drivers/gpu/drm/drm_fourcc.c - arm/linux - Git at Google

 /*
  * Copyright (c) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  *
  * DRM core format related functions
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
  * the above copyright notice appear in all copies and that both that copyright
  * notice and this permission notice appear in supporting documentation, and
  * that the name of the copyright holders not be used in advertising or
  * publicity pertaining to distribution of the software without specific,
  * written prior permission.  The copyright holders make no representations
  * about the suitability of this software for any purpose.  It is provided "as
  * is" without express or implied warranty.
  *
  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  * OF THIS SOFTWARE.
  */

 #include <linux/bug.h>
 #include <linux/ctype.h>
 #include <linux/export.h>
 #include <linux/kernel.h>

 #include <drm/drmP.h>
 #include <drm/drm_fourcc.h>

 static char printable_char(int c)
 {
 	return isascii(c) && isprint(c) ? c : '?';
 }

 /**
  * drm_mode_legacy_fb_format - compute drm fourcc code from legacy description
  * @bpp: bits per pixels
  * @depth: bit depth per pixel
  *
  * Computes a drm fourcc pixel format code for the given @bpp/@depth values.
  * Useful in fbdev emulation code, since that deals in those values.
  */
 uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
 {
 	uint32_t fmt;

 	switch (bpp) {
 	case 8:
 		fmt = DRM_FORMAT_C8;
 		break;
 	case 16:
 		if (depth == 15)
 			fmt = DRM_FORMAT_XRGB1555;
 		else
 			fmt = DRM_FORMAT_RGB565;
 		break;
 	case 24:
 		fmt = DRM_FORMAT_RGB888;
 		break;
 	case 32:
 		if (depth == 24)
 			fmt = DRM_FORMAT_XRGB8888;
 		else if (depth == 30)
 			fmt = DRM_FORMAT_XRGB2101010;
 		else
 			fmt = DRM_FORMAT_ARGB8888;
 		break;
 	default:
 		DRM_ERROR("bad bpp, assuming x8r8g8b8 pixel format\n");
 		fmt = DRM_FORMAT_XRGB8888;
 		break;
 	}

 	return fmt;
 }
 EXPORT_SYMBOL(drm_mode_legacy_fb_format);

 /**
  * drm_get_format_name - return a string for drm fourcc format
  * @format: format to compute name of
  *
  * Note that the buffer returned by this function is owned by the caller
  * and will need to be freed using kfree().
  */
 char *drm_get_format_name(uint32_t format)
 {
 	char *buf = kmalloc(32, GFP_KERNEL);

 	snprintf(buf, 32,
 		 "%c%c%c%c %s-endian (0x%08x)",
 		 printable_char(format & 0xff),
 		 printable_char((format >> 8) & 0xff),
 		 printable_char((format >> 16) & 0xff),
 		 printable_char((format >> 24) & 0x7f),
 		 format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
 		 format);

 	return buf;
 }
 EXPORT_SYMBOL(drm_get_format_name);

 /**
  * drm_fb_get_bpp_depth - get the bpp/depth values for format
  * @format: pixel format (DRM_FORMAT_*)
  * @depth: storage for the depth value
  * @bpp: storage for the bpp value
  *
  * This only supports RGB formats here for compat with code that doesn't use
  * pixel formats directly yet.
  */
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 			  int *bpp)
 {
 	char *format_name;

 	switch (format) {
 	case DRM_FORMAT_C8:
 	case DRM_FORMAT_RGB332:
 	case DRM_FORMAT_BGR233:
 		*depth = 8;
 		*bpp = 8;
 		break;
 	case DRM_FORMAT_XRGB1555:
 	case DRM_FORMAT_XBGR1555:
 	case DRM_FORMAT_RGBX5551:
 	case DRM_FORMAT_BGRX5551:
 	case DRM_FORMAT_ARGB1555:
 	case DRM_FORMAT_ABGR1555:
 	case DRM_FORMAT_RGBA5551:
 	case DRM_FORMAT_BGRA5551:
 		*depth = 15;
 		*bpp = 16;
 		break;
 	case DRM_FORMAT_RGB565:
 	case DRM_FORMAT_BGR565:
 		*depth = 16;
 		*bpp = 16;
 		break;
 	case DRM_FORMAT_RGB888:
 	case DRM_FORMAT_BGR888:
 		*depth = 24;
 		*bpp = 24;
 		break;
 	case DRM_FORMAT_XRGB8888:
 	case DRM_FORMAT_XBGR8888:
 	case DRM_FORMAT_RGBX8888:
 	case DRM_FORMAT_BGRX8888:
 		*depth = 24;
 		*bpp = 32;
 		break;
 	case DRM_FORMAT_XRGB2101010:
 	case DRM_FORMAT_XBGR2101010:
 	case DRM_FORMAT_RGBX1010102:
 	case DRM_FORMAT_BGRX1010102:
 	case DRM_FORMAT_ARGB2101010:
 	case DRM_FORMAT_ABGR2101010:
 	case DRM_FORMAT_RGBA1010102:
 	case DRM_FORMAT_BGRA1010102:
 		*depth = 30;
 		*bpp = 32;
 		break;
 	case DRM_FORMAT_ARGB8888:
 	case DRM_FORMAT_ABGR8888:
 	case DRM_FORMAT_RGBA8888:
 	case DRM_FORMAT_BGRA8888:
 		*depth = 32;
 		*bpp = 32;
 		break;
 	default:
 		format_name = drm_get_format_name(format);
 		DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
 		kfree(format_name);
 		*depth = 0;
 		*bpp = 0;
 		break;
 	}
 }
 EXPORT_SYMBOL(drm_fb_get_bpp_depth);

