drm: Add support for a panel-orientation connector property, v6

On some devices the LCD panel is mounted in the casing in such a way that
the up/top side of the panel does not match with the top side of the
device (e.g. it is mounted upside-down).

This commit adds the necessary infra for lcd-panel drm_connector-s to
have a "panel orientation" property to communicate how the panel is
orientated vs the casing.

Userspace can use this property to check for non-normal orientation and
then adjust the displayed image accordingly by rotating it to compensate.

Changes in v2:
-Store panel_orientation in drm_display_info, so that drm_fb_helper.c can
 access it easily
-Have a single drm_connector_init_panel_orientation_property rather then
 create and attach functions. The caller is expected to set
 drm_display_info.panel_orientation before calling this, then this will
 check for platform specific quirks overriding the panel_orientation and if
 the panel_orientation is set after this then it will attach the property.

Changes in v6:
-Use an enum (with kerneldoc) rather then #defines for
 DRM_MODE_PANEL_ORIENTATION_*

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171125193553.23986-4-hdegoede@redhat.com

1 files changed, 7 insertions, 0 deletions

diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index f7ef0023d68b..a0afeb591dcb 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -735,6 +735,13 @@ struct drm_mode_config {
 	 */
 	struct drm_property *non_desktop_property;
 
+	/**
+	 * @panel_orientation_property: Optional connector property indicating
+	 * how the lcd-panel is mounted inside the casing (e.g. normal or
+	 * upside-down).
+	 */
+	struct drm_property *panel_orientation_property;
+
 	/* dumb ioctl parameters */
 	uint32_t preferred_depth, prefer_shadow;