drivers/gpu/drm/drm_rect.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * Copyright (C) 2011-2013 Intel Corporation
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */

 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <drm/drmP.h>
 #include <drm/drm_rect.h>

 /**
  * drm_rect_intersect - intersect two rectangles
  * @r1: first rectangle
  * @r2: second rectangle
  *
  * Calculate the intersection of rectangles @r1 and @r2.
  * @r1 will be overwritten with the intersection.
  *
  * RETURNS:
  * %true if rectangle @r1 is still visible after the operation,
  * %false otherwise.
  */
 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
 {
 	r1->x1 = max(r1->x1, r2->x1);
 	r1->y1 = max(r1->y1, r2->y1);
 	r1->x2 = min(r1->x2, r2->x2);
 	r1->y2 = min(r1->y2, r2->y2);

 	return drm_rect_visible(r1);
 }
 EXPORT_SYMBOL(drm_rect_intersect);

 /**
  * drm_rect_clip_scaled - perform a scaled clip operation
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @clip: clip rectangle
  * @hscale: horizontal scaling factor
  * @vscale: vertical scaling factor
  *
  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
  * same amounts multiplied by @hscale and @vscale.
  *
  * RETURNS:
  * %true if rectangle @dst is still visible after being clipped,
  * %false otherwise
  */
 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
 			  const struct drm_rect *clip,
 			  int hscale, int vscale)
 {
 	int diff;

 	diff = clip->x1 - dst->x1;
 	if (diff > 0) {
 		int64_t tmp = src->x1 + (int64_t) diff * hscale;
 		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 	}
 	diff = clip->y1 - dst->y1;
 	if (diff > 0) {
 		int64_t tmp = src->y1 + (int64_t) diff * vscale;
 		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 	}
 	diff = dst->x2 - clip->x2;
 	if (diff > 0) {
 		int64_t tmp = src->x2 - (int64_t) diff * hscale;
 		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 	}
 	diff = dst->y2 - clip->y2;
 	if (diff > 0) {
 		int64_t tmp = src->y2 - (int64_t) diff * vscale;
 		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
 	}

 	return drm_rect_intersect(dst, clip);
 }
 EXPORT_SYMBOL(drm_rect_clip_scaled);

 static int drm_calc_scale(int src, int dst)
 {
 	int scale = 0;

 	if (WARN_ON(src < 0 || dst < 0))
 		return -EINVAL;

 	if (dst == 0)
 		return 0;

 	scale = src / dst;

 	return scale;
 }

 /**
  * drm_rect_calc_hscale - calculate the horizontal scaling factor
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @min_hscale: minimum allowed horizontal scaling factor
  * @max_hscale: maximum allowed horizontal scaling factor
  *
  * Calculate the horizontal scaling factor as
  * (@src width) / (@dst width).
  *
  * RETURNS:
  * The horizontal scaling factor, or errno of out of limits.
  */
 int drm_rect_calc_hscale(const struct drm_rect *src,
 			 const struct drm_rect *dst,
 			 int min_hscale, int max_hscale)
 {
 	int src_w = drm_rect_width(src);
 	int dst_w = drm_rect_width(dst);
 	int hscale = drm_calc_scale(src_w, dst_w);

 	if (hscale < 0 || dst_w == 0)
 		return hscale;

 	if (hscale < min_hscale || hscale > max_hscale)
 		return -ERANGE;

 	return hscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_hscale);

 /**
  * drm_rect_calc_vscale - calculate the vertical scaling factor
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @min_vscale: minimum allowed vertical scaling factor
  * @max_vscale: maximum allowed vertical scaling factor
  *
  * Calculate the vertical scaling factor as
  * (@src height) / (@dst height).
  *
  * RETURNS:
  * The vertical scaling factor, or errno of out of limits.
  */
 int drm_rect_calc_vscale(const struct drm_rect *src,
 			 const struct drm_rect *dst,
 			 int min_vscale, int max_vscale)
 {
 	int src_h = drm_rect_height(src);
 	int dst_h = drm_rect_height(dst);
 	int vscale = drm_calc_scale(src_h, dst_h);

 	if (vscale < 0 || dst_h == 0)
 		return vscale;

 	if (vscale < min_vscale || vscale > max_vscale)
 		return -ERANGE;

 	return vscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_vscale);

