[libcamera-devel] [RFC PATCH v2 1/3] ipa: ipu3: Separate out frame context queue as a distinct class

[Umang Jain]

There are cases where we need more checks and balance to be carried out
by the frame context queue class. For that, separate it out as a
distinct class on which we can build upon.

For now, a minimialistic implementation is provided with .get(frame)
helper which returns a IPAFrameContext for the required frame.
Going ahead more such helpers can be provided to access/modify the
frame context queue.

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
 src/ipa/ipu3/ipa_context.cpp | 49 ++++++++++++++++++++++++++++++++++--
 src/ipa/ipu3/ipa_context.h   | 11 +++++++-
 src/ipa/ipu3/ipu3.cpp        |  6 ++---
 3 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/src/ipa/ipu3/ipa_context.cpp b/src/ipa/ipu3/ipa_context.cpp
index 13cdb835..e5010e3f 100644
--- a/src/ipa/ipu3/ipa_context.cpp
+++ b/src/ipa/ipu3/ipa_context.cpp
@@ -7,12 +7,18 @@
 
 #include "ipa_context.h"
 
+#include <libcamera/base/log.h>
+
 /**
  * \file ipa_context.h
  * \brief Context and state information shared between the algorithms
  */
 
-namespace libcamera::ipa::ipu3 {
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(IPAIPU3)
+
+namespace ipa::ipu3 {
 
 /**
  * \struct IPASessionConfiguration
@@ -211,4 +217,43 @@ IPAFrameContext::IPAFrameContext(uint32_t id, const ControlList &reqControls)
  * \brief Analogue gain multiplier
  */
 
-} /* namespace libcamera::ipa::ipu3 */
+/**
+ * \brief FCQueue constructor
+ */
+FCQueue::FCQueue()
+{
+	clear();
+}
+
+/**
+ * Retrieve the IPAFrameContext for the frame
+ * \param[in] frame Frame number for which the IPAFrameContext needs to
+ * retrieved
+ *
+ * \return Reference to the IPAFrameContext
+ */
+IPAFrameContext &FCQueue::get(uint32_t frame)
+{
+	IPAFrameContext &frameContext = this->at(frame % kMaxFrameContexts);
+
+	if (frame != frameContext.frame) {
+		LOG(IPAIPU3, Warning)
+			<< "Got wrong frame context for frame" << frame
+			<< " or frame context doesn't exist yet";
+	}
+
+	return frameContext;
+}
+
+/**
+ * \brief Clear the FCQueue by resetting all the entries in the ring-buffer
+ */
+void FCQueue::clear()
+{
+	IPAFrameContext initFrameContext;
+	this->fill(initFrameContext);
+}
+
+} /* namespace ipa::ipu3 */
+
+} /* namespace libcamera */
diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
index 42e11141..61454b41 100644
--- a/src/ipa/ipu3/ipa_context.h
+++ b/src/ipa/ipu3/ipa_context.h
@@ -89,11 +89,20 @@ struct IPAFrameContext {
 	ControlList frameControls;
 };
 
+class FCQueue : public std::array<IPAFrameContext, kMaxFrameContexts>
+{
+public:
+	FCQueue();
+
+	void clear();
+	IPAFrameContext &get(uint32_t frame);
+};
+
 struct IPAContext {
 	IPASessionConfiguration configuration;
 	IPAActiveState activeState;
 
-	std::array<IPAFrameContext, kMaxFrameContexts> frameContexts;
+	FCQueue frameContexts;
 };
 
 } /* namespace ipa::ipu3 */
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index 2f6bb672..c48d2f62 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -456,8 +456,8 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
 
 	/* Clean IPAActiveState at each reconfiguration. */
 	context_.activeState = {};
-	IPAFrameContext initFrameContext;
-	context_.frameContexts.fill(initFrameContext);
+	context_.frameContexts.clear();
+
 
 	if (!validateSensorControls()) {
 		LOG(IPAIPU3, Error) << "Sensor control validation failed.";
@@ -569,7 +569,7 @@ void IPAIPU3::processStatsBuffer(const uint32_t frame,
 	const ipu3_uapi_stats_3a *stats =
 		reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
 
-	IPAFrameContext &frameContext = context_.frameContexts[frame % kMaxFrameContexts];
+	IPAFrameContext &frameContext = context_.frameContexts.get(frame);
 
 	if (frameContext.frame != frame)
 		LOG(IPAIPU3, Warning) << "Frame " << frame << " does not match its frame context";
-- 
2.31.1