text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * Copyright (C) 2019 Mentor Graphics Inc.
   */
  
  #include <linux/types.h>
  #include <linux/init.h>
  #include <linux/errno.h>
  #include <linux/err.h>
  #include <linux/sizes.h>
  #include "ipu-prv.h"
  
  #define QUANT_MAP(q)					\
  	((q) == V4L2_QUANTIZATION_FULL_RANGE ||		\
  	 (q) == V4L2_QUANTIZATION_DEFAULT ? 0 : 1)
  
  /* identity matrix */
  static const struct ipu_ic_csc_params identity = {
  	.coeff = {
  		{  128,    0,    0, },
  		{    0,  128,    0, },
  		{    0,    0,  128, },
  	},
  	.offset = { 0, 0, 0, },
  	.scale = 2,
  };
  
  /*
   * RGB full-range to RGB limited-range
   *
   * R_lim = 0.8588 * R_full + 16
   * G_lim = 0.8588 * G_full + 16
   * B_lim = 0.8588 * B_full + 16
   */
  static const struct ipu_ic_csc_params rgbf2rgbl = {
  	.coeff = {
  		{  220,    0,    0, },
  		{    0,  220,    0, },
  		{    0,    0,  220, },
  	},
  	.offset = { 64, 64, 64, },
  	.scale = 1,
  };
  
  /*
   * RGB limited-range to RGB full-range
   *
   * R_full = 1.1644 * (R_lim - 16)
   * G_full = 1.1644 * (G_lim - 16)
   * B_full = 1.1644 * (B_lim - 16)
   */
  static const struct ipu_ic_csc_params rgbl2rgbf = {
  	.coeff = {
  		{  149,    0,    0, },
  		{    0,  149,    0, },
  		{    0,    0,  149, },
  	},
  	.offset = { -37, -37, -37, },
  	.scale = 2,
  };
  
  /*
   * YUV full-range to YUV limited-range
   *
   * Y_lim  = 0.8588 * Y_full + 16
   * Cb_lim = 0.8784 * (Cb_full - 128) + 128
   * Cr_lim = 0.8784 * (Cr_full - 128) + 128
   */
  static const struct ipu_ic_csc_params yuvf2yuvl = {
  	.coeff = {
  		{  220,    0,    0, },
  		{    0,  225,    0, },
  		{    0,    0,  225, },
  	},
  	.offset = { 64, 62, 62, },
  	.scale = 1,
  	.sat = true,
  };
  
  /*
   * YUV limited-range to YUV full-range
   *
   * Y_full  = 1.1644 * (Y_lim - 16)
   * Cb_full = 1.1384 * (Cb_lim - 128) + 128
   * Cr_full = 1.1384 * (Cr_lim - 128) + 128
   */
  static const struct ipu_ic_csc_params yuvl2yuvf = {
  	.coeff = {
  		{  149,    0,    0, },
  		{    0,  146,    0, },
  		{    0,    0,  146, },
  	},
  	.offset = { -37, -35, -35, },
  	.scale = 2,
  };
  
  static const struct ipu_ic_csc_params *rgb2rgb[] = {
  	&identity,
  	&rgbf2rgbl,
  	&rgbl2rgbf,
  	&identity,
  };
  
  static const struct ipu_ic_csc_params *yuv2yuv[] = {
  	&identity,
  	&yuvf2yuvl,
  	&yuvl2yuvf,
  	&identity,
  };
  
  /*
   * BT.601 RGB full-range to YUV full-range
   *
   * Y =  .2990 * R + .5870 * G + .1140 * B
   * U = -.1687 * R - .3313 * G + .5000 * B + 128
   * V =  .5000 * R - .4187 * G - .0813 * B + 128
   */
  static const struct ipu_ic_csc_params rgbf2yuvf_601 = {
  	.coeff = {
  		{   77,  150,   29, },
  		{  -43,  -85,  128, },
  		{  128, -107,  -21, },
  	},
  	.offset = { 0, 512, 512, },
  	.scale = 1,
  };
  
  /* BT.601 RGB full-range to YUV limited-range */
  static const struct ipu_ic_csc_params rgbf2yuvl_601 = {
  	.coeff = {
  		{   66,  129,   25, },
  		{  -38,  -74,  112, },
  		{  112,  -94,  -18, },
  	},
  	.offset = { 64, 512, 512, },
  	.scale = 1,
  	.sat = true,
  };
  
  /* BT.601 RGB limited-range to YUV full-range */
  static const struct ipu_ic_csc_params rgbl2yuvf_601 = {
  	.coeff = {
  		{   89,  175,   34, },
  		{  -50,  -99,  149, },
  		{  149, -125,  -24, },
  	},
  	.offset = { -75, 512, 512, },
  	.scale = 1,
  };
  
