ipa: raspberrypi: Generalise the SMIA metadata parser

Instead of having each CamHelper subclass the MdParserSmia, change the
implementation of MdParserSmia to be more generic. The MdParserSmia now gets
given a list of registers to search for and helper functions are used to compute
exposure lines and gain codes from these registers.

Update the imx219 and imx477 CamHelpers by using this new mechanism.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 55 insertions, 12 deletions

diff --git a/src/ipa/raspberrypi/md_parser_smia.cpp b/src/ipa/raspberrypi/md_parser_smia.cpp
index 0a148755..ea5eac41 100644
--- a/src/ipa/raspberrypi/md_parser_smia.cpp
+++ b/src/ipa/raspberrypi/md_parser_smia.cpp
@@ -4,11 +4,12 @@
  *
  * md_parser_smia.cpp - SMIA specification based embedded data parser
  */
-#include <assert.h>
 
+#include <libcamera/base/log.h>
 #include "md_parser.hpp"
 
 using namespace RPiController;
+using namespace libcamera;
 
 /*
  * This function goes through the embedded data to find the offsets (not
@@ -26,18 +27,61 @@ constexpr unsigned int REG_LOW_BITS = 0xa5;
 constexpr unsigned int REG_VALUE = 0x5a;
 constexpr unsigned int REG_SKIP = 0x55;
 
-MdParserSmia::ParseStatus MdParserSmia::findRegs(libcamera::Span<const uint8_t> buffer,
-						 uint32_t regs[], int offsets[],
-						 unsigned int num_regs)
+MdParserSmia::MdParserSmia(std::initializer_list<uint32_t> registerList)
 {
-	assert(num_regs > 0);
+	for (auto r : registerList)
+		offsets_[r] = {};
+}
+
+MdParser::Status MdParserSmia::Parse(libcamera::Span<const uint8_t> buffer,
+				     RegisterMap &registers)
+{
+	if (reset_) {
+		/*
+		 * Search again through the metadata for all the registers
+		 * requested.
+		 */
+		ASSERT(bits_per_pixel_);
+
+		for (const auto &kv : offsets_)
+			offsets_[kv.first] = {};
+
+		ParseStatus ret = findRegs(buffer);
+		/*
+		 * > 0 means "worked partially but parse again next time",
+		 * < 0 means "hard error".
+		 *
+		 * In either case, we retry parsing on the next frame.
+		 */
+		if (ret != PARSE_OK)
+			return ERROR;
+
+		reset_ = false;
+	}
+
+	/* Populate the register values requested. */
+	registers.clear();
+	for (const auto &[reg, offset] : offsets_) {
+		if (!offset) {
+			reset_ = true;
+			return NOTFOUND;
+		}
+		registers[reg] = buffer[offset.value()];
+	}
+
+	return OK;
+}
+
+MdParserSmia::ParseStatus MdParserSmia::findRegs(libcamera::Span<const uint8_t> buffer)
+{
+	ASSERT(offsets_.size());
 
 	if (buffer[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;
+	unsigned int reg_num = 0, regs_done = 0;
 
 	while (1) {
 		int tag = buffer[current_offset++];
@@ -89,13 +133,12 @@ MdParserSmia::ParseStatus MdParserSmia::findRegs(libcamera::Span<const uint8_t>
 			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;
+				auto reg = offsets_.find(reg_num);
+
+				if (reg != offsets_.end()) {
+					offsets_[reg_num] = current_offset - 1;
 
-					if (++first_reg == num_regs)
+					if (++regs_done == offsets_.size())
 						return PARSE_OK;
 				}
 				reg_num++;