1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/media/platform/mtk-jpeg/mtk_jpeg_parse.c b/drivers/media/platform/mtk-jpeg/mtk_jpeg_parse.c
new file mode 100644
index 0000000..3886854
--- /dev/null
+++ b/drivers/media/platform/mtk-jpeg/mtk_jpeg_parse.c
@@ -0,0 +1,160 @@
+/*
+ * 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++];
+}
+
+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;
+}
+
+static void read_skip(struct mtk_jpeg_stream *stream, long len)
+{
+	if (len <= 0)
+		return;
+	while (len--)
+		read_byte(stream);
+}
+
+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;
+}
+
+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;
+}