  /* BT.601 RGB limited-range to YUV limited-range */
  static const struct ipu_ic_csc_params rgbl2yuvl_601 = {
  	.coeff = {
  		{   77,  150,   29, },
  		{  -44,  -87,  131, },
  		{  131, -110,  -21, },
  	},
  	.offset = { 0, 512, 512, },
  	.scale = 1,
  	.sat = true,
  };
  
  /*
   * BT.601 YUV full-range to RGB full-range
   *
   * R = 1. * Y +      0 * (Cb - 128) + 1.4020 * (Cr - 128)
   * G = 1. * Y -  .3441 * (Cb - 128) -  .7141 * (Cr - 128)
   * B = 1. * Y + 1.7720 * (Cb - 128) +      0 * (Cr - 128)
   *
   * equivalently (factoring out the offsets):
   *
   * R = 1. * Y  +      0 * Cb + 1.4020 * Cr - 179.456
   * G = 1. * Y  -  .3441 * Cb -  .7141 * Cr + 135.450
   * B = 1. * Y  + 1.7720 * Cb +      0 * Cr - 226.816
   */
  static const struct ipu_ic_csc_params yuvf2rgbf_601 = {
  	.coeff = {
  		{  128,    0,  179, },
  		{  128,  -44,  -91, },
  		{  128,  227,    0, },
  	},
  	.offset = { -359, 271, -454, },
  	.scale = 2,
  };
  
  /* BT.601 YUV full-range to RGB limited-range */
  static const struct ipu_ic_csc_params yuvf2rgbl_601 = {
  	.coeff = {
  		{  110,    0,  154, },
  		{  110,  -38,  -78, },
  		{  110,  195,    0, },
  	},
  	.offset = { -276, 265, -358, },
  	.scale = 2,
  };
  
  /* BT.601 YUV limited-range to RGB full-range */
  static const struct ipu_ic_csc_params yuvl2rgbf_601 = {
  	.coeff = {
  		{   75,    0,  102, },
  		{   75,  -25,  -52, },
  		{   75,  129,    0, },
  	},
  	.offset = { -223, 136, -277, },
  	.scale = 3,
  };
  
  /* BT.601 YUV limited-range to RGB limited-range */
  static const struct ipu_ic_csc_params yuvl2rgbl_601 = {
  	.coeff = {
  		{  128,    0,  175, },
  		{  128,  -43,  -89, },
  		{  128,  222,    0, },
  	},
  	.offset = { -351, 265, -443, },
  	.scale = 2,
  };
  
  static const struct ipu_ic_csc_params *rgb2yuv_601[] = {
  	&rgbf2yuvf_601,
  	&rgbf2yuvl_601,
  	&rgbl2yuvf_601,
  	&rgbl2yuvl_601,
  };
  
  static const struct ipu_ic_csc_params *yuv2rgb_601[] = {
  	&yuvf2rgbf_601,
  	&yuvf2rgbl_601,
  	&yuvl2rgbf_601,
  	&yuvl2rgbl_601,
  };
  
  /*
   * REC.709 encoding from RGB full range to YUV full range:
   *
   * Y =  .2126 * R + .7152 * G + .0722 * B
   * U = -.1146 * R - .3854 * G + .5000 * B + 128
   * V =  .5000 * R - .4542 * G - .0458 * B + 128
   */
  static const struct ipu_ic_csc_params rgbf2yuvf_709 = {
  	.coeff = {
  		{  54,  183,  19 },
  		{ -29,  -99, 128 },
  		{ 128, -116, -12 },
  	},
  	.offset = { 0, 512, 512 },
  	.scale = 1,
  };
  
  /* Rec.709 RGB full-range to YUV limited-range */
  static const struct ipu_ic_csc_params rgbf2yuvl_709 = {
  	.coeff = {
  		{   47,  157,   16, },
  		{  -26,  -87,  112, },
  		{  112, -102,  -10, },
  	},
  	.offset = { 64, 512, 512, },
  	.scale = 1,
  	.sat = true,
  };
  
  /* Rec.709 RGB limited-range to YUV full-range */
  static const struct ipu_ic_csc_params rgbl2yuvf_709 = {
  	.coeff = {
  		{   63,  213,   22, },
  		{  -34, -115,  149, },
  		{  149, -135,  -14, },
  	},
  	.offset = { -75, 512, 512, },
  	.scale = 1,
  };
  
  /* Rec.709 RGB limited-range to YUV limited-range */
  static const struct ipu_ic_csc_params rgbl2yuvl_709 = {
  	.coeff = {
  		{   54,  183,   18, },
  		{  -30, -101,  131, },
  		{  131, -119,  -12, },
  	},
  	.offset = { 0, 512, 512, },
  	.scale = 1,
  	.sat = true,
  };
  
