test: sensor: ina237: add emulator unit test

Add emulator unit test of the INA237.

Signed-off-by: Eric Holmberg <eric.holmberg@northriversystems.co.nz>

drivers/sensor/ina23x/ina237.c

@@ -20,22 +20,29 @@ LOG_MODULE_REGISTER(INA237, CONFIG_SENSOR_LOG_LEVEL);
 #define INA237_CAL_SCALING 8192ULL
 
 /** @brief The LSB value for the bus voltage register, in microvolts/LSB. */
-#define INA237_BUS_VOLTAGE_UV_LSB 3125
+#define INA237_BUS_VOLTAGE_TO_uV(x) ((x) * 3125U)
 
 /** @brief Power scaling (scaled by 10) */
 #define INA237_POWER_SCALING 2
 
+/**
+ * @brief Scale die temperture from 0.125 degC/bit to micro-degrees C
+ *  Note that the bottom 4 bits are reserved and are always zero.
+ */
+#define INA237_DIETEMP_TO_uDegC(x) (((x) >> 4) * 125000)
+
 static int ina237_channel_get(const struct device *dev, enum sensor_channel chan,
 			      struct sensor_value *val)
 {
 	struct ina237_data *data = dev->data;
 	const struct ina237_config *config = dev->config;
 	uint32_t bus_uv, current_ua, power_uw;
-	int32_t sign;
+	int32_t temp_uDegC;
+	int32_t sign = 1;
 
 	switch (chan) {
 	case SENSOR_CHAN_VOLTAGE:
-		bus_uv = data->bus_voltage * INA237_BUS_VOLTAGE_UV_LSB;
+		bus_uv = INA237_BUS_VOLTAGE_TO_uV(data->bus_voltage);
 
 		val->val1 = bus_uv / 1000000U;
 		val->val2 = bus_uv % 1000000U;
@@ -67,6 +74,17 @@ static int ina237_channel_get(const struct device *dev, enum sensor_channel chan
 		val->val2 = (int32_t)(power_uw % 1000000U);
 		break;
 
+	case SENSOR_CHAN_DIE_TEMP:
+		temp_uDegC = INA237_DIETEMP_TO_uDegC(data->die_temp);
+
+		val->val1 = temp_uDegC / 1000000L;
+		val->val2 = abs(temp_uDegC) % 1000000L;
+
+		if (temp_uDegC < 0) {
+			val->val2 = -val->val2;
+		}
+		break;
+
 	default:
 		return -ENOTSUP;
 	}
@@ -155,6 +173,14 @@ static int ina237_read_data(const struct device *dev)
 		}
 	}
 
+	if ((data->chan == SENSOR_CHAN_ALL) || (data->chan == SENSOR_CHAN_DIE_TEMP)) {
+		ret = ina23x_reg_read_16(&config->bus, INA237_REG_DIETEMP, &data->die_temp);
+		if (ret < 0) {
+			LOG_ERR("Failed to read temperature");
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -169,7 +195,7 @@ static int ina237_sample_fetch(const struct device *dev, enum sensor_channel cha
 	struct ina237_data *data = dev->data;
 
 	if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_VOLTAGE && chan != SENSOR_CHAN_CURRENT &&
-	    chan != SENSOR_CHAN_POWER) {
+	    chan != SENSOR_CHAN_POWER && chan != SENSOR_CHAN_DIE_TEMP) {
 		return -ENOTSUP;
 	}
 

drivers/sensor/ina23x/ina237.h

@@ -21,7 +21,7 @@
 #define INA237_REG_CALIB      0x02
 #define INA237_REG_SHUNT_VOLT 0x04
 #define INA237_REG_BUS_VOLT   0x05
-#define INA237_REG_MASK       0x06
+#define INA237_REG_DIETEMP    0x06
 #define INA237_REG_CURRENT    0x07
 #define INA237_REG_POWER      0x08
 #define INA237_REG_ALERT      0x0B
@@ -40,6 +40,7 @@ struct ina237_data {
 	uint16_t current;
 	uint16_t bus_voltage;
 	uint32_t power;
+	int16_t die_temp;
 	enum sensor_channel chan;
 	struct ina23x_trigger trigger;
 };

tests/drivers/sensor/ina237/CMakeLists.txt

@@ -0,0 +1,13 @@
+# Copyright (c) 2023 North River Systems Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(device)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})
+
+# Include the INA23x driver path and unit-test path for private header inclusion
+zephyr_include_directories(./src)
+zephyr_include_directories($ENV{ZEPHYR_BASE}/drivers/sensor/ina23x)

