOMAIN_AUX_C) |			\
 	BIT(POWER_DOMAIN_AUDIO) |			\
 	BIT(POWER_DOMAIN_VGA) |				\
+	BIT(POWER_DOMAIN_GMBUS) |			\
 	BIT(POWER_DOMAIN_INIT))
 #define BXT_DISPLAY_POWERWELL_1_POWER_DOMAINS (		\
 	BXT_DISPLAY_POWERWELL_2_POWER_DOMAINS |		\
@@ -1483,6 +1484,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 	BIT(POWER_DOMAIN_AUX_B) |			\
 	BIT(POWER_DOMAIN_AUX_C) |			\
 	BIT(POWER_DOMAIN_AUX_D) |			\
+	BIT(POWER_DOMAIN_GMBUS) |			\
 	BIT(POWER_DOMAIN_INIT))
 #define HSW_DISPLAY_POWER_DOMAINS (				\
 	(POWER_DOMAIN_MASK & ~HSW_ALWAYS_ON_POWER_DOMAINS) |	\
@@ -1845,6 +1847,8 @@ int intel_power_domains_init(struct drm_i915_private *dev_priv)
 	i915.disable_power_well = sanitize_disable_power_well_option(dev_priv,
 						     i915.disable_power_well);
 
+	BUILD_BUG_ON(POWER_DOMAIN_NUM > 31);
+
 	mutex_init(&power_domains->lock);
 
 	/*
@@ -2064,36 +2068,6 @@ void intel_power_domains_init_hw(struct drm_i915_private *dev_priv)
 }
 
 /**
- * intel_aux_display_runtime_get - grab an auxiliary power domain reference
- * @dev_priv: i915 device instance
- *
- * This function grabs a power domain reference for the auxiliary power domain
- * (for access to the GMBUS and DP AUX blocks) and ensures that it and all its
- * parents are powered up. Therefore users should only grab a reference to the
- * innermost power domain they need.
- *
- * Any power domain reference obtained by this function must have a symmetric
- * call to intel_aux_display_runtime_put() to release the reference again.
- */
-void intel_aux_display_runtime_get(struct drm_i915_private *dev_priv)
-{
-	intel_runtime_pm_get(dev_priv);
-}
-
-/**
- * intel_aux_display_runtime_put - release an auxiliary power domain reference
- * @dev_priv: i915 device instance
- *
- * This function drops the auxiliary power domain reference obtained by
- * intel_aux_display_runtime_get() and might power down the corresponding
- * hardware block right away if this is the last reference.
- */
-void intel_aux_display_runtime_put(struct drm_i915_private *dev_priv)
-{
-	intel_runtime_pm_put(dev_priv);
-}
-
-/**
  * intel_runtime_pm_get - grab a runtime pm reference
  * @dev_priv: i915 device instance
  *