From 570bcd3c83259bfdcc06817d92ce5ef0aa656fc0 Mon Sep 17 00:00:00 2001
From: Jason Yuan <jasonyuan@google.com>
Date: Thu, 23 Mar 2023 13:56:27 -0700
Subject: [PATCH] test: adc: current sense amplifier

adds tests for the current sense amplifier binding macro and rescaling
function.

Signed-off-by: Jason Yuan <jasonyuan@google.com>
---
 .../adc_rescale/boards/native_posix.overlay   | 20 +++++++-
 tests/drivers/adc/adc_rescale/src/main.c      | 50 +++++++++++++++++--
 2 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/tests/drivers/adc/adc_rescale/boards/native_posix.overlay b/tests/drivers/adc/adc_rescale/boards/native_posix.overlay
index bf937a69849..aa146b86369 100644
--- a/tests/drivers/adc/adc_rescale/boards/native_posix.overlay
+++ b/tests/drivers/adc/adc_rescale/boards/native_posix.overlay
@@ -16,13 +16,20 @@
 
 	sensor1: css {
 		compatible = "current-sense-shunt";
-		io-channels = <&adc0 0>;
+		io-channels = <&adc0 1>;
 		shunt-resistor-micro-ohms = <500000>;
 	};
 
+	sensor2: csa {
+		compatible = "current-sense-amplifier";
+		io-channels = <&adc0 2>;
+		sense-resistor-micro-ohms = <5000>;
+		sense-gain-mult = <100>;
+	};
+
 	adc0: adc {
 		compatible = "zephyr,adc-emul";
-		nchannels = <2>;
+		nchannels = <3>;
 		ref-internal-mv = <3300>;
 		ref-external1-mv = <5000>;
 		#io-channel-cells = <1>;
@@ -51,4 +58,13 @@
 		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
 		zephyr,resolution = <12>;
 	};
+
+	channel@2 {
+		reg = <2>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,vref-mv = <3300>;
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
 };
diff --git a/tests/drivers/adc/adc_rescale/src/main.c b/tests/drivers/adc/adc_rescale/src/main.c
index 27106f0f76e..e8af4d4f58a 100644
--- a/tests/drivers/adc/adc_rescale/src/main.c
+++ b/tests/drivers/adc/adc_rescale/src/main.c
@@ -8,6 +8,7 @@
 #include <zephyr/drivers/adc/adc_emul.h>
 #include <zephyr/drivers/adc/voltage_divider.h>
 #include <zephyr/drivers/adc/current_sense_shunt.h>
+#include <zephyr/drivers/adc/current_sense_amplifier.h>
 #include <zephyr/kernel.h>
 #include <zephyr/ztest.h>
 
@@ -16,6 +17,7 @@
 
 #define ADC_TEST_NODE_0 DT_NODELABEL(sensor0)
 #define ADC_TEST_NODE_1 DT_NODELABEL(sensor1)
+#define ADC_TEST_NODE_2 DT_NODELABEL(sensor2)
 
 /**
  * @brief Get ADC emulated device
@@ -88,9 +90,9 @@ ZTEST_USER(adc_rescale, test_adc_voltage_divider)
 }
 
 /*
- * test_adc_current_sensor
+ * test_adc_current_sense_shunt
  */
-static int test_task_current_sensor(void)
+static int test_task_current_sense_shunt(void)
 {
 	int ret;
 	int32_t calculated_current = 0;
@@ -122,9 +124,49 @@ static int test_task_current_sensor(void)
 	return TC_PASS;
 }
 
-ZTEST_USER(adc_rescale, test_adc_current_sensor)
+ZTEST_USER(adc_rescale, test_adc_current_sense_shunt)
 {
-	zassert_true(test_task_current_sensor() == TC_PASS);
+	zassert_true(test_task_current_sense_shunt() == TC_PASS);
+}
+
+/*
+ * test_adc_current_sense_amplifier
+ */
+static int test_task_current_sense_amplifier(void)
+{
+	int ret;
+	int32_t calculated_current = 0;
+	int32_t input_mv = 3000;
+	const struct current_sense_amplifier_dt_spec adc_node_2 =
+		CURRENT_SENSE_AMPLIFIER_DT_SPEC_GET(ADC_TEST_NODE_2);
+
+	ret = init_adc(&adc_node_2.port, input_mv);
+	zassert_equal(ret, 0, "Setting up of the third channel failed with code %d", ret);
+
+	struct adc_sequence sequence = {
+		.buffer = &calculated_current,
+		.buffer_size = sizeof(calculated_current),
+	};
+	adc_sequence_init_dt(&adc_node_2.port, &sequence);
+
+	ret = adc_read(adc_node_2.port.dev, &sequence);
+	zassert_equal(ret, 0, "adc_read() failed with code %d", ret);
+
+	ret = adc_raw_to_millivolts_dt(&adc_node_2.port, &calculated_current);
+	zassert_equal(ret, 0, "adc_raw_to_millivolts_dt() failed with code %d", ret);
+
+	current_sense_amplifier_scale_dt(&adc_node_2, &calculated_current);
+
+	zassert_within(calculated_current, input_mv * 2, MV_OUTPUT_EPS,
+		       "%u != %u should have set value", calculated_current,
+		       input_mv * 2);
+
+	return TC_PASS;
+}
+
+ZTEST_USER(adc_rescale, test_adc_current_sense_amplifier)
+{
+	zassert_true(test_task_current_sense_amplifier() == TC_PASS);
 }
 
 void *adc_rescale_setup(void)