 /**
  * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @min_hscale: minimum allowed horizontal scaling factor
  * @max_hscale: maximum allowed horizontal scaling factor
  *
  * Calculate the horizontal scaling factor as
  * (@src width) / (@dst width).
  *
  * If the calculated scaling factor is below @min_vscale,
  * decrease the height of rectangle @dst to compensate.
  *
  * If the calculated scaling factor is above @max_vscale,
  * decrease the height of rectangle @src to compensate.
  *
  * RETURNS:
  * The horizontal scaling factor.
  */
 int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
 				 struct drm_rect *dst,
 				 int min_hscale, int max_hscale)
 {
 	int src_w = drm_rect_width(src);
 	int dst_w = drm_rect_width(dst);
 	int hscale = drm_calc_scale(src_w, dst_w);

 	if (hscale < 0 || dst_w == 0)
 		return hscale;

 	if (hscale < min_hscale) {
 		int max_dst_w = src_w / min_hscale;

 		drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);

 		return min_hscale;
 	}

 	if (hscale > max_hscale) {
 		int max_src_w = dst_w * max_hscale;

 		drm_rect_adjust_size(src, max_src_w - src_w, 0);

 		return max_hscale;
 	}

 	return hscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);

 /**
  * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @min_vscale: minimum allowed vertical scaling factor
  * @max_vscale: maximum allowed vertical scaling factor
  *
  * Calculate the vertical scaling factor as
  * (@src height) / (@dst height).
  *
  * If the calculated scaling factor is below @min_vscale,
  * decrease the height of rectangle @dst to compensate.
  *
  * If the calculated scaling factor is above @max_vscale,
  * decrease the height of rectangle @src to compensate.
  *
  * RETURNS:
  * The vertical scaling factor.
  */
 int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 				 struct drm_rect *dst,
 				 int min_vscale, int max_vscale)
 {
 	int src_h = drm_rect_height(src);
 	int dst_h = drm_rect_height(dst);
 	int vscale = drm_calc_scale(src_h, dst_h);

 	if (vscale < 0 || dst_h == 0)
 		return vscale;

 	if (vscale < min_vscale) {
 		int max_dst_h = src_h / min_vscale;

 		drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);

 		return min_vscale;
 	}

 	if (vscale > max_vscale) {
 		int max_src_h = dst_h * max_vscale;

 		drm_rect_adjust_size(src, 0, max_src_h - src_h);

 		return max_vscale;
 	}

 	return vscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);

 /**
  * drm_rect_debug_print - print the rectangle information
  * @prefix: prefix string
  * @r: rectangle to print
  * @fixed_point: rectangle is in 16.16 fixed point format
  */
 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
 {
 	if (fixed_point)
 		DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
 	else
 		DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
 }
 EXPORT_SYMBOL(drm_rect_debug_print);

 /**
  * drm_rect_rotate - Rotate the rectangle
  * @r: rectangle to be rotated
  * @width: Width of the coordinate space
  * @height: Height of the coordinate space
  * @rotation: Transformation to be applied
  *
  * Apply @rotation to the coordinates of rectangle @r.
  *
  * @width and @height combined with @rotation define
  * the location of the new origin.
  *
  * @width correcsponds to the horizontal and @height
  * to the vertical axis of the untransformed coordinate
  * space.
  */
 void drm_rect_rotate(struct drm_rect *r,
 		     int width, int height,
 		     unsigned int rotation)
 {
 	struct drm_rect tmp;

 	if (rotation & (DRM_REFLECT_X | DRM_REFLECT_Y)) {
 		tmp = *r;

