linux/drivers/hwmon/emc6w201.c
Guenter Roeck 86266ca0e2 hwmon: (emc6w201) Fix DIV_ROUND_CLOSEST problem with unsigned divisors
Result of DIV_ROUND_CLOSEST is undefined for negative dividends if the divisor
variable type is unsigned. Fix by declaring divisor as signed variable.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
2012-12-22 02:16:40 -08:00

554 lines
16 KiB
C

/*
* emc6w201.c - Hardware monitoring driver for the SMSC EMC6W201
* Copyright (C) 2011 Jean Delvare <khali@linux-fr.org>
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
/*
* Addresses to scan
*/
static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };
/*
* The EMC6W201 registers
*/
#define EMC6W201_REG_IN(nr) (0x20 + (nr))
#define EMC6W201_REG_TEMP(nr) (0x26 + (nr))
#define EMC6W201_REG_FAN(nr) (0x2C + (nr) * 2)
#define EMC6W201_REG_COMPANY 0x3E
#define EMC6W201_REG_VERSTEP 0x3F
#define EMC6W201_REG_CONFIG 0x40
#define EMC6W201_REG_IN_LOW(nr) (0x4A + (nr) * 2)
#define EMC6W201_REG_IN_HIGH(nr) (0x4B + (nr) * 2)
#define EMC6W201_REG_TEMP_LOW(nr) (0x56 + (nr) * 2)
#define EMC6W201_REG_TEMP_HIGH(nr) (0x57 + (nr) * 2)
#define EMC6W201_REG_FAN_MIN(nr) (0x62 + (nr) * 2)
enum { input, min, max } subfeature;
/*
* Per-device data
*/
struct emc6w201_data {
struct device *hwmon_dev;
struct mutex update_lock;
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
/* registers values */
u8 in[3][6];
s8 temp[3][6];
u16 fan[2][5];
};
/*
* Combine LSB and MSB registers in a single value
* Locking: must be called with data->update_lock held
*/
static u16 emc6w201_read16(struct i2c_client *client, u8 reg)
{
int lsb, msb;
lsb = i2c_smbus_read_byte_data(client, reg);
msb = i2c_smbus_read_byte_data(client, reg + 1);
if (unlikely(lsb < 0 || msb < 0)) {
dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
16, "read", reg);
return 0xFFFF; /* Arbitrary value */
}
return (msb << 8) | lsb;
}
/*
* Write 16-bit value to LSB and MSB registers
* Locking: must be called with data->update_lock held
*/
static int emc6w201_write16(struct i2c_client *client, u8 reg, u16 val)
{
int err;
err = i2c_smbus_write_byte_data(client, reg, val & 0xff);
if (likely(!err))
err = i2c_smbus_write_byte_data(client, reg + 1, val >> 8);
if (unlikely(err < 0))
dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
16, "write", reg);
return err;
}
/* Read 8-bit value from register */
static u8 emc6w201_read8(struct i2c_client *client, u8 reg)
{
int val;
val = i2c_smbus_read_byte_data(client, reg);
if (unlikely(val < 0)) {
dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
8, "read", reg);
return 0x00; /* Arbitrary value */
}
return val;
}
/* Write 8-bit value to register */
static int emc6w201_write8(struct i2c_client *client, u8 reg, u8 val)
{
int err;
err = i2c_smbus_write_byte_data(client, reg, val);
if (unlikely(err < 0))
dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
8, "write", reg);
return err;
}
static struct emc6w201_data *emc6w201_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct emc6w201_data *data = i2c_get_clientdata(client);
int nr;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
for (nr = 0; nr < 6; nr++) {
data->in[input][nr] =
emc6w201_read8(client,
EMC6W201_REG_IN(nr));
data->in[min][nr] =
emc6w201_read8(client,
EMC6W201_REG_IN_LOW(nr));
data->in[max][nr] =
emc6w201_read8(client,
EMC6W201_REG_IN_HIGH(nr));
}
for (nr = 0; nr < 6; nr++) {
data->temp[input][nr] =
emc6w201_read8(client,
EMC6W201_REG_TEMP(nr));
data->temp[min][nr] =
emc6w201_read8(client,
EMC6W201_REG_TEMP_LOW(nr));
data->temp[max][nr] =
emc6w201_read8(client,
EMC6W201_REG_TEMP_HIGH(nr));
}
for (nr = 0; nr < 5; nr++) {
