mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Axel Lin](/assets/img/avatar_default.png)
Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
200 lines
5.2 KiB
C
200 lines
5.2 KiB
C
/*
|
|
* Driver for Linear Technology LTC4260 I2C Positive Voltage Hot Swap Controller
|
|
*
|
|
* Copyright (c) 2014 Guenter Roeck
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/hwmon.h>
|
|
#include <linux/hwmon-sysfs.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/regmap.h>
|
|
|
|
/* chip registers */
|
|
#define LTC4260_CONTROL 0x00
|
|
#define LTC4260_ALERT 0x01
|
|
#define LTC4260_STATUS 0x02
|
|
#define LTC4260_FAULT 0x03
|
|
#define LTC4260_SENSE 0x04
|
|
#define LTC4260_SOURCE 0x05
|
|
#define LTC4260_ADIN 0x06
|
|
|
|
/*
|
|
* Fault register bits
|
|
*/
|
|
#define FAULT_OV (1 << 0)
|
|
#define FAULT_UV (1 << 1)
|
|
#define FAULT_OC (1 << 2)
|
|
#define FAULT_POWER_BAD (1 << 3)
|
|
#define FAULT_FET_SHORT (1 << 5)
|
|
|
|
/* Return the voltage from the given register in mV or mA */
|
|
static int ltc4260_get_value(struct device *dev, u8 reg)
|
|
{
|
|
struct regmap *regmap = dev_get_drvdata(dev);
|
|
unsigned int val;
|
|
int ret;
|
|
|
|
ret = regmap_read(regmap, reg, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
switch (reg) {
|
|
case LTC4260_ADIN:
|
|
/* 10 mV resolution. Convert to mV. */
|
|
val = val * 10;
|
|
break;
|
|
case LTC4260_SOURCE:
|
|
/* 400 mV resolution. Convert to mV. */
|
|
val = val * 400;
|
|
break;
|
|
case LTC4260_SENSE:
|
|
/*
|
|
* 300 uV resolution. Convert to current as measured with
|
|
* an 1 mOhm sense resistor, in mA. If a different sense
|
|
* resistor is installed, calculate the actual current by
|
|
* dividing the reported current by the sense resistor value
|
|
* in mOhm.
|
|
*/
|
|
val = val * 300;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return val;
|
|
}
|
|
|
|
static ssize_t ltc4260_show_value(struct device *dev,
|
|
struct device_attribute *da, char *buf)
|
|
{
|
|
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
|
|
int value;
|
|
|
|
value = ltc4260_get_value(dev, attr->index);
|
|
if (value < 0)
|
|
return value;
|
|
return snprintf(buf, PAGE_SIZE, "%d\n", value);
|
|
}
|
|
|
|
static ssize_t ltc4260_show_bool(struct device *dev,
|
|
struct device_attribute *da, char *buf)
|
|
{
|
|
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
|
|
struct regmap *regmap = dev_get_drvdata(dev);
|
|
unsigned int fault;
|
|
int ret;
|
|
|
|
ret = regmap_read(regmap, LTC4260_FAULT, &fault);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
fault &= attr->index;
|
|
if (fault) /* Clear reported faults in chip register */
|
|
regmap_update_bits(regmap, LTC4260_FAULT, attr->index, 0);
|
|
|
|
return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
|
|
}
|
|
|
|
/* Voltages */
|
|
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4260_show_value, NULL,
|
|
LTC4260_SOURCE);
|
|
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4260_show_value, NULL,
|
|
LTC4260_ADIN);
|
|
|
|
/*
|
|
* Voltage alarms
|
|
* UV/OV faults are associated with the input voltage, and the POWER BAD and
|
|
* FET SHORT faults are associated with the output voltage.
|
|
*/
|
|
static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ltc4260_show_bool, NULL,
|
|
FAULT_UV);
|
|
static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc4260_show_bool, NULL,
|
|
FAULT_OV);
|
|
static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, ltc4260_show_bool, NULL,
|
|
FAULT_POWER_BAD | FAULT_FET_SHORT);
|
|
|
|
/* Current (via sense resistor) */
|
|
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4260_show_value, NULL,
|
|
LTC4260_SENSE);
|
|
|
|
/* Overcurrent alarm */
|
|
static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc4260_show_bool, NULL,
|
|
FAULT_OC);
|
|
|
|
static struct attribute *ltc4260_attrs[] = {
|
|
&sensor_dev_attr_in1_input.dev_attr.attr,
|
|
&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
|
|
&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
|
|
&sensor_dev_attr_in2_input.dev_attr.attr,
|
|
&sensor_dev_attr_in2_alarm.dev_attr.attr,
|
|
|
|
&sensor_dev_attr_curr1_input.dev_attr.attr,
|
|
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
|
|
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(ltc4260);
|
|
|
|
static const struct regmap_config ltc4260_regmap_config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
.max_register = LTC4260_ADIN,
|
|
};
|
|
|
|
static int ltc4260_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct device *dev = &client->dev;
|
|
struct device *hwmon_dev;
|
|
struct regmap *regmap;
|
|
|
|
regmap = devm_regmap_init_i2c(client, <c4260_regmap_config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(dev, "failed to allocate register map\n");
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
/* Clear faults */
|
|
regmap_write(regmap, LTC4260_FAULT, 0x00);
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
|
|
regmap,
|
|
ltc4260_groups);
|
|
return PTR_ERR_OR_ZERO(hwmon_dev);
|
|
}
|
|
|
|
static const struct i2c_device_id ltc4260_id[] = {
|
|
{"ltc4260", 0},
|
|
{ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, ltc4260_id);
|
|
|
|
static struct i2c_driver ltc4260_driver = {
|
|
.driver = {
|
|
.name = "ltc4260",
|
|
},
|
|
.probe = ltc4260_probe,
|
|
.id_table = ltc4260_id,
|
|
};
|
|
|
|
module_i2c_driver(ltc4260_driver);
|
|
|
|
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
|
|
MODULE_DESCRIPTION("LTC4260 driver");
|
|
MODULE_LICENSE("GPL");
|