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linux/drivers/hwmon/ina3221.c
Guenter Roeck 9ad0df1ada hwmon: (ina3221) Fix negative limits 
The result of an integer divide by an unsigned is undefined.
This causes unexpected results when writing negative values
into the limit registers.

Maintain the shunt_resistors variables as signed integer to avoid
the problem. Also, for simplicity and ease of use, clamp shunt
resistor value on writes instead of rejecting bad values.

Cc: Andrew F. Davis <afd@ti.com>
Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-06-27 18:58:04 -07:00

446 lines
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/*
* INA3221 Triple Current/Voltage Monitor
*
* Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
* Andrew F. Davis <afd@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#define INA3221_DRIVER_NAME "ina3221"
#define INA3221_CONFIG 0x00
#define INA3221_SHUNT1 0x01
#define INA3221_BUS1 0x02
#define INA3221_SHUNT2 0x03
#define INA3221_BUS2 0x04
#define INA3221_SHUNT3 0x05
#define INA3221_BUS3 0x06
#define INA3221_CRIT1 0x07
#define INA3221_WARN1 0x08
#define INA3221_CRIT2 0x09
#define INA3221_WARN2 0x0a
#define INA3221_CRIT3 0x0b
#define INA3221_WARN3 0x0c
#define INA3221_MASK_ENABLE 0x0f
#define INA3221_CONFIG_MODE_SHUNT BIT(1)
#define INA3221_CONFIG_MODE_BUS BIT(2)
#define INA3221_CONFIG_MODE_CONTINUOUS BIT(3)
#define INA3221_RSHUNT_DEFAULT 10000
enum ina3221_fields {
/* Configuration */
F_RST,
/* Alert Flags */
F_WF3, F_WF2, F_WF1,
F_CF3, F_CF2, F_CF1,
/* sentinel */
F_MAX_FIELDS
};
static const struct reg_field ina3221_reg_fields[] = {
[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
};
enum ina3221_channels {
INA3221_CHANNEL1,
INA3221_CHANNEL2,
INA3221_CHANNEL3,
INA3221_NUM_CHANNELS
};
static const unsigned int register_channel[] = {
[INA3221_SHUNT1] = INA3221_CHANNEL1,
[INA3221_SHUNT2] = INA3221_CHANNEL2,
[INA3221_SHUNT3] = INA3221_CHANNEL3,
[INA3221_CRIT1] = INA3221_CHANNEL1,
[INA3221_CRIT2] = INA3221_CHANNEL2,
[INA3221_CRIT3] = INA3221_CHANNEL3,
[INA3221_WARN1] = INA3221_CHANNEL1,
[INA3221_WARN2] = INA3221_CHANNEL2,
[INA3221_WARN3] = INA3221_CHANNEL3,
};
/**
* struct ina3221_data - device specific information
* @regmap: Register map of the device
* @fields: Register fields of the device
* @shunt_resistors: Array of resistor values per channel
*/
struct ina3221_data {
struct regmap *regmap;
struct regmap_field *fields[F_MAX_FIELDS];
int shunt_resistors[INA3221_NUM_CHANNELS];
};
static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
int *val)
{
unsigned int regval;
int ret;
ret = regmap_read(ina->regmap, reg, &regval);
if (ret)
return ret;
*val = sign_extend32(regval >> 3, 12);
return 0;
}
static ssize_t ina3221_show_bus_voltage(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int reg = sd_attr->index;
int val, voltage_mv, ret;
ret = ina3221_read_value(ina, reg, &val);
if (ret)
return ret;
voltage_mv = val * 8;
return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
}
static ssize_t ina3221_show_shunt_voltage(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int reg = sd_attr->index;
int val, voltage_uv, ret;
ret = ina3221_read_value(ina, reg, &val);
if (ret)
return ret;
voltage_uv = val * 40;
return snprintf(buf, PAGE_SIZE, "%d\n", voltage_uv);
}
static ssize_t ina3221_show_current(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int reg = sd_attr->index;
unsigned int channel = register_channel[reg];
int resistance_uo = ina->shunt_resistors[channel];
int val, current_ma, voltage_nv, ret;
ret = ina3221_read_value(ina, reg, &val);
if (ret)
return ret;
voltage_nv = val * 40000;
current_ma = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
}
static ssize_t ina3221_set_current(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int reg = sd_attr->index;
unsigned int channel = register_channel[reg];
int resistance_uo = ina->shunt_resistors[channel];
int val, current_ma, voltage_uv, ret;
ret = kstrtoint(buf, 0, &current_ma);
if (ret)
return ret;
/* clamp current */
current_ma = clamp_val(current_ma,
INT_MIN / resistance_uo,
INT_MAX / resistance_uo);
voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
/* clamp voltage */
voltage_uv = clamp_val(voltage_uv, -163800, 163800);
/* 1 / 40uV(scale) << 3(register shift) = 5 */
val = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
ret = regmap_write(ina->regmap, reg, val);
if (ret)
return ret;
return count;
}
static ssize_t ina3221_show_shunt(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int channel = sd_attr->index;
unsigned int resistance_uo;
resistance_uo = ina->shunt_resistors[channel];
return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
}
static ssize_t ina3221_set_shunt(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int channel = sd_attr->index;
int val;
int ret;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
val = clamp_val(val, 1, INT_MAX);
ina->shunt_resistors[channel] = val;
return count;
}
static ssize_t ina3221_show_alert(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int field = sd_attr->index;
unsigned int regval;
int ret;
ret = regmap_field_read(ina->fields[field], &regval);
if (ret)
return ret;
return snprintf(buf, PAGE_SIZE, "%d\n", regval);
}
/* bus voltage */
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO,
ina3221_show_bus_voltage, NULL, INA3221_BUS1);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO,
