drivers/gpu/drm/sun4i/sun8i_csc.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/sun4i/sun8i_csc.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/sun4i/sun8i_csc.c
Extension
.c
Size
6895 bytes
Lines
249
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) Jernej Skrabec <jernej.skrabec@siol.net>
 */

#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_plane.h>
#include <drm/drm_print.h>

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

enum sun8i_csc_mode {
	SUN8I_CSC_MODE_OFF,
	SUN8I_CSC_MODE_YUV2RGB,
	SUN8I_CSC_MODE_YVU2RGB,
};

static const u32 ccsc_base[][2] = {
	[CCSC_MIXER0_LAYOUT]	= {CCSC00_OFFSET, CCSC01_OFFSET},
	[CCSC_MIXER1_LAYOUT]	= {CCSC10_OFFSET, CCSC11_OFFSET},
	[CCSC_D1_MIXER0_LAYOUT]	= {CCSC00_OFFSET, CCSC01_D1_OFFSET},
};

/*
 * 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] = {
	[DRM_COLOR_YCBCR_LIMITED_RANGE] = {
		[DRM_COLOR_YCBCR_BT601] = {
			0x000004A8, 0x00000000, 0x00000662, 0xFFFC8451,
			0x000004A8, 0xFFFFFE6F, 0xFFFFFCC0, 0x00021E4D,
			0x000004A8, 0x00000811, 0x00000000, 0xFFFBACA9,
		},
		[DRM_COLOR_YCBCR_BT709] = {
			0x000004A8, 0x00000000, 0x0000072B, 0xFFFC1F99,
			0x000004A8, 0xFFFFFF26, 0xFFFFFDDF, 0x00013383,
			0x000004A8, 0x00000873, 0x00000000, 0xFFFB7BEF,
		}
	},
	[DRM_COLOR_YCBCR_FULL_RANGE] = {
		[DRM_COLOR_YCBCR_BT601] = {
			0x00000400, 0x00000000, 0x0000059B, 0xFFFD322E,
			0x00000400, 0xFFFFFEA0, 0xFFFFFD25, 0x00021DD5,
			0x00000400, 0x00000716, 0x00000000, 0xFFFC74BD,
		},
		[DRM_COLOR_YCBCR_BT709] = {
			0x00000400, 0x00000000, 0x0000064C, 0xFFFCD9B4,
			0x00000400, 0xFFFFFF41, 0xFFFFFE21, 0x00014F96,
			0x00000400, 0x0000076C, 0x00000000, 0xFFFC49EF,
		}
	},
};

/*
 * 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] = {
	[DRM_COLOR_YCBCR_LIMITED_RANGE] = {
		[DRM_COLOR_YCBCR_BT601] = {
			0x0002542A, 0x00000000, 0x0003312A, 0xFFC00000,
			0x0002542A, 0xFFFF376B, 0xFFFE5FC3, 0xFE000000,
			0x0002542A, 0x000408D2, 0x00000000, 0xFE000000,
		},
		[DRM_COLOR_YCBCR_BT709] = {
			0x0002542A, 0x00000000, 0x000395E2, 0xFFC00000,

Annotation

Implementation Notes