data->fan[input][nr] =
emc6w201_read16(client,
EMC6W201_REG_FAN(nr));
data->fan[min][nr] =
emc6w201_read16(client,
EMC6W201_REG_FAN_MIN(nr));
}
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
/*
* Sysfs callback functions
*/
static const s16 nominal_mv[6] = { 2500, 1500, 3300, 5000, 1500, 1500 };
static ssize_t show_in(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct emc6w201_data *data = emc6w201_update_device(dev);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
return sprintf(buf, "%u\n",
(unsigned)data->in[sf][nr] * nominal_mv[nr] / 0xC0);
}
static ssize_t set_in(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct emc6w201_data *data = i2c_get_clientdata(client);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
int err;
long val;
u8 reg;
err = kstrtol(buf, 10, &val);
if (err < 0)
return err;
val = DIV_ROUND_CLOSEST(val * 0xC0, nominal_mv[nr]);
reg = (sf == min) ? EMC6W201_REG_IN_LOW(nr)
: EMC6W201_REG_IN_HIGH(nr);
mutex_lock(&data->update_lock);
data->in[sf][nr] = SENSORS_LIMIT(val, 0, 255);
err = emc6w201_write8(client, reg, data->in[sf][nr]);
mutex_unlock(&data->update_lock);
return err < 0 ? err : count;
}
static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct emc6w201_data *data = emc6w201_update_device(dev);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
return sprintf(buf, "%d\n", (int)data->temp[sf][nr] * 1000);
}
static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct emc6w201_data *data = i2c_get_clientdata(client);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
int err;
long val;
u8 reg;
err = kstrtol(buf, 10, &val);
if (err < 0)
return err;
val /= 1000;
reg = (sf == min) ? EMC6W201_REG_TEMP_LOW(nr)
: EMC6W201_REG_TEMP_HIGH(nr);
mutex_lock(&data->update_lock);
data->temp[sf][nr] = SENSORS_LIMIT(val, -127, 128);
err = emc6w201_write8(client, reg, data->temp[sf][nr]);
mutex_unlock(&data->update_lock);
return err < 0 ? err : count;
}
static ssize_t show_fan(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct emc6w201_data *data = emc6w201_update_device(dev);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
unsigned rpm;
if (data->fan[sf][nr] == 0 || data->fan[sf][nr] == 0xFFFF)
rpm = 0;
else
rpm = 5400000U / data->fan[sf][nr];
return sprintf(buf, "%u\n", rpm);
}
static ssize_t set_fan(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct emc6w201_data *data = i2c_get_clientdata(client);
int sf = to_sensor_dev_attr_2(devattr)->index;
int nr = to_sensor_dev_attr_2(devattr)->nr;
int err;
unsigned long val;
err = kstrtoul(buf, 10, &val);
if (err < 0)
return err;
if (val == 0) {
val = 0xFFFF;
} else {
val = DIV_ROUND_CLOSEST(5400000U, val);
val = SENSORS_LIMIT(val, 0, 0xFFFE);
}
mutex_lock(&data->update_lock);
data->fan[sf][nr] = val;
err = emc6w201_write16(client, EMC6W201_REG_FAN_MIN(nr),
data->fan[sf][nr]);
mutex_unlock(&data->update_lock);
return err < 0 ? err : count;
}
static SENSOR_DEVICE_ATTR_2(in0_input, S_IRUGO, show_in, NULL, 0, input);
static SENSOR_DEVICE_ATTR_2(in0_min, S_IRUGO | S_IWUSR, show_in, set_in,
0, min);
static SENSOR_DEVICE_ATTR_2(in0_max, S_IRUGO | S_IWUSR, show_in, set_in,
0, max);
static SENSOR_DEVICE_ATTR_2(in1_input, S_IRUGO, show_in, NULL, 1, input);
static SENSOR_DEVICE_ATTR_2(in1_min, S_IRUGO | S_IWUSR, show_in, set_in,
1, min);
static SENSOR_DEVICE_ATTR_2(in1_max, S_IRUGO | S_IWUSR, show_in, set_in,
1, max);
static SENSOR_DEVICE_ATTR_2(in2_input, S_IRUGO, show_in, NULL, 2, input);
static SENSOR_DEVICE_ATTR_2(in2_min, S_IRUGO | S_IWUSR, show_in, set_in,
2, min);
static SENSOR_DEVICE_ATTR_2(in2_max, S_IRUGO | S_IWUSR, show_in, set_in,
