/*
* jc42.c - driver for Jedec JC42.4 compliant temperature sensors
*
* Copyright (c) 2010 Ericsson AB.
*
* Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
*
* JC42.4 compliant temperature sensors are typically used on memory modules.
*
* 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[] = {
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
/* JC42 registers. All registers are 16 bit. */
#define JC42_REG_CAP 0x00
#define JC42_REG_CONFIG 0x01
#define JC42_REG_TEMP_UPPER 0x02
#define JC42_REG_TEMP_LOWER 0x03
#define JC42_REG_TEMP_CRITICAL 0x04
#define JC42_REG_TEMP 0x05
#define JC42_REG_MANID 0x06
#define JC42_REG_DEVICEID 0x07
/* Status bits in temperature register */
#define JC42_ALARM_CRIT_BIT 15
#define JC42_ALARM_MAX_BIT 14
#define JC42_ALARM_MIN_BIT 13
/* Configuration register defines */
#define JC42_CFG_CRIT_ONLY (1 << 2)
#define JC42_CFG_TCRIT_LOCK (1 << 6)
#define JC42_CFG_EVENT_LOCK (1 << 7)
#define JC42_CFG_SHUTDOWN (1 << 8)
#define JC42_CFG_HYST_SHIFT 9
#define JC42_CFG_HYST_MASK (0x03 << 9)
/* Capabilities */
#define JC42_CAP_RANGE (1 << 2)
/* Manufacturer IDs */
#define ADT_MANID 0x11d4 /* Analog Devices */
#define ATMEL_MANID 0x001f /* Atmel */
#define MAX_MANID 0x004d /* Maxim */
#define IDT_MANID 0x00b3 /* IDT */
#define MCP_MANID 0x0054 /* Microchip */
#define NXP_MANID 0x1131 /* NXP Semiconductors */
#define ONS_MANID 0x1b09 /* ON Semiconductor */
#define STM_MANID 0x104a /* ST Microelectronics */
/* Supported chips */
/* Analog Devices */
#define ADT7408_DEVID 0x0801
#define ADT7408_DEVID_MASK 0xffff
/* Atmel */
#define AT30TS00_DEVID 0x8201
#define AT30TS00_DEVID_MASK 0xffff
/* IDT */
#define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */
#define TS3000B3_DEVID_MASK 0xffff
#define TS3000GB2_DEVID 0x2912 /* Also matches TSE2002GB2 */
#define TS3000GB2_DEVID_MASK 0xffff
/* Maxim */
#define MAX6604_DEVID 0x3e00
#define MAX6604_DEVID_MASK 0xffff
/* Microchip */
#define MCP9804_DEVID 0x0200
#define MCP9804_DEVID_MASK 0xfffc
#define MCP98242_DEVID 0x2000
#define MCP98242_DEVID_MASK 0xfffc
#define MCP98243_DEVID 0x2100
#define MCP98243_DEVID_MASK 0xfffc
#define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
#define MCP9843_DEVID_MASK 0xfffe
/* NXP */
#define SE97_DEVID 0xa200
#define SE97_DEVID_MASK 0xfffc
#define SE98_DEVID 0xa100
#define SE98_DEVID_MASK 0xfffc
/* ON Semiconductor */
#define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
#define CAT6095_DEVID_MASK 0xffe0
/* ST Microelectronics */
#define STTS424_DEVID 0x0101
#define STTS424_DEVID_MASK 0xffff
#define STTS424E_DEVID 0x0000
#define STTS424E_DEVID_MASK 0xfffe
#define STTS2002_DEVID 0x0300
#define STTS2002_DEVID_MASK 0xffff
#define STTS3000_DEVID 0x0200
#define STTS3000_DEVID_MASK 0xffff
static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
struct jc42_chips {
u16 manid;
u16 devid;
u16 devid_mask;
};
static struct jc42_chips jc42_chips[] = {
{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
{ IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
{ IDT_MANID, TS3000GB2_DEVID, TS3000GB2_DEVID_MASK },
{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
};
/* Each client has this additional data */
struct jc42_data {
struct device *hwmon_dev;
struct mutex update_lock; /* protect register access */
bool extended; /* true if extended range supported */
bool valid;
unsigned long last_updated; /* In jiffies */
u16 orig_config; /* original configuration */
u16 config; /* current configuration */
u16 temp_input; /* Temperatures */
u16 temp_crit;
u16 temp_min;
u16 temp_max;
};
static int jc42_probe(struct i2c_client *client,
const struct i2c_device_id *id);
static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
static int jc42_remove(struct i2c_client *client);
static struct jc42_data *jc42_update_device(struct device *dev);
static const struct i2c_device_id jc42_id[] = {
{ "jc42", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, jc42_id);
#ifdef CONFIG_PM
static int jc42_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct jc42_data *data = i2c_get_clientdata(client);
data->config |= JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
return 0;
}
static int jc42_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct jc42_data *data = i2c_get_clientdata(client);
data->config &= ~JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
return 0;
}
static const struct dev_pm_ops jc42_dev_pm_ops = {
.suspend = jc42_suspend,
.resume = jc42_resume,
};
#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
#else
