[PATCH 28/32] drm: Add drm_framebuffer_plane_{width,height}()

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Add variants of drm_format_plane_{width,height}() that take an entire fb
object instead of just the format. These should be more efficent as they
can just look up the format info from the fb->format pointer rather than
having to look it up (using a linear search based on the format).

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_framebuffer.c | 44 +++++++++++++++++++++++++++++++++++++++
 include/drm/drm_framebuffer.h     |  6 ++++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 47478678d609..28d697ae1faf 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -793,3 +793,47 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
 	drm_framebuffer_unreference(fb);
 }
 EXPORT_SYMBOL(drm_framebuffer_remove);
+
+/**
+ * drm_framebuffer_plane_width - width of the plane given the first plane
+ * @width: width of the first plane
+ * @fb: the framebuffer
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+int drm_framebuffer_plane_width(int width,
+				const struct drm_framebuffer *fb, int plane)
+{
+	if (plane >= fb->format->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return width;
+
+	return width / fb->format->hsub;
+}
+EXPORT_SYMBOL(drm_framebuffer_plane_width);
+
+/**
+ * drm_framebuffer_plane_height - height of the plane given the first plane
+ * @height: height of the first plane
+ * @fb: the framebuffer
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+int drm_framebuffer_plane_height(int height,
+				 const struct drm_framebuffer *fb, int plane)
+{
+	if (plane >= fb->format->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return height;
+
+	return height / fb->format->vsub;
+}
+EXPORT_SYMBOL(drm_framebuffer_plane_height);
diff --git a/include/drm/drm_framebuffer.h b/include/drm/drm_framebuffer.h
index 741b3a994d1f..cdcfb86b3f74 100644
--- a/include/drm/drm_framebuffer.h
+++ b/include/drm/drm_framebuffer.h
@@ -268,4 +268,10 @@ static inline uint32_t drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
 					  struct drm_framebuffer, head);	\
 	     &fb->head != (&(dev)->mode_config.fb_list);			\
 	     fb = list_next_entry(fb, head))
+
+int drm_framebuffer_plane_width(int width,
+				const struct drm_framebuffer *fb, int plane);
+int drm_framebuffer_plane_height(int height,
+				 const struct drm_framebuffer *fb, int plane);
+
 #endif
-- 
2.7.4