linux/drivers/hwmon/ltc4151.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

217 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Linear Technology LTC4151 High Voltage I2C Current
* and Voltage Monitor
*
* Copyright (C) 2011 AppearTV AS
*
* Derived from:
*
* Driver for Linear Technology LTC4261 I2C Negative Voltage Hot
* Swap Controller
* Copyright (C) 2010 Ericsson AB.
*
* Datasheet: http://www.linear.com/docs/Datasheet/4151fc.pdf
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/init.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>
/* chip registers */
#define LTC4151_SENSE_H 0x00
#define LTC4151_SENSE_L 0x01
#define LTC4151_VIN_H 0x02
#define LTC4151_VIN_L 0x03
#define LTC4151_ADIN_H 0x04
#define LTC4151_ADIN_L 0x05
struct ltc4151_data {
struct i2c_client *client;
struct mutex update_lock;
bool valid;
unsigned long last_updated; /* in jiffies */
unsigned int shunt; /* in micro ohms */
/* Registers */
u8 regs[6];
};
static struct ltc4151_data *ltc4151_update_device(struct device *dev)
{
struct ltc4151_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
struct ltc4151_data *ret = data;
mutex_lock(&data->update_lock);
/*
* The chip's A/D updates 6 times per second
* (Conversion Rate 6 - 9 Hz)
*/
if (time_after(jiffies, data->last_updated + HZ / 6) || !data->valid) {
int i;
dev_dbg(&client->dev, "Starting ltc4151 update\n");
/* Read all registers */
for (i = 0; i < ARRAY_SIZE(data->regs); i++) {
int val;
val = i2c_smbus_read_byte_data(client, i);
if (unlikely(val < 0)) {
dev_dbg(dev,
"Failed to read ADC value: error %d\n",
val);
ret = ERR_PTR(val);
goto abort;
}
data->regs[i] = val;
}
data->last_updated = jiffies;
data->valid = 1;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
/* Return the voltage from the given register in mV */
static int ltc4151_get_value(struct ltc4151_data *data, u8 reg)
{
u32 val;
val = (data->regs[reg] << 4) + (data->regs[reg + 1] >> 4);
switch (reg) {
case LTC4151_ADIN_H:
/* 500uV resolution. Convert to mV. */
val = val * 500 / 1000;
break;
case LTC4151_SENSE_H:
/*
* 20uV resolution. Convert to current as measured with
* a given sense resistor, in mA.
*/
val = val * 20 * 1000 / data->shunt;
break;
case LTC4151_VIN_H:
/* 25 mV per increment */
val = val * 25;
break;
default:
/* If we get here, the developer messed up */
WARN_ON_ONCE(1);
val = 0;
break;
}
return val;
}
static ssize_t ltc4151_value_show(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ltc4151_data *data = ltc4151_update_device(dev);
int value;
if (IS_ERR(data))
return PTR_ERR(data);
value = ltc4151_get_value(data, attr->index);
return snprintf(buf, PAGE_SIZE, "%d\n", value);
}
/*
* Input voltages.
*/
static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4151_value, LTC4151_VIN_H);
static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4151_value, LTC4151_ADIN_H);
/* Currents (via sense resistor) */
static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4151_value, LTC4151_SENSE_H);
/*
* Finally, construct an array of pointers to members of the above objects,
* as required for sysfs_create_group()
*/
static struct attribute *ltc4151_attrs[] = {
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
NULL,
};
ATTRIBUTE_GROUPS(ltc4151);
static int ltc4151_probe(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
struct device *dev = &client->dev;
struct ltc4151_data *data;
struct device *hwmon_dev;
u32 shunt;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (of_property_read_u32(client->dev.of_node,
"shunt-resistor-micro-ohms", &shunt))
shunt = 1000; /* 1 mOhm if not set via DT */
if (shunt == 0)
return -EINVAL;
data->shunt = shunt;
data->client = client;
mutex_init(&data->update_lock);
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data,
ltc4151_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id ltc4151_id[] = {
{ "ltc4151", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ltc4151_id);
static const struct of_device_id __maybe_unused ltc4151_match[] = {
{ .compatible = "lltc,ltc4151" },
{},
};
MODULE_DEVICE_TABLE(of, ltc4151_match);
/* This is the driver that will be inserted */
static struct i2c_driver ltc4151_driver = {
.driver = {
.name = "ltc4151",
.of_match_table = of_match_ptr(ltc4151_match),
},
.probe_new = ltc4151_probe,
.id_table = ltc4151_id,
};
module_i2c_driver(ltc4151_driver);
MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>");
MODULE_DESCRIPTION("LTC4151 driver");
MODULE_LICENSE("GPL");