ina3221_show_bus_voltage, NULL, INA3221_BUS2);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO,
ina3221_show_bus_voltage, NULL, INA3221_BUS3);
/* calculated current */
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO,
ina3221_show_current, NULL, INA3221_SHUNT1);
static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO,
ina3221_show_current, NULL, INA3221_SHUNT2);
static SENSOR_DEVICE_ATTR(curr3_input, S_IRUGO,
ina3221_show_current, NULL, INA3221_SHUNT3);
/* shunt resistance */
static SENSOR_DEVICE_ATTR(shunt1_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
static SENSOR_DEVICE_ATTR(shunt2_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
static SENSOR_DEVICE_ATTR(shunt3_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
/* critical current */
static SENSOR_DEVICE_ATTR(curr1_crit, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_CRIT1);
static SENSOR_DEVICE_ATTR(curr2_crit, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_CRIT2);
static SENSOR_DEVICE_ATTR(curr3_crit, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_CRIT3);
/* critical current alert */
static SENSOR_DEVICE_ATTR(curr1_crit_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_CF1);
static SENSOR_DEVICE_ATTR(curr2_crit_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_CF2);
static SENSOR_DEVICE_ATTR(curr3_crit_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_CF3);
/* warning current */
static SENSOR_DEVICE_ATTR(curr1_max, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_WARN1);
static SENSOR_DEVICE_ATTR(curr2_max, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_WARN2);
static SENSOR_DEVICE_ATTR(curr3_max, S_IRUGO | S_IWUSR,
ina3221_show_current, ina3221_set_current, INA3221_WARN3);
/* warning current alert */
static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_WF1);
static SENSOR_DEVICE_ATTR(curr2_max_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_WF2);
static SENSOR_DEVICE_ATTR(curr3_max_alarm, S_IRUGO,
ina3221_show_alert, NULL, F_WF3);
/* shunt voltage */
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO,
ina3221_show_shunt_voltage, NULL, INA3221_SHUNT1);
static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO,
ina3221_show_shunt_voltage, NULL, INA3221_SHUNT2);
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO,
ina3221_show_shunt_voltage, NULL, INA3221_SHUNT3);
static struct attribute *ina3221_attrs[] = {
/* channel 1 */
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
&sensor_dev_attr_curr1_crit.dev_attr.attr,
&sensor_dev_attr_curr1_crit_alarm.dev_attr.attr,
&sensor_dev_attr_curr1_max.dev_attr.attr,
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
/* channel 2 */
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_curr2_input.dev_attr.attr,
&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
&sensor_dev_attr_curr2_crit.dev_attr.attr,
&sensor_dev_attr_curr2_crit_alarm.dev_attr.attr,
&sensor_dev_attr_curr2_max.dev_attr.attr,
&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
/* channel 3 */
&sensor_dev_attr_in3_input.dev_attr.attr,
&sensor_dev_attr_curr3_input.dev_attr.attr,
&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
&sensor_dev_attr_curr3_crit.dev_attr.attr,
&sensor_dev_attr_curr3_crit_alarm.dev_attr.attr,
&sensor_dev_attr_curr3_max.dev_attr.attr,
&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
NULL,
};
ATTRIBUTE_GROUPS(ina3221);
static const struct regmap_range ina3221_yes_ranges[] = {
regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
};
static const struct regmap_access_table ina3221_volatile_table = {
.yes_ranges = ina3221_yes_ranges,
.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
};
static const struct regmap_config ina3221_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.cache_type = REGCACHE_RBTREE,
.volatile_table = &ina3221_volatile_table,
};
static int ina3221_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct ina3221_data *ina;
struct device *hwmon_dev;
int i, ret;
ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
if (!ina)
return -ENOMEM;
ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
if (IS_ERR(ina->regmap)) {
dev_err(dev, "Unable to allocate register map\n");
return PTR_ERR(ina->regmap);
}
for (i = 0; i < F_MAX_FIELDS; i++) {
ina->fields[i] = devm_regmap_field_alloc(dev,
ina->regmap,
ina3221_reg_fields[i]);
if (IS_ERR(ina->fields[i])) {
dev_err(dev, "Unable to allocate regmap fields\n");
return PTR_ERR(ina->fields[i]);
}
}
for (i = 0; i < INA3221_NUM_CHANNELS; i++)
ina->shunt_resistors[i] = INA3221_RSHUNT_DEFAULT;
ret = regmap_field_write(ina->fields[F_RST], true);
if (ret) {
dev_err(dev, "Unable to reset device\n");
return ret;
}
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name,
ina, ina3221_groups);
if (IS_ERR(hwmon_dev)) {
dev_err(dev, "Unable to register hwmon device\n");
return PTR_ERR(hwmon_dev);
}
return 0;
}
static const struct of_device_id ina3221_of_match_table[] = {
{ .compatible = "ti,ina3221", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
static const struct i2c_device_id ina3221_ids[] = {
{ "ina3221", 0 },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, ina3221_ids);
static struct i2c_driver ina3221_i2c_driver = {
.probe = ina3221_probe,
.driver = {
.name = INA3221_DRIVER_NAME,
.of_match_table = ina3221_of_match_table,
},
.id_table = ina3221_ids,
};
module_i2c_driver(ina3221_i2c_driver);
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
MODULE_LICENSE("GPL v2");
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