[PATCH v3 2/4] drm/panel: set display info in panel attach

[Derek Basehore]

Devicetree systems can set panel orientation via a panel binding, but
there's no way, as is, to propagate this setting to the connector,
where the property need to be added.
To address this, this patch sets orientation, as well as other fixed
values for the panel, in the drm_panel_attach function. These values
are stored from probe in the drm_panel struct.

Signed-off-by: Derek Basehore <dbasehore at chromium.org>
---
 drivers/gpu/drm/drm_panel.c | 28 ++++++++++++++++++++++++++++
 include/drm/drm_panel.h     | 14 ++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 507099af4b57..5690fca30236 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -104,11 +104,23 @@ EXPORT_SYMBOL(drm_panel_remove);
  */
 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector)
 {
+	struct drm_display_info *info;
+
 	if (panel->connector)
 		return -EBUSY;
 
 	panel->connector = connector;
 	panel->drm = connector->dev;
+	info = &connector->display_info;
+	info->width_mm = panel->width_mm;
+	info->height_mm = panel->height_mm;
+	info->bpc = panel->bpc;
+	info->panel_orientation = panel->orientation;
+	info->bus_flags = panel->bus_flags;
+	if (panel->bus_formats)
+		drm_display_info_set_bus_formats(&connector->display_info,
+						 panel->bus_formats,
+						 panel->num_bus_formats);
 
 	return 0;
 }
@@ -128,6 +140,22 @@ EXPORT_SYMBOL(drm_panel_attach);
  */
 int drm_panel_detach(struct drm_panel *panel)
 {
+	struct drm_display_info *info;
+
+	if (!panel->connector)
+		goto out;
+
+	info = &panel->connector->display_info;
+	info->width_mm = 0;
+	info->height_mm = 0;
+	info->bpc = 0;
+	info->panel_orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+	info->bus_flags = 0;
+	kfree(info->bus_formats);
+	info->bus_formats = NULL;
+	info->num_bus_formats = 0;
+
+out:
 	panel->connector = NULL;
 	panel->drm = NULL;
 
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 3564952f1a4f..760ca5865962 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -37,6 +37,8 @@ struct display_timing;
  * struct drm_panel_funcs - perform operations on a given panel
  * @disable: disable panel (turn off back light, etc.)
  * @unprepare: turn off panel
+ * @detach: detach panel->connector (clear internal state, etc.)
+ * @attach: attach panel->connector (update internal state, etc.)
  * @prepare: turn on panel and perform set up
  * @enable: enable panel (turn on back light, etc.)
  * @get_modes: add modes to the connector that the panel is attached to and
@@ -93,6 +95,18 @@ struct drm_panel {
 
 	const struct drm_panel_funcs *funcs;
 
+	/*
+	 * panel information to be set in the connector when the panel is
+	 * attached.
+	 */
+	unsigned int width_mm;
+	unsigned int height_mm;
+	unsigned int bpc;
+	int orientation;
+	const u32 *bus_formats;
+	unsigned int num_bus_formats;
+	u32 bus_flags;
+
 	struct list_head list;
 };
 
-- 
2.22.0.410.gd8fdbe21b5-goog