#define JC42_DEV_PM_OPS NULL
#endif /* CONFIG_PM */
/* This is the driver that will be inserted */
static struct i2c_driver jc42_driver = {
.class = I2C_CLASS_SPD,
.driver = {
.name = "jc42",
.pm = JC42_DEV_PM_OPS,
},
.probe = jc42_probe,
.remove = jc42_remove,
.id_table = jc42_id,
.detect = jc42_detect,
.address_list = normal_i2c,
};
#define JC42_TEMP_MIN_EXTENDED (-40000)
#define JC42_TEMP_MIN 0
#define JC42_TEMP_MAX 125000
static u16 jc42_temp_to_reg(int temp, bool extended)
{
int ntemp = clamp_val(temp,
extended ? JC42_TEMP_MIN_EXTENDED :
JC42_TEMP_MIN, JC42_TEMP_MAX);
/* convert from 0.001 to 0.0625 resolution */
return (ntemp * 2 / 125) & 0x1fff;
}
static int jc42_temp_from_reg(s16 reg)
{
reg &= 0x1fff;
/* sign extend register */
if (reg & 0x1000)
reg |= 0xf000;
/* convert from 0.0625 to 0.001 resolution */
return reg * 125 / 2;
}
/* sysfs stuff */
/* read routines for temperature limits */
#define show(value) \
static ssize_t show_##value(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct jc42_data *data = jc42_update_device(dev); \
if (IS_ERR(data)) \
return PTR_ERR(data); \
return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \
}
show(temp_input);
show(temp_crit);
show(temp_min);
show(temp_max);
/* read routines for hysteresis values */
static ssize_t show_temp_crit_hyst(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct jc42_data *data = jc42_update_device(dev);
int temp, hyst;
if (IS_ERR(data))
return PTR_ERR(data);
temp = jc42_temp_from_reg(data->temp_crit);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
return sprintf(buf, "%d\n", temp - hyst);
}
static ssize_t show_temp_max_hyst(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct jc42_data *data = jc42_update_device(dev);
int temp, hyst;
if (IS_ERR(data))
return PTR_ERR(data);
temp = jc42_temp_from_reg(data->temp_max);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
return sprintf(buf, "%d\n", temp - hyst);
}
/* write routines */
#define set(value, reg) \
static ssize_t set_##value(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
struct i2c_client *client = to_i2c_client(dev); \
struct jc42_data *data = i2c_get_clientdata(client); \
int err, ret = count; \
long val; \
if (kstrtol(buf, 10, &val) < 0) \
return -EINVAL; \
mutex_lock(&data->update_lock); \
data->value = jc42_temp_to_reg(val, data->extended); \
err = i2c_smbus_write_word_swapped(client, reg, data->value); \
if (err < 0) \
ret = err; \
mutex_unlock(&data->update_lock); \
return ret; \
}
set(temp_min, JC42_REG_TEMP_LOWER);
set(temp_max, JC42_REG_TEMP_UPPER);
set(temp_crit, JC42_REG_TEMP_CRITICAL);
/*
* JC42.4 compliant chips only support four hysteresis values.
* Pick best choice and go from there.
*/
static ssize_t set_temp_crit_hyst(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct jc42_data *data = i2c_get_clientdata(client);
unsigned long val;
int diff, hyst;
int err;
int ret = count;
if (kstrtoul(buf, 10, &val) < 0)
return -EINVAL;
diff = jc42_temp_from_reg(data->temp_crit) - val;
hyst = 0;
if (diff > 0) {
if (diff < 2250)
hyst = 1; /* 1.5 degrees C */
else if (diff < 4500)
hyst = 2; /* 3.0 degrees C */
else
hyst = 3; /* 6.0 degrees C */
}
mutex_lock(&data->update_lock);
data->config = (data->config & ~JC42_CFG_HYST_MASK)
| (hyst << JC42_CFG_HYST_SHIFT);
err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
data->config);
if (err < 0)
ret = err;
mutex_unlock(&data->update_lock);
return ret;
}
static ssize_t show_alarm(struct device *dev,
struct device_attribute *attr, char *buf)
{
u16 bit = to_sensor_dev_attr(attr)->index;
struct jc42_data *data = jc42_update_device(dev);
u16 val;
if (IS_ERR(data))
return PTR_ERR(data);
val = data->temp_input;
if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
val = 0;
return sprintf(buf, "%u\n", (val >> bit) & 1);
}
static DEVICE_ATTR(temp1_input, S_IRUGO,
show_temp_input, NULL);
static DEVICE_ATTR(temp1_crit, S_IRUGO,
show_temp_crit, set_temp_crit);
static DEVICE_ATTR(temp1_min, S_IRUGO,
show_temp_min, set_temp_min);
static DEVICE_ATTR(temp1_max, S_IRUGO,
show_temp_max, set_temp_max);
static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
show_temp_crit_hyst, set_temp_crit_hyst);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
show_temp_max_hyst, NULL);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
JC42_ALARM_CRIT_BIT);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
JC42_ALARM_MIN_BIT);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
JC42_ALARM_MAX_BIT);
static struct attribute *jc42_attributes[] = {
&dev_