inteldrm diff that requires testing

[Mark Kettenis]

The diff below makes the HDMI output on Intel Bay Trail machines work.
Very useful for machines like the Lenovo Ideacentre Stick 300.  But
this needs to be tested on other hardware as well.  Especially on
machines with external displays.


Index: intel_i2c.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/drm/i915/intel_i2c.c,v
retrieving revision 1.7
diff -u -p -r1.7 intel_i2c.c
--- intel_i2c.c 26 Sep 2015 22:00:00 -0000      1.7
+++ intel_i2c.c 15 Apr 2016 14:58:13 -0000
@@ -144,6 +144,8 @@ intel_gmbus_acquire_bus(void *cookie, in
        struct intel_gmbus *bus = cookie;
        struct inteldrm_softc *dev_priv = bus->dev_priv;
 
+       intel_aux_display_runtime_get(dev_priv);
+
        I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, bus->reg0);
 
        return (0);
@@ -156,6 +158,8 @@ intel_gmbus_release_bus(void *cookie, in
        struct inteldrm_softc *dev_priv = bus->dev_priv;
 
        I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
+
+       intel_aux_display_runtime_put(dev_priv);
 }
 
 int
@@ -371,8 +375,12 @@ intel_setup_gmbus(struct drm_device *dev
        struct drm_i915_private *dev_priv = dev->dev_private;
        int i;
 
-       if (HAS_PCH_SPLIT(dev))
+       if (HAS_PCH_NOP(dev))
+               return 0;
+       else if (HAS_PCH_SPLIT(dev))
                dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
+       else if (IS_VALLEYVIEW(dev))
+               dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE;
        else
                dev_priv->gpio_mmio_base = 0;
 
@@ -399,6 +407,8 @@ intel_setup_gmbus(struct drm_device *dev
                bus->controller.ic_read_byte = intel_gpio_read_byte;
                bus->controller.ic_write_byte = intel_gpio_write_byte;
        }
+
+       intel_i2c_reset(dev_priv->dev);
 
        return (0);
 }