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

   1 /*
   2  * Copyright (c) 2016 MediaTek Inc.
   3  * Author: Ming Hsiu Tsai <minghsiu.tsai@mediatek.com>
   4  *         Rick Chang <rick.chang@mediatek.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/videodev2.h>
  18
  19 #include "mtk_jpeg_parse.h"
  20
  21 #define TEM     0x01
  22 #define SOF0    0xc0
  23 #define RST     0xd0
  24 #define SOI     0xd8
  25 #define EOI     0xd9
  26
  27 struct mtk_jpeg_stream {
  28         u8 *addr;
  29         u32 size;
  30         u32 curr;
  31 };
  32
  33 static int read_byte(struct mtk_jpeg_stream *stream)
  34 {
  35         if (stream->curr >= stream->size)
  36                 return -1;
  37         return stream->addr[stream->curr++];
  38 }
  39
  40 static int read_word_be(struct mtk_jpeg_stream *stream, u32 *word)
  41 {
  42         u32 temp;
  43         int byte;
  44
  45         byte = read_byte(stream);
  46         if (byte == -1)
  47                 return -1;
  48         temp = byte << 8;
  49         byte = read_byte(stream);
  50         if (byte == -1)
  51                 return -1;
  52         *word = (u32)byte | temp;
  53
  54         return 0;
  55 }
  56
  57 static void read_skip(struct mtk_jpeg_stream *stream, long len)
  58 {
  59         if (len <= 0)
  60                 return;
  61         while (len--)
  62                 read_byte(stream);
  63 }
  64
  65 static bool mtk_jpeg_do_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va,
  66                               u32 src_size)
  67 {
  68         bool notfound = true;
  69         struct mtk_jpeg_stream stream;
  70
  71         stream.addr = src_addr_va;
  72         stream.size = src_size;
  73         stream.curr = 0;
  74
  75         while (notfound) {
  76                 int i, length, byte;
  77                 u32 word;
  78
  79                 byte = read_byte(&stream);
  80                 if (byte == -1)
  81                         return false;
  82                 if (byte != 0xff)
  83                         continue;
  84                 do
  85                         byte = read_byte(&stream);
  86                 while (byte == 0xff);
  87                 if (byte == -1)
  88                         return false;
  89                 if (byte == 0)
  90                         continue;
  91
  92                 length = 0;
  93                 switch (byte) {
  94                 case SOF0:
  95                         /* length */
  96                         if (read_word_be(&stream, &word))
  97                                 break;
  98
  99                         /* precision */
 100                         if (read_byte(&stream) == -1)
 101                                 break;
 102
 103                         if (read_word_be(&stream, &word))
 104                                 break;
 105                         param->pic_h = word;
 106
 107                         if (read_word_be(&stream, &word))
 108                                 break;
 109                         param->pic_w = word;
 110
 111                         param->comp_num = read_byte(&stream);
 112                         if (param->comp_num != 1 && param->comp_num != 3)
 113                                 break;
 114
 115                         for (i = 0; i < param->comp_num; i++) {
 116                                 param->comp_id[i] = read_byte(&stream);
 117                                 if (param->comp_id[i] == -1)
 118                                         break;
 119
 120                                 /* sampling */
 121                                 byte = read_byte(&stream);
 122                                 if (byte == -1)
 123                                         break;
 124                                 param->sampling_w[i] = (byte >> 4) & 0x0F;
 125                                 param->sampling_h[i] = byte & 0x0F;
 126
 127                                 param->qtbl_num[i] = read_byte(&stream);
 128                                 if (param->qtbl_num[i] == -1)
 129                                         break;
 130                         }
 131
 132                         notfound = !(i == param->comp_num);
 133                         break;
 134                 case RST ... RST + 7:
 135                 case SOI:
 136                 case EOI:
 137                 case TEM:
 138                         break;
 139                 default:
 140                         if (read_word_be(&stream, &word))
 141                                 break;
 142                         length = (long)word - 2;
 143                         read_skip(&stream, length);
 144                         break;
 145                 }
 146         }
 147
 148         return !notfound;
 149 }
 150
 151 bool mtk_jpeg_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va,
 152                     u32 src_size)
 153 {
 154         if (!mtk_jpeg_do_parse(param, src_addr_va, src_size))
 155                 return false;
 156         if (mtk_jpeg_dec_fill_param(param))
 157                 return false;
 158
 159         return true;
 160 }