drivers/media/platform/verisilicon/hantro_mpeg2.c

Source file repositories/reference/linux-study-clean/drivers/media/platform/verisilicon/hantro_mpeg2.c

File Facts

System
Linux kernel
Corpus path
drivers/media/platform/verisilicon/hantro_mpeg2.c
Extension
.c
Size
1470 bytes
Lines
62
Domain
Driver Families
Bucket
drivers/media
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
/*
 * Hantro VPU codec driver
 *
 * Copyright (C) 2018 Rockchip Electronics Co., Ltd.
 */

#include "hantro.h"

static const u8 zigzag[64] = {
	0,   1,  8, 16,  9,  2,  3, 10,
	17, 24, 32, 25, 18, 11,  4,  5,
	12, 19, 26, 33, 40, 48, 41, 34,
	27, 20, 13,  6,  7, 14, 21, 28,
	35, 42, 49, 56, 57, 50, 43, 36,
	29, 22, 15, 23, 30, 37, 44, 51,
	58, 59, 52, 45, 38, 31, 39, 46,
	53, 60, 61, 54, 47, 55, 62, 63
};

void hantro_mpeg2_dec_copy_qtable(u8 *qtable,
				  const struct v4l2_ctrl_mpeg2_quantisation *ctrl)
{
	int i, n;

	if (!qtable || !ctrl)
		return;

	for (i = 0; i < ARRAY_SIZE(zigzag); i++) {
		n = zigzag[i];
		qtable[n + 0] = ctrl->intra_quantiser_matrix[i];
		qtable[n + 64] = ctrl->non_intra_quantiser_matrix[i];
		qtable[n + 128] = ctrl->chroma_intra_quantiser_matrix[i];
		qtable[n + 192] = ctrl->chroma_non_intra_quantiser_matrix[i];
	}
}

int hantro_mpeg2_dec_init(struct hantro_ctx *ctx)
{
	struct hantro_dev *vpu = ctx->dev;

	ctx->mpeg2_dec.qtable.size = ARRAY_SIZE(zigzag) * 4;
	ctx->mpeg2_dec.qtable.cpu =
		dma_alloc_coherent(vpu->dev,
				   ctx->mpeg2_dec.qtable.size,
				   &ctx->mpeg2_dec.qtable.dma,
				   GFP_KERNEL);
	if (!ctx->mpeg2_dec.qtable.cpu)
		return -ENOMEM;
	return 0;
}

void hantro_mpeg2_dec_exit(struct hantro_ctx *ctx)
{
	struct hantro_dev *vpu = ctx->dev;

	dma_free_coherent(vpu->dev,
			  ctx->mpeg2_dec.qtable.size,
			  ctx->mpeg2_dec.qtable.cpu,
			  ctx->mpeg2_dec.qtable.dma);
}

Annotation

Implementation Notes