2, max);
static SENSOR_DEVICE_ATTR_2(in3_input, S_IRUGO, show_in, NULL, 3, input);
static SENSOR_DEVICE_ATTR_2(in3_min, S_IRUGO | S_IWUSR, show_in, set_in,
3, min);
static SENSOR_DEVICE_ATTR_2(in3_max, S_IRUGO | S_IWUSR, show_in, set_in,
3, max);
static SENSOR_DEVICE_ATTR_2(in4_input, S_IRUGO, show_in, NULL, 4, input);
static SENSOR_DEVICE_ATTR_2(in4_min, S_IRUGO | S_IWUSR, show_in, set_in,
4, min);
static SENSOR_DEVICE_ATTR_2(in4_max, S_IRUGO | S_IWUSR, show_in, set_in,
4, max);
static SENSOR_DEVICE_ATTR_2(in5_input, S_IRUGO, show_in, NULL, 5, input);
static SENSOR_DEVICE_ATTR_2(in5_min, S_IRUGO | S_IWUSR, show_in, set_in,
5, min);
static SENSOR_DEVICE_ATTR_2(in5_max, S_IRUGO | S_IWUSR, show_in, set_in,
5, max);
static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, input);
static SENSOR_DEVICE_ATTR_2(temp1_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
0, min);
static SENSOR_DEVICE_ATTR_2(temp1_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
0, max);
static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, input);
static SENSOR_DEVICE_ATTR_2(temp2_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
1, min);
static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
1, max);
static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, 2, input);
static SENSOR_DEVICE_ATTR_2(temp3_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
2, min);
static SENSOR_DEVICE_ATTR_2(temp3_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
2, max);
static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp, NULL, 3, input);
static SENSOR_DEVICE_ATTR_2(temp4_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
3, min);
static SENSOR_DEVICE_ATTR_2(temp4_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
3, max);
static SENSOR_DEVICE_ATTR_2(temp5_input, S_IRUGO, show_temp, NULL, 4, input);
static SENSOR_DEVICE_ATTR_2(temp5_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
4, min);
static SENSOR_DEVICE_ATTR_2(temp5_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
4, max);
static SENSOR_DEVICE_ATTR_2(temp6_input, S_IRUGO, show_temp, NULL, 5, input);
static SENSOR_DEVICE_ATTR_2(temp6_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
5, min);
static SENSOR_DEVICE_ATTR_2(temp6_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
5, max);
static SENSOR_DEVICE_ATTR_2(fan1_input, S_IRUGO, show_fan, NULL, 0, input);
static SENSOR_DEVICE_ATTR_2(fan1_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
0, min);
static SENSOR_DEVICE_ATTR_2(fan2_input, S_IRUGO, show_fan, NULL, 1, input);
static SENSOR_DEVICE_ATTR_2(fan2_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
1, min);
static SENSOR_DEVICE_ATTR_2(fan3_input, S_IRUGO, show_fan, NULL, 2, input);
static SENSOR_DEVICE_ATTR_2(fan3_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
2, min);
static SENSOR_DEVICE_ATTR_2(fan4_input, S_IRUGO, show_fan, NULL, 3, input);
static SENSOR_DEVICE_ATTR_2(fan4_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
3, min);
static SENSOR_DEVICE_ATTR_2(fan5_input, S_IRUGO, show_fan, NULL, 4, input);
static SENSOR_DEVICE_ATTR_2(fan5_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
4, min);
static struct attribute *emc6w201_attributes[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in0_min.dev_attr.attr,
&sensor_dev_attr_in0_max.dev_attr.attr,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in1_min.dev_attr.attr,
&sensor_dev_attr_in1_max.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in2_min.dev_attr.attr,
&sensor_dev_attr_in2_max.dev_attr.attr,
&sensor_dev_attr_in3_input.dev_attr.attr,
