drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_parse.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2016 MediaTek Inc.
   4  * Author: Ming Hsiu Tsai <minghsiu.tsai@mediatek.com>
   5  *         Rick Chang <rick.chang@mediatek.com>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/videodev2.h>
  10 #include <media/jpeg.h>
  11
  12 #include "mtk_jpeg_dec_parse.h"
  13
  14 struct mtk_jpeg_stream {
  15         u8 *addr;
  16         u32 size;
  17         u32 curr;
  18 };
  19
  20 static int read_byte(struct mtk_jpeg_stream *stream)
  21 {
  22         if (stream->curr >= stream->size)
  23                 return -1;
  24         return stream->addr[stream->curr++];
  25 }
  26
  27 static int read_word_be(struct mtk_jpeg_stream *stream, u32 *word)
  28 {
  29         u32 temp;
  30         int byte;
  31
  32         byte = read_byte(stream);
  33         if (byte == -1)
  34                 return -1;
  35         temp = byte << 8;
  36         byte = read_byte(stream);
  37         if (byte == -1)
  38                 return -1;
  39         *word = (u32)byte | temp;
  40
  41         return 0;
  42 }
  43
  44 static void read_skip(struct mtk_jpeg_stream *stream, long len)
  45 {
  46         if (len <= 0)
  47                 return;
  48         while (len--)
  49                 read_byte(stream);
  50 }
  51
  52 static bool mtk_jpeg_do_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va,
  53                               u32 src_size)
  54 {
  55         bool notfound = true;
  56         struct mtk_jpeg_stream stream;
  57
  58         stream.addr = src_addr_va;
  59         stream.size = src_size;
  60         stream.curr = 0;
  61
  62         while (notfound) {
  63                 int i, length, byte;
  64                 u32 word;
  65
  66                 byte = read_byte(&stream);
  67                 if (byte == -1)
  68                         return false;
  69                 if (byte != 0xff)
  70                         continue;
  71                 do
  72                         byte = read_byte(&stream);
  73                 while (byte == 0xff);
  74                 if (byte == -1)
  75                         return false;
  76                 if (byte == 0)
  77                         continue;
  78
  79                 length = 0;
  80                 switch (byte) {
  81                 case JPEG_MARKER_SOF0:
  82                         /* length */
  83                         if (read_word_be(&stream, &word))
  84                                 break;
  85
  86                         /* precision */
  87                         if (read_byte(&stream) == -1)
  88                                 break;
  89
  90                         if (read_word_be(&stream, &word))
  91                                 break;
  92                         param->pic_h = word;
  93
  94                         if (read_word_be(&stream, &word))
  95                                 break;
  96                         param->pic_w = word;
  97
  98                         param->comp_num = read_byte(&stream);
  99                         if (param->comp_num != 1 && param->comp_num != 3)
 100                                 break;
 101
 102                         for (i = 0; i < param->comp_num; i++) {
 103                                 param->comp_id[i] = read_byte(&stream);
 104                                 if (param->comp_id[i] == -1)
 105                                         break;
 106
 107                                 /* sampling */
 108                                 byte = read_byte(&stream);
 109                                 if (byte == -1)
 110                                         break;
 111                                 param->sampling_w[i] = (byte >> 4) & 0x0F;
 112                                 param->sampling_h[i] = byte & 0x0F;
 113
 114                                 param->qtbl_num[i] = read_byte(&stream);
 115                                 if (param->qtbl_num[i] == -1)
 116                                         break;
 117                         }
 118
 119                         notfound = !(i == param->comp_num);
 120                         break;
 121                 case JPEG_MARKER_RST ... JPEG_MARKER_RST + 7:
 122                 case JPEG_MARKER_SOI:
 123                 case JPEG_MARKER_EOI:
 124                 case JPEG_MARKER_TEM:
 125                         break;
 126                 default:
 127                         if (read_word_be(&stream, &word))
 128                                 break;
 129                         length = (long)word - 2;
 130                         read_skip(&stream, length);
 131                         break;
 132                 }
 133         }
 134
 135         return !notfound;
 136 }
 137
 138 bool mtk_jpeg_parse(struct mtk_jpeg_dec_param *param, u8 *src_addr_va,
 139                     u32 src_size)
 140 {
 141         if (!mtk_jpeg_do_parse(param, src_addr_va, src_size))
 142                 return false;
 143         if (mtk_jpeg_dec_fill_param(param))
 144                 return false;
 145
 146         return true;
 147 }