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 }
148