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linux-next/drivers/hwmon/w83773g.c
Guenter Roeck 571e3f3a8e hwmon: (w83773g) Fix fault detection and reporting
Smatch reports:

drivers/hwmon/w83773g.c:105
	get_fault() warn: shift has higher precedence than mask

Code analysis shows that the code is indeed wrong.
Fix it, and while we are at it, drop unnecessary typecast.

Fixes: 86a10c802362 ("hwmon: Add W83773G driver")
Cc: Lei YU <mine260309@gmail.com>
Reviewed-by: Lei YU <mine260309@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2018-01-02 15:05:34 -08:00

330 lines
7.3 KiB
C

/*
* Copyright (C) 2017 IBM Corp.
*
* 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.
*
* Driver for the Nuvoton W83773G SMBus temperature sensor IC.
* Supported models: W83773G
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
/* W83773 has 3 channels */
#define W83773_CHANNELS 3
/* The W83773 registers */
#define W83773_CONVERSION_RATE_REG_READ 0x04
#define W83773_CONVERSION_RATE_REG_WRITE 0x0A
#define W83773_MANUFACTURER_ID_REG 0xFE
#define W83773_LOCAL_TEMP 0x00
static const u8 W83773_STATUS[2] = { 0x02, 0x17 };
static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 };
static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 };
static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 };
static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 };
/* this is the number of sensors in the device */
static const struct i2c_device_id w83773_id[] = {
{ "w83773g" },
{ }
};
MODULE_DEVICE_TABLE(i2c, w83773_id);
static const struct of_device_id w83773_of_match[] = {
{
.compatible = "nuvoton,w83773g"
},
{ },
};
MODULE_DEVICE_TABLE(of, w83773_of_match);
static inline long temp_of_local(s8 reg)
{
return reg * 1000;
}
static inline long temp_of_remote(s8 hb, u8 lb)
{
return (hb << 3 | lb >> 5) * 125;
}
static int get_local_temp(struct regmap *regmap, long *val)
{
unsigned int regval;
int ret;
ret = regmap_read(regmap, W83773_LOCAL_TEMP, &regval);
if (ret < 0)
return ret;
*val = temp_of_local(regval);
return 0;
}
static int get_remote_temp(struct regmap *regmap, int index, long *val)
{
unsigned int regval_high;
unsigned int regval_low;
int ret;
ret = regmap_read(regmap, W83773_TEMP_MSB[index], &regval_high);
if (ret < 0)
return ret;
ret = regmap_read(regmap, W83773_TEMP_LSB[index], &regval_low);
if (ret < 0)
return ret;
*val = temp_of_remote(regval_high, regval_low);
return 0;
}
static int get_fault(struct regmap *regmap, int index, long *val)
{
unsigned int regval;
int ret;
ret = regmap_read(regmap, W83773_STATUS[index], &regval);
if (ret < 0)
return ret;
*val = (regval & 0x04) >> 2;
return 0;
}
static int get_offset(struct regmap *regmap, int index, long *val)
{
unsigned int regval_high;
unsigned int regval_low;
int ret;
ret = regmap_read(regmap, W83773_OFFSET_MSB[index], &regval_high);
if (ret < 0)
return ret;
ret = regmap_read(regmap, W83773_OFFSET_LSB[index], &regval_low);
if (ret < 0)
return ret;
*val = temp_of_remote(regval_high, regval_low);
return 0;
}
static int set_offset(struct regmap *regmap, int index, long val)
{
int ret;
u8 high_byte;
u8 low_byte;
val = clamp_val(val, -127825, 127825);
/* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */
val /= 125;
high_byte = val >> 3;
low_byte = (val & 0x07) << 5;
ret = regmap_write(regmap, W83773_OFFSET_MSB[index], high_byte);
if (ret < 0)
return ret;
return regmap_write(regmap, W83773_OFFSET_LSB[index], low_byte);
}
static int get_update_interval(struct regmap *regmap, long *val)
{
unsigned int regval;
int ret;
ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, &regval);
if (ret < 0)
return ret;
*val = 16000 >> regval;