 		if (rotation & DRM_REFLECT_X) {
 			r->x1 = width - tmp.x2;
 			r->x2 = width - tmp.x1;
 		}

 		if (rotation & DRM_REFLECT_Y) {
 			r->y1 = height - tmp.y2;
 			r->y2 = height - tmp.y1;
 		}
 	}

 	switch (rotation & DRM_ROTATE_MASK) {
 	case DRM_ROTATE_0:
 		break;
 	case DRM_ROTATE_90:
 		tmp = *r;
 		r->x1 = tmp.y1;
 		r->x2 = tmp.y2;
 		r->y1 = width - tmp.x2;
 		r->y2 = width - tmp.x1;
 		break;
 	case DRM_ROTATE_180:
 		tmp = *r;
 		r->x1 = width - tmp.x2;
 		r->x2 = width - tmp.x1;
 		r->y1 = height - tmp.y2;
 		r->y2 = height - tmp.y1;
 		break;
 	case DRM_ROTATE_270:
 		tmp = *r;
 		r->x1 = height - tmp.y2;
 		r->x2 = height - tmp.y1;
 		r->y1 = tmp.x1;
 		r->y2 = tmp.x2;
 		break;
 	default:
 		break;
 	}
 }
 EXPORT_SYMBOL(drm_rect_rotate);

 /**
  * drm_rect_rotate_inv - Inverse rotate the rectangle
  * @r: rectangle to be rotated
  * @width: Width of the coordinate space
  * @height: Height of the coordinate space
  * @rotation: Transformation whose inverse is to be applied
  *
  * Apply the inverse of @rotation to the coordinates
  * of rectangle @r.
  *
  * @width and @height combined with @rotation define
  * the location of the new origin.
  *
  * @width correcsponds to the horizontal and @height
  * to the vertical axis of the original untransformed
  * coordinate space, so that you never have to flip
  * them when doing a rotatation and its inverse.
  * That is, if you do:
  *
  * drm_rotate(&r, width, height, rotation);
  * drm_rotate_inv(&r, width, height, rotation);
  *
  * you will always get back the original rectangle.
  */
 void drm_rect_rotate_inv(struct drm_rect *r,
 			 int width, int height,
 			 unsigned int rotation)
 {
 	struct drm_rect tmp;

 	switch (rotation & DRM_ROTATE_MASK) {
 	case DRM_ROTATE_0:
 		break;
 	case DRM_ROTATE_90:
 		tmp = *r;
 		r->x1 = width - tmp.y2;
 		r->x2 = width - tmp.y1;
 		r->y1 = tmp.x1;
 		r->y2 = tmp.x2;
 		break;
 	case DRM_ROTATE_180:
 		tmp = *r;
 		r->x1 = width - tmp.x2;
 		r->x2 = width - tmp.x1;
 		r->y1 = height - tmp.y2;
 		r->y2 = height - tmp.y1;
 		break;
 	case DRM_ROTATE_270:
 		tmp = *r;
 		r->x1 = tmp.y1;
 		r->x2 = tmp.y2;
 		r->y1 = height - tmp.x2;
 		r->y2 = height - tmp.x1;
 		break;
 	default:
 		break;
 	}

 	if (rotation & (DRM_REFLECT_X | DRM_REFLECT_Y)) {
 		tmp = *r;

 		if (rotation & DRM_REFLECT_X) {
 			r->x1 = width - tmp.x2;
 			r->x2 = width - tmp.x1;
 		}

 		if (rotation & DRM_REFLECT_Y) {
 			r->y1 = height - tmp.y2;
 			r->y2 = height - tmp.y1;
 		}
 	}
 }
 EXPORT_SYMBOL(drm_rect_rotate_inv);
	/*
	* Copyright (C) 2011-2013 Intel Corporation
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*/

	#include <linux/errno.h>
	#include <linux/export.h>
	#include <linux/kernel.h>
	#include <drm/drmP.h>
	#include <drm/drm_rect.h>