tests/drivers/sensor/ina237/boards/native_posix.overlay

@@ -0,0 +1,17 @@
+/* Copyright (c) 2023 North River Systems Ltd
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/sensor/ina237.h>
+
+&i2c0 {
+	status = "okay";
+
+	ina237_default_test: ina237@40 {
+		compatible = "ti,ina237";
+		reg = <0x40>;
+		rshunt-micro-ohms = <400>;
+		current-lsb-microamps = <123>;
+		status = "okay";
+	};
+};

tests/drivers/sensor/ina237/prj.conf

@@ -0,0 +1,14 @@
+# Copyright (c) 2023 North River Systems Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_ZTEST=y
+CONFIG_ZTEST_NEW_API=y
+CONFIG_SENSOR=y
+CONFIG_EMUL=y
+
+CONFIG_I2C_EMUL=y
+CONFIG_I2C_LOG_LEVEL_DBG=y
+
+CONFIG_INA237=y
+
+CONFIG_CBPRINTF_FP_SUPPORT=y

tests/drivers/sensor/ina237/src/ina237_emul.c

@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2023 North River Systems Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Emulator for the TI INA237 I2C power monitor
+ */
+#define DT_DRV_COMPAT ti_ina237
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/i2c_emul.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/sys/byteorder.h>
+#include <ina237.h>
+#include <ina237_emul.h>
+
+LOG_MODULE_REGISTER(INA237_EMUL, CONFIG_SENSOR_LOG_LEVEL);
+
+/* Register ID, size, and value table */
+struct ina237_reg {
+	uint8_t id;
+	uint8_t bytes;
+	uint32_t value;
+};
+
+/* Emulator configuration passed into driver instance */
+struct ina237_emul_cfg {
+	uint16_t addr;
+};
+
+struct ina237_emul_data {
+	struct ina237_reg ina237_regs[INA237_REGISTER_COUNT];
+};
+
+static struct ina237_reg *get_register(struct ina237_emul_data *data, int reg)
+{
+	for (int i = 0; i < INA237_REGISTER_COUNT; i++) {
+		if (data->ina237_regs[i].id == reg) {
+			return &data->ina237_regs[i];
+		}
+	}
+	return NULL;
+}
+
+int ina237_mock_set_register(void *data_ptr, int reg, uint32_t value)
+{
+	struct ina237_reg *reg_ptr = get_register(data_ptr, reg);
+
+	if (reg_ptr == NULL) {
+		return -EINVAL;
+	}
+
+	reg_ptr->value = value;
+	return 0;
+}
+
+int ina237_mock_get_register(void *data_ptr, int reg, uint32_t *value_ptr)
+{
+	struct ina237_reg *reg_ptr = get_register(data_ptr, reg);
+
+	if (reg_ptr == NULL || value_ptr == NULL) {
+		return -EINVAL;
+	}
+
+	*value_ptr = reg_ptr->value;
+	return 0;
+}
+
+static int ina237_emul_transfer_i2c(const struct emul *target, struct i2c_msg msgs[], int num_msgs,
+				    int addr)
+{
+	struct ina237_emul_data *data = (struct ina237_emul_data *)target->data;
+
+	/* The INA237 uses big-endian read 16, read 24, and write 16 transactions */
+	if (!msgs || num_msgs < 1 || num_msgs > 2) {
+		LOG_ERR("Invalid number of messages: %d", num_msgs);
