136  * direction_for_rotation() - Get the correct reading direction for a given rotation
141  * direction in this plane which correspond to a "left to right writing" in the CRTC.
152 	 * The CRTC writing direction is from A to B. The plane reading direction  in direction_for_rotation()
154 	 * The reading direction is computed by rotating the vector AB (top-left to top-right) in a  in direction_for_rotation()
175 	WARN_ONCE(true, "The inverse of the rotation gives an incorrect direction.");  in direction_for_rotation()
183  * @direction: direction of the reading
186  * must be rotated and have a shape of 1*pixel_count if @direction is vertical and a shape of
187  * pixel_count*1 if @direction is horizontal.
197 static void clamp_line_coordinates(enum pixel_read_direction direction,  in clamp_line_coordinates()  argument
207 	/* Get the correct number of pixel to blend, it depends of the direction */  in clamp_line_coordinates()
208 	switch (direction) {  in clamp_line_coordinates()
225 	switch (direction) {  in clamp_line_coordinates()
312 	/* Get the correct reading direction in the source buffer. */  in blend_line()
314 	enum pixel_read_direction direction =  in blend_line()  local
318 	clamp_line_coordinates(direction, current_plane, &src_line, &src_x_start, &src_y_start,  in blend_line()
333 	if (direction == READ_RIGHT_TO_LEFT) {  in blend_line()
336 	} else if (direction == READ_BOTTOM_TO_TOP) {  in blend_line()
348 	current_plane->pixel_read_line(current_plane, src_x_start, src_y_start, direction,  in blend_line()