cregit-Linux how code gets into the kernel

Release 4.13 drivers/media/platform/mtk-jpeg/mtk_jpeg_parse.c

/*
 * Copyright (c) 2016 MediaTek Inc.
 * Author: Ming Hsiu Tsai <minghsiu.tsai@mediatek.com>
 *         Rick Chang <rick.chang@mediatek.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/videodev2.h>

#include "mtk_jpeg_parse.h"


#define TEM	0x01

#define SOF0	0xc0

#define RST	0xd0

#define SOI	0xd8

#define EOI	0xd9


struct mtk_jpeg_stream {
	
u8 *addr;
	
u32 size;
	
u32 curr;
};


static int read_byte(struct mtk_jpeg_stream *stream) { if (stream->curr >= stream->size) return -1; return stream->addr[stream->curr++]; }

Contributors

PersonTokensPropCommitsCommitProp
Rick Chang36100.00%1100.00%
Total36100.00%1100.00%


static int read_word_be(struct mtk_jpeg_stream *stream, u32 *word) { u32 temp; int byte; byte = read_byte(stream); if (byte == -1) return -1; temp = byte << 8; byte = read_byte(stream); if (byte == -1) return -1; *word = (u32)byte | temp; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Rick Chang76100.00%1100.00%
Total76100.00%1100.00%


static void read_skip(struct mtk_jpeg_stream *stream, long len) { if (len <= 0) return; while (len--) read_byte(stream); }

Contributors

PersonTokensPropCommitsCommitProp
Rick Chang31100.00%1100.00%
Total31100.00%1100.00%


static bool mtk_jpeg_do_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va, u32 src_size) { bool notfound = true; struct mtk_jpeg_stream stream; stream.addr = src_addr_va; stream.size = src_size; stream.curr = 0; while (notfound) { int i, length, byte; u32 word; byte = read_byte(&stream); if (byte == -1) return false; if (byte != 0xff) continue; do byte = read_byte(&stream); while (byte == 0xff); if (byte == -1) return false; if (byte == 0) continue; length = 0; switch (byte) { case SOF0: /* length */ if (read_word_be(&stream, &word)) break; /* precision */ if (read_byte(&stream) == -1) break; if (read_word_be(&stream, &word)) break; param->pic_h = word; if (read_word_be(&stream, &word)) break; param->pic_w = word; param->comp_num = read_byte(&stream); if (param->comp_num != 1 && param->comp_num != 3) break; for (i = 0; i < param->comp_num; i++) { param->comp_id[i] = read_byte(&stream); if (param->comp_id[i] == -1) break; /* sampling */ byte = read_byte(&stream); if (byte == -1) break; param->sampling_w[i] = (byte >> 4) & 0x0F; param->sampling_h[i] = byte & 0x0F; param->qtbl_num[i] = read_byte(&stream); if (param->qtbl_num[i] == -1) break; } notfound = !(i == param->comp_num); break; case RST ... RST + 7: case SOI: case EOI: case TEM: break; default: if (read_word_be(&stream, &word)) break; length = (long)word - 2; read_skip(&stream, length); break; } } return !notfound; }

Contributors

PersonTokensPropCommitsCommitProp
Rick Chang395100.00%1100.00%
Total395100.00%1100.00%


bool mtk_jpeg_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va, u32 src_size) { if (!mtk_jpeg_do_parse(param, src_addr_va, src_size)) return false; if (mtk_jpeg_dec_fill_param(param)) return false; return true; }

Contributors

PersonTokensPropCommitsCommitProp
Rick Chang45100.00%1100.00%
Total45100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Rick Chang628100.00%1100.00%
Total628100.00%1100.00%
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