+		return -EIO;
+	}
+
+	if (msgs[0].flags & I2C_MSG_READ) {
+		LOG_ERR("Expected write");
+		return -EIO;
+	}
+
+	if (num_msgs == 1) {
+		/* Write16 Transaction */
+		if (msgs[0].len != 3) {
+			LOG_ERR("Expected 3 bytes");
+			return -EIO;
+		}
+
+		/* Write 2 bytes */
+		uint8_t reg = msgs[0].buf[0];
+		uint16_t val = sys_get_be16(&msgs[0].buf[1]);
+
+		struct ina237_reg *reg_ptr = get_register(data, reg);
+
+		if (!reg_ptr) {
+			LOG_ERR("Invalid register: %02x", reg);
+			return -EIO;
+		}
+		reg_ptr->value = val;
+		LOG_DBG("Write reg %02x: %04x", reg, val);
+	} else {
+		/* Read 2 or 3 bytes */
+		if ((msgs[1].flags & I2C_MSG_READ) == I2C_MSG_WRITE) {
+			LOG_ERR("Expected read");
+			return -EIO;
+		}
+		uint8_t reg = msgs[0].buf[0];
+
+		struct ina237_reg *reg_ptr = get_register(data, reg);
+
+		if (!reg_ptr) {
+			LOG_ERR("Invalid register: %02x", reg);
+			return -EIO;
+		}
+
+		if (msgs[1].len == 2) {
+			sys_put_be16(reg_ptr->value, msgs[1].buf);
+			LOG_DBG("Read16 reg %02x: %04x", reg, reg_ptr->value);
+		} else if (msgs[1].len == 3) {
+			sys_put_be24(reg_ptr->value, msgs[1].buf);
+			LOG_DBG("Read24 reg %02x: %06x", reg, reg_ptr->value);
+		} else {
+			LOG_ERR("Invalid read length: %d", msgs[1].len);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int ina237_emul_init(const struct emul *target, const struct device *parent)
+{
+	ARG_UNUSED(target);
+	ARG_UNUSED(parent);
+
+	return 0;
+}
+
+static const struct i2c_emul_api ina237_emul_api_i2c = {
+	.transfer = ina237_emul_transfer_i2c,
+};
+
+#define INA237_EMUL(n)									\
+	static const struct ina237_emul_cfg ina237_emul_cfg_##n = {			\
+		.addr = DT_INST_REG_ADDR(n)						\
+	};										\
+	static struct ina237_emul_data ina237_emul_data_##n = {				\
+		.ina237_regs = {							\
+			{INA237_REG_CONFIG, 2, 0},					\
+			{INA237_REG_ADC_CONFIG, 2, 0xFB68},				\
+			{INA237_REG_CALIB, 2, 0x1000},					\
+			{INA237_REG_SHUNT_VOLT, 2, 0},					\
+			{INA237_REG_BUS_VOLT, 2, 0},					\
+			{INA237_REG_DIETEMP, 2, 0},					\
+			{INA237_REG_CURRENT, 2, 0},					\
+			{INA237_REG_POWER, 3, 0},					\
+			{INA237_REG_ALERT, 2, 0x0001},					\
+			{INA237_REG_SOVL, 2, 0x7FFF},					\
+			{INA237_REG_SUVL, 2, 0x8000},					\
+			{INA237_REG_BOVL, 2, 0x7FFF},					\
+			{INA237_REG_BUVL, 2, 0},					\
+			{INA237_REG_TEMP_LIMIT, 2, 0x7FFF},				\
+			{INA237_REG_PWR_LIMIT, 2, 0xFFFF},				\
+			{INA237_REG_MANUFACTURER_ID, 2, INA237_MANUFACTURER_ID},	\
+		}};									\
+	EMUL_DT_INST_DEFINE(n, ina237_emul_init, &ina237_emul_data_##n, &ina237_emul_cfg_##n, \
+			    &ina237_emul_api_i2c, NULL)
+
+DT_INST_FOREACH_STATUS_OKAY(INA237_EMUL)