 /**
  * drm_format_num_planes - get the number of planes for format
  * @format: pixel format (DRM_FORMAT_*)
  *
  * Returns:
  * The number of planes used by the specified pixel format.
  */
 int drm_format_num_planes(uint32_t format)
 {
 	switch (format) {
 	case DRM_FORMAT_YUV410:
 	case DRM_FORMAT_YVU410:
 	case DRM_FORMAT_YUV411:
 	case DRM_FORMAT_YVU411:
 	case DRM_FORMAT_YUV420:
 	case DRM_FORMAT_YVU420:
 	case DRM_FORMAT_YUV422:
 	case DRM_FORMAT_YVU422:
 	case DRM_FORMAT_YUV444:
 	case DRM_FORMAT_YVU444:
 		return 3;
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21:
 	case DRM_FORMAT_NV16:
 	case DRM_FORMAT_NV61:
 	case DRM_FORMAT_NV24:
 	case DRM_FORMAT_NV42:
 		return 2;
 	default:
 		return 1;
 	}
 }
 EXPORT_SYMBOL(drm_format_num_planes);

 /**
  * drm_format_plane_cpp - determine the bytes per pixel value
  * @format: pixel format (DRM_FORMAT_*)
  * @plane: plane index
  *
  * Returns:
  * The bytes per pixel value for the specified plane.
  */
 int drm_format_plane_cpp(uint32_t format, int plane)
 {
 	unsigned int depth;
 	int bpp;

 	if (plane >= drm_format_num_planes(format))
 		return 0;

 	switch (format) {
 	case DRM_FORMAT_YUYV:
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_UYVY:
 	case DRM_FORMAT_VYUY:
 		return 2;
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21:
 	case DRM_FORMAT_NV16:
 	case DRM_FORMAT_NV61:
 	case DRM_FORMAT_NV24:
 	case DRM_FORMAT_NV42:
 		return plane ? 2 : 1;
 	case DRM_FORMAT_YUV410:
 	case DRM_FORMAT_YVU410:
 	case DRM_FORMAT_YUV411:
 	case DRM_FORMAT_YVU411:
 	case DRM_FORMAT_YUV420:
 	case DRM_FORMAT_YVU420:
 	case DRM_FORMAT_YUV422:
 	case DRM_FORMAT_YVU422:
 	case DRM_FORMAT_YUV444:
 	case DRM_FORMAT_YVU444:
 		return 1;
 	default:
 		drm_fb_get_bpp_depth(format, &depth, &bpp);
 		return bpp >> 3;
 	}
 }
 EXPORT_SYMBOL(drm_format_plane_cpp);

 /**
  * drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor
  * @format: pixel format (DRM_FORMAT_*)
  *
  * Returns:
  * The horizontal chroma subsampling factor for the
  * specified pixel format.
  */
 int drm_format_horz_chroma_subsampling(uint32_t format)
 {
 	switch (format) {
 	case DRM_FORMAT_YUV411:
 	case DRM_FORMAT_YVU411:
 	case DRM_FORMAT_YUV410:
 	case DRM_FORMAT_YVU410:
 		return 4;
 	case DRM_FORMAT_YUYV:
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_UYVY:
 	case DRM_FORMAT_VYUY:
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21:
 	case DRM_FORMAT_NV16:
 	case DRM_FORMAT_NV61:
 	case DRM_FORMAT_YUV422:
 	case DRM_FORMAT_YVU422:
 	case DRM_FORMAT_YUV420:
 	case DRM_FORMAT_YVU420:
 		return 2;
 	default:
 		return 1;
 	}
 }
 EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);