  /*
   * Inverse REC.709 encoding from YUV full range to RGB full range:
   *
   * R = 1. * Y +      0 * (Cb - 128) + 1.5748 * (Cr - 128)
   * G = 1. * Y -  .1873 * (Cb - 128) -  .4681 * (Cr - 128)
   * B = 1. * Y + 1.8556 * (Cb - 128) +      0 * (Cr - 128)
   *
   * equivalently (factoring out the offsets):
   *
   * R = 1. * Y  +      0 * Cb + 1.5748 * Cr - 201.574
   * G = 1. * Y  -  .1873 * Cb -  .4681 * Cr +  83.891
   * B = 1. * Y  + 1.8556 * Cb +      0 * Cr - 237.517
   */
  static const struct ipu_ic_csc_params yuvf2rgbf_709 = {
  	.coeff = {
  		{  128,   0, 202 },
  		{  128, -24, -60 },
  		{  128, 238,   0 },
  	},
  	.offset = { -403, 168, -475 },
  	.scale = 2,
  };
  
  /* Rec.709 YUV full-range to RGB limited-range */
  static const struct ipu_ic_csc_params yuvf2rgbl_709 = {
  	.coeff = {
  		{  110,    0,  173, },
  		{  110,  -21,  -51, },
  		{  110,  204,    0, },
  	},
  	.offset = { -314, 176, -376, },
  	.scale = 2,
  };
  
  /* Rec.709 YUV limited-range to RGB full-range */
  static const struct ipu_ic_csc_params yuvl2rgbf_709 = {
  	.coeff = {
  		{   75,    0,  115, },
  		{   75,  -14,  -34, },
  		{   75,  135,    0, },
  	},
  	.offset = { -248, 77, -289, },
  	.scale = 3,
  };
  
  /* Rec.709 YUV limited-range to RGB limited-range */
  static const struct ipu_ic_csc_params yuvl2rgbl_709 = {
  	.coeff = {
  		{  128,    0,  197, },
  		{  128,  -23,  -59, },
  		{  128,  232,    0, },
  	},
  	.offset = { -394, 164, -464, },
  	.scale = 2,
  };
  
  static const struct ipu_ic_csc_params *rgb2yuv_709[] = {
  	&rgbf2yuvf_709,
  	&rgbf2yuvl_709,
  	&rgbl2yuvf_709,
  	&rgbl2yuvl_709,
  };
  
  static const struct ipu_ic_csc_params *yuv2rgb_709[] = {
  	&yuvf2rgbf_709,
  	&yuvf2rgbl_709,
  	&yuvl2rgbf_709,
  	&yuvl2rgbl_709,
  };
  
  static int calc_csc_coeffs(struct ipu_ic_csc *csc)
  {
  	const struct ipu_ic_csc_params **params_tbl;
  	int tbl_idx;
  
  	tbl_idx = (QUANT_MAP(csc->in_cs.quant) << 1) |
  		QUANT_MAP(csc->out_cs.quant);
  
  	if (csc->in_cs.cs == csc->out_cs.cs) {
  		csc->params = (csc->in_cs.cs == IPUV3_COLORSPACE_YUV) ?
  			*yuv2yuv[tbl_idx] : *rgb2rgb[tbl_idx];
  
  		return 0;
  	}
  
  	/* YUV <-> RGB encoding is required */
  
  	switch (csc->out_cs.enc) {
  	case V4L2_YCBCR_ENC_601:
  		params_tbl = (csc->in_cs.cs == IPUV3_COLORSPACE_YUV) ?
  			yuv2rgb_601 : rgb2yuv_601;
  		break;
  	case V4L2_YCBCR_ENC_709:
  		params_tbl = (csc->in_cs.cs == IPUV3_COLORSPACE_YUV) ?
  			yuv2rgb_709 : rgb2yuv_709;
  		break;
  	default:
  		return -ENOTSUPP;
  	}
  
  	csc->params = *params_tbl[tbl_idx];
  
  	return 0;
  }
  
  int __ipu_ic_calc_csc(struct ipu_ic_csc *csc)
  {
  	return calc_csc_coeffs(csc);
  }
  EXPORT_SYMBOL_GPL(__ipu_ic_calc_csc);
  
  int ipu_ic_calc_csc(struct ipu_ic_csc *csc,
  		    enum v4l2_ycbcr_encoding in_enc,
  		    enum v4l2_quantization in_quant,
  		    enum ipu_color_space in_cs,
  		    enum v4l2_ycbcr_encoding out_enc,
  		    enum v4l2_quantization out_quant,
  		    enum ipu_color_space out_cs)
  {
  	ipu_ic_fill_colorspace(&csc->in_cs, in_enc, in_quant, in_cs);
  	ipu_ic_fill_colorspace(&csc->out_cs, out_enc, out_quant, out_cs);
  
  	return __ipu_ic_calc_csc(csc);
  }
  EXPORT_SYMBOL_GPL(ipu_ic_calc_csc);
  