	/**
	* drm_rect_intersect - intersect two rectangles
	* @r1: first rectangle
	* @r2: second rectangle
	*
	* Calculate the intersection of rectangles @r1 and @r2.
	* @r1 will be overwritten with the intersection.
	*
	* RETURNS:
	* %true if rectangle @r1 is still visible after the operation,
	* %false otherwise.
	*/
	bool drm_rect_intersect(struct drm_rect r1, const struct drm_rect r2)
	{
	r1->x1 = max(r1->x1, r2->x1);
	r1->y1 = max(r1->y1, r2->y1);
	r1->x2 = min(r1->x2, r2->x2);
	r1->y2 = min(r1->y2, r2->y2);

	return drm_rect_visible(r1);
	}
	EXPORT_SYMBOL(drm_rect_intersect);

	/**
	* drm_rect_clip_scaled - perform a scaled clip operation
	* @src: source window rectangle
	* @dst: destination window rectangle
	* @clip: clip rectangle
	* @hscale: horizontal scaling factor
	* @vscale: vertical scaling factor
	*
	* Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
	* same amounts multiplied by @hscale and @vscale.
	*
	* RETURNS:
	* %true if rectangle @dst is still visible after being clipped,
	* %false otherwise
	*/
	bool drm_rect_clip_scaled(struct drm_rect src, struct drm_rect dst,
	const struct drm_rect *clip,
	int hscale, int vscale)
	{
	int diff;

	diff = clip->x1 - dst->x1;
	if (diff > 0) {
	int64_t tmp = src->x1 + (int64_t) diff * hscale;
	src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
	}
	diff = clip->y1 - dst->y1;
	if (diff > 0) {
	int64_t tmp = src->y1 + (int64_t) diff * vscale;
	src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
	}
	diff = dst->x2 - clip->x2;
	if (diff > 0) {
	int64_t tmp = src->x2 - (int64_t) diff * hscale;
	src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
	}
	diff = dst->y2 - clip->y2;
	if (diff > 0) {
	int64_t tmp = src->y2 - (int64_t) diff * vscale;
	src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
	}

	return drm_rect_intersect(dst, clip);
	}
	EXPORT_SYMBOL(drm_rect_clip_scaled);

	static int drm_calc_scale(int src, int dst)
	{
	int scale = 0;

	if (WARN_ON(src < 0 \|\| dst < 0))
	return -EINVAL;

	if (dst == 0)
	return 0;

	scale = src / dst;

	return scale;
	}

	/**
	* drm_rect_calc_hscale - calculate the horizontal scaling factor
	* @src: source window rectangle
	* @dst: destination window rectangle
	* @min_hscale: minimum allowed horizontal scaling factor
	* @max_hscale: maximum allowed horizontal scaling factor
	*
	* Calculate the horizontal scaling factor as
	* (@src width) / (@dst width).
	*
	* RETURNS:
	* The horizontal scaling factor, or errno of out of limits.
	*/
	int drm_rect_calc_hscale(const struct drm_rect *src,
	const struct drm_rect *dst,
	int min_hscale, int max_hscale)
	{
	int src_w = drm_rect_width(src);
	int dst_w = drm_rect_width(dst);
	int hscale = drm_calc_scale(src_w, dst_w);

	if (hscale < 0 \|\| dst_w == 0)
	return hscale;

	if (hscale < min_hscale \|\| hscale > max_hscale)
	return -ERANGE;

	return hscale;
	}
	EXPORT_SYMBOL(drm_rect_calc_hscale);

