From: Nathan Rossi <nathan.rossi@xxxxxxxx> The INA238 is a I2C power monitor similar to other INA2xx devices, providing shunt voltage, bus voltage, current, power and temperature measurements. Signed-off-by: Nathan Rossi <nathan.rossi@xxxxxxxx> --- Documentation/hwmon/ina238.rst | 57 ++++++ drivers/hwmon/Kconfig | 12 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/ina238.c | 453 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 523 insertions(+) create mode 100644 Documentation/hwmon/ina238.rst create mode 100644 drivers/hwmon/ina238.c diff --git a/Documentation/hwmon/ina238.rst b/Documentation/hwmon/ina238.rst new file mode 100644 index 0000000000..612fab185d --- /dev/null +++ b/Documentation/hwmon/ina238.rst @@ -0,0 +1,57 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +Kernel driver ina238 +==================== + +Supported chips: + + * Texas Instruments INA238 + + Prefix: 'ina238' + + Addresses: I2C 0x40 - 0x4f + + Datasheet: + https://www.ti.com/lit/gpn/ina238 + +Author: Nathan Rossi <nathan.rossi@xxxxxxxx> + +Description +----------- + +The INA238 is a current shunt, power and temperature monitor with an I2C +interface. It includes a number of programmable functions including alerts, +conversion rate, sample averaging and selectable shunt voltage accuracy. + +The shunt value in micro-ohms can be set via platform data or device tree at +compile-time or via the shunt_resistor attribute in sysfs at run-time. Please +refer to the Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml for bindings +if the device tree is used. + +Sysfs entries +------------- + +======================= ======================================================= +in0_input Shunt voltage (mV) +in0_lcrit Critical low shunt voltage +in0_crit Critical high shunt voltage + +in1_input Bus voltage (mV) +in1_lcrit Critical low bus voltage (mV) +in1_crit Critical high bus voltage (mV) + +power1_input Power measurement (uW) +power1_crit Critical power limit (uW) + +curr1_input Current measurement (mA) + +temp1_input Die temperature measurement (mC) +temp1_crit Critical die temperature limit (mC) + +shunt_resistor Shunt resistance (uOhm) +======================= ======================================================= + +.. note:: + + - Configure `shunt_resistor` before configure `power1_crit`, because power + value is calculated based on `shunt_resistor` set. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 7fde4c6e1e..cae8e62734 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1872,6 +1872,18 @@ config SENSORS_INA2XX This driver can also be built as a module. If so, the module will be called ina2xx. +config SENSORS_INA238 + tristate "Texas Instruments INA238" + depends on I2C + select REGMAP_I2C + help + If you say yes here you get support for the INA238 power monitor + chip. This driver supports voltage, current, power and temperature + measurements as well as alert configuration. + + This driver can also be built as a module. If so, the module + will be called ina238. + config SENSORS_INA3221 tristate "Texas Instruments INA3221 Triple Power Monitor" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index baee6a8d4d..1ddb26f57a 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -90,6 +90,7 @@ obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o obj-$(CONFIG_SENSORS_INA209) += ina209.o obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o +obj-$(CONFIG_SENSORS_INA238) += ina238.o obj-$(CONFIG_SENSORS_INA3221) += ina3221.o obj-$(CONFIG_SENSORS_INTEL_M10_BMC_HWMON) += intel-m10-bmc-hwmon.o obj-$(CONFIG_SENSORS_IT87) += it87.o diff --git a/drivers/hwmon/ina238.c b/drivers/hwmon/ina238.c new file mode 100644 index 0000000000..001b490b79 --- /dev/null +++ b/drivers/hwmon/ina238.c @@ -0,0 +1,453 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Texas Instruments INA238 power monitor chip + * Datasheet: https://www.ti.com/product/ina238 + * + * Copyright (C) 2021 Nathan Rossi <nathan.rossi@xxxxxxxx> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/jiffies.h> +#include <linux/of_device.h> +#include <linux/of.h> +#include <linux/delay.h> +#include <linux/util_macros.h> +#include <linux/regmap.h> + +#include <linux/platform_data/ina2xx.h> + +/* INA238 register definitions */ +#define INA238_CONFIG 0x0 +#define INA238_ADC_CONFIG 0x1 +#define INA238_SHUNT_CALIBRATION 0x2 +#define INA238_SHUNT_VOLTAGE 0x4 +#define INA238_BUS_VOLTAGE 0x5 +#define INA238_DIE_TEMP 0x6 +#define INA238_CURRENT 0x7 +#define INA238_POWER 0x8 +#define INA238_DIAG_ALERT 0xb +#define INA238_SHUNT_OVER_VOLTAGE 0xc +#define INA238_SHUNT_UNDER_VOLTAGE 0xd +#define INA238_BUS_OVER_VOLTAGE 0xe +#define INA238_BUS_UNDER_VOLTAGE 0xf +#define INA238_TEMP_LIMIT 0x10 +#define INA238_POWER_LIMIT 0x11 +#define INA238_DEVICE_ID 0x3f + +#define INA238_REGISTERS 0x11 + +#define INA238_RSHUNT_DEFAULT 10000 /* uOhm */ + +/* Default configuration of device on reset. */ +#define INA238_CONFIG_DEFAULT 0 +/* 16 sample averaging, 1052us conversion time, continuous mode */ +#define INA238_ADC_CONFIG_DEFAULT 0xfb6a +/* + * This driver uses a fixed calibration value in order to scale current/power + * based on a fixed shunt resistor value. This allows for conversion within the + * device to avoid integer limits whilst current/power accuracy is scaled + * relative to the shunt resistor value within the driver. This is similar to + * how the ina2xx driver handles current/power scaling. + * + * The end result of this is that increasing shunt values (from a fixed 20 mOhm + * shunt) increase the effective current/power accuracy whilst limiting the + * range and decreasing shunt values decrease the effective accuracy but + * increase the range. + * + * The value of the Current register is calculated given the following: + * Current (A) = (shunt voltage register * 5) * calibration / 81920 + * + * The maximum shunt voltage is 163.835 mV (0x7fff, ADC_RANGE = 0). With the + * maximum current value of 0x7fff and a fixed shunt value results in a + * calibration value of 16384 (0x4000). + * + * 0x7fff = (0x7fff * 5) * calibration / 81920 + * calibration = 0x4000 + * + * Equivalent calibration is applied for the Power register (maximum value for + * bus voltage is 102396.875 mV, 0x7fff), where the maximum power that can + * occur is ~16776192 uW (register value 0x147a8): + * + * This scaling means the resulting values for Current and Power registers need + * to be scaled by the difference between the fixed shunt resistor and the + * actual shunt resistor: + * + * shunt = 0x4000 / (819.2 * 10^6) / 0.001 = 20000 uOhms (with 1mA/lsb) + * + * Current (mA) = register value * 20000 / rshunt + * Power (W) = 0.2 * register value * 20000 / rshunt + */ +#define INA238_CALIBRATION_VALUE 16384 +#define INA238_FIXED_SHUNT 20000 + +#define INA238_SHUNT_VOLTAGE_LSB 5 /* 5 uV/lsb */ +#define INA238_BUS_VOLTAGE_LSB 3125 /* 3.125 mV/lsb */ +#define INA238_DIE_TEMP_LSB 125 /* 125 mC/lsb */ + +static struct regmap_config ina238_regmap_config = { + .reg_bits = 8, + .val_bits = 16, +}; + +struct ina238_data { + struct i2c_client *client; + struct mutex config_lock; + struct regmap *regmap; + long rshunt; +}; + +static ssize_t ina238_value_show(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ina238_data *data = dev_get_drvdata(dev); + unsigned int regval; + long long val = 0; + u8 regdata[3]; + int err; + + if (attr->index == INA238_POWER) { + /* Handle reading the POWER register as 24-bit */ + err = i2c_smbus_read_i2c_block_data(data->client, attr->index, 3, + regdata); + if (err != 3) + return err; + regval = (regdata[0] << 16) | (regdata[1] << 8) | regdata[2]; + } else { + err = regmap_read(data->regmap, attr->index, ®val); + if (err < 0) + return err; + } + + switch (attr->index) { + case INA238_SHUNT_VOLTAGE: + /* Signed register, result in mV */ + val = div_s64((s16)regval * INA238_SHUNT_VOLTAGE_LSB, + 1000); + break; + case INA238_BUS_VOLTAGE: + /* Result in mV */ + val = div_s64((s16)regval * INA238_BUS_VOLTAGE_LSB, 1000); + break; + case INA238_CURRENT: + /* Signed register, fixed 1mA current lsb. result in mA */ + val = div_s64((s16)regval * INA238_FIXED_SHUNT, data->rshunt); + break; + case