| Message ID | 20211027074212.690611-3-nathan@nathanrossi.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Driver for TI INA238 I2C Power Monitor | expand |
On 10/27/21 12:42 AM, Nathan Rossi wrote: > From: Nathan Rossi <nathan.rossi@digi.com> > > 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@digi.com> > --- > Changes in v2: > - Add ina238 documentation to hwmon/index > - Remove unused header includes and sort > - Set regmap_config max_register in struct initialization > - Remove shunt-resistor attribute and associated functions > - Rename crit/lcrit attributes to max/min > - Rework to use the hwmon_chip_info API > - Add max_alarm and min_alarm channels and associated alert/alarm config > - Add device tree ti,shunt-gain property use and ADCRANGE setup > --- > Documentation/hwmon/ina238.rst | 56 ++++ > Documentation/hwmon/index.rst | 1 + > drivers/hwmon/Kconfig | 12 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/ina238.c | 672 +++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 742 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..d9f4799844 > --- /dev/null > +++ b/Documentation/hwmon/ina238.rst > @@ -0,0 +1,56 @@ > +.. 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@digi.com> > + > +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_min Minimum shunt voltage threshold (mV) > +in0_min_alarm Minimum shunt voltage alarm > +in0_max Maximum shunt voltage threshold (mV) > +in0_max_alarm Maximum shunt voltage alarm > + > +in1_input Bus voltage (mV) > +in1_min Minimum bus voltage threshold (mV) > +in1_min_alarm Minimum shunt voltage alarm > +in1_max Maximum bus voltage threshold (mV) > +in1_max_alarm Maximum shunt voltage alarm > + > +power1_input Power measurement (uW) > +power1_max Maximum power threshold (uW) > +power1_max_alarm Maximum power alarm > + > +curr1_input Current measurement (mA) > + > +temp1_input Die temperature measurement (mC) > +temp1_max Maximum die temperature threshold (mC) > +temp1_max_alarm Maximum die temperature alarm > +======================= ======================================================= > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index 7046bf1870..6f30c8c9c7 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -76,6 +76,7 @@ Hardware Monitoring Kernel Drivers > ibmpowernv > ina209 > ina2xx > + ina238 > ina3221 > intel-m10-bmc-hwmon > ir35221 > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 7fde4c6e1e..21aff4cef7 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 alarm 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..f9d031bdfe > --- /dev/null > +++ b/drivers/hwmon/ina238.c > @@ -0,0 +1,672 @@ > +// 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@digi.com> > + */ > + > +#include <linux/err.h> > +#include <linux/hwmon-sysfs.h> Unnecessary. > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.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_CONFIG_ADCRANGE BIT(4) > + > +#define INA238_DIAG_ALERT_TMPOL BIT(7) > +#define INA238_DIAG_ALERT_SHNTOL BIT(6) > +#define INA238_DIAG_ALERT_SHNTUL BIT(5) > +#define INA238_DIAG_ALERT_BUSOL BIT(4) > +#define INA238_DIAG_ALERT_BUSUL BIT(3) > +#define INA238_DIAG_ALERT_POL BIT(2) > + > +#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 > +/* Configure alerts to be based on averaged value (SLOWALERT) */ > +#define INA238_DIAG_ALERT_DEFAULT 0x2000 > +/* > + * 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, gain = 4). > + * 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 / 4 * gain > + * Power (W) = 0.2 * register value * 20000 / rshunt / 4 * gain > + */ > +#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 = { > + .max_register = INA238_REGISTERS, > + .reg_bits = 8, > + .val_bits = 16, > +}; > + > +struct ina238_data { > + struct i2c_client *client; > + struct mutex config_lock; > + struct regmap *regmap; > + u32 rshunt; > + u32 gain; > +}; > + > +static int ina238_read_reg24(const struct i2c_client *client, u8 reg, u32 *val) > +{ > + u8 data[3]; > + int err; > + > + /* 24-bit register read */ > + err = i2c_smbus_read_i2c_block_data(client, reg, 3, data); > + if (err != 3) > + return err; i2c_smbus_read_i2c_block_data() can return 1 or 2, which should be reported as error. You need something like if (err < 0) return err; if (err != 3) return -EIO; > + *val = (data[0] << 16) | (data[1] << 8) | data[2]; > + > + return 0; > +} > + > +static int ina238_read_in(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int reg, mask; > + int regval; > + int err; > + > + switch (channel) { > + case 0: > + switch (attr) { > + case hwmon_in_input: > + reg = INA238_SHUNT_VOLTAGE; > + break; > + case hwmon_in_max: > + reg = INA238_SHUNT_OVER_VOLTAGE; > + break; > + case hwmon_in_min: > + reg = INA238_SHUNT_UNDER_VOLTAGE; > + break; > + case hwmon_in_max_alarm: > + reg = INA238_DIAG_ALERT; > + mask = INA238_DIAG_ALERT_SHNTOL; > + break; > + case hwmon_in_min_alarm: > + reg = INA238_DIAG_ALERT; > + mask = INA238_DIAG_ALERT_SHNTUL; > + break; > + default: > + return -EOPNOTSUPP; > + } > + break; > + case 1: > + switch (attr) { > + case hwmon_in_input: > + reg = INA238_BUS_VOLTAGE; > + break; > + case hwmon_in_max: > + reg = INA238_BUS_OVER_VOLTAGE; > + break; > + case hwmon_in_min: > + reg = INA238_BUS_UNDER_VOLTAGE; > + break; > + case hwmon_in_max_alarm: > + reg = INA238_DIAG_ALERT; > + mask = INA238_DIAG_ALERT_BUSOL; > + break; > + case hwmon_in_min_alarm: > + reg = INA238_DIAG_ALERT; > + mask = INA238_DIAG_ALERT_BUSUL; > + break; > + default: > + return -EOPNOTSUPP; > + } > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + err = regmap_read(data->regmap, reg, ®val); > + if (err < 0) > + return err; > + > + switch (attr) { > + case hwmon_in_input: > + case hwmon_in_max: > + case hwmon_in_min: > + /* signed register, value in mV */ > + if (channel == 0) > + /* gain of 1 -> LSB / 4 */ > + *val = div_s64((s16)regval * INA238_SHUNT_VOLTAGE_LSB, > + 1000 * (4 - data->gain + 1)); > + else > + *val = div_s64((s16)regval * INA238_BUS_VOLTAGE_LSB, > + 1000); Pleae check the use of 64-bit divide operations. The above operations never overflow a long, not even a 32-bit long, and div_s64() is therefore unencessary. I am quite sure the same applies to current read operations, though I didn't check. > + break; > + case hwmon_in_max_alarm: > + case hwmon_in_min_alarm: > + *val = regval & mask ? 1 : 0; *val = !!(regval & mask); > + break; > + } > + > + return 0; > +} > + > +static int ina238_write_in(struct device *dev, u32 attr, int channel, > + long val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int regval; > + > + if (attr != hwmon_in_max && attr != hwmon_in_min) > + return -EOPNOTSUPP; > + > + /* convert decimal to register value */ > + switch (channel) { > + case 0: > + /* signed */ > + regval = div_s64((s64)val * 1000LL * (4 - data->gain + 1), > + INA238_SHUNT_VOLTAGE_LSB); I am quite sure the typecast is unnecessary here. Also, if you'd use clamp_val() prior to the multiply/divide operation, I am quite sure you would not need to use 64-bit divide operations. > + if (regval > S16_MAX || regval < S16_MIN) > + return -EINVAL; We usually handle limit writes out of range with clamp_val() and do not expect users to find the valid range for a given chip. regval = clamp_val(regval, S16_MIN, S16_MAX); > + > + switch (attr) { > + case hwmon_in_max: > + return regmap_write(data->regmap, > + INA238_SHUNT_OVER_VOLTAGE, regval); > + case hwmon_in_min: > + return regmap_write(data->regmap, > + INA238_SHUNT_UNDER_VOLTAGE, regval); > + default: > + return -EOPNOTSUPP; > + } > + case 1: > + regval = div_u64((u64)val * 1000ULL, INA238_BUS_VOLTAGE_LSB); This converts -1 to a really large value, which then overflows before being divided. The result is more or less random. I think you'll need to use clamp_val first here. > + if (regval > U16_MAX || regval < 0) > + return -EINVAL; regval = clamp_val(regval, 0, U16_MAX); > + > + switch (attr) { > + case hwmon_in_max: > + return regmap_write(data->regmap, > + INA238_BUS_OVER_VOLTAGE, regval); > + case hwmon_in_min: > + return regmap_write(data->regmap, > + INA238_BUS_UNDER_VOLTAGE, regval); > + default: > + return -EOPNOTSUPP; > + } > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ina238_read_current(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int regval; > + int err; > + > + if (channel != 0) > + return -EOPNOTSUPP; > + > + switch (attr) { > + case hwmon_curr_input: > + err = regmap_read(data->regmap, INA238_CURRENT, ®val); > + if (err < 0) > + return err; > + > + /* Signed register, fixed 1mA current lsb. result in mA */ > + *val = div_s64((s16)regval * INA238_FIXED_SHUNT * data->gain, > + data->rshunt * 4); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static int ina238_read_power(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + long long power; > + int regval; > + int err; > + > + if (channel != 0) > + return -EOPNOTSUPP; > + > + switch (attr) { > + case hwmon_power_input: > + err = ina238_read_reg24(data->client, INA238_POWER, ®val); > + if (err) > + return err; > + > + /* Fixed 1mA lsb, scaled by 1000000 to have result in uW */ > + power = div_u64(regval * 1000ULL * INA238_FIXED_SHUNT * > + data->gain, 20 * data->rshunt); > + /* Clamp value to maximum value of long */ > + *val = clamp_val(power, 0, LONG_MAX); > + break; > + case hwmon_power_max: > + err = regmap_read(data->regmap, INA238_POWER_LIMIT, ®val); > + if (err) > + return err; > + > + /* > + * Truncated 24-bit compare register, lower 8-bits are > + * truncated. Same conversion to/from uW as POWER register. > + */ > + power = div_u64((regval << 8) * 1000ULL * INA238_FIXED_SHUNT * > + data->gain, 20 * data->rshunt); > + /* Clamp value to maximum value of long */ > + *val = clamp_val(power, 0, LONG_MAX); > + break; > + case hwmon_power_max_alarm: > + err = regmap_read(data->regmap, INA238_DIAG_ALERT, ®val); > + if (err) > + return err; > + > + *val = regval & INA238_DIAG_ALERT_POL ? 1 : 0; *val = !!(regval & INA238_DIAG_ALERT_POL); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static int ina238_write_power(struct device *dev, u32 attr, int channel, > + long val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int regval; > + > + if (channel != 0 || attr != hwmon_power_max) > + return -EOPNOTSUPP; > + > + /* > + * Compared against the 24-bit power register, lower 8-bits are > + * truncated. Same conversion to/from uW as POWER register. > + */ > + regval = div_u64((u64)val * 20ULL * data->rshunt, > + 1000ULL * INA238_FIXED_SHUNT * (u64)data->gain); Same problem as above - negative values of val will have in unpredictable results. The last typecat should be unnecessary. > + regval = regval >> 8; > + if (regval > U16_MAX || regval < 0) > + return -EINVAL; regval = clamp_val(...); > + > + return regmap_write(data->regmap, INA238_POWER_LIMIT, regval); > +} > + > +static int ina238_read_temp(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int regval; > + int err; > + > + if (channel != 0) > + return -EOPNOTSUPP; > + > + switch (attr) { > + case hwmon_temp_input: > + err = regmap_read(data->regmap, INA238_DIE_TEMP, ®val); > + if (err) > + return err; > + > + /* Signed, bits 15-4 of register, result in mC */ > + *val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; > + break; > + case hwmon_temp_max: > + err = regmap_read(data->regmap, INA238_TEMP_LIMIT, ®val); > + if (err) > + return err; > + > + /* Signed, bits 15-4 of register, result in mC */ > + *val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; > + break; > + case hwmon_temp_max_alarm: > + err = regmap_read(data->regmap, INA238_DIAG_ALERT, ®val); > + if (err) > + return err; > + > + *val = regval & INA238_DIAG_ALERT_TMPOL ? 1 : 0; *val = !!