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
14struct mtk_jpeg_stream {
15 u8 *addr;
16 u32 size;
17 u32 curr;
18};
19
20static 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
27static 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
44static 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
52static 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: &stream);
67 if (byte == -1)
68 return false;
69 if (byte != 0xff)
70 continue;
71 do
72 byte = read_byte(stream: &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: &stream, word: &word))
84 break;
85
86 /* precision */
87 if (read_byte(stream: &stream) == -1)
88 break;
89
90 if (read_word_be(stream: &stream, word: &word))
91 break;
92 param->pic_h = word;
93
94 if (read_word_be(stream: &stream, word: &word))
95 break;
96 param->pic_w = word;
97
98 param->comp_num = read_byte(stream: &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: &stream);
104 if (param->comp_id[i] == -1)
105 break;
106
107 /* sampling */
108 byte = read_byte(stream: &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: &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: &stream, word: &word))
128 break;
129 length = (long)word - 2;
130 read_skip(stream: &stream, len: length);
131 break;
132 }
133 }
134
135 return !notfound;
136}
137
138bool 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}
148

source code of linux/drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_parse.c