INA238_POWER: + /* Fixed 1mA lsb, scaled by 1000000 to have result in uW */ + val = div_u64(regval * 1000LL * INA238_FIXED_SHUNT, 5 * data->rshunt); + break; + case INA238_DIE_TEMP: + /* Bits 15-4 of register, result in mC */ + val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; + break; + case INA238_SHUNT_CALIBRATION: + val = regval; + break; + default: + WARN_ON_ONCE(1); + break; + } + + return snprintf(buf, PAGE_SIZE, "%lld\n", val); +} + +static int ina238_set_shunt(struct device *dev, struct ina238_data *data, + long val) +{ + if (val == 0) + return -EINVAL; + + mutex_lock(&data->config_lock); + data->rshunt = val; + mutex_unlock(&data->config_lock); + + return 0; +} + +static ssize_t ina238_shunt_show(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct ina238_data *data = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt); +} + +static ssize_t ina238_shunt_store(struct device *dev, + struct device_attribute *da, + const char *buf, size_t count) +{ + struct ina238_data *data = dev_get_drvdata(dev); + unsigned long val; + int status; + + status = kstrtoul(buf, 10, &val); + if (status < 0) + return status; + + status = ina238_set_shunt(dev, data, val); + if (status < 0) + return status; + return count; +} + +static ssize_t ina238_alert_show(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ina238_data *data = dev_get_drvdata(dev); + long long val = 0; + int regval; + int ret; + + ret = regmap_read(data->regmap, attr->index, ®val); + if (ret) + return ret; + + switch (attr->index) { + case INA238_SHUNT_OVER_VOLTAGE: + case INA238_SHUNT_UNDER_VOLTAGE: + val = div_s64((s16)regval * INA238_SHUNT_VOLTAGE_LSB, 1000); + break; + case INA238_BUS_OVER_VOLTAGE: + case INA238_BUS_UNDER_VOLTAGE: + val = div_u64(regval * INA238_BUS_VOLTAGE_LSB, 1000); + break; + case INA238_POWER_LIMIT: + /* + * Truncated 24-bit compare register, lower 8-bits are + * truncated. Same conversion to/from uW as POWER register. + */ + val = div_u64((regval << 8) * 1000ULL * INA238_FIXED_SHUNT, + 5 * data->rshunt); + break; + case INA238_TEMP_LIMIT: + /* Signed, bits 15-4 of register */ + val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; + break; + default: + WARN_ON_ONCE(1); + break; + } + + return snprintf(buf, PAGE_SIZE, "%lld\n", val); +} + +static ssize_t ina238_alert_store(struct device *dev, + struct device_attribute *da, + const char *buf, size_t count) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ina238_data *data = dev_get_drvdata(dev); + long long val; + int regval; + int ret; + + ret = kstrtoll(buf, 10, &val); + if (ret < 0) + return ret; + + /* convert decimal to register value */ + switch (attr->index) { + case INA238_SHUNT_OVER_VOLTAGE: + case INA238_SHUNT_UNDER_VOLTAGE: + /* signed */ + regval = div_s64((val * 1000), INA238_SHUNT_VOLTAGE_LSB); + if (regval > S16_MAX || regval < S16_MIN) { + ret = -EINVAL; + goto abort; + } + break; + case INA238_BUS_OVER_VOLTAGE: + case INA238_BUS_UNDER_VOLTAGE: + regval = div_u64((val * 1000), INA238_BUS_VOLTAGE_LSB); + if (regval > U16_MAX || regval < 0) { + ret = -EINVAL; + goto abort; + } + break; + case INA238_POWER_LIMIT: + /* + * Compared against the 24-bit power register, lower 8-bits are + * truncated. Same conversion to/from uW as POWER register. + */ + regval = div_u64(val * 5 * data->rshunt, + 1000 * INA238_FIXED_SHUNT) >> 8; + if (regval > U16_MAX || regval < 0) { + ret = -EINVAL; + goto abort; + } + break; + case INA238_TEMP_LIMIT: + /* Bits 15-4 of register */ + regval = (div_s64(val, INA238_DIE_TEMP_LSB) << 4); + if (regval > S16_MAX || regval < S16_MIN) { + ret = -EINVAL; + goto abort; + } + regval = regval & 0xfff0; + break; + default: + WARN_ON_ONCE(1); + break; + } + + mutex_lock(&data->config_lock); + + ret = regmap_write(data->regmap, attr->index, regval); + if (ret < 0) + goto abort; + + ret = count; +abort: + mutex_unlock(&data->config_lock); + return ret; +} + +/* shunt voltage */ +static SENSOR_DEVICE_ATTR_RO(in0_input, ina238_value, INA238_SHUNT_VOLTAGE); +/* shunt voltage over/under alert */ +static