drivers: sensor: ina23x: add ina23x common module

That's needed to not duplicate code between INA230/231
and the upcoming INA237 variant.

Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>

drivers/sensor/ina23x/CMakeLists.txt

@@ -3,4 +3,5 @@
 zephyr_library()
 
 zephyr_library_sources(ina23x.c)
+zephyr_library_sources(ina23x_common.c)
 zephyr_library_sources_ifdef(CONFIG_INA23X_TRIGGER ina23x_trigger.c)

drivers/sensor/ina23x/ina23x_common.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2021 Grinn
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <sys/byteorder.h>
+#include "ina23x_common.h"
+
+int ina23x_reg_read_24(const struct i2c_dt_spec *bus, uint8_t reg, uint32_t *val)
+{
+	uint8_t data[3];
+	int ret;
+
+	ret = i2c_burst_read_dt(bus, reg, data, sizeof(data));
+	if (ret < 0) {
+		return ret;
+	}
+
+	*val = sys_get_be24(data);
+
+	return ret;
+}
+
+int ina23x_reg_read_16(const struct i2c_dt_spec *bus, uint8_t reg, uint16_t *val)
+{
+	uint8_t data[2];
+	int ret;
+
+	ret = i2c_burst_read_dt(bus, reg, data, sizeof(data));
+	if (ret < 0) {
+		return ret;
+	}
+
+	*val = sys_get_be16(data);
+
+	return ret;
+}
+
+int ina23x_reg_write(const struct i2c_dt_spec *bus, uint8_t reg, uint16_t val)
+{
+	uint8_t tx_buf[3];
+
+	tx_buf[0] = reg;
+	sys_put_be16(val, &tx_buf[1]);
+
+	return i2c_write_dt(bus, tx_buf, sizeof(tx_buf));
+}

drivers/sensor/ina23x/ina23x_common.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2021  Grinn
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_DRIVERS_SENSOR_INA23X_COMMON_H_
+#define ZEPHYR_DRIVERS_SENSOR_INA23X_COMMON_H_
+
+#include <drivers/i2c.h>
+
+/**
+ * @brief Macro used to test if the current's sign bit is set
+ */
+#define INA23X_CURRENT_SIGN_BIT        BIT(15)
+
+/**
+ * @brief Macro used to check if the current's LSB is 1mA
+ */
+#define INA23X_CURRENT_LSB_1MA         1
+
+int ina23x_reg_read_24(const struct i2c_dt_spec *bus, uint8_t reg, uint32_t *val);
+int ina23x_reg_read_16(const struct i2c_dt_spec *bus, uint8_t reg, uint16_t *val);
+int ina23x_reg_write(const struct i2c_dt_spec *bus, uint8_t reg, uint16_t val);
+
+#endif /* ZEPHYR_DRIVERS_SENSOR_INA23X_COMMON_H_ */

dts/bindings/sensor/ti,ina23x-common.yaml

@@ -0,0 +1,33 @@
+#
+# Copyright 2021 Grinn
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+include: i2c-device.yaml
+
+properties:
+    config:
+      type: int
+      required: true
+      description: |
+        Value of the configuration register
+        e.g shunt voltage and bus voltage ADC conversion
+        times and averaging, operating mode for INA230 or
+        delay for initial ADC conversion, shunt full scale range
+        for INA237.
+
+    current-lsb:
+      type: int
+      required: true
+      description: |
+        Value of Current LSB in milliamps. When set to 1mA,
+        Current is read in A, Bus Voltage in V, Shunt
+        Voltage in V, and Power in mW. Any other value
+        results in Current, Voltage, and Power registers
+        being read in counts.
+
+    rshunt:
+      type: int
+      required: true
+      description: Shunt resistor value in milliohms