drm/i915/lvds: Use the GMBUS pin if specified in VBT

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 1317731bc8ed..95e035a6009e 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -771,7 +771,8 @@ static void intel_find_lvds_downclock(struct drm_device *dev,
  * If it is not present, return false.
  * If no child dev is parsed from VBT, it assumes that the LVDS is present.
  */
-static bool lvds_is_present_in_vbt(struct drm_device *dev)
+static bool lvds_is_present_in_vbt(struct drm_device *dev,
+                                   u8 *i2c_pin)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
         int i;
@@ -790,6 +791,9 @@ static bool lvds_is_present_in_vbt(struct drm_device *dev)
                     child->device_type != DEVICE_TYPE_LFP)
                         continue;
 
+                if (child->i2c_pin)
+                    *i2c_pin = child->i2c_pin;
+
                 /* However, we cannot trust the BIOS writers to populate
                  * the VBT correctly.  Since LVDS requires additional
                  * information from AIM blocks, a non-zero addin offset is
@@ -810,7 +814,7 @@ static bool lvds_is_present_in_vbt(struct drm_device *dev)
         return false;
 }
 
-static bool intel_lvds_ddc_probe(struct drm_device *dev)
+static bool intel_lvds_ddc_probe(struct drm_device *dev, u8 pin)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
         u8 buf = 0;
@@ -822,7 +826,7 @@ static bool intel_lvds_ddc_probe(struct drm_device *dev)
                         .buf = &buf,
                 },
         };
-        struct i2c_adapter *i2c = &dev_priv->gmbus[GMBUS_PORT_PANEL].adapter;
+        struct i2c_adapter *i2c = &dev_priv->gmbus[pin].adapter;
         return i2c_transfer(i2c, msgs, 1) == 1;
 }
 
@@ -844,13 +848,15 @@ void intel_lvds_init(struct drm_device *dev)
         struct drm_display_mode *scan; /* *modes, *bios_mode; */
         struct drm_crtc *crtc;
         u32 lvds;
-        int pipe, gpio = GPIOC;
+        int pipe;
+        u8 pin;
 
         /* Skip init on machines we know falsely report LVDS */
         if (dmi_check_system(intel_no_lvds))
                 return;
 
-        if (!lvds_is_present_in_vbt(dev)) {
+        pin = GMBUS_PORT_PANEL;
+        if (!lvds_is_present_in_vbt(dev, &pin)) {
                 DRM_DEBUG_KMS("LVDS is not present in VBT\n");
                 return;
         }
@@ -862,10 +868,9 @@ void intel_lvds_init(struct drm_device *dev)
                         DRM_DEBUG_KMS("disable LVDS for eDP support\n");
                         return;
                 }
-                gpio = PCH_GPIOC;
         }
 
-        if (!intel_lvds_ddc_probe(dev)) {
+        if (!intel_lvds_ddc_probe(dev, pin)) {
                 DRM_DEBUG_KMS("LVDS did not respond to DDC probe\n");
                 return;
         }
@@ -930,7 +935,7 @@ void intel_lvds_init(struct drm_device *dev)
          * preferred mode is the right one.
          */
         intel_lvds->edid = drm_get_edid(connector,
-                                        &dev_priv->gmbus[GMBUS_PORT_PANEL].adapter);
+                                        &dev_priv->gmbus[pin].adapter);
 
         if (!intel_lvds->edid) {
                 /* Didn't get an EDID, so