From a6f25b727698a2382e332ab566ed39ee30f8efdc Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Tue, 12 Dec 2017 19:47:26 +0100
Subject: [PATCH 4/6] drm: Check for "panel orientation" connector property

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).

Kernel 4.16 introduces a new "panel-orientation" property on the drm
connector which allows modesetting applications / code to check for
such LCD panels.

This commit adds support for this new property and passes this to the
pixel_buffer code using the new ply_pixel_buffer_new_with_device_rotation
method, so that the pixel_buffer code will automatically rotate the
image to correct for the panel orientation.

https://bugs.freedesktop.org/show_bug.cgi?id=104714
---
 src/plugins/renderers/drm/plugin.c | 51 +++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/plugins/renderers/drm/plugin.c b/src/plugins/renderers/drm/plugin.c
index b93e8e4..f495854 100644
--- a/src/plugins/renderers/drm/plugin.c
+++ b/src/plugins/renderers/drm/plugin.c
@@ -367,6 +367,53 @@ destroy_output_buffer (ply_renderer_backend_t *backend,
         ply_renderer_buffer_free (backend, buffer);
 }
 
+static int
+connector_orientation_prop_to_rotation (drmModePropertyPtr prop,
+                                        int orientation)
+{
+        const char *name = prop->enums[orientation].name;
+
+        if (strcmp (name, "Upside Down") == 0)
+                return PLY_PIXEL_BUFFER_ROTATE_UPSIDE_DOWN;
+
+        if (strcmp (name, "Left Side Up") == 0) {
+                /* Left side up, rotate counter clockwise to correct */
+                return PLY_PIXEL_BUFFER_ROTATE_COUNTER_CLOCKWISE;
+        }
+
+        if (strcmp (name, "Right Side Up") == 0) {
+                /* Left side up, rotate clockwise to correct */
+                return PLY_PIXEL_BUFFER_ROTATE_CLOCKWISE;
+        }
+
+        return PLY_PIXEL_BUFFER_ROTATE_UPRIGHT;
+}
+
+static int
+ply_renderer_connector_get_rotation (ply_renderer_backend_t *backend,
+                                     drmModeConnector       *connector)
+{
+        drmModePropertyPtr prop;
+        int i, rotation;
+
+        for (i = 0; i < connector->count_props; i++) {
+                prop = drmModeGetProperty (backend->device_fd, connector->props[i]);
+                if (!prop)
+                        continue;
+
+                if ((prop->flags & DRM_MODE_PROP_ENUM) &&
+                    strcmp (prop->name, "panel orientation") == 0) {
+                         rotation = connector_orientation_prop_to_rotation (prop, connector->prop_values[i]);
+                         drmModeFreeProperty (prop);
+                         return rotation;
+                }
+
+                drmModeFreeProperty (prop);
+        }
+
+        return PLY_PIXEL_BUFFER_ROTATE_UPRIGHT;
+}
+
 static bool
 ply_renderer_head_add_connector (ply_renderer_head_t *head,
                                  drmModeConnector    *connector,
@@ -402,6 +449,7 @@ ply_renderer_head_new (ply_renderer_backend_t *backend,
 {
         ply_renderer_head_t *head;
         drmModeModeInfo *mode;
+        int rotation;
 
         head = calloc (1, sizeof(ply_renderer_head_t));
 
@@ -425,7 +473,8 @@ ply_renderer_head_new (ply_renderer_backend_t *backend,
         ply_renderer_head_add_connector (head, connector, connector_mode_index);
         assert (ply_array_get_size (head->connector_ids) > 0);
 
-        head->pixel_buffer = ply_pixel_buffer_new (head->area.width, head->area.height);
+        rotation = ply_renderer_connector_get_rotation (backend, connector);
+        head->pixel_buffer = ply_pixel_buffer_new_with_device_rotation (head->area.width, head->area.height, rotation);
         ply_pixel_buffer_set_device_scale (head->pixel_buffer,
                                            ply_get_device_scale (head->area.width,
                                                                  head->area.height,
-- 
2.17.0