You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
161 lines
4.3 KiB
161 lines
4.3 KiB
/*
|
|
* Driver for Linear Technology LTC2990 power monitor
|
|
*
|
|
* Copyright (C) 2014 Topic Embedded Products
|
|
* Author: Mike Looijmans <mike.looijmans@topic.nl>
|
|
*
|
|
* License: GPLv2
|
|
*
|
|
* This driver assumes the chip is wired as a dual current monitor, and
|
|
* reports the voltage drop across two series resistors. It also reports
|
|
* the chip's internal temperature and Vcc power supply voltage.
|
|
*/
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/hwmon.h>
|
|
#include <linux/hwmon-sysfs.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
|
|
#define LTC2990_STATUS 0x00
|
|
#define LTC2990_CONTROL 0x01
|
|
#define LTC2990_TRIGGER 0x02
|
|
#define LTC2990_TINT_MSB 0x04
|
|
#define LTC2990_V1_MSB 0x06
|
|
#define LTC2990_V2_MSB 0x08
|
|
#define LTC2990_V3_MSB 0x0A
|
|
#define LTC2990_V4_MSB 0x0C
|
|
#define LTC2990_VCC_MSB 0x0E
|
|
|
|
#define LTC2990_CONTROL_KELVIN BIT(7)
|
|
#define LTC2990_CONTROL_SINGLE BIT(6)
|
|
#define LTC2990_CONTROL_MEASURE_ALL (0x3 << 3)
|
|
#define LTC2990_CONTROL_MODE_CURRENT 0x06
|
|
#define LTC2990_CONTROL_MODE_VOLTAGE 0x07
|
|
|
|
/* convert raw register value to sign-extended integer in 16-bit range */
|
|
static int ltc2990_voltage_to_int(int raw)
|
|
{
|
|
if (raw & BIT(14))
|
|
return -(0x4000 - (raw & 0x3FFF)) << 2;
|
|
else
|
|
return (raw & 0x3FFF) << 2;
|
|
}
|
|
|
|
/* Return the converted value from the given register in uV or mC */
|
|
static int ltc2990_get_value(struct i2c_client *i2c, u8 reg, int *result)
|
|
{
|
|
int val;
|
|
|
|
val = i2c_smbus_read_word_swapped(i2c, reg);
|
|
if (unlikely(val < 0))
|
|
return val;
|
|
|
|
switch (reg) {
|
|
case LTC2990_TINT_MSB:
|
|
/* internal temp, 0.0625 degrees/LSB, 13-bit */
|
|
val = (val & 0x1FFF) << 3;
|
|
*result = (val * 1000) >> 7;
|
|
break;
|
|
case LTC2990_V1_MSB:
|
|
case LTC2990_V3_MSB:
|
|
/* Vx-Vy, 19.42uV/LSB. Depends on mode. */
|
|
*result = ltc2990_voltage_to_int(val) * 1942 / (4 * 100);
|
|
break;
|
|
case LTC2990_VCC_MSB:
|
|
/* Vcc, 305.18μV/LSB, 2.5V offset */
|
|
*result = (ltc2990_voltage_to_int(val) * 30518 /
|
|
(4 * 100 * 1000)) + 2500;
|
|
break;
|
|
default:
|
|
return -EINVAL; /* won't happen, keep compiler happy */
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t ltc2990_show_value(struct device *dev,
|
|
struct device_attribute *da, char *buf)
|
|
{
|
|
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
|
|
int value;
|
|
int ret;
|
|
|
|
ret = ltc2990_get_value(dev_get_drvdata(dev), attr->index, &value);
|
|
if (unlikely(ret < 0))
|
|
return ret;
|
|
|
|
return snprintf(buf, PAGE_SIZE, "%d\n", value);
|
|
}
|
|
|
|
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ltc2990_show_value, NULL,
|
|
LTC2990_TINT_MSB);
|
|
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL,
|
|
LTC2990_V1_MSB);
|
|
static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL,
|
|
LTC2990_V3_MSB);
|
|
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL,
|
|
LTC2990_VCC_MSB);
|
|
|
|
static struct attribute *ltc2990_attrs[] = {
|
|
&sensor_dev_attr_temp1_input.dev_attr.attr,
|
|
&sensor_dev_attr_curr1_input.dev_attr.attr,
|
|
&sensor_dev_attr_curr2_input.dev_attr.attr,
|
|
&sensor_dev_attr_in0_input.dev_attr.attr,
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(ltc2990);
|
|
|
|
static int ltc2990_i2c_probe(struct i2c_client *i2c,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
int ret;
|
|
struct device *hwmon_dev;
|
|
|
|
if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
|
|
I2C_FUNC_SMBUS_WORD_DATA))
|
|
return -ENODEV;
|
|
|
|
/* Setup continuous mode, current monitor */
|
|
ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
|
|
LTC2990_CONTROL_MEASURE_ALL |
|
|
LTC2990_CONTROL_MODE_CURRENT);
|
|
if (ret < 0) {
|
|
dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
|
|
return ret;
|
|
}
|
|
/* Trigger once to start continuous conversion */
|
|
ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
|
|
if (ret < 0) {
|
|
dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
|
|
return ret;
|
|
}
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
|
|
i2c->name,
|
|
i2c,
|
|
ltc2990_groups);
|
|
|
|
return PTR_ERR_OR_ZERO(hwmon_dev);
|
|
}
|
|
|
|
static const struct i2c_device_id ltc2990_i2c_id[] = {
|
|
{ "ltc2990", 0 },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
|
|
|
|
static struct i2c_driver ltc2990_i2c_driver = {
|
|
.driver = {
|
|
.name = "ltc2990",
|
|
},
|
|
.probe = ltc2990_i2c_probe,
|
|
.id_table = ltc2990_i2c_id,
|
|
};
|
|
|
|
module_i2c_driver(ltc2990_i2c_driver);
|
|
|
|
MODULE_DESCRIPTION("LTC2990 Sensor Driver");
|
|
MODULE_AUTHOR("Topic Embedded Products");
|
|
MODULE_LICENSE("GPL v2");
|
|
|