drm/i915: Give encoders useful names

Rather than let the core generate usless encoder names, let's pass in
something that actually identifies the piece of hardware we're dealing
with.

v2: Use 'DSI %c' instead of 'MIPI %c' for DSI encoders (Jani)
v3: Use port_name() in DSI code since we have it

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464371966-15190-7-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index 286baec..a456f2e 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -406,6 +406,18 @@
 	return mode;
 }
 
+static char intel_dvo_port_name(i915_reg_t dvo_reg)
+{
+	if (i915_mmio_reg_equal(dvo_reg, DVOA))
+		return 'A';
+	else if (i915_mmio_reg_equal(dvo_reg, DVOB))
+		return 'B';
+	else if (i915_mmio_reg_equal(dvo_reg, DVOC))
+		return 'C';
+	else
+		return '?';
+}
+
 void intel_dvo_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -428,8 +440,6 @@
 	intel_dvo->attached_connector = intel_connector;
 
 	intel_encoder = &intel_dvo->base;
-	drm_encoder_init(dev, &intel_encoder->base,
-			 &intel_dvo_enc_funcs, encoder_type, NULL);
 
 	intel_encoder->disable = intel_disable_dvo;
 	intel_encoder->enable = intel_enable_dvo;
@@ -496,6 +506,10 @@
 		if (!dvoinit)
 			continue;
 
+		drm_encoder_init(dev, &intel_encoder->base,
+				 &intel_dvo_enc_funcs, encoder_type,
+				 "DVO %c", intel_dvo_port_name(dvo->dvo_reg));
+
 		intel_encoder->type = INTEL_OUTPUT_DVO;
 		intel_encoder->crtc_mask = (1 << 0) | (1 << 1);
 		switch (dvo->type) {