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

2 files changed, 47 insertions, 0 deletions

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 66d6c99..f39ff52 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -176,6 +176,35 @@ enum drm_link_status {
 };
 
 /**
+ * enum drm_panel_orientation - panel_orientation info for &drm_display_info
+ *
+ * This enum is used to track the (LCD) panel orientation. There are no
+ * separate #defines for the uapi!
+ *
+ * @DRM_MODE_PANEL_ORIENTATION_UNKNOWN: The drm driver has not provided any
+ *					panel orientation information (normal
+ *					for non panels) in this case the "panel
+ *					orientation" connector prop will not be
+ *					attached.
+ * @DRM_MODE_PANEL_ORIENTATION_NORMAL:	The top side of the panel matches the
+ *					top side of the device's casing.
+ * @DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP: The top side of the panel matches the
+ *					bottom side of the device's casing, iow
+ *					the panel is mounted upside-down.
+ * @DRM_MODE_PANEL_ORIENTATION_LEFT_UP:	The left side of the panel matches the
+ *					top side of the device's casing.
+ * @DRM_MODE_PANEL_ORIENTATION_RIGHT_UP: The right side of the panel matches the
+ *					top side of the device's casing.
+ */
+enum drm_panel_orientation {
+	DRM_MODE_PANEL_ORIENTATION_UNKNOWN = -1,
+	DRM_MODE_PANEL_ORIENTATION_NORMAL = 0,
+	DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP,
+	DRM_MODE_PANEL_ORIENTATION_LEFT_UP,
+	DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
+};
+
+/**
  * struct drm_display_info - runtime data about the connected sink
  *
  * Describes a given display (e.g. CRT or flat panel) and its limitations. For
@@ -223,6 +252,15 @@ struct drm_display_info {
 #define DRM_COLOR_FORMAT_YCRCB420	(1<<3)
 
 	/**
+	 * @panel_orientation: Read only connector property for built-in panels,
+	 * indicating the orientation of the panel vs the device's casing.
+	 * drm_connector_init() sets this to DRM_MODE_PANEL_ORIENTATION_UNKNOWN.
+	 * When not UNKNOWN this gets used by the drm_fb_helpers to rotate the
+	 * fb to compensate and gets exported as prop to userspace.
+	 */
+	int panel_orientation;
+
+	/**
 	 * @color_formats: HDMI Color formats, selects between RGB and YCrCb
 	 * modes. Used DRM_COLOR_FORMAT\_ defines, which are _not_ the same ones
 	 * as used to describe the pixel format in framebuffers, and also don't
@@ -1035,6 +1073,8 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 					    const struct edid *edid);
 void drm_mode_connector_set_link_status_property(struct drm_connector *connector,
 						 uint64_t link_status);
+int drm_connector_init_panel_orientation_property(
+	struct drm_connector *connector, int width, int height);
 
 /**
  * struct drm_tile_group - Tile group metadata
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index f7ef002..a0afeb5 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;