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alistair23-linux/drivers/hwmon/ltc2990.c
Tom Levens 5d9ca430ea hwmon: (ltc2990) support all measurement modes 
Updated version of the ltc2990 driver which supports all measurement
modes (current, voltage, temperature) available in the chip.

If devicetree is used, the mode must be specified with the property
"lltc,meas-mode". The format and possible values of the property are
described in the binding.

If devicetree is not used, the mode of the chip will not be configured.
Unless the chip is configured by another source, only the internal
temperature and supply voltage will be measured.

Signed-off-by: Tom Levens <tom.levens@cern.ch>
Tested-By: mike.looijmans@topic.nl
[groeck: Fixed compiler warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2018-05-21 07:52:01 -07:00

292 lines
7.6 KiB
C
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/*
* Driver for Linear Technology LTC2990 power monitor
*
* Copyright (C) 2014 Topic Embedded Products
* Author: Mike Looijmans <mike.looijmans@topic.nl>
*
* License: GPLv2
*/
#include <linux/bitops.h>
#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>
#include <linux/of.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_IN0 BIT(0)
#define LTC2990_IN1 BIT(1)
#define LTC2990_IN2 BIT(2)
#define LTC2990_IN3 BIT(3)
#define LTC2990_IN4 BIT(4)
#define LTC2990_CURR1 BIT(5)
#define LTC2990_CURR2 BIT(6)
#define LTC2990_TEMP1 BIT(7)
#define LTC2990_TEMP2 BIT(8)
#define LTC2990_TEMP3 BIT(9)
#define LTC2990_NONE 0
#define LTC2990_ALL GENMASK(9, 0)
#define LTC2990_MODE0_SHIFT 0
#define LTC2990_MODE0_MASK GENMASK(2, 0)
#define LTC2990_MODE1_SHIFT 3
#define LTC2990_MODE1_MASK GENMASK(1, 0)
/* Enabled measurements for mode bits 2..0 */
static const int ltc2990_attrs_ena_0[] = {
LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
LTC2990_CURR1 | LTC2990_TEMP3,
LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
LTC2990_TEMP2 | LTC2990_CURR2,
LTC2990_TEMP2 | LTC2990_TEMP3,
LTC2990_CURR1 | LTC2990_CURR2,
LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
};
/* Enabled measurements for mode bits 4..3 */
static const int ltc2990_attrs_ena_1[] = {
LTC2990_NONE,
LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
LTC2990_ALL
};
struct ltc2990_data {
struct i2c_client *i2c;
u32 mode[2];
};
/* Return the converted value from the given register in uV or mC */
static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
{
int val;
u8 reg;
switch (index) {
case LTC2990_IN0:
reg = LTC2990_VCC_MSB;
break;
case LTC2990_IN1:
case LTC2990_CURR1:
case LTC2990_TEMP2:
reg = LTC2990_V1_MSB;
break;
case LTC2990_IN2:
reg = LTC2990_V2_MSB;
break;
case LTC2990_IN3:
case LTC2990_CURR2:
case LTC2990_TEMP3:
reg = LTC2990_V3_MSB;
break;
case LTC2990_IN4:
reg = LTC2990_V4_MSB;
break;
case LTC2990_TEMP1:
reg = LTC2990_TINT_MSB;
break;
default:
return -EINVAL;
}
val = i2c_smbus_read_word_swapped(i2c, reg);
if (unlikely(val < 0))
return val;
switch (index) {
case LTC2990_TEMP1:
case LTC2990_TEMP2:
case LTC2990_TEMP3:
/* temp, 0.0625 degrees/LSB */
*result = sign_extend32(val, 12) * 1000 / 16;
break;
case LTC2990_CURR1:
case LTC2990_CURR2:
/* Vx-Vy, 19.42uV/LSB */
*result = sign_extend32(val, 14) * 1942 / 100;
break;
case LTC2990_IN0:
/* Vcc, 305.18uV/LSB, 2.5V offset */
*result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
break;
case LTC2990_IN1:
case LTC2990_IN2:
case LTC2990_IN3:
case LTC2990_IN4:
/* Vx, 305.18uV/LSB */
*result = sign_extend32(val, 14) * 30518 / (100 * 1000);
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);
struct ltc2990_data *data = dev_get_drvdata(dev);
int value;
int ret;
ret = ltc2990_get_value(data->i2c, attr->index, &value);
if (unlikely(ret < 0))
return ret;
return snprintf(buf, PAGE_SIZE, "%d\n", value);
}
static umode_t ltc2990_attrs_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct ltc2990_data *data = dev_get_drvdata(dev);
struct device_attribute *da =
container_of(a, struct device_attribute, attr);
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
(ltc2990_attrs_ena_0[data->mode[0]] &
ltc2990_attrs_ena_1[data->mode[1]]);
if (attr->index & attrs_mask)
return a->mode;
return 0;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_TEMP1);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_TEMP2);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_TEMP3);
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_CURR1);
static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_CURR2);
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_IN0);
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_IN1);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_IN2);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_IN3);
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc2990_show_value, NULL,
LTC2990_IN4);
static struct attribute *ltc2990_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp2_input.dev_attr.attr,
&sensor_dev_attr_temp3_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,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in3_input.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
NULL,
};
static const struct attribute_group ltc2990_group = {
.attrs = ltc2990_attrs,
.is_visible = ltc2990_attrs_visible,
};
__ATTRIBUTE_GROUPS(ltc2990);
static int ltc2990_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
int ret;
struct device *hwmon_dev;
struct ltc2990_data *data;
struct device_node *of_node = i2c->dev.of_node;
if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
if (unlikely(!data))
return -ENOMEM;
data->i2c = i2c;
if (of_node) {
ret = of_property_read_u32_array(of_node, "lltc,meas-mode",
data->mode, 2);
if (ret < 0)
return ret;
if (data->mode[0] & ~LTC2990_MODE0_MASK ||
data->mode[1] & ~LTC2990_MODE1_MASK)
return -EINVAL;
} else {
ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
if (ret < 0)
return ret;
data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
}
/* Setup continuous mode */
ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
data->mode[0] << LTC2990_MODE0_SHIFT |
data->mode[1] << LTC2990_MODE1_SHIFT);
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,
data,
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");
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