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hwmon: Add driver for TI INA233 Current and Power Monitor
Driver for Texas Instruments INA233 Current and Power Monitor With I2C-, SMBus-, and PMBus-Compatible Interface Signed-off-by: Leo Yang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Guenter Roeck <[email protected]>
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‎Documentation/hwmon/ina233.rst

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.. SPDX-License-Identifier: GPL-2.0
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Kernel driver ina233
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====================
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Supported chips:
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* TI INA233
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Prefix: 'ina233'
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* Datasheet
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Publicly available at the TI website : https://www.ti.com/lit/ds/symlink/ina233.pdf
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Author: Leo Yang <[email protected]>
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Usage Notes
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-----------
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The shunt resistor value can be configured by a device tree property;
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see Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml for details.
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Description
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-----------
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This driver supports hardware monitoring for TI INA233.
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The driver is a client driver to the core PMBus driver. Please see
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Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
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The driver provides the following attributes for input voltage:
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**in1_input**
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**in1_label**
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**in1_max**
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**in1_max_alarm**
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**in1_min**
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**in1_min_alarm**
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The driver provides the following attributes for shunt voltage:
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**in2_input**
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**in2_label**
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The driver provides the following attributes for output voltage:
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**in3_input**
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**in3_label**
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**in3_alarm**
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The driver provides the following attributes for output current:
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**curr1_input**
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**curr1_label**
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**curr1_max**
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**curr1_max_alarm**
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The driver provides the following attributes for input power:
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**power1_input**
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**power1_label**

‎Documentation/hwmon/index.rst

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@@ -91,6 +91,7 @@ Hardware Monitoring Kernel Drivers
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ibmpowernv
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ina209
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ina2xx
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ina233
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ina238
9596
ina3221
9697
inspur-ipsps1

‎MAINTAINERS

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S: Orphan
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F: drivers/video/fbdev/imsttfb.c
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INA233 HARDWARE MONITOR DRIVERS
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M: Leo Yang <[email protected]>
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L: [email protected]
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S: Maintained
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F: Documentation/hwmon/ina233.rst
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F: drivers/hwmon/pmbus/ina233.c
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INDEX OF FURTHER KERNEL DOCUMENTATION
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M: Carlos Bilbao <[email protected]>
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S: Maintained

‎drivers/hwmon/pmbus/Kconfig

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This driver can also be built as a module. If so, the module will
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be called dps920ab.
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config SENSORS_INA233
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tristate "Texas Instruments INA233 and compatibles"
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help
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If you say yes here you get hardware monitoring support for Texas
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Instruments INA233.
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This driver can also be built as a module. If so, the module will
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be called ina233.
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config SENSORS_INSPUR_IPSPS
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tristate "INSPUR Power System Power Supply"
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help

‎drivers/hwmon/pmbus/Makefile

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obj-$(CONFIG_SENSORS_FSP_3Y) += fsp-3y.o
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obj-$(CONFIG_SENSORS_IBM_CFFPS) += ibm-cffps.o
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obj-$(CONFIG_SENSORS_DPS920AB) += dps920ab.o
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obj-$(CONFIG_SENSORS_INA233) += ina233.o
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obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
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obj-$(CONFIG_SENSORS_IR35221) += ir35221.o
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obj-$(CONFIG_SENSORS_IR36021) += ir36021.o