 /**
  * drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor
  * @format: pixel format (DRM_FORMAT_*)
  *
  * Returns:
  * The vertical chroma subsampling factor for the
  * specified pixel format.
  */
 int drm_format_vert_chroma_subsampling(uint32_t format)
 {
 	switch (format) {
 	case DRM_FORMAT_YUV410:
 	case DRM_FORMAT_YVU410:
 		return 4;
 	case DRM_FORMAT_YUV420:
 	case DRM_FORMAT_YVU420:
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21:
 		return 2;
 	default:
 		return 1;
 	}
 }
 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);
	/*
	* Copyright (c) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
	*
	* DRM core format related functions
	*
	* Permission to use, copy, modify, distribute, and sell this software and its
	* documentation for any purpose is hereby granted without fee, provided that
	* the above copyright notice appear in all copies and that both that copyright
	* notice and this permission notice appear in supporting documentation, and
	* that the name of the copyright holders not be used in advertising or
	* publicity pertaining to distribution of the software without specific,
	* written prior permission. The copyright holders make no representations
	* about the suitability of this software for any purpose. It is provided "as
	* is" without express or implied warranty.
	*
	* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
	* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
	* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	* OF THIS SOFTWARE.
	*/

	#include <linux/bug.h>
	#include <linux/ctype.h>
	#include <linux/export.h>
	#include <linux/kernel.h>

	#include <drm/drmP.h>
	#include <drm/drm_fourcc.h>

	static char printable_char(int c)
	{
	return isascii(c) && isprint(c) ? c : '?';
	}

	/**
	* drm_mode_legacy_fb_format - compute drm fourcc code from legacy description
	* @bpp: bits per pixels
	* @depth: bit depth per pixel
	*
	* Computes a drm fourcc pixel format code for the given @bpp/@depth values.
	* Useful in fbdev emulation code, since that deals in those values.
	*/
	uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
	{
	uint32_t fmt;

	switch (bpp) {
	case 8:
	fmt = DRM_FORMAT_C8;
	break;
	case 16:
	if (depth == 15)
	fmt = DRM_FORMAT_XRGB1555;
	else
	fmt = DRM_FORMAT_RGB565;
	break;
	case 24:
	fmt = DRM_FORMAT_RGB888;
	break;
	case 32:
	if (depth == 24)
	fmt = DRM_FORMAT_XRGB8888;
	else if (depth == 30)
	fmt = DRM_FORMAT_XRGB2101010;
	else
	fmt = DRM_FORMAT_ARGB8888;
	break;
	default:
	DRM_ERROR("bad bpp, assuming x8r8g8b8 pixel format\n");
	fmt = DRM_FORMAT_XRGB8888;
	break;
	}

	return fmt;
	}
	EXPORT_SYMBOL(drm_mode_legacy_fb_format);

	/**
	* drm_get_format_name - return a string for drm fourcc format
	* @format: format to compute name of
	*
	* Note that the buffer returned by this function is owned by the caller
	* and will need to be freed using kfree().
	*/
	char *drm_get_format_name(uint32_t format)
	{
	char *buf = kmalloc(32, GFP_KERNEL);

	snprintf(buf, 32,
	"%c%c%c%c %s-endian (0x%08x)",
	printable_char(format & 0xff),
	printable_char((format >> 8) & 0xff),
	printable_char((format >> 16) & 0xff),
	printable_char((format >> 24) & 0x7f),
	format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
	format);

	return buf;
	}
	EXPORT_SYMBOL(drm_get_format_name);

	/**
	* drm_fb_get_bpp_depth - get the bpp/depth values for format
	* @format: pixel format (DRM_FORMAT_*)
	* @depth: storage for the depth value
	* @bpp: storage for the bpp value
	*
	* This only supports RGB formats here for compat with code that doesn't use
	* pixel formats directly yet.
	*/
	void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
	int *bpp)
	{
	char *format_name;

