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-rw-r--r--src/ipa/raspberrypi/md_parser.cpp101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/ipa/raspberrypi/md_parser.cpp b/src/ipa/raspberrypi/md_parser.cpp
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+++ b/src/ipa/raspberrypi/md_parser.cpp
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+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi (Trading) Limited
+ *
+ * md_parser.cpp - image sensor metadata parsers
+ */
+
+#include <assert.h>
+#include <map>
+#include <string.h>
+
+#include "md_parser.hpp"
+
+using namespace RPi;
+
+// This function goes through the embedded data to find the offsets (not
+// values!), in the data block, where the values of the given registers can
+// subsequently be found.
+
+// Embedded data tag bytes, from Sony IMX219 datasheet but general to all SMIA
+// sensors, I think.
+
+#define LINE_START 0x0a
+#define LINE_END_TAG 0x07
+#define REG_HI_BITS 0xaa
+#define REG_LOW_BITS 0xa5
+#define REG_VALUE 0x5a
+#define REG_SKIP 0x55
+
+MdParserSmia::ParseStatus MdParserSmia::findRegs(unsigned char *data,
+ uint32_t regs[], int offsets[],
+ unsigned int num_regs)
+{
+ assert(num_regs > 0);
+ if (data[0] != LINE_START)
+ return NO_LINE_START;
+
+ unsigned int current_offset = 1; // after the LINE_START
+ unsigned int current_line_start = 0, current_line = 0;
+ unsigned int reg_num = 0, first_reg = 0;
+ ParseStatus retcode = PARSE_OK;
+ while (1) {
+ int tag = data[current_offset++];
+ if ((bits_per_pixel_ == 10 &&
+ (current_offset + 1 - current_line_start) % 5 == 0) ||
+ (bits_per_pixel_ == 12 &&
+ (current_offset + 1 - current_line_start) % 3 == 0)) {
+ if (data[current_offset++] != REG_SKIP)
+ return BAD_DUMMY;
+ }
+ int data_byte = data[current_offset++];
+ //printf("Offset %u, tag 0x%02x data_byte 0x%02x\n", current_offset-1, tag, data_byte);
+ if (tag == LINE_END_TAG) {
+ if (data_byte != LINE_END_TAG)
+ return BAD_LINE_END;
+ if (num_lines_ && ++current_line == num_lines_)
+ return MISSING_REGS;
+ if (line_length_bytes_) {
+ current_offset =
+ current_line_start + line_length_bytes_;
+ // Require whole line to be in the buffer (if buffer size set).
+ if (buffer_size_bytes_ &&
+ current_offset + line_length_bytes_ >
+ buffer_size_bytes_)
+ return MISSING_REGS;
+ if (data[current_offset] != LINE_START)
+ return NO_LINE_START;
+ } else {
+ // allow a zero line length to mean "hunt for the next line"
+ while (data[current_offset] != LINE_START &&
+ current_offset < buffer_size_bytes_)
+ current_offset++;
+ if (current_offset == buffer_size_bytes_)
+ return NO_LINE_START;
+ }
+ // inc current_offset to after LINE_START
+ current_line_start =
+ current_offset++;
+ } else {
+ if (tag == REG_HI_BITS)
+ reg_num = (reg_num & 0xff) | (data_byte << 8);
+ else if (tag == REG_LOW_BITS)
+ reg_num = (reg_num & 0xff00) | data_byte;
+ else if (tag == REG_SKIP)
+ reg_num++;
+ else if (tag == REG_VALUE) {
+ while (reg_num >=
+ // assumes registers are in order...
+ regs[first_reg]) {
+ if (reg_num == regs[first_reg])
+ offsets[first_reg] =
+ current_offset - 1;
+ if (++first_reg == num_regs)
+ return retcode;
+ }
+ reg_num++;
+ } else
+ return ILLEGAL_TAG;
+ }
+ }
+}