drm/i915: detect digital outputs on Haswell
Digital port detection on Haswell is indicated by the presence of a bit in
DDI_BUF_CTL for port A, and by a different register for ports B, C and D.
So we check for those bits during the initialization time and let the hdmi
function know about those.
Note that this bit does not indicates whether the output is DP or HDMI.
However, the DDI buffers can be programmed in a way that is shared between
DP/HDMI and FDI/HDMI except for PORT E.
So for now, we detect those digital outputs as being HDMI, but proper DP
support is still pending.
Note that DDI A can only drive eDP, so we do not handle it here for hdmi
initialization.
v2: simplify Haswell handling logic
v3: use generic function for handling digital outputs.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index f44aae1..22bb0dd 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -220,3 +220,32 @@
DRM_DEBUG_KMS("FDI train done.\n");
}
+
+/* For DDI connections, it is possible to support different outputs over the
+ * same DDI port, such as HDMI or DP or even VGA via FDI. So we don't know by
+ * the time the output is detected what exactly is on the other end of it. This
+ * function aims at providing support for this detection and proper output
+ * configuration.
+ */
+void intel_ddi_init(struct drm_device *dev, enum port port)
+{
+ /* For now, we don't do any proper output detection and assume that we
+ * handle HDMI only */
+
+ switch(port){
+ case PORT_A:
+ /* We don't handle eDP and DP yet */
+ DRM_DEBUG_DRIVER("Found digital output on DDI port A\n");
+ break;
+ /* Assume that the ports B, C and D are working in HDMI mode for now */
+ case PORT_B:
+ case PORT_C:
+ case PORT_D:
+ intel_hdmi_init(dev, DDI_BUF_CTL(port));
+ break;
+ default:
+ DRM_DEBUG_DRIVER("No handlers defined for port %d, skipping DDI initialization\n",
+ port);
+ break;
+ }
+}