‎drivers/hwmon/pmbus/ina233.c

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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Hardware monitoring driver for ina233
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*
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* Copyright (c) 2025 Leo Yang
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*/
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include "pmbus.h"
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#define MFR_READ_VSHUNT 0xd1
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#define MFR_CALIBRATION 0xd4
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#define INA233_MAX_CURRENT_DEFAULT 32768000 /* uA */
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#define INA233_RSHUNT_DEFAULT 2000 /* uOhm */
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#define MAX_M_VAL 32767
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static void calculate_coef(int *m, int *R, u32 current_lsb, int power_coef)
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{
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u64 scaled_m;
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int scale_factor = 0;
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int scale_coef = 1;
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/*
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* 1000000 from Current_LSB A->uA .
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* scale_coef is for scaling up to minimize rounding errors,
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* If there is no decimal information, no need to scale.
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*/
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if (1000000 % current_lsb) {
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/* Scaling to keep integer precision */
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scale_factor = -3;
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scale_coef = 1000;
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}
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/*
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* Unit Conversion (Current_LSB A->uA) and use scaling(scale_factor)
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* to keep integer precision.
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* Formulae referenced from spec.
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*/
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scaled_m = div64_u64(1000000 * scale_coef, (u64)current_lsb * power_coef);
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/* Maximize while keeping it bounded.*/
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while (scaled_m > MAX_M_VAL) {
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scaled_m = div_u64(scaled_m, 10);
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scale_factor++;
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}
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/* Scale up only if fractional part exists. */
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while (scaled_m * 10 < MAX_M_VAL && scale_coef != 1) {
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scaled_m *= 10;
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scale_factor--;
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}
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*m = scaled_m;
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*R = scale_factor;
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}
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static int ina233_read_word_data(struct i2c_client *client, int page,
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int phase, int reg)
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{
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int ret;
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switch (reg) {
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case PMBUS_VIRT_READ_VMON:
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ret = pmbus_read_word_data(client, 0, 0xff, MFR_READ_VSHUNT);
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/* Adjust returned value to match VIN coefficients */
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/* VIN: 1.25 mV VSHUNT: 2.5 uV LSB */
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ret = DIV_ROUND_CLOSEST(ret * 25, 12500);
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break;
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default:
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ret = -ENODATA;
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break;
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}
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return ret;
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}
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static int ina233_probe(struct i2c_client *client)
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{
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struct device *dev = &client->dev;
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int ret, m, R;
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u32 rshunt;
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u32 max_current;
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u32 current_lsb;
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u16 calibration;
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struct pmbus_driver_info *info;
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info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info),
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GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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info->pages = 1;
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info->format[PSC_VOLTAGE_IN] = direct;
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info->format[PSC_VOLTAGE_OUT] = direct;
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info->format[PSC_CURRENT_OUT] = direct;
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info->format[PSC_POWER] = direct;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_INPUT
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| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
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| PMBUS_HAVE_POUT
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| PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
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info->m[PSC_VOLTAGE_IN] = 8;
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info->R[PSC_VOLTAGE_IN] = 2;
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info->m[PSC_VOLTAGE_OUT] = 8;
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info->R[PSC_VOLTAGE_OUT] = 2;
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info->read_word_data = ina233_read_word_data;
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/* If INA233 skips current/power, shunt-resistor and current-lsb aren't needed. */
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/* read rshunt value (uOhm) */
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ret = device_property_read_u32(dev, "shunt-resistor", &rshunt);
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if (ret) {
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if (ret != -EINVAL)
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return dev_err_probe(dev, ret, "Shunt resistor property read fail.\n");
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rshunt = INA233_RSHUNT_DEFAULT;
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}
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if (!rshunt)
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return dev_err_probe(dev, -EINVAL,
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"Shunt resistor cannot be zero.\n");
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/* read Maximum expected current value (uA) */
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ret = device_property_read_u32(dev, "ti,maximum-expected-current-microamp", &max_current);
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if (ret) {
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if (ret != -EINVAL)
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return dev_err_probe(dev, ret,
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"Maximum expected current property read fail.\n");
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max_current = INA233_MAX_CURRENT_DEFAULT;
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}
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if (max_current < 32768)
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return dev_err_probe(dev, -EINVAL,
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"Maximum expected current cannot less then 32768.\n");
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/* Calculate Current_LSB according to the spec formula */
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current_lsb = max_current / 32768;
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/* calculate current coefficient */
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calculate_coef(&m, &R, current_lsb, 1);
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info->m[PSC_CURRENT_OUT] = m;
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info->R[PSC_CURRENT_OUT] = R;
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/* calculate power coefficient */
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calculate_coef(&m, &R, current_lsb, 25);
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info->m[PSC_POWER] = m;
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info->R[PSC_POWER] = R;
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/* write MFR_CALIBRATION register, Apply formula from spec with unit scaling. */
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calibration = div64_u64(5120000000ULL, (u64)rshunt * current_lsb);
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if (calibration > 0x7FFF)
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return dev_err_probe(dev, -EINVAL,
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"Product of Current_LSB %u and shunt resistor %u too small, MFR_CALIBRATION reg exceeds 0x7FFF.\n",
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current_lsb, rshunt);
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ret = i2c_smbus_write_word_data(client, MFR_CALIBRATION, calibration);
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if (ret < 0)
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return dev_err_probe(dev, ret, "Unable to write calibration.\n");
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dev_dbg(dev, "power monitor %s (Rshunt = %u uOhm, Current_LSB = %u uA/bit)\n",
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client->name, rshunt, current_lsb);
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return pmbus_do_probe(client, info);
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}
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static const struct i2c_device_id ina233_id[] = {
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{"ina233", 0},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ina233_id);
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static const struct of_device_id __maybe_unused ina233_of_match[] = {
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{ .compatible = "ti,ina233" },
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{}
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};
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MODULE_DEVICE_TABLE(of, ina233_of_match);
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static struct i2c_driver ina233_driver = {
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.driver = {
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.name = "ina233",
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.of_match_table = of_match_ptr(ina233_of_match),
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},
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.probe = ina233_probe,
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.id_table = ina233_id,
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};
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module_i2c_driver(ina233_driver);
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MODULE_AUTHOR("Leo Yang <[email protected]>");
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MODULE_DESCRIPTION("PMBus driver for INA233 and compatible chips");
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MODULE_LICENSE("GPL");
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MODULE_IMPORT_NS("PMBUS");

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