tests/drivers/sensor/ina237/src/ina237_emul.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2023 North River Systems Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Emulator for the TI INA237 I2C power monitor
+ */
+#ifndef INA237_EMUL_H_
+#define INA237_EMUL_H_
+
+#define INA237_REGISTER_COUNT 16
+
+int ina237_mock_set_register(void *data_ptr, int reg, uint32_t value);
+int ina237_mock_get_register(void *data_ptr, int reg, uint32_t *value_ptr);
+
+#endif /* INA237_EMUL_H_ */

tests/drivers/sensor/ina237/src/ina237_test.c

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2023 North River Systems Ltd
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/i2c_emul.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/ztest.h>
+
+#include <ina237_emul.h>
+#include <ina237.h>
+
+struct ina237_fixture {
+	const struct device *dev;
+	const struct emul *mock;
+	const uint16_t current_lsb_uA;
+	const uint16_t rshunt_uOhms;
+	const uint16_t config;
+};
+
+/**
+ * @brief Verify devicetree default configuration is correct.
+ */
+ZTEST(ina237_0, test_default_config)
+{
+	const struct ina237_config *config;
+	const struct device *dev = DEVICE_DT_GET(DT_NODELABEL(ina237_default_test));
+
+	zassert_not_null(dev);
+	config = dev->config;
+	zassert_not_null(config);
+
+	/* confirm default DT settings */
+	zexpect_equal(0xFB68, config->adc_config,
+		"0xFB68 != adc_config (0x%x)", config->adc_config);
+	zexpect_equal(0x0000, config->config);
+}
+
+/**
+ * @brief Verify bus voltages for all ina237 nodes in DT
+ *
+ * @param fixture
+ */
+static void test_bus_voltage(struct ina237_fixture *fixture)
+{
+	zassert_not_null(fixture->mock);
+
+	/* 16-bit signed value for voltage register (but always positive) 3.125 mV/bit */
+	const int16_t voltage_reg_vectors[] = {
+		32767,
+		27200,	/* 85V maximum voltage */
+		1000,
+		100,
+		1,
+		0,
+	};
+
+	for (int idx = 0; idx < ARRAY_SIZE(voltage_reg_vectors); idx++) {
+		struct sensor_value sensor_val;
+
+		ina237_mock_set_register(fixture->mock->data, INA237_REG_BUS_VOLT,
+			voltage_reg_vectors[idx]);
+
+		/* Verify sensor value is correct */
+		zassert_ok(sensor_sample_fetch(fixture->dev));
+		zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_VOLTAGE, &sensor_val));
+
+		double voltage_actual_V = sensor_value_to_double(&sensor_val);
+		double voltage_expected_V = voltage_reg_vectors[idx] * 3.125e-3;
+
+		zexpect_within(voltage_expected_V, voltage_actual_V, 1e-6,
+			"Expected %.6f A, got %.6f A", voltage_expected_V, voltage_actual_V);
+	}
+}
+
+
+static void test_temperature(struct ina237_fixture *fixture)
+{
+	zassert_not_null(fixture->mock);
+
+	/* 12-bit signed value with bottom 4-bits reserved - 125 mDegC / bit */
+	const int16_t temp_reg_vectors[] = {
+		16000,	/* 125C */
+		1000,
+		100,
+		1,
+		0,
+		-100,
+		-1000,
+		-5120,	/* -40C */
+	};
+
+	for (int idx = 0; idx < ARRAY_SIZE(temp_reg_vectors); idx++) {
+		struct sensor_value sensor_val;
+
+		ina237_mock_set_register(fixture->mock->data, INA237_REG_DIETEMP,
+		temp_reg_vectors[idx]);
+
+		/* Verify sensor value is correct */
+		zassert_ok(sensor_sample_fetch(fixture->dev));
+		zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_DIE_TEMP, &sensor_val));
+
+		double temp_actual_degC = sensor_value_to_double(&sensor_val);
+		double temp_expected_degC = (temp_reg_vectors[idx] / 16) * 125e-3;
+
+		zexpect_within(temp_expected_degC, temp_actual_degC, 125e-3,
+			"Expected %.6f A, got %.6f A", temp_expected_degC, temp_actual_degC);
+	}
+}
+
+/* Create a test fixture for each enabled ina237 device node */
+#define DT_DRV_COMPAT ti_ina237
+#define INA237_FIXTURE_ENTRY(inst) \
+	{ \
+		.dev = DEVICE_DT_INST_GET(inst), \
+		.mock = EMUL_DT_GET(DT_DRV_INST(inst)), \
+		.current_lsb_uA = DT_INST_PROP(inst, current_lsb_microamps), \
+		.rshunt_uOhms = DT_INST_PROP(inst, rshunt_micro_ohms), \
+		.config = DT_INST_PROP(inst, config), \
+	},
+
+static struct ina237_fixture fixtures[] = {
+	DT_INST_FOREACH_STATUS_OKAY(INA237_FIXTURE_ENTRY)
+};
+
+/* Create a test suite for each enabled ina237 device node */
+#define INA237_TESTS(inst) \
+	ZTEST(ina237_##inst, test_bus_voltage) { test_bus_voltage(&fixtures[inst]); } \
+	ZTEST(ina237_##inst, test_temperature) { test_temperature(&fixtures[inst]); } \
+	ZTEST_SUITE(ina237_##inst, NULL, NULL, NULL, NULL, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(INA237_TESTS)

tests/drivers/sensor/ina237/testcase.yaml

@@ -0,0 +1,10 @@
+# Copyright (c) 2023 North River Systems Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+tests:
+  drivers.sensor.ina237:
+    tags:
+      - drivers
+      - sensor
+      - subsys
+    platform_allow: native_posix