/*
* Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
*
* The LM95241 is a sensor chip made by National Semiconductors.
* It reports up to three temperatures (its own plus up to two external ones).
* Complete datasheet can be obtained from National's website at:
* http://www.national.com/ds.cgi/LM/LM95241.pdf
*
* 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.
*/
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#define DEVNAME "lm95241"
static const unsigned short normal_i2c[] = {
0x19, 0x2a, 0x2b, I2C_CLIENT_END };
/* LM95241 registers */
#define LM95241_REG_R_MAN_ID 0xFE
#define LM95241_REG_R_CHIP_ID 0xFF
#define LM95241_REG_R_STATUS 0x02
#define LM95241_REG_RW_CONFIG 0x03
#define LM95241_REG_RW_REM_FILTER 0x06
#define LM95241_REG_RW_TRUTHERM 0x07
#define LM95241_REG_W_ONE_SHOT 0x0F
#define LM95241_REG_R_LOCAL_TEMPH 0x10
#define LM95241_REG_R_REMOTE1_TEMPH 0x11
#define LM95241_REG_R_REMOTE2_TEMPH 0x12
#define LM95241_REG_R_LOCAL_TEMPL 0x20
#define LM95241_REG_R_REMOTE1_TEMPL 0x21
#define LM95241_REG_R_REMOTE2_TEMPL 0x22
#define LM95241_REG_RW_REMOTE_MODEL 0x30
/* LM95241 specific bitfields */
#define CFG_STOP BIT(6)
#define CFG_CR0076 0x00
#define CFG_CR0182 BIT(4)
#define CFG_CR1000 BIT(5)
#define CFG_CR2700 (BIT(4) | BIT(5))
#define CFG_CRMASK (BIT(4) | BIT(5))
#define R1MS_MASK BIT(0)
#define R2MS_MASK BIT(2)
#define R1DF_MASK BIT(1)
#define R2DF_MASK BIT(2)
#define R1FE_MASK BIT(0)
#define R2FE_MASK BIT(2)
#define R1DM BIT(0)
#define R2DM BIT(1)
#define TT1_SHIFT 0
#define TT2_SHIFT 4
#define TT_OFF 0
#define TT_ON 1
#define TT_MASK 7
#define NATSEMI_MAN_ID 0x01
#define LM95231_CHIP_ID 0xA1
#define LM95241_CHIP_ID 0xA4
static const u8 lm95241_reg_address[] = {
LM95241_REG_R_LOCAL_TEMPH,
LM95241_REG_R_LOCAL_TEMPL,
LM95241_REG_R_REMOTE1_TEMPH,
LM95241_REG_R_REMOTE1_TEMPL,
LM95241_REG_R_REMOTE2_TEMPH,
LM95241_REG_R_REMOTE2_TEMPL
};
/* Client data (each client gets its own) */
struct lm95241_data {
struct i2c_client *client;
struct mutex update_lock;
unsigned long last_updated; /* in jiffies */
unsigned long interval; /* in milli-seconds */
char valid; /* zero until following fields are valid */
/* registers values */
u8 temp[ARRAY_SIZE(lm95241_reg_address)];
u8 status, config, model, trutherm;
};
/* Conversions */
static int temp_from_reg_signed(u8 val_h, u8 val_l)
{
s16 val_hl = (val_h << 8) | val_l;
return val_hl * 1000 / 256;
}
static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
{
u16 val_hl = (val_h << 8) | val_l;
return val_hl * 1000 / 256;
}
static struct lm95241_data *lm95241_update_device(struct device *dev)
{
struct lm95241_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated
+ msecs_to_jiffies(data->interval)) ||
!data->valid) {
int i;
dev_dbg(dev, "Updating lm95241 data.\n");
for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
data->temp[i]
= i2c_smbus_read_byte_data(client,
lm95241_reg_address[i]);
data->status = i2c_smbus_read_byte_data(client,
LM95241_REG_R_STATUS);
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
long *val)
{
struct lm95241_data *data = dev_get_drvdata(dev);
switch (attr) {
case hwmon_chip_update_interval:
*val = data->interval;
return 0;
default:
return -EOPNOTSUPP;
}
}
static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
long *val)
{
struct lm95241_data *data = lm95241_update_device(dev);
switch (attr) {
case hwmon_temp_input:
if (!channel || (data->config & BIT(channel - 1)))
*val = temp_from_reg_signed(data->temp[channel * 2],
data->temp[channel * 2 + 1]);
else
*val = temp_from_reg_unsigned(data->temp[channel * 2],
data->temp[channel * 2 + 1]);
return 0;
case hwmon_temp_min:
if (channel == 1)
*val = (data->config & R1DF_MASK) ? -128000 : 0;
else
*val = (data->config & R2DF_MASK) ? -128000 : 0;
return 0;
case hwmon_temp_max:
if (channel == 1)
*val = (data->config & R1DF_MASK) ? 127875 : 255875;
else
*val = (data->config & R2DF_MASK) ? 127875 : 255875;
return 0;
case hwmon_temp_type:
if (channel == 1)
*val = (data->model & R1MS_MASK) ? 1 : 2;
else
*val = (data->model & R2MS_MASK) ? 1 : 2;
return 0;
case hwmon_temp_fault:
if (channel == 1)
*val = !!(data->status & R1DM);
else
*val = !!(data->status & R2DM);
return 0;
default:
return -EOPNOTSUPP;
}
}
static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
switch (type) {
case hwmon_chip:
return lm95241_read_chip(dev, attr, channel, val);
case hwmon_temp:
return lm95241_read_temp(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
long val)
{
struct lm95241_data *data = dev_get_drvdata(dev);
int convrate;
u8 config;
int ret;
mutex_lock(&data->update_lock);
switch (attr) {
case hwmon_chip_update_interval:
config = data->config & ~CFG_CRMASK;
if (val < 130) {
convrate = 76;
config |= CFG_CR0076;
} else if (val < 590) {
convrate = 182;
config |= CFG_CR0182;
} else if (val < 1850) {
convrate = 1000;
config |= CFG_CR1000;
} else {
convrate = 2700;
config |= CFG_CR2700;
}
data->interval = convrate;
data->config = config;
ret = i2c_smbus_write_byte_data(data->client,
