/*
* LM73 Sensor driver
* Based on LM75
*
* Copyright (C) 2007, CenoSYS (www.cenosys.com).
* Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
*
* Guillaume Ligneul <guillaume.ligneul@gmail.com>
* Adrien Demarez <adrien.demarez@bolloretelecom.eu>
* Jeremy Laine <jeremy.laine@bolloretelecom.eu>
* Chris Verges <kg4ysn@gmail.com>
*
* This software program is licensed subject to the GNU General Public License
* (GPL).Version 2,June 1991, available at
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
*/
#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>
/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
0x4d, 0x4e, I2C_CLIENT_END };
/* LM73 registers */
#define LM73_REG_INPUT 0x00
#define LM73_REG_CONF 0x01
#define LM73_REG_MAX 0x02
#define LM73_REG_MIN 0x03
#define LM73_REG_CTRL 0x04
#define LM73_REG_ID 0x07
#define LM73_ID 0x9001 /* 0x0190, byte-swapped */
#define DRVNAME "lm73"
#define LM73_TEMP_MIN (-256000 / 250)
#define LM73_TEMP_MAX (255750 / 250)
#define LM73_CTRL_RES_SHIFT 5
#define LM73_CTRL_RES_MASK (BIT(5) | BIT(6))
#define LM73_CTRL_TO_MASK BIT(7)
#define LM73_CTRL_HI_SHIFT 2
#define LM73_CTRL_LO_SHIFT 1
static const unsigned short lm73_convrates[] = {
14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */
28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */
56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */
112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */
};
struct lm73_data {
struct device *hwmon_dev;
struct mutex lock;
u8 ctrl; /* control register value */
};
/*-----------------------------------------------------------------------*/
static ssize_t set_temp(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
long temp;
short value;
s32 err;
int status = kstrtol(buf, 10, &temp);
if (status < 0)
return status;
/* Write value */
value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5;
err = i2c_smbus_write_word_swapped(client, attr->index, value);
return (err < 0) ? err : count;
}
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
int temp;
s32 err = i2c_smbus_read_word_swapped(client, attr->index);
if (err < 0)
return err;
/* use integer division instead of equivalent right shift to
guarantee arithmetic shift and preserve the sign */
temp = (((s16) err) * 250) / 32;
return scnprintf(buf, PAGE_SIZE, "%d\n", temp);
}
static ssize_t set_convrate(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm73_data *data = i2c_get_clientdata(client);
unsigned long convrate;
s32 err;
int res = 0;
err = kstrtoul(buf, 10, &convrate);
if (err < 0)
return err;
/*
* Convert the desired conversion rate into register bits.
* res is already initialized, and everything past the second-to-last
* value in the array is treated as belonging to the last value
* in the array.
*/
while (res < (ARRAY_SIZE(lm73_convrates) - 1) &&
convrate > lm73_convrates[res])
res++;
mutex_lock(&data->lock);
data->ctrl &= LM73_CTRL_TO_MASK;
data->ctrl |= res << LM73_CTRL_RES_SHIFT;
err = i2c_smbus_write_byte_data(client, LM73_REG_CTRL, data->ctrl);
mutex_unlock(&data->lock);
if (err < 0)
return err;
return count;
}
static ssize_t show_convrate(struct device *dev, struct device_attribute *da,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm73_data *data = i2c_get_clientdata(client);
int res;
res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT;
return scnprintf(buf, PAGE_SIZE, "%hu\n", lm73_convrates[res]);
}
static ssize_t show_maxmin_alarm(struct device *dev,
struct device_attribute *da, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct lm73_data *data = i2c_get_clientdata(client);
s32 ctrl;
mutex_lock(&data->lock);
ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL);
if (ctrl < 0)
goto abort;
data->ctrl = ctrl;
mutex_unlock(&data->lock);
return scnprintf(buf, PAGE_SIZE, "%d\n", (ctrl >> attr->index) & 1);
abort:
mutex_unlock(&data->lock);
return ctrl;
}
/*-----------------------------------------------------------------------*/
/* sysfs attributes for hwmon */
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
show_temp, set_temp, LM73_REG_MAX);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
show_temp, set_temp, LM73_REG_MIN);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
show_temp, NULL, LM73_REG_INPUT);
static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
show_convrate, set_convrate, 0);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
show_maxmin_alarm, NULL, LM73_CTRL_HI_SHIFT);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO,
show_maxmin_alarm, NULL, LM73_CTRL_LO_SHIFT);
static struct attribute *lm73_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_update_interval.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
NULL
};
static const struct attribute_group lm73_group = {
.attrs = lm73_attributes,
};
/*-----------------------------------------------------------------------*/
/* device probe and removal */
static int
lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
int status;
struct lm73_data *data;
int ctrl;
data = devm_kzalloc(&client->dev, sizeof(struct lm73_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->lock);
ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL);
if (ctrl < 0)
return ctrl;
data->ctrl = ctrl;
/* Register sysfs hooks */
status = sysfs_create_group(&client->dev.kobj, &lm73_group);
if (status)
return status;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
status = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
dev_info(&client->dev, "%s: sensor '%s'\n",
dev_name(data->hwmon_dev), client->name);
return 0;
exit_remove:
sysfs_remove_group(&client->dev.kobj, &lm73_group);
return status;
}
static int lm73_remove(struct i2c_client *client)
{
struct lm73_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &lm73_group);
return 0;
}
static const struct i2c_device_id lm73_ids[] = {
{ "lm73", 0 },
{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, lm73_ids);
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm73_detect(struct i2c_client *new_client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = new_client->adapter;
int id, ctrl, conf;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
/*
* Do as much detection as possible with byte reads first, as word
* reads can confuse other devices.
*/
ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
if (ctrl < 0 || (ctrl & 0x10))
return -ENODEV;
conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF);
if (conf < 0 || (conf & 0x0c))
return -ENODEV;
id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID);
if (id < 0 || id != (LM73_ID & 0xff))
return -ENODEV;
/* Check device ID */
id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
if (id < 0 || id != LM73_ID)
return -ENODEV;
strlcpy(info->type, "lm73", I2C_NAME_SIZE);
return 0;
}
static struct i2c_driver lm73_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "lm73",
},
.probe = lm73_probe,
.remove = lm73_remove,
.id_table = lm73_ids,
.detect = lm73_detect,
.address_list = normal_i2c,
};
module_i2c_driver(lm73_driver);
MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
MODULE_DESCRIPTION("LM73 driver");
MODULE_LICENSE("GPL");
