1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*
* 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/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>
#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
/* 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 */
*result = sign_extend32(val, 12) * 1000 / 16;
break;
case LTC2990_V1_MSB:
case LTC2990_V3_MSB:
/* Vx-Vy, 19.42uV/LSB. Depends on mode. */
*result = sign_extend32(val, 14) * 1942 / 100;
break;
case LTC2990_VCC_MSB:
/* Vcc, 305.18μV/LSB, 2.5V offset */
*result = sign_extend32(val, 14) * 30518 / (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");
|