SENSOR_DEVICE_ATTR_RW(in0_crit, ina238_alert, INA238_SHUNT_OVER_VOLTAGE); +static SENSOR_DEVICE_ATTR_RW(in0_lcrit, ina238_alert, + INA238_SHUNT_UNDER_VOLTAGE); + +/* bus voltage */ +static SENSOR_DEVICE_ATTR_RO(in1_input, ina238_value, INA238_BUS_VOLTAGE); +/* bus voltage over/under alert */ +static SENSOR_DEVICE_ATTR_RW(in1_crit, ina238_alert, INA238_BUS_OVER_VOLTAGE); +static SENSOR_DEVICE_ATTR_RW(in1_lcrit, ina238_alert, INA238_BUS_UNDER_VOLTAGE); + +/* calculated current */ +static SENSOR_DEVICE_ATTR_RO(curr1_input, ina238_value, INA238_CURRENT); + +/* calculated power */ +static SENSOR_DEVICE_ATTR_RO(power1_input, ina238_value, INA238_POWER); +static SENSOR_DEVICE_ATTR_RW(power1_crit, ina238_alert, INA238_POWER_LIMIT); + +/* die temperature */ +static SENSOR_DEVICE_ATTR_RO(temp1_input, ina238_value, INA238_DIE_TEMP); +static SENSOR_DEVICE_ATTR_RW(temp1_crit, ina238_alert, INA238_TEMP_LIMIT); + +/* shunt resistance */ +static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina238_shunt, + INA238_SHUNT_CALIBRATION); + +static struct attribute *ina238_attrs[] = { + &sensor_dev_attr_in0_input.dev_attr.attr, + &sensor_dev_attr_in0_crit.dev_attr.attr, + &sensor_dev_attr_in0_lcrit.dev_attr.attr, + &sensor_dev_attr_in1_input.dev_attr.attr, + &sensor_dev_attr_in1_crit.dev_attr.attr, + &sensor_dev_attr_in1_lcrit.dev_attr.attr, + &sensor_dev_attr_curr1_input.dev_attr.attr, + &sensor_dev_attr_power1_input.dev_attr.attr, + &sensor_dev_attr_power1_crit.dev_attr.attr, + &sensor_dev_attr_temp1_input.dev_attr.attr, + &sensor_dev_attr_temp1_crit.dev_attr.attr, + &sensor_dev_attr_shunt_resistor.dev_attr.attr, + NULL, +}; +ATTRIBUTE_GROUPS(ina238); + +static int ina238_probe(struct i2c_client *client) +{ + struct ina2xx_platform_data *pdata = dev_get_platdata(&client->dev); + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct ina238_data *data; + u32 val; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + /* set the device type */ + mutex_init(&data->config_lock); + + ina238_regmap_config.max_register = INA238_REGISTERS; + data->regmap = devm_regmap_init_i2c(client, &ina238_regmap_config); + if (IS_ERR(data->regmap)) { + dev_err(dev, "failed to allocate register map\n"); + return PTR_ERR(data->regmap); + } + + /* load shunt value */ + val = INA238_RSHUNT_DEFAULT; + if (device_property_read_u32(dev, "shunt-resistor", &val) < 0 && pdata) + val = pdata->shunt_uohms; + ret = ina238_set_shunt(dev, data, val); + if (ret) { + dev_err(dev, "error configuring the device: %d\n", ret); + return ret; + } + + /* Setup CONFIG register */ + ret = regmap_write(data->regmap, INA238_CONFIG, INA238_CONFIG_DEFAULT); + if (ret < 0) { + dev_err(dev, "error configuring the device: %d\n", ret); + return -ENODEV; + } + + /* Setup ADC_CONFIG register */ + ret = regmap_write(data->regmap, INA238_ADC_CONFIG, + INA238_ADC_CONFIG_DEFAULT); + if (ret < 0) { + dev_err(dev, "error configuring the device: %d\n", ret); + return -ENODEV; + } + + /* Setup SHUNT_CALIBRATION register with fixed value */ + ret = regmap_write(data->regmap, INA238_SHUNT_CALIBRATION, + INA238_CALIBRATION_VALUE); + if (ret < 0) { + dev_err(dev, "error configuring the device: %d\n", ret); + return -ENODEV; + } + + hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, + data, ina238_groups); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n", + client->name, data->rshunt); + + return 0; +} + +static const struct i2c_device_id ina238_id[] = { + { "ina238", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ina238_id); + +static const struct of_device_id __maybe_unused ina238_of_match[] = { + { .compatible = "ti,ina238" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ina238_of_match); + +static struct i2c_driver ina238_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "ina238", + .of_match_table = of_match_ptr(ina238_of_match), + }, + .probe_new = ina238_probe, + .id_table = ina238_id, +}; + +module_i2c_driver(ina238_driver); + +MODULE_AUTHOR("Nathan Rossi <nathan.rossi@xxxxxxxx>"); +MODULE_DESCRIPTION("ina238 driver"); +MODULE_LICENSE("GPL"); --- 2.33.0
