linux-stable/drivers/hwmon/ltc4222.c
Stephen Kitt 6748703856 hwmon: use simple i2c probe function
Many hwmon drivers don't use the id information provided by the old
i2c probe function, and the remainder can easily be adapted to the new
form ("probe_new") by calling i2c_match_id explicitly.

This avoids scanning the identifier tables during probes.

Drivers which didn't use the id are converted as-is; drivers which did
are modified as follows:

* if the information in i2c_client is sufficient, that's used instead
  (client->name);
* anything else is handled by calling i2c_match_id() with the same
  level of error-handling (if any) as before.

A few drivers aren't included in this patch because they have a
different set of maintainers. They will be covered by other patches.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200813160222.1503401-1-steve@sk2.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-09-23 09:42:39 -07:00

221 lines
6.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Linear Technology LTC4222 Dual Hot Swap controller
*
* Copyright (c) 2014 Guenter Roeck
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/bitops.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 LTC4222_CONTROL1 0xd0
#define LTC4222_ALERT1 0xd1
#define LTC4222_STATUS1 0xd2
#define LTC4222_FAULT1 0xd3
#define LTC4222_CONTROL2 0xd4
#define LTC4222_ALERT2 0xd5
#define LTC4222_STATUS2 0xd6
#define LTC4222_FAULT2 0xd7
#define LTC4222_SOURCE1 0xd8
#define LTC4222_SOURCE2 0xda
#define LTC4222_ADIN1 0xdc
#define LTC4222_ADIN2 0xde
#define LTC4222_SENSE1 0xe0
#define LTC4222_SENSE2 0xe2
#define LTC4222_ADC_CONTROL 0xe4
/*
* Fault register bits
*/
#define FAULT_OV BIT(0)
#define FAULT_UV BIT(1)
#define FAULT_OC BIT(2)
#define FAULT_POWER_BAD BIT(3)
#define FAULT_FET_BAD BIT(5)
/* Return the voltage from the given register in mV or mA */
static int ltc4222_get_value(struct device *dev, u8 reg)
{
struct regmap *regmap = dev_get_drvdata(dev);
unsigned int val;
u8 buf[2];
int ret;
ret = regmap_bulk_read(regmap, reg, buf, 2);
if (ret < 0)
return ret;
val = ((buf[0] << 8) + buf[1]) >> 6;
switch (reg) {
case LTC4222_ADIN1:
case LTC4222_ADIN2:
/* 1.25 mV resolution. Convert to mV. */
val = DIV_ROUND_CLOSEST(val * 5, 4);
break;
case LTC4222_SOURCE1:
case LTC4222_SOURCE2:
/* 31.25 mV resolution. Convert to mV. */
val = DIV_ROUND_CLOSEST(val * 125, 4);
break;
case LTC4222_SENSE1:
case LTC4222_SENSE2:
/*
* 62.5 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 = DIV_ROUND_CLOSEST(val * 125, 2);
break;
default:
return -EINVAL;
}
return val;
}
static ssize_t ltc4222_value_show(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
int value;
value = ltc4222_get_value(dev, attr->index);
if (value < 0)
return value;
return snprintf(buf, PAGE_SIZE, "%d\n", value);
}
static ssize_t ltc4222_bool_show(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
struct regmap *regmap = dev_get_drvdata(dev);
unsigned int fault;
int ret;
ret = regmap_read(regmap, attr->nr, &fault);
if (ret < 0)
return ret;
fault &= attr->index;
if (fault) /* Clear reported faults in chip register */
regmap_update_bits(regmap, attr->nr, attr->index, 0);
return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
}
/* Voltages */
static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4222_value, LTC4222_SOURCE1);
static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4222_value, LTC4222_ADIN1);
static SENSOR_DEVICE_ATTR_RO(in3_input, ltc4222_value, LTC4222_SOURCE2);
static SENSOR_DEVICE_ATTR_RO(in4_input, ltc4222_value, LTC4222_ADIN2);
/*
* Voltage alarms
* UV/OV faults are associated with the input voltage, and power bad and fet
* faults are associated with the output voltage.
*/
static SENSOR_DEVICE_ATTR_2_RO(in1_min_alarm, ltc4222_bool, LTC4222_FAULT1,
FAULT_UV);
static SENSOR_DEVICE_ATTR_2_RO(in1_max_alarm, ltc4222_bool, LTC4222_FAULT1,
FAULT_OV);
static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, ltc4222_bool, LTC4222_FAULT1,
FAULT_POWER_BAD | FAULT_FET_BAD);
static SENSOR_DEVICE_ATTR_2_RO(in3_min_alarm, ltc4222_bool, LTC4222_FAULT2,
FAULT_UV);
static SENSOR_DEVICE_ATTR_2_RO(in3_max_alarm, ltc4222_bool, LTC4222_FAULT2,
FAULT_OV);
static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, ltc4222_bool, LTC4222_FAULT2,
FAULT_POWER_BAD | FAULT_FET_BAD);
/* Current (via sense resistor) */
static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4222_value, LTC4222_SENSE1);
static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc4222_value, LTC4222_SENSE2);
/* Overcurrent alarm */
static SENSOR_DEVICE_ATTR_2_RO(curr1_max_alarm, ltc4222_bool, LTC4222_FAULT1,
FAULT_OC);
static SENSOR_DEVICE_ATTR_2_RO(curr2_max_alarm, ltc4222_bool, LTC4222_FAULT2,
FAULT_OC);
static struct attribute *ltc4222_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_in3_input.dev_attr.attr,
&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
&sensor_dev_attr_in3_max_alarm.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
&sensor_dev_attr_in4_alarm.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
&sensor_dev_attr_curr2_input.dev_attr.attr,
&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
NULL,
};
ATTRIBUTE_GROUPS(ltc4222);
static const struct regmap_config ltc4222_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = LTC4222_ADC_CONTROL,
};
static int ltc4222_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct regmap *regmap;
regmap = devm_regmap_init_i2c(client, &ltc4222_regmap_config);
if (IS_ERR(regmap)) {
dev_err(dev, "failed to allocate register map\n");
return PTR_ERR(regmap);
}
/* Clear faults */
regmap_write(regmap, LTC4222_FAULT1, 0x00);
regmap_write(regmap, LTC4222_FAULT2, 0x00);
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
regmap,
ltc4222_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id ltc4222_id[] = {
{"ltc4222", 0},
{ }
};
MODULE_DEVICE_TABLE(i2c, ltc4222_id);
static struct i2c_driver ltc4222_driver = {
.driver = {
.name = "ltc4222",
},
.probe_new = ltc4222_probe,
.id_table = ltc4222_id,
};
module_i2c_driver(ltc4222_driver);
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("LTC4222 driver");
MODULE_LICENSE("GPL");