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>

6 files changed, 13 insertions, 40 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index a3b22bdacd44..8aab974b0564 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2734,6 +2734,8 @@ static const char *power_domain_str(enum intel_display_power_domain domain)
                 return "AUX_C";
         case POWER_DOMAIN_AUX_D:
                 return "AUX_D";
+        case POWER_DOMAIN_GMBUS:
+                return "GMBUS";
         case POWER_DOMAIN_INIT:
                 return "INIT";
         default:
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 95bb27de774f..a01e51581c4c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -199,6 +199,7 @@ enum intel_display_power_domain {
         POWER_DOMAIN_AUX_B,
         POWER_DOMAIN_AUX_C,
         POWER_DOMAIN_AUX_D,
+        POWER_DOMAIN_GMBUS,
         POWER_DOMAIN_INIT,
 
         POWER_DOMAIN_NUM,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 449c28a85c9f..f2a1142bff34 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1379,8 +1379,6 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
                              enum intel_display_power_domain domain);
 void intel_display_power_put(struct drm_i915_private *dev_priv,
                              enum intel_display_power_domain domain);
-void intel_aux_display_runtime_get(struct drm_i915_private *dev_priv);
-void intel_aux_display_runtime_put(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_get(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 9eafa191cee2..0e5ce70aba76 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1335,21 +1335,17 @@ intel_hdmi_set_edid(struct drm_connector *connector, bool force)
 {
         struct drm_i915_private *dev_priv = to_i915(connector->dev);
         struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
-        struct intel_encoder *intel_encoder =
-                &hdmi_to_dig_port(intel_hdmi)->base;
-        enum intel_display_power_domain power_domain;
         struct edid *edid = NULL;
         bool connected = false;
 
-        power_domain = intel_display_port_power_domain(intel_encoder);
-        intel_display_power_get(dev_priv, power_domain);
+        intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
         if (force)
                 edid = drm_get_edid(connector,
                                     intel_gmbus_get_adapter(dev_priv,
                                     intel_hdmi->ddc_bus));
 
-        intel_display_power_put(dev_priv, power_domain);
+        intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
 
         to_intel_connector(connector)->detect_edid = edid;
         if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 1369fc41d039..8324654037b6 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -483,7 +483,7 @@ gmbus_xfer(struct i2c_adapter *adapter,
         int i = 0, inc, try = 0;
         int ret = 0;
 
-        intel_aux_display_runtime_get(dev_priv);
+        intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
         mutex_lock(&dev_priv->gmbus_mutex);
 
         if (bus->force_bit) {
@@ -595,7 +595,9 @@ timeout:
 
 out:
         mutex_unlock(&dev_priv->gmbus_mutex);
-        intel_aux_display_runtime_put(dev_priv);
+
+        intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
+
         return ret;
 }
 
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
  *