&sensor_dev_attr_in3_min.dev_attr.attr,
&sensor_dev_attr_in3_max.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
&sensor_dev_attr_in4_min.dev_attr.attr,
&sensor_dev_attr_in4_max.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
&sensor_dev_attr_in5_min.dev_attr.attr,
&sensor_dev_attr_in5_max.dev_attr.attr,
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp2_input.dev_attr.attr,
&sensor_dev_attr_temp2_min.dev_attr.attr,
&sensor_dev_attr_temp2_max.dev_attr.attr,
&sensor_dev_attr_temp3_input.dev_attr.attr,
&sensor_dev_attr_temp3_min.dev_attr.attr,
&sensor_dev_attr_temp3_max.dev_attr.attr,
&sensor_dev_attr_temp4_input.dev_attr.attr,
&sensor_dev_attr_temp4_min.dev_attr.attr,
&sensor_dev_attr_temp4_max.dev_attr.attr,
&sensor_dev_attr_temp5_input.dev_attr.attr,
&sensor_dev_attr_temp5_min.dev_attr.attr,
&sensor_dev_attr_temp5_max.dev_attr.attr,
&sensor_dev_attr_temp6_input.dev_attr.attr,
&sensor_dev_attr_temp6_min.dev_attr.attr,
&sensor_dev_attr_temp6_max.dev_attr.attr,
&sensor_dev_attr_fan1_input.dev_attr.attr,
&sensor_dev_attr_fan1_min.dev_attr.attr,
&sensor_dev_attr_fan2_input.dev_attr.attr,
&sensor_dev_attr_fan2_min.dev_attr.attr,
&sensor_dev_attr_fan3_input.dev_attr.attr,
&sensor_dev_attr_fan3_min.dev_attr.attr,
&sensor_dev_attr_fan4_input.dev_attr.attr,
&sensor_dev_attr_fan4_min.dev_attr.attr,
&sensor_dev_attr_fan5_input.dev_attr.attr,
&sensor_dev_attr_fan5_min.dev_attr.attr,
NULL
};
static const struct attribute_group emc6w201_group = {
.attrs = emc6w201_attributes,
};
/*
* Driver interface
*/
/* Return 0 if detection is successful, -ENODEV otherwise */
static int emc6w201_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int company, verstep, config;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
/* Identification */
company = i2c_smbus_read_byte_data(client, EMC6W201_REG_COMPANY);
if (company != 0x5C)
return -ENODEV;
verstep = i2c_smbus_read_byte_data(client, EMC6W201_REG_VERSTEP);
if (verstep < 0 || (verstep & 0xF0) != 0xB0)
return -ENODEV;
if ((verstep & 0x0F) > 2) {
dev_dbg(&client->dev, "Unknwown EMC6W201 stepping %d\n",
verstep & 0x0F);
return -ENODEV;
}
/* Check configuration */
config = i2c_smbus_read_byte_data(client, EMC6W201_REG_CONFIG);
if (config < 0 || (config & 0xF4) != 0x04)
return -ENODEV;
if (!(config & 0x01)) {
dev_err(&client->dev, "Monitoring not enabled\n");
return -ENODEV;
}
strlcpy(info->type, "emc6w201", I2C_NAME_SIZE);
return 0;
}
static int emc6w201_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct emc6w201_data *data;
int err;
data = devm_kzalloc(&client->dev, sizeof(struct emc6w201_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* Create sysfs attribute */
err = sysfs_create_group(&client->dev.kobj, &emc6w201_group);
if (err)
return err;
/* Expose as a hwmon device */
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
return 0;
exit_remove:
sysfs_remove_group(&client->dev.kobj, &emc6w201_group);
return err;
}
static int emc6w201_remove(struct i2c_client *client)
{
struct emc6w201_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &emc6w201_group);
return 0;
}
static const struct i2c_device_id emc6w201_id[] = {
{ "emc6w201", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, emc6w201_id);
static struct i2c_driver emc6w201_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "emc6w201",
},
.probe = emc6w201_probe,
.remove = emc6w201_remove,
.id_table = emc6w201_id,
.detect = emc6w201_detect,
.address_list = normal_i2c,
};
module_i2c_driver(emc6w201_driver);
MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("SMSC EMC6W201 hardware monitoring driver");
MODULE_LICENSE("GPL");