[RFC PATCH 2/3] test: ipa: libipa: Add CameraSensorHelper Gain Model tests

[Kieran Bingham]

Introduce a test that validates conversion of the gain model
in each CameraSensorHelper.

It should be expected that if a gainCode produces a given gain
value, then converting that gain back should produce the same
result.

This test fails on the following CameraSensorHelpers:
 - imx219 imx258 imx283 imx290 imx296 imx327 imx335 imx477

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---

This test also fails on the ar0521 helper as that has a defined code
limit of '63', which the test does not yet have a way to infer.

Adding a 'maxCode' helper to the base class may be the way to go here,
and would also let us define a maximum value for other helpers directly.

 test/ipa/camera_sensor_helper.cpp | 69 +++++++++++++++++++++++++++++++
 test/ipa/meson.build              |  1 +
 2 files changed, 70 insertions(+)
 create mode 100644 test/ipa/camera_sensor_helper.cpp

diff --git a/test/ipa/camera_sensor_helper.cpp b/test/ipa/camera_sensor_helper.cpp
new file mode 100644
index 000000000000..2d37628f87c4
--- /dev/null
+++ b/test/ipa/camera_sensor_helper.cpp
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Ideas on Board Oy.
+ */
+
+#include "libipa/camera_sensor_helper.h"
+
+#include <iostream>
+#include <string.h>
+
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+using namespace libcamera::ipa;
+
+class CameraSensorHelperTest : public Test
+{
+protected:
+	int testGainModel(std::string model)
+	{
+		int ret = TestPass;
+
+		std::unique_ptr<CameraSensorHelper> camHelper_;
+
+		camHelper_ = CameraSensorHelperFactoryBase::create(model);
+		if (!camHelper_) {
+			std::cout
+				<< "Failed to create camera sensor helper for "
+				<< model;
+			return TestFail;
+		}
+
+		for (unsigned int i = 0; i < 240; i++) {
+			float gain = camHelper_->gain(i);
+			uint32_t gainCode = camHelper_->gainCode(gain);
+
+			if (i != gainCode) {
+				std::cout << model << ": Gain conversions failed: "
+					  << i << " : " << gain << " : "
+					  << gainCode << std::endl;
+
+				ret = TestFail;
+			}
+		};
+
+		return ret;
+	}
+
+	int run() override
+	{
+		unsigned int failures = 0;
+
+		std::vector<CameraSensorHelperFactoryBase *> factories;
+
+		for (auto factory : CameraSensorHelperFactoryBase::factories()) {
+			const std::string &model = factory->name();
+
+			cout << "Testing CameraSensorHelper for " << model << endl;
+
+			if (testGainModel(factory->name()) == TestFail)
+				failures++;
+		}
+
+		return failures ? TestFail : TestPass;
+	}
+};
+
+TEST_REGISTER(CameraSensorHelperTest)
diff --git a/test/ipa/meson.build b/test/ipa/meson.build
index 180b0da0a51a..c99385a7cb8b 100644
--- a/test/ipa/meson.build
+++ b/test/ipa/meson.build
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: CC0-1.0
 
 ipa_test = [
+    {'name': 'camera_sensor_helper', 'sources': ['camera_sensor_helper.cpp']},
     {'name': 'ipa_module_test', 'sources': ['ipa_module_test.cpp']},
     {'name': 'ipa_interface_test', 'sources': ['ipa_interface_test.cpp']},
 ]
-- 
2.34.1