1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/media/platform/sti/delta/delta-mjpeg-hdr.c b/drivers/media/platform/sti/delta/delta-mjpeg-hdr.c
new file mode 100644
index 000000000000..a8fd8fa0ecb5
--- /dev/null
+++ b/drivers/media/platform/sti/delta/delta-mjpeg-hdr.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2013
+ * Author: Hugues Fruchet <hugues.fruchet@st.com> for STMicroelectronics.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include "delta.h"
+#include "delta-mjpeg.h"
+
+#define MJPEG_SOF_0  0xc0
+#define MJPEG_SOF_1  0xc1
+#define MJPEG_SOI    0xd8
+#define MJPEG_MARKER 0xff
+
+static char *header_str(struct mjpeg_header *header,
+			char *str,
+			unsigned int len)
+{
+	char *cur = str;
+	unsigned int left = len;
+
+	if (!header)
+		return "";
+
+	snprintf(cur, left, "[MJPEG header]\n"
+			"|- length     = %d\n"
+			"|- precision  = %d\n"
+			"|- width      = %d\n"
+			"|- height     = %d\n"
+			"|- components = %d\n",
+			header->length,
+			header->sample_precision,
+			header->frame_width,
+			header->frame_height,
+			header->nb_of_components);
+
+	return str;
+}
+
+static int delta_mjpeg_read_sof(struct delta_ctx *pctx,
+				unsigned char *data, unsigned int size,
+				struct mjpeg_header *header)
+{
+	struct delta_dev *delta = pctx->dev;
+	unsigned int offset = 0;
+
+	if (size < 64)
+		goto err_no_more;
+
+	memset(header, 0, sizeof(*header));
+	header->length           = be16_to_cpu(*(__be16 *)(data + offset));
+	offset += sizeof(u16);
+	header->sample_precision = *(u8 *)(data + offset);
+	offset += sizeof(u8);
+	header->frame_height     = be16_to_cpu(*(__be16 *)(data + offset));
+	offset += sizeof(u16);
+	header->frame_width      = be16_to_cpu(*(__be16 *)(data + offset));
+	offset += sizeof(u16);
+	header->nb_of_components = *(u8 *)(data + offset);
+	offset += sizeof(u8);
+
+	if (header->nb_of_components >= MJPEG_MAX_COMPONENTS) {
+		dev_err(delta->dev,
+			"%s   unsupported number of components (%d > %d)\n",
+			pctx->name, header->nb_of_components,
+			MJPEG_MAX_COMPONENTS);
+		return -EINVAL;
+	}
+
+	if ((offset + header->nb_of_components *
+	     sizeof(header->components[0])) > size)
+		goto err_no_more;
+
+	return 0;
+
+err_no_more:
+	dev_err(delta->dev,
+		"%s   sof: reached end of %d size input stream\n",
+		pctx->name, size);
+	return -ENODATA;
+}
+
+int delta_mjpeg_read_header(struct delta_ctx *pctx,
+			    unsigned char *data, unsigned int size,
+			    struct mjpeg_header *header,
+			    unsigned int *data_offset)
+{
+	struct delta_dev *delta = pctx->dev;
+	unsigned char str[200];
+
+	unsigned int ret = 0;
+	unsigned int offset = 0;
+	unsigned int soi = 0;
+
+	if (size < 2)
+		goto err_no_more;
+
+	offset = 0;
+	while (1) {
+		if (data[offset] == MJPEG_MARKER)
+			switch (data[offset + 1]) {
+			case MJPEG_SOI:
+				soi = 1;
+				*data_offset = offset;
+				break;
+
+			case MJPEG_SOF_0:
+			case MJPEG_SOF_1:
+				if (!soi) {
+					dev_err(delta->dev,
+						"%s   wrong sequence, got SOF while SOI not seen\n",
+						pctx->name);
+					return -EINVAL;
+				}
+
+				ret = delta_mjpeg_read_sof(pctx,
+							   &data[offset + 2],
+							   size - (offset + 2),
+							   header);
+				if (ret)
+					goto err;
+
+				goto done;
+
+			default:
+				break;
+			}
+
+		offset++;
+		if ((offset + 2) >= size)
+			goto err_no_more;
+	}
+
+done:
+	dev_dbg(delta->dev,
+		"%s   found header @ offset %d:\n%s", pctx->name,
+		*data_offset,
+		header_str(header, str, sizeof(str)));
+	return 0;
+
+err_no_more:
+	dev_err(delta->dev,
+		"%s   no header found within %d bytes input stream\n",
+		pctx->name, size);
+	return -ENODATA;
+
+err:
+	return ret;
+}