linux/drivers/gpu/drm/sun4i/sun8i_csc.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) Jernej Skrabec <[email protected]>
 */

#include <drm/drm_print.h>

#include "sun8i_csc.h"
#include "sun8i_mixer.h"

static const u32 ccsc_base[][2] = …;

/*
 * Factors are in two's complement format, 10 bits for fractinal part.
 * First tree values in each line are multiplication factor and last
 * value is constant, which is added at the end.
 */

static const u32 yuv2rgb[2][2][12] = …;

/*
 * DE3 has a bit different CSC units. Factors are in two's complement format.
 * First three factors in a row are multiplication factors which have 17 bits
 * for fractional part. Fourth value in a row is comprised of two factors.
 * Upper 16 bits represents difference, which is subtracted from the input
 * value before multiplication and lower 16 bits represents constant, which
 * is addes at the end.
 *
 * x' = c00 * (x + d0) + c01 * (y + d1) + c02 * (z + d2) + const0
 * y' = c10 * (x + d0) + c11 * (y + d1) + c12 * (z + d2) + const1
 * z' = c20 * (x + d0) + c21 * (y + d1) + c22 * (z + d2) + const2
 *
 * Please note that above formula is true only for Blender CSC. Other DE3 CSC
 * units takes only positive value for difference. From what can be deducted
 * from BSP driver code, those units probably automatically assume that
 * difference has to be subtracted.
 *
 * Layout of factors in table:
 * c00 c01 c02 [d0 const0]
 * c10 c11 c12 [d1 const1]
 * c20 c21 c22 [d2 const2]
 */

static const u32 yuv2rgb_de3[2][3][12] = …;

static void sun8i_csc_set_coefficients(struct regmap *map, u32 base,
				       enum sun8i_csc_mode mode,
				       enum drm_color_encoding encoding,
				       enum drm_color_range range)
{ … }

static void sun8i_de3_ccsc_set_coefficients(struct regmap *map, int layer,
					    enum sun8i_csc_mode mode,
					    enum drm_color_encoding encoding,
					    enum drm_color_range range)
{ … }

static void sun8i_csc_enable(struct regmap *map, u32 base, bool enable)
{ … }

static void sun8i_de3_ccsc_enable(struct regmap *map, int layer, bool enable)
{ … }

void sun8i_csc_set_ccsc_coefficients(struct sun8i_mixer *mixer, int layer,
				     enum sun8i_csc_mode mode,
				     enum drm_color_encoding encoding,
				     enum drm_color_range range)
{ … }

void sun8i_csc_enable_ccsc(struct sun8i_mixer *mixer, int layer, bool enable)
{ … }