(regval & INA238_DIAG_ALERT_TMPOL); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static int ina238_write_temp(struct device *dev, u32 attr, int channel, > + long val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int regval; > + > + if (channel != 0 || attr != hwmon_temp_max) > + return -EOPNOTSUPP; > + > + /* Signed, bits 15-4 of register */ > + regval = (div_s64(val, INA238_DIE_TEMP_LSB) << 4); > + if (regval > S16_MAX || regval < S16_MIN) > + return -EINVAL; regval = clamp_val(regval, S16_MIN, S16_MAX) & 0xfff0; > + regval = regval & 0xfff0; > + > + return regmap_write(data->regmap, INA238_TEMP_LIMIT, regval); > +} > + > +static int ina238_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + switch (type) { > + case hwmon_in: > + return ina238_read_in(dev, attr, channel, val); > + case hwmon_curr: > + return ina238_read_current(dev, attr, channel, val); > + case hwmon_power: > + return ina238_read_power(dev, attr, channel, val); > + case hwmon_temp: > + return ina238_read_temp(dev, attr, channel, val); > + default: > + return -EOPNOTSUPP; > + } > + return 0; > +} > + > +static int ina238_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct ina238_data *data = dev_get_drvdata(dev); > + int err; > + > + mutex_lock(&data->config_lock); > + > + switch (type) { > + case hwmon_in: > + err = ina238_write_in(dev, attr, channel, val); > + break; > + case hwmon_power: > + err = ina238_write_power(dev, attr, channel, val); > + break; > + case hwmon_temp: > + err = ina238_write_temp(dev, attr, channel, val); > + break; > + default: > + err = -EOPNOTSUPP; > + break; > + } > + > + mutex_unlock(&data->config_lock); > + return err; > +} > + > +static umode_t ina238_is_visible(const void *drvdata, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_in: > + if (channel != 0 && channel != 1) > + return 0; FWIW, channel checks are not really needed. > + > + switch (attr) { > + case hwmon_in_input: > + case hwmon_in_max_alarm: > + case hwmon_in_min_alarm: > + return 0444; > + case hwmon_in_max: > + case hwmon_in_min: > + return 0644; > + default: > + return 0; > + } > + case hwmon_curr: > + if (channel != 0) > + return 0; > + > + switch (attr) { > + case hwmon_curr_input: > + return 0444; > + default: > + return 0; > + } > + case hwmon_power: > + if (channel != 0) > + return 0; > + > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_max_alarm: > + return 0444; > + case hwmon_power_max: > + return 0644; > + default: > + return 0; > + } > + case hwmon_temp: > + if (channel != 0) > + return 0; > + > + switch (attr) { > + case hwmon_temp_input: > + case hwmon_temp_max_alarm: > + return 0444; > + case hwmon_temp_max: > + return 0644; > + default: > + return 0; > + } > + default: > + return 0; > + } > +} > + > +#define INA238_HWMON_IN_CONFIG (HWMON_I_INPUT | \ > + HWMON_I_MAX | HWMON_I_MAX_ALARM | \ > + HWMON_I_MIN | HWMON_I_MIN_ALARM) > + > +static const struct hwmon_channel_info *ina238_info[] = { > + HWMON_CHANNEL_INFO(in, > + /* 0: shunt voltage */ > + INA238_HWMON_IN_CONFIG, > + /* 1: bus voltage */ > + INA238_HWMON_IN_CONFIG), > + HWMON_CHANNEL_INFO(curr, > + /* 0: current through shunt */ > + HWMON_C_INPUT), > + HWMON_CHANNEL_INFO(power, > + /* 0: power */ > + HWMON_P_INPUT | HWMON_P_MAX | HWMON_P_MAX_ALARM), > + HWMON_CHANNEL_INFO(temp, > + /* 0: die temperature */ > + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_ALARM), > + NULL > +}; > + > +static const struct hwmon_ops ina238_hwmon_ops = { > + .is_visible = ina238_is_visible, > + .read = ina238_read, > + .write = ina238_write, > +}; > + > +static const struct hwmon_chip_info ina238_chip_info = { > + .ops = &ina238_hwmon_ops, > + .info = ina238_info, > +}; > + > +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; > + int config; > + int ret; > + > + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + /* set the device type */ Pointless comment. I don't even understand what it is supposed to mean. > + mutex_init(&data->config_lock); > + > + 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 */ > + data->rshunt = INA238_RSHUNT_DEFAULT; > + if (device_property_read_u32(dev, "shunt-resistor", &data->rshunt) < 0 && > + pdata) Drop the continuation line. Lines longer than 80 columns are fine when improving readability, and that is definitely the case here. > + data->rshunt = pdata->shunt_uohms; > + if (data->rshunt == 0) { > + dev_err(dev, "invalid shunt resister value %u\n", data->rshunt); > + return -EINVAL; > + } > + > + /* load shunt gain value */ > + if (device_property_read_u32(dev, "ti,shunt-gain", &data->gain) < 0) > + data->gain = 4; /* Default of ADCRANGE = 0 */ > + if (data->gain != 1 && data->gain != 4) { > + dev_err(dev, "invalid shunt gain value %u\n", data->gain); > + return -EINVAL; > + } I think ti,shunt-gain needs a better explanation in the .yaml file, for people writing devicetree files to understand how the gain value converts to a register value. > + > + /* Setup CONFIG register */ > + config = INA238_CONFIG_DEFAULT; > + if (data->gain == 1) > + config |= INA238_CONFIG_ADCRANGE; /* ADCRANGE = 1 is /1 */ > + ret = regmap_write(data->regmap, INA238_CONFIG, config); > + 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; > + } > + > + /* Setup alert/alarm configuration */ > + ret = regmap_write(data->regmap, INA238_DIAG_ALERT, > + INA238_DIAG_ALERT_DEFAULT); > + if (ret < 0) { > + dev_err(dev, "error configuring the device: %d\n", ret); > + return -ENODEV; > + } > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, > + &ina238_chip_info, > + NULL); > + if (IS_ERR(hwmon_dev)) > + return PTR_ERR(hwmon_dev); > + > + dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n", > + client->name, data->rshunt, data->gain); > + > + 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@digi.com>"); > +MODULE_DESCRIPTION("ina238 driver"); > +MODULE_LICENSE("GPL"); > --- > 2.33.0 >
diff --git a/Documentation/hwmon/ina238.rst b/Documentation/hwmon/ina238.rst new file mode 100644 index 0000000000..d9f4799844 --- /dev/null +++ b/Documentation/hwmon/ina238.rst @@ -0,0 +1,56 @@ +.. 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@digi.com> + +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_min Minimum shunt voltage threshold (mV) +in0_min_alarm Minimum shunt voltage alarm +in0_max Maximum shunt voltage threshold (mV) +in0_max_alarm Maximum shunt voltage alarm + +in1_input Bus voltage (mV) +in1_min Minimum bus voltage threshold (mV) +in1_min_alarm Minimum shunt voltage alarm +in1_max Maximum bus voltage threshold (mV) +in1_max_alarm Maximum shunt voltage alarm + +power1_input Power measurement (uW) +power1_max Maximum power threshold (uW) +power1_max_alarm Maximum power alarm + +curr1_input Current measurement (mA) + +temp1_input Die temperature measurement (mC) +temp1_max Maximum die temperature threshold (mC) +temp1_max_alarm Maximum die temperature alarm +======================= ======================================================= diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 7046bf1870..6f30c8c9c7 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -76,6 +76,7 @@ Hardware Monitoring Kernel Drivers ibmpowernv ina209 ina2xx + ina238 ina3221 intel-m10-bmc-hwmon ir35221 diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 7fde4c6e1e..21aff4cef7 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 alarm 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..f9d031bdfe --- /dev/null +++ b/drivers/hwmon/ina238.c @@ -0,0 +1,672 @@ +// 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@digi.com> + */ + +#include <linux/err.h> +#include <linux/hwmon-sysfs.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.