linux/drivers/hwmon/tc74.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

173 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* An hwmon driver for the Microchip TC74
*
* Copyright 2015 Maciej Szmigiero <mail@maciej.szmigiero.name>
*
* Based on ad7414.c:
* Copyright 2006 Stefan Roese, DENX Software Engineering
* Copyright 2008 Sean MacLennan, PIKA Technologies
* Copyright 2008 Frank Edelhaeuser, Spansion Inc.
*/
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
/* TC74 registers */
#define TC74_REG_TEMP 0x00
#define TC74_REG_CONFIG 0x01
struct tc74_data {
struct i2c_client *client;
struct mutex lock; /* atomic read data updates */
bool valid; /* validity of fields below */
unsigned long next_update; /* In jiffies */
s8 temp_input; /* Temp value in dC */
};
static int tc74_update_device(struct device *dev)
{
struct tc74_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int ret;
ret = mutex_lock_interruptible(&data->lock);
if (ret)
return ret;
if (time_after(jiffies, data->next_update) || !data->valid) {
s32 value;
value = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
if (value < 0) {
dev_dbg(&client->dev, "TC74_REG_CONFIG read err %d\n",
(int)value);
ret = value;
goto ret_unlock;
}
if (!(value & BIT(6))) {
/* not ready yet */
ret = -EAGAIN;
goto ret_unlock;
}
value = i2c_smbus_read_byte_data(client, TC74_REG_TEMP);
if (value < 0) {
dev_dbg(&client->dev, "TC74_REG_TEMP read err %d\n",
(int)value);
ret = value;
goto ret_unlock;
}
data->temp_input = value;
data->next_update = jiffies + HZ / 4;
data->valid = true;
}
ret_unlock:
mutex_unlock(&data->lock);
return ret;
}
static ssize_t temp_input_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tc74_data *data = dev_get_drvdata(dev);
int ret;
ret = tc74_update_device(dev);
if (ret)
return ret;
return sprintf(buf, "%d\n", data->temp_input * 1000);
}
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
static struct attribute *tc74_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(tc74);
static int tc74_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct tc74_data *data;
struct device *hwmon_dev;
s32 conf;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -EOPNOTSUPP;
data = devm_kzalloc(dev, sizeof(struct tc74_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
mutex_init(&data->lock);
/* Make sure the chip is powered up. */
conf = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
if (conf < 0) {
dev_err(dev, "unable to read config register\n");
return conf;
}
if (conf & 0x3f) {
dev_err(dev, "invalid config register value\n");
return -ENODEV;
}
if (conf & BIT(7)) {
s32 ret;
conf &= ~BIT(7);
ret = i2c_smbus_write_byte_data(client, TC74_REG_CONFIG, conf);
if (ret)
dev_warn(dev, "unable to disable STANDBY\n");
}
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name,
data, tc74_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id tc74_id[] = {
{ "tc74", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, tc74_id);
static struct i2c_driver tc74_driver = {
.driver = {
.name = "tc74",
},
.probe_new = tc74_probe,
.id_table = tc74_id,
};
module_i2c_driver(tc74_driver);
MODULE_AUTHOR("Maciej Szmigiero <mail@maciej.szmigiero.name>");
MODULE_DESCRIPTION("TC74 driver");
MODULE_LICENSE("GPL");