	switch (format) {
	case DRM_FORMAT_C8:
	case DRM_FORMAT_RGB332:
	case DRM_FORMAT_BGR233:
	*depth = 8;
	*bpp = 8;
	break;
	case DRM_FORMAT_XRGB1555:
	case DRM_FORMAT_XBGR1555:
	case DRM_FORMAT_RGBX5551:
	case DRM_FORMAT_BGRX5551:
	case DRM_FORMAT_ARGB1555:
	case DRM_FORMAT_ABGR1555:
	case DRM_FORMAT_RGBA5551:
	case DRM_FORMAT_BGRA5551:
	*depth = 15;
	*bpp = 16;
	break;
	case DRM_FORMAT_RGB565:
	case DRM_FORMAT_BGR565:
	*depth = 16;
	*bpp = 16;
	break;
	case DRM_FORMAT_RGB888:
	case DRM_FORMAT_BGR888:
	*depth = 24;
	*bpp = 24;
	break;
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_XBGR8888:
	case DRM_FORMAT_RGBX8888:
	case DRM_FORMAT_BGRX8888:
	*depth = 24;
	*bpp = 32;
	break;
	case DRM_FORMAT_XRGB2101010:
	case DRM_FORMAT_XBGR2101010:
	case DRM_FORMAT_RGBX1010102:
	case DRM_FORMAT_BGRX1010102:
	case DRM_FORMAT_ARGB2101010:
	case DRM_FORMAT_ABGR2101010:
	case DRM_FORMAT_RGBA1010102:
	case DRM_FORMAT_BGRA1010102:
	*depth = 30;
	*bpp = 32;
	break;
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_ABGR8888:
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_BGRA8888:
	*depth = 32;
	*bpp = 32;
	break;
	default:
	format_name = drm_get_format_name(format);
	DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
	kfree(format_name);
	*depth = 0;
	*bpp = 0;
	break;
	}
	}
	EXPORT_SYMBOL(drm_fb_get_bpp_depth);

	/**
	* drm_format_num_planes - get the number of planes for format
	* @format: pixel format (DRM_FORMAT_*)
	*
	* Returns:
	* The number of planes used by the specified pixel format.
	*/
	int drm_format_num_planes(uint32_t format)
	{
	switch (format) {
	case DRM_FORMAT_YUV410:
	case DRM_FORMAT_YVU410:
	case DRM_FORMAT_YUV411:
	case DRM_FORMAT_YVU411:
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YUV422:
	case DRM_FORMAT_YVU422:
	case DRM_FORMAT_YUV444:
	case DRM_FORMAT_YVU444:
	return 3;
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
	case DRM_FORMAT_NV24:
	case DRM_FORMAT_NV42:
	return 2;
	default:
	return 1;
	}
	}
	EXPORT_SYMBOL(drm_format_num_planes);

	/**
	* drm_format_plane_cpp - determine the bytes per pixel value
	* @format: pixel format (DRM_FORMAT_*)
	* @plane: plane index
	*
	* Returns:
	* The bytes per pixel value for the specified plane.
	*/
	int drm_format_plane_cpp(uint32_t format, int plane)
	{
	unsigned int depth;
	int bpp;

	if (plane >= drm_format_num_planes(format))
	return 0;

	switch (format) {
	case DRM_FORMAT_YUYV:
	case DRM_FORMAT_YVYU:
	case DRM_FORMAT_UYVY:
	case DRM_FORMAT_VYUY:
	return 2;
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
	case DRM_FORMAT_NV24:
	case DRM_FORMAT_NV42:
	return plane ? 2 : 1;
	case DRM_FORMAT_YUV410:
	case DRM_FORMAT_YVU410:
	case DRM_FORMAT_YUV411:
	case DRM_FORMAT_YVU411:
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_YUV422:
	case DRM_FORMAT_YVU422:
	case DRM_FORMAT_YUV444:
	case DRM_FORMAT_YVU444:
	return 1;
	default:
	drm_fb_get_bpp_depth(format, &depth, &bpp);
	return bpp >> 3;
	}
	}
	EXPORT_SYMBOL(drm_format_plane_cpp);

	/**
	* drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor
	* @format: pixel format (DRM_FORMAT_*)
	*
	* Returns:
	* The horizontal chroma subsampling factor for the
	* specified pixel format.
	*/
	int drm_format_horz_chroma_subsampling(uint32_t format)
	{
	switch (format) {
	case DRM_FORMAT_YUV411:
	case DRM_FORMAT_YVU411:
	case DRM_FORMAT_YUV410:
	case DRM_FORMAT_YVU410:
	return 4;
	case DRM_FORMAT_YUYV:
	case DRM_FORMAT_YVYU:
	case DRM_FORMAT_UYVY:
	case DRM_FORMAT_VYUY:
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	case DRM_FORMAT_NV16:
	case DRM_FORMAT_NV61:
	case DRM_FORMAT_YUV422:
	case DRM_FORMAT_YVU422:
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
	return 2;
	default:
	return 1;
	}
	}
	EXPORT_SYMBOL(drm_format_horz_chroma_subsampling);

	/**
	* drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor
	* @format: pixel format (DRM_FORMAT_*)
	*
	* Returns:
	* The vertical chroma subsampling factor for the
	* specified pixel format.
	*/
	int drm_format_vert_chroma_subsampling(uint32_t format)
	{
	switch (format) {
	case DRM_FORMAT_YUV410:
	case DRM_FORMAT_YVU410:
	return 4;
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
	case DRM_FORMAT_NV12:
	case DRM_FORMAT_NV21:
	return 2;
	default:
	return 1;
	}
	}
	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);