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_CONFIG_ADCRANGE BIT(4) + +#define INA238_DIAG_ALERT_TMPOL BIT(7) +#define INA238_DIAG_ALERT_SHNTOL BIT(6) +#define INA238_DIAG_ALERT_SHNTUL BIT(5) +#define INA238_DIAG_ALERT_BUSOL BIT(4) +#define INA238_DIAG_ALERT_BUSUL BIT(3) +#define INA238_DIAG_ALERT_POL BIT(2) + +#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 +/* Configure alerts to be based on averaged value (SLOWALERT) */ +#define INA238_DIAG_ALERT_DEFAULT 0x2000 +/* + * 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, gain = 4). + * 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 / 4 * gain + * Power (W) = 0.2 * register value * 20000 / rshunt / 4 * gain + */ +#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 = { + .max_register = INA238_REGISTERS, + .reg_bits = 8, + .val_bits = 16, +}; + +struct ina238_data { + struct i2c_client *client; + struct mutex config_lock; + struct regmap *regmap; + u32 rshunt; + u32 gain; +}; + +static int ina238_read_reg24(const struct i2c_client *client, u8 reg, u32 *val) +{ + u8 data[3]; + int err; + + /* 24-bit register read */ + err = i2c_smbus_read_i2c_block_data(client, reg, 3, data); + if (err != 3) + return err; + *val = (data[0] << 16) | (data[1] << 8) | data[2]; + + return 0; +} + +static int ina238_read_in(struct device *dev, u32 attr, int channel, + long *val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int reg, mask; + int regval; + int err; + + switch (channel) { + case 0: + switch (attr) { + case hwmon_in_input: + reg = INA238_SHUNT_VOLTAGE; + break; + case hwmon_in_max: + reg = INA238_SHUNT_OVER_VOLTAGE; + break; + case hwmon_in_min: + reg = INA238_SHUNT_UNDER_VOLTAGE; + break; + case hwmon_in_max_alarm: + reg = INA238_DIAG_ALERT; + mask = INA238_DIAG_ALERT_SHNTOL; + break; + case hwmon_in_min_alarm: + reg = INA238_DIAG_ALERT; + mask = INA238_DIAG_ALERT_SHNTUL; + break; + default: + return -EOPNOTSUPP; + } + break; + case 1: + switch (attr) { + case hwmon_in_input: + reg = INA238_BUS_VOLTAGE; + break; + case hwmon_in_max: + reg = INA238_BUS_OVER_VOLTAGE; + break; + case hwmon_in_min: + reg = INA238_BUS_UNDER_VOLTAGE; + break; + case hwmon_in_max_alarm: + reg = INA238_DIAG_ALERT; + mask = INA238_DIAG_ALERT_BUSOL; + break; + case hwmon_in_min_alarm: + reg = INA238_DIAG_ALERT; + mask = INA238_DIAG_ALERT_BUSUL; + break; + default: + return -EOPNOTSUPP; + } + break; + default: + return -EOPNOTSUPP; + } + + err = regmap_read(data->regmap, reg, ®val); + if (err < 0) + return err; + + switch (attr) { + case hwmon_in_input: + case hwmon_in_max: + case hwmon_in_min: + /* signed register, value in mV */ + if (channel == 0) + /* gain of 1 -> LSB / 4 */ + *val = div_s64((s16)regval * INA238_SHUNT_VOLTAGE_LSB, + 1000 * (4 - data->gain + 1)); + else + *val = div_s64((s16)regval * INA238_BUS_VOLTAGE_LSB, + 1000); + break; + case hwmon_in_max_alarm: + case hwmon_in_min_alarm: + *val = regval & mask ? 1 : 0; + break; + } + + return 0; +} + +static int ina238_write_in(struct device *dev, u32 attr, int channel, + long val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int regval; + + if (attr != hwmon_in_max && attr != hwmon_in_min) + return -EOPNOTSUPP; + + /* convert decimal to register value */ + switch (channel) { + case 0: + /* signed */ + regval = div_s64((s64)val * 1000LL * (4 - data->gain + 1), + INA238_SHUNT_VOLTAGE_LSB); + if (regval > S16_MAX || regval < S16_MIN) + return -EINVAL; + + switch (attr) { + case hwmon_in_max: + return regmap_write(data->regmap, + INA238_SHUNT_OVER_VOLTAGE, regval); + case hwmon_in_min: + return regmap_write(data->regmap, + INA238_SHUNT_UNDER_VOLTAGE, regval); + default: + return -EOPNOTSUPP; + } + case 1: + regval = div_u64((u64)val * 1000ULL, INA238_BUS_VOLTAGE_LSB); + if (regval > U16_MAX || regval < 0) + return -EINVAL; + + switch (attr) { + case hwmon_in_max: + return regmap_write(data->regmap, + INA238_BUS_OVER_VOLTAGE, regval); + case hwmon_in_min: + return regmap_write(data->regmap, + INA238_BUS_UNDER_VOLTAGE, regval); + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static int ina238_read_current(struct device *dev, u32 attr, int channel, + long *val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int regval; + int err; + + if (channel != 0) + return -EOPNOTSUPP; + + switch (attr) { + case hwmon_curr_input: + err = regmap_read(data->regmap, INA238_CURRENT, ®val); + if (err < 0) + return err; + + /* Signed register, fixed 1mA current lsb. result in mA */ + *val = div_s64((s16)regval * INA238_FIXED_SHUNT * data->gain, + data->rshunt * 4); + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int ina238_read_power(struct device *dev, u32 attr, int channel, + long *val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + long long power; + int regval; + int err; + + if (channel != 0) + return -EOPNOTSUPP; + + switch (attr) { + case hwmon_power_input: + err = ina238_read_reg24(data->client, INA238_POWER, ®val); + if (err) + return err; + + /* Fixed 1mA lsb, scaled by 1000000 to have result in uW */ + power = div_u64(regval * 1000ULL * INA238_FIXED_SHUNT * + data->gain, 20 * data->rshunt); + /* Clamp value to maximum value of long */ + *val = clamp_val(power, 0, LONG_MAX); + break; + case hwmon_power_max: + err = regmap_read(data->regmap, INA238_POWER_LIMIT, ®val); + if (err) + return err; + + /* + * Truncated 24-bit compare register, lower 8-bits are + * truncated. Same conversion to/from uW as POWER register. + */ + power = div_u64((regval << 8) * 1000ULL * INA238_FIXED_SHUNT * + data->gain, 20 * data->rshunt); + /* Clamp value to maximum value of long */ + *val = clamp_val(power, 0, LONG_MAX); + break; + case hwmon_power_max_alarm: + err = regmap_read(data->regmap, INA238_DIAG_ALERT, ®val); + if (err) + return err; + + *val = regval & INA238_DIAG_ALERT_POL ? 1 : 0; + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int ina238_write_power(struct device *dev, u32 attr, int channel, + long val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int regval; + + if (channel != 0 || attr != hwmon_power_max) + return -EOPNOTSUPP; + + /* + * Compared against the 24-bit power register, lower 8-bits are + * truncated. Same conversion to/from uW as POWER register. + */ + regval = div_u64((u64)val * 20ULL * data->rshunt, + 1000ULL * INA238_FIXED_SHUNT * (u64)data->gain); + regval = regval >> 8; + if (regval > U16_MAX || regval < 0) + return -EINVAL; + + return regmap_write(data->regmap, INA238_POWER_LIMIT, regval); +} + +static int ina238_read_temp(struct device *dev, u32 attr, int channel, + long *val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int regval; + int err; + + if (channel != 0) + return -EOPNOTSUPP; + + switch (attr) { + case hwmon_temp_input: + err = regmap_read(data->regmap, INA238_DIE_TEMP, ®val); + if (err) + return err; + + /* Signed, bits 15-4 of register, result in mC */ + *val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; + break; + case hwmon_temp_max: + err = regmap_read(data->regmap, INA238_TEMP_LIMIT, ®val); + if (err) + return err; + + /* Signed, bits 15-4 of register, result in mC */ + *val = ((s16)regval >> 4) * INA238_DIE_TEMP_LSB; + break; + case hwmon_temp_max_alarm: + err = regmap_read(data->regmap, INA238_DIAG_ALERT, ®val); + if (err) + return err; + + *val = regval & INA238_DIAG_ALERT_TMPOL ? 1 : 0; + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int ina238_write_temp(struct device *dev, u32 attr, int channel, + long val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int regval; + + if (channel != 0 || attr != hwmon_temp_max) + return -EOPNOTSUPP; + + /* Signed, bits 15-4 of register */ + regval = (div_s64(val, INA238_DIE_TEMP_LSB) << 4); + if (regval > S16_MAX || regval < S16_MIN) + return -EINVAL; + regval = regval & 0xfff0; + + return regmap_write(data->regmap, INA238_TEMP_LIMIT, regval); +} + +static int ina238_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + switch (type) { + case hwmon_in: + return ina238_read_in(dev, attr, channel, val); + case hwmon_curr: + return ina238_read_current(dev, attr, channel, val); + case hwmon_power: + return ina238_read_power(dev, attr, channel, val); + case hwmon_temp: + return ina238_read_temp(dev, attr, channel, val); + default: + return -EOPNOTSUPP; + } + return 0; +} + +static int ina238_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct ina238_data *data = dev_get_drvdata(dev); + int err; + + mutex_lock(&data->config_lock); + + switch (type) { + case hwmon_in: + err = ina238_write_in(dev, attr, channel, val); + break; + case hwmon_power: + err = ina238_write_power(dev, attr, channel, val); + break; + case hwmon_temp: + err = ina238_write_temp(dev, attr, channel, val); + break; + default: + err = -EOPNOTSUPP; + break; + } + + mutex_unlock(&data->config_lock); + return err; +} + +static umode_t ina238_is_visible(const void *drvdata, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_in: + if (channel != 0 && channel != 1) + return 0; + + switch (attr) { + case hwmon_in_input: + case hwmon_in_max_alarm: + case hwmon_in_min_alarm: + return 0444; + case hwmon_in_max: + case hwmon_in_min: + return 0644; + default: + return 0; + } + case hwmon_curr: + if (channel != 0) + return 0; + + switch (attr) { + case hwmon_curr_input: + return 0444; + default: + return 0; + } + case hwmon_power: + if (channel != 0) + return 0; + + switch (attr) { + case hwmon_power_input: + case hwmon_power_max_alarm: + return 0444; + case hwmon_power_max: + return 0644; + default: + return 0; + } + case hwmon_temp: + if (channel != 0) + return 0; + + switch (attr) { + case hwmon_temp_input: + case hwmon_temp_max_alarm: + return 0444; + case hwmon_temp_max: + return 0644; + default: + return 0; + } + default: + return 0; + } +} + +#define INA238_HWMON_IN_CONFIG (HWMON_I_INPUT | \ + HWMON_I_MAX | HWMON_I_MAX_ALARM | \ + HWMON_I_MIN | HWMON_I_MIN_ALARM) + +static const struct hwmon_channel_info *ina238_info[] = { + HWMON_CHANNEL_INFO(in, + /* 0: shunt voltage */ + INA238_HWMON_IN_CONFIG, + /* 1: bus voltage */ + INA238_HWMON_IN_CONFIG), + HWMON_CHANNEL_INFO(curr, + /* 0: current through shunt */ + HWMON_C_INPUT), + HWMON_CHANNEL_INFO(power, + /* 0: power */ + HWMON_P_INPUT | HWMON_P_MAX | HWMON_P_MAX_ALARM), + HWMON_CHANNEL_INFO(temp, + /* 0: die temperature */ + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_ALARM), + NULL +}; + +static const struct hwmon_ops ina238_hwmon_ops = { + .is_visible = ina238_is_visible, + .read = ina238_read, + .write = ina238_write, +}; + +static const struct hwmon_chip_info ina238_chip_info = { + .ops = &ina238_hwmon_ops, + .info = ina238_info, +}; + +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; + int config; + 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); + + 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 */ + data->rshunt = INA238_RSHUNT_DEFAULT; + if (device_property_read_u32(dev, "shunt-resistor", &data->rshunt) < 0 && + pdata) + data->rshunt = pdata->shunt_uohms; + if (data->rshunt == 0) { + dev_err(dev, "invalid shunt resister value %u\n", data->rshunt); + return -EINVAL; + } + + /* load shunt gain value */ + if (device_property_read_u32(dev, "ti,shunt-gain", &data->gain) < 0) + data->gain = 4; /* Default of ADCRANGE = 0 */ + if (data->gain != 1 && data->gain != 4) { + dev_err(dev, "invalid shunt gain value %u\n", data->gain); + return -EINVAL; + } + + /* Setup CONFIG register */ + config = INA238_CONFIG_DEFAULT; + if (data->gain == 1) + config |= INA238_CONFIG_ADCRANGE; /* ADCRANGE = 1 is /1 */ + ret = regmap_write(data->regmap, INA238_CONFIG, config); + 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; + } + + /* Setup alert/alarm configuration */ + ret = regmap_write(data->regmap, INA238_DIAG_ALERT, + INA238_DIAG_ALERT_DEFAULT); + if (ret < 0) { + dev_err(dev, "error configuring the device: %d\n", ret); + return -ENODEV; + } + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, + &ina238_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n", + client->name, data->rshunt, data->gain); + + 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@digi.com>"); +MODULE_DESCRIPTION("ina238 driver"); +MODULE_LICENSE("GPL");