	/**
	* drm_rect_calc_vscale - calculate the vertical scaling factor
	* @src: source window rectangle
	* @dst: destination window rectangle
	* @min_vscale: minimum allowed vertical scaling factor
	* @max_vscale: maximum allowed vertical scaling factor
	*
	* Calculate the vertical scaling factor as
	* (@src height) / (@dst height).
	*
	* RETURNS:
	* The vertical scaling factor, or errno of out of limits.
	*/
	int drm_rect_calc_vscale(const struct drm_rect *src,
	const struct drm_rect *dst,
	int min_vscale, int max_vscale)
	{
	int src_h = drm_rect_height(src);
	int dst_h = drm_rect_height(dst);
	int vscale = drm_calc_scale(src_h, dst_h);

	if (vscale < 0 \|\| dst_h == 0)
	return vscale;

	if (vscale < min_vscale \|\| vscale > max_vscale)
	return -ERANGE;

	return vscale;
	}
	EXPORT_SYMBOL(drm_rect_calc_vscale);

	/**
	* drm_calc_hscale_relaxed - calculate the horizontal scaling factor
	* @src: source window rectangle
	* @dst: destination window rectangle
	* @min_hscale: minimum allowed horizontal scaling factor
	* @max_hscale: maximum allowed horizontal scaling factor
	*
	* Calculate the horizontal scaling factor as
	* (@src width) / (@dst width).
	*
	* If the calculated scaling factor is below @min_vscale,
	* decrease the height of rectangle @dst to compensate.
	*
	* If the calculated scaling factor is above @max_vscale,
	* decrease the height of rectangle @src to compensate.
	*
	* RETURNS:
	* The horizontal scaling factor.
	*/
	int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
	struct drm_rect *dst,
	int min_hscale, int max_hscale)
	{
	int src_w = drm_rect_width(src);
	int dst_w = drm_rect_width(dst);
	int hscale = drm_calc_scale(src_w, dst_w);

	if (hscale < 0 \|\| dst_w == 0)
	return hscale;

	if (hscale < min_hscale) {
	int max_dst_w = src_w / min_hscale;

	drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);

	return min_hscale;
	}

	if (hscale > max_hscale) {
	int max_src_w = dst_w * max_hscale;

	drm_rect_adjust_size(src, max_src_w - src_w, 0);

	return max_hscale;
	}

	return hscale;
	}
	EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);

	/**
	* drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
	* @src: source window rectangle
	* @dst: destination window rectangle
	* @min_vscale: minimum allowed vertical scaling factor
	* @max_vscale: maximum allowed vertical scaling factor
	*
	* Calculate the vertical scaling factor as
	* (@src height) / (@dst height).
	*
	* If the calculated scaling factor is below @min_vscale,
	* decrease the height of rectangle @dst to compensate.
	*
	* If the calculated scaling factor is above @max_vscale,
	* decrease the height of rectangle @src to compensate.
	*
	* RETURNS:
	* The vertical scaling factor.
	*/
	int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
	struct drm_rect *dst,
	int min_vscale, int max_vscale)
	{
	int src_h = drm_rect_height(src);
	int dst_h = drm_rect_height(dst);
	int vscale = drm_calc_scale(src_h, dst_h);

	if (vscale < 0 \|\| dst_h == 0)
	return vscale;

	if (vscale < min_vscale) {
	int max_dst_h = src_h / min_vscale;

	drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);

	return min_vscale;
	}

	if (vscale > max_vscale) {
	int max_src_h = dst_h * max_vscale;

	drm_rect_adjust_size(src, 0, max_src_h - src_h);

	return max_vscale;
	}

	return vscale;
	}
	EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);

	/**
	* drm_rect_debug_print - print the rectangle information
	* @prefix: prefix string
	* @r: rectangle to print
	* @fixed_point: rectangle is in 16.16 fixed point format
	*/
	void drm_rect_debug_print(const char prefix, const struct drm_rect r, bool fixed_point)
	{
	if (fixed_point)
	DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
	else
	DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
	}
	EXPORT_SYMBOL(drm_rect_debug_print);

