MonitorManager: add EDID properties to the output DBus description

Add "edid-file", if we have one (in the KMS case, where we can point
people to the right sysfs file), or "edid" with inline data.
These are needed by colord to build the default ICC profile for
uncalibrated displays.

src/core/monitor-private.h

@@ -258,6 +258,12 @@ struct _MetaMonitorManagerClass
   MetaDBusDisplayConfigSkeletonClass parent_class;
 
   void (*read_current) (MetaMonitorManager *);
+
+  char* (*get_edid_file) (MetaMonitorManager *,
+                          MetaOutput         *);
+  GBytes* (*read_edid) (MetaMonitorManager *,
+                        MetaOutput         *);
+
   void (*apply_configuration) (MetaMonitorManager  *,
                                MetaCRTCInfo       **,
                                unsigned int         ,

src/core/monitor-xrandr.c

@@ -466,6 +466,75 @@ meta_monitor_manager_xrandr_read_current (MetaMonitorManager *manager)
     }
 }
 
+static guint8 *
+get_edid_property (Display  *dpy,
+                   RROutput  output,
+                   Atom      atom,
+                   gsize    *len)
+{
+  unsigned char *prop;
+  int actual_format;
+  unsigned long nitems, bytes_after;
+  Atom actual_type;
+  guint8 *result;
+
+  XRRGetOutputProperty (dpy, output, atom,
+                        0, 100, False, False,
+                        AnyPropertyType,
+                        &actual_type, &actual_format,
+                        &nitems, &bytes_after, &prop);
+
+  if (actual_type == XA_INTEGER && actual_format == 8)
+    {
+      result = g_memdup (prop, nitems);
+      if (len)
+        *len = nitems;
+    }
+  else
+    {
+      result = NULL;
+    }
+
+  XFree (prop);
+    
+  return result;
+}
+
+static GBytes *
+meta_monitor_manager_xrandr_read_edid (MetaMonitorManager *manager,
+                                       MetaOutput         *output)
+{
+  MetaMonitorManagerXrandr *manager_xrandr = META_MONITOR_MANAGER_XRANDR (manager);
+  Atom edid_atom;
+  guint8 *result;
+  gsize len;
+
+  edid_atom = XInternAtom (manager_xrandr->xdisplay, "EDID", FALSE);
+  result = get_edid_property (manager_xrandr->xdisplay, output->output_id, edid_atom, &len);
+
+  if (!result)
+    {
+      edid_atom = XInternAtom (manager_xrandr->xdisplay, "EDID_DATA", FALSE);
+      result = get_edid_property (manager_xrandr->xdisplay, output->output_id, edid_atom, &len);
+    }
+
+  if (!result)
+    {
+      edid_atom = XInternAtom (manager_xrandr->xdisplay, "XFree86_DDC_EDID1_RAWDATA", FALSE);
+      result = get_edid_property (manager_xrandr->xdisplay, output->output_id, edid_atom, &len);
+    }
+
+  if (result)
+    {
+      if (len > 0 && len % 128 == 0)
+        return g_bytes_new_take (result, len);
+      else
+        g_free (result);
+    }
+
+  return NULL;
+}
+
 static void
 meta_monitor_manager_xrandr_set_power_save_mode (MetaMonitorManager *manager,
 						 MetaPowerSave       mode)
@@ -766,6 +835,7 @@ meta_monitor_manager_xrandr_class_init (MetaMonitorManagerXrandrClass *klass)
   object_class->finalize = meta_monitor_manager_xrandr_finalize;
 
   manager_class->read_current = meta_monitor_manager_xrandr_read_current;
+  manager_class->read_edid = meta_monitor_manager_xrandr_read_edid;
   manager_class->apply_configuration = meta_monitor_manager_xrandr_apply_configuration;
   manager_class->set_power_save_mode = meta_monitor_manager_xrandr_set_power_save_mode;
   manager_class->change_backlight = meta_monitor_manager_xrandr_change_backlight;

src/core/monitor.c

@@ -339,6 +339,20 @@ apply_config_dummy (MetaMonitorManager *manager,
   invalidate_logical_config (manager);
 }
 
+static GBytes *
+read_edid_dummy (MetaMonitorManager *manager,
+                 MetaOutput         *output)
+{
+  return NULL;
+}
+
+static char *
+get_edid_file_dummy (MetaMonitorManager *manager,
+                     MetaOutput         *output)
+{
+  return NULL;
+}
+
 static void
 meta_monitor_manager_init (MetaMonitorManager *manager)
 {
@@ -633,6 +647,8 @@ meta_monitor_manager_class_init (MetaMonitorManagerClass *klass)
   object_class->finalize = meta_monitor_manager_finalize;
 
   klass->read_current = read_current_dummy;
+  klass->read_edid = read_edid_dummy;
+  klass->get_edid_file = get_edid_file_dummy;
   klass->apply_configuration = apply_config_dummy;
 
   signals[MONITORS_CHANGED] =
@@ -703,6 +719,7 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
                                            GDBusMethodInvocation *invocation)
 {
   MetaMonitorManager *manager = META_MONITOR_MANAGER (skeleton);
+  MetaMonitorManagerClass *manager_class = META_MONITOR_MANAGER_GET_CLASS (skeleton);
   GVariantBuilder crtc_builder, output_builder, mode_builder;
   unsigned int i, j;
 
@@ -737,6 +754,8 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
     {
       MetaOutput *output = &manager->outputs[i];
       GVariantBuilder crtcs, modes, clones, properties;
+      GBytes *edid;
+      char *edid_file;
 
       g_variant_builder_init (&crtcs, G_VARIANT_TYPE ("au"));
       for (j = 0; j < output->n_possible_crtcs; j++)
@@ -769,6 +788,25 @@ meta_monitor_manager_handle_get_resources (MetaDBusDisplayConfig *skeleton,
       g_variant_builder_add (&properties, "{sv}", "presentation",
                              g_variant_new_boolean (output->is_presentation));
 
+      edid_file = manager_class->get_edid_file (manager, output);
+      if (edid_file)
+        {
+          g_variant_builder_add (&properties, "{sv}", "edid-file",
+                                 g_variant_new_take_string (edid_file));
+        }
+      else
+        {
+          edid = manager_class->read_edid (manager, output);
+
+          if (edid)
+            {
+              g_variant_builder_add (&properties, "{sv}", "edid",
+                                     g_variant_new_from_bytes (G_VARIANT_TYPE ("ay"),
+                                                               edid, TRUE));
+              g_bytes_unref (edid);
+            }
+        }
+
       g_variant_builder_add (&output_builder, "(uxiausauaua{sv})",
                              i, /* ID */
                              output->output_id,