drm/kms: add a function that can add the mode for the output device without EDID

Add a function that can be used to add the default mode for the output device
without EDID.
It will add the default mode that meets with the requirements of given
hdisplay/vdisplay limit.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index f84a98f..e2d5f51 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1215,3 +1215,49 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
        return num_modes;
 }
 EXPORT_SYMBOL(drm_add_edid_modes);
+
+/**
+ * drm_add_modes_noedid - add modes for the connectors without EDID
+ * @connector: connector we're probing
+ * @hdisplay: the horizontal display limit
+ * @vdisplay: the vertical display limit
+ *
+ * Add the specified modes to the connector's mode list. Only when the
+ * hdisplay/vdisplay is not beyond the given limit, it will be added.
+ *
+ * Return number of modes added or 0 if we couldn't find any.
+ */
+int drm_add_modes_noedid(struct drm_connector *connector,
+                       int hdisplay, int vdisplay)
+{
+       int i, count, num_modes = 0;
+       struct drm_display_mode *mode, *ptr;
+       struct drm_device *dev = connector->dev;
+
+       count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
+       if (hdisplay < 0)
+               hdisplay = 0;
+       if (vdisplay < 0)
+               vdisplay = 0;
+
+       for (i = 0; i < count; i++) {
+               ptr = &drm_dmt_modes[i];
+               if (hdisplay && vdisplay) {
+                       /*
+                        * Only when two are valid, they will be used to check
+                        * whether the mode should be added to the mode list of
+                        * the connector.
+                        */
+                       if (ptr->hdisplay > hdisplay ||
+                                       ptr->vdisplay > vdisplay)
+                               continue;
+               }
+               mode = drm_mode_duplicate(dev, ptr);
+               if (mode) {
+                       drm_mode_probed_add(connector, mode);
+                       num_modes++;
+               }
+       }
+       return num_modes;
+}
+EXPORT_SYMBOL(drm_add_modes_noedid);

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index b0427a7..ae1e9e1 100644 (file)
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -750,4 +750,6 @@ extern struct drm_display_mode *drm_cvt_mode(struct drm_device *dev,
 extern struct drm_display_mode *drm_gtf_mode(struct drm_device *dev,
                                int hdisplay, int vdisplay, int vrefresh,
                                bool interlaced, int margins);
+extern int drm_add_modes_noedid(struct drm_connector *connector,
+                               int hdisplay, int vdisplay);
 #endif /* __DRM_CRTC_H__ */