LM95241_REG_RW_CONFIG, config);
break;
default:
ret = -EOPNOTSUPP;
break;
}
mutex_unlock(&data->update_lock);
return ret;
}
static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
long val)
{
struct lm95241_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int ret;
mutex_lock(&data->update_lock);
switch (attr) {
case hwmon_temp_min:
if (channel == 1) {
if (val < 0)
data->config |= R1DF_MASK;
else
data->config &= ~R1DF_MASK;
} else {
if (val < 0)
data->config |= R2DF_MASK;
else
data->config &= ~R2DF_MASK;
}
data->valid = 0;
ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
data->config);
break;
case hwmon_temp_max:
if (channel == 1) {
if (val <= 127875)
data->config |= R1DF_MASK;
else
data->config &= ~R1DF_MASK;
} else {
if (val <= 127875)
data->config |= R2DF_MASK;
else
data->config &= ~R2DF_MASK;
}
data->valid = 0;
ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
data->config);
break;
case hwmon_temp_type:
if (val != 1 && val != 2) {
ret = -EINVAL;
break;
}
if (channel == 1) {
data->trutherm &= ~(TT_MASK << TT1_SHIFT);
if (val == 1) {
data->model |= R1MS_MASK;
data->trutherm |= (TT_ON << TT1_SHIFT);
} else {
data->model &= ~R1MS_MASK;
data->trutherm |= (TT_OFF << TT1_SHIFT);
}
} else {
data->trutherm &= ~(TT_MASK << TT2_SHIFT);
if (val == 1) {
data->model |= R2MS_MASK;
data->trutherm |= (TT_ON << TT2_SHIFT);
} else {
data->model &= ~R2MS_MASK;
data->trutherm |= (TT_OFF << TT2_SHIFT);
}
}
ret = i2c_smbus_write_byte_data(client,
LM95241_REG_RW_REMOTE_MODEL,
data->model);
if (ret < 0)
break;
ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
data->trutherm);
break;
default:
ret = -EOPNOTSUPP;
break;
}
mutex_unlock(&data->update_lock);
return ret;
}
static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
switch (type) {
case hwmon_chip:
return lm95241_write_chip(dev, attr, channel, val);
case hwmon_temp:
return lm95241_write_temp(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static umode_t lm95241_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 S_IRUGO | S_IWUSR;
}
break;
case hwmon_temp:
switch (attr) {
case hwmon_temp_input:
return S_IRUGO;
case hwmon_temp_fault:
return S_IRUGO;
case hwmon_temp_min:
case hwmon_temp_max:
case hwmon_temp_type:
return S_IRUGO | S_IWUSR;
}
break;
default:
break;
}
return 0;
}
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm95241_detect(struct i2c_client *new_client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = new_client->adapter;
const char *name;
int mfg_id, chip_id;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
if (mfg_id != NATSEMI_MAN_ID)
return -ENODEV;
chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
switch (chip_id) {
case LM95231_CHIP_ID:
name = "lm95231";
break;
case LM95241_CHIP_ID:
name = "lm95241";
break;
default:
return -ENODEV;
}
/* Fill the i2c board info */
strlcpy(info->type, name, I2C_NAME_SIZE);
return 0;
}
static void lm95241_init_client(struct i2c_client *client,
struct lm95241_data *data)
{
data->interval = 1000;
data->config = CFG_CR1000;
data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
R1FE_MASK | R2FE_MASK);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
data->trutherm);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
data->model);
}
static const u32 lm95241_chip_config[] = {
HWMON_C_UPDATE_INTERVAL,
0
};
static const struct hwmon_channel_info lm95241_chip = {
.type = hwmon_chip,
.config = lm95241_chip_config,
};
static const u32 lm95241_temp_config[] = {
HWMON_T_INPUT,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
HWMON_T_FAULT,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
HWMON_T_FAULT,
0
};
static const struct hwmon_channel_info lm95241_temp = {
.type = hwmon_temp,
.config = lm95241_temp_config,
};
static const struct hwmon_channel_info *lm95241_info[] = {
&lm95241_chip,
&lm95241_temp,
NULL
};
static const struct hwmon_ops lm95241_hwmon_ops = {
.is_visible = lm95241_is_visible,
.read = lm95241_read,
.write = lm95241_write,
};
static const struct hwmon_chip_info lm95241_chip_info = {
.ops = &lm95241_hwmon_ops,
.info = lm95241_info,
};
static int lm95241_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct lm95241_data *data;
struct device *hwmon_dev;
data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
mutex_init(&data->update_lock);
/* Initialize the LM95241 chip */
lm95241_init_client(client, data);
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data,
&lm95241_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
/* Driver data (common to all clients) */
static const struct i2c_device_id lm95241_id[] = {
{ "lm95231", 0 },
{ "lm95241", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm95241_id);
static struct i2c_driver lm95241_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = DEVNAME,
},
.probe = lm95241_probe,
.id_table = lm95241_id,
.detect = lm95241_detect,
.address_list = normal_i2c,
};
module_i2c_driver(lm95241_driver);
MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
MODULE_LICENSE("GPL");