drm/i915: Introduce new intel_output_name()

That we can use for debugging purposes.

v2: Use designated initializers for the 'names' array (Paulo Zanoni,
    Jani Nikula).
    Add a check in case the array has a hole (which can now remain
    unnoticed with designated initializers) (Jani Nikula)

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (for v1)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -10262,6 +10262,28 @@ static bool has_edp_a(struct drm_device *dev)
 	return true;
 }
 
+const char *intel_output_name(int output)
+{
+	static const char *names[] = {
+		[INTEL_OUTPUT_UNUSED] = "Unused",
+		[INTEL_OUTPUT_ANALOG] = "Analog",
+		[INTEL_OUTPUT_DVO] = "DVO",
+		[INTEL_OUTPUT_SDVO] = "SDVO",
+		[INTEL_OUTPUT_LVDS] = "LVDS",
+		[INTEL_OUTPUT_TVOUT] = "TV",
+		[INTEL_OUTPUT_HDMI] = "HDMI",
+		[INTEL_OUTPUT_DISPLAYPORT] = "DisplayPort",
+		[INTEL_OUTPUT_EDP] = "eDP",
+		[INTEL_OUTPUT_DSI] = "DSI",
+		[INTEL_OUTPUT_UNKNOWN] = "Unknown",
+	};
+
+	if (output < 0 || output >= ARRAY_SIZE(names) || !names[output])
+		return "Invalid";
+
+	return names[output];
+}
+
 static void intel_setup_outputs(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;

drivers/gpu/drm/i915/intel_drv.h

@@ -625,6 +625,7 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 
 
 /* intel_display.c */
+const char *intel_output_name(int output);
 int intel_pch_rawclk(struct drm_device *dev);
 void intel_mark_busy(struct drm_device *dev);
 void intel_mark_fb_busy(struct drm_i915_gem_object *obj,