	/**
	* drm_rect_rotate - Rotate the rectangle
	* @r: rectangle to be rotated
	* @width: Width of the coordinate space
	* @height: Height of the coordinate space
	* @rotation: Transformation to be applied
	*
	* Apply @rotation to the coordinates of rectangle @r.
	*
	* @width and @height combined with @rotation define
	* the location of the new origin.
	*
	* @width correcsponds to the horizontal and @height
	* to the vertical axis of the untransformed coordinate
	* space.
	*/
	void drm_rect_rotate(struct drm_rect *r,
	int width, int height,
	unsigned int rotation)
	{
	struct drm_rect tmp;

	if (rotation & (DRM_REFLECT_X \| DRM_REFLECT_Y)) {
	tmp = *r;

	if (rotation & DRM_REFLECT_X) {
	r->x1 = width - tmp.x2;
	r->x2 = width - tmp.x1;
	}

	if (rotation & DRM_REFLECT_Y) {
	r->y1 = height - tmp.y2;
	r->y2 = height - tmp.y1;
	}
	}

	switch (rotation & DRM_ROTATE_MASK) {
	case DRM_ROTATE_0:
	break;
	case DRM_ROTATE_90:
	tmp = *r;
	r->x1 = tmp.y1;
	r->x2 = tmp.y2;
	r->y1 = width - tmp.x2;
	r->y2 = width - tmp.x1;
	break;
	case DRM_ROTATE_180:
	tmp = *r;
	r->x1 = width - tmp.x2;
	r->x2 = width - tmp.x1;
	r->y1 = height - tmp.y2;
	r->y2 = height - tmp.y1;
	break;
	case DRM_ROTATE_270:
	tmp = *r;
	r->x1 = height - tmp.y2;
	r->x2 = height - tmp.y1;
	r->y1 = tmp.x1;
	r->y2 = tmp.x2;
	break;
	default:
	break;
	}
	}
	EXPORT_SYMBOL(drm_rect_rotate);

	/**
	* drm_rect_rotate_inv - Inverse rotate the rectangle
	* @r: rectangle to be rotated
	* @width: Width of the coordinate space
	* @height: Height of the coordinate space
	* @rotation: Transformation whose inverse is to be applied
	*
	* Apply the inverse of @rotation to the coordinates
	* of rectangle @r.
	*
	* @width and @height combined with @rotation define
	* the location of the new origin.
	*
	* @width correcsponds to the horizontal and @height
	* to the vertical axis of the original untransformed
	* coordinate space, so that you never have to flip
	* them when doing a rotatation and its inverse.
	* That is, if you do:
	*
	* drm_rotate(&r, width, height, rotation);
	* drm_rotate_inv(&r, width, height, rotation);
	*
	* you will always get back the original rectangle.
	*/
	void drm_rect_rotate_inv(struct drm_rect *r,
	int width, int height,
	unsigned int rotation)
	{
	struct drm_rect tmp;

	switch (rotation & DRM_ROTATE_MASK) {
	case DRM_ROTATE_0:
	break;
	case DRM_ROTATE_90:
	tmp = *r;
	r->x1 = width - tmp.y2;
	r->x2 = width - tmp.y1;
	r->y1 = tmp.x1;
	r->y2 = tmp.x2;
	break;
	case DRM_ROTATE_180:
	tmp = *r;
	r->x1 = width - tmp.x2;
	r->x2 = width - tmp.x1;
	r->y1 = height - tmp.y2;
	r->y2 = height - tmp.y1;
	break;
	case DRM_ROTATE_270:
	tmp = *r;
	r->x1 = tmp.y1;
	r->x2 = tmp.y2;
	r->y1 = height - tmp.x2;
	r->y2 = height - tmp.x1;
	break;
	default:
	break;
	}

	if (rotation & (DRM_REFLECT_X \| DRM_REFLECT_Y)) {
	tmp = *r;

	if (rotation & DRM_REFLECT_X) {
	r->x1 = width - tmp.x2;
	r->x2 = width - tmp.x1;
	}

	if (rotation & DRM_REFLECT_Y) {
	r->y1 = height - tmp.y2;
	r->y2 = height - tmp.y1;
	}
	}
	}
	EXPORT_SYMBOL(drm_rect_rotate_inv);