return 0;
}
static int set_update_interval(struct regmap *regmap, long val)
{
int rate;
/*
* For valid rates, interval can be calculated as
* interval = (1 << (8 - rate)) * 62.5;
* Rounded rate is therefore
* rate = 8 - __fls(interval * 8 / (62.5 * 7));
* Use clamp_val() to avoid overflows, and to ensure valid input
* for __fls.
*/
val = clamp_val(val, 62, 16000) * 10;
rate = 8 - __fls((val * 8 / (625 * 7)));
return regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate);
}
static int w83773_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct regmap *regmap = dev_get_drvdata(dev);
if (type == hwmon_chip) {
if (attr == hwmon_chip_update_interval)
return get_update_interval(regmap, val);
return -EOPNOTSUPP;
}
switch (attr) {
case hwmon_temp_input:
if (channel == 0)
return get_local_temp(regmap, val);
return get_remote_temp(regmap, channel - 1, val);
case hwmon_temp_fault:
return get_fault(regmap, channel - 1, val);
case hwmon_temp_offset:
return get_offset(regmap, channel - 1, val);
default:
return -EOPNOTSUPP;
}
}
static int w83773_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct regmap *regmap = dev_get_drvdata(dev);
if (type == hwmon_chip && attr == hwmon_chip_update_interval)
return set_update_interval(regmap, val);
if (type == hwmon_temp && attr == hwmon_temp_offset)
return set_offset(regmap, channel - 1, val);
return -EOPNOTSUPP;
}
static umode_t w83773_is_visible(const void *data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
switch (type) {
case hwmon_chip:
switch (attr) {
case hwmon_chip_update_interval:
return 0644;
}
break;
case hwmon_temp:
switch (attr) {
case hwmon_temp_input:
case hwmon_temp_fault:
return 0444;
case hwmon_temp_offset:
return 0644;
}
break;
default:
break;
}
return 0;
}
static const u32 w83773_chip_config[] = {
HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
0
};
static const struct hwmon_channel_info w83773_chip = {
.type = hwmon_chip,
.config = w83773_chip_config,
};
static const u32 w83773_temp_config[] = {
HWMON_T_INPUT,
HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET,
HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET,
0
};
static const struct hwmon_channel_info w83773_temp = {
.type = hwmon_temp,
.config = w83773_temp_config,
};
static const struct hwmon_channel_info *w83773_info[] = {
&w83773_chip,
&w83773_temp,
NULL
};
static const struct hwmon_ops w83773_ops = {
.is_visible = w83773_is_visible,
.read = w83773_read,
.write = w83773_write,
};
static const struct hwmon_chip_info w83773_chip_info = {
.ops = &w83773_ops,
.info = w83773_info,
};
static const struct regmap_config w83773_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int w83773_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct regmap *regmap;
int ret;
regmap = devm_regmap_init_i2c(client, &w83773_regmap_config);
if (IS_ERR(regmap)) {
dev_err(dev, "failed to allocate register map\n");
return PTR_ERR(regmap);
}
/* Set the conversion rate to 2 Hz */
ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05);
if (ret < 0) {
dev_err(&client->dev, "error writing config rate register\n");
return ret;
}
i2c_set_clientdata(client, regmap);
hwmon_dev = devm_hwmon_device_register_with_info(dev,
client->name,
regmap,
&w83773_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static struct i2c_driver w83773_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "w83773g",
.of_match_table = of_match_ptr(w83773_of_match),
},
.probe = w83773_probe,
.id_table = w83773_id,
};
module_i2c_driver(w83773_driver);
MODULE_AUTHOR("Lei YU <mine260309@gmail.com>");
MODULE_DESCRIPTION("W83773G temperature sensor driver");
MODULE_LICENSE("GPL");