drm: Add drm_format_plane_width() and drm_format_plane_height()
Add a few helpers to get the dimensions of the chroma plane(s).
v2: Add kernel-doc (Daniel)
v3: Fix kerneldoc "Returns:" style (Daniel)
Uninline the functions and check for num_planes (Daniel)
v4: Add the required EXPORT_SYMBOL()s
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455031784-10941-1-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 4132d58..65258ac 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -5738,6 +5738,48 @@
EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);
/**
+ * drm_format_plane_width - width of the plane given the first plane
+ * @width: width of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+int drm_format_plane_width(int width, uint32_t format, int plane)
+{
+ if (plane >= drm_format_num_planes(format))
+ return 0;
+
+ if (plane == 0)
+ return width;
+
+ return width / drm_format_horz_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_width);
+
+/**
+ * drm_format_plane_height - height of the plane given the first plane
+ * @height: height of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+int drm_format_plane_height(int height, uint32_t format, int plane)
+{
+ if (plane >= drm_format_num_planes(format))
+ return 0;
+
+ if (plane == 0)
+ return height;
+
+ return height / drm_format_vert_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_height);
+
+/**
* drm_rotation_simplify() - Try to simplify the rotation
* @rotation: Rotation to be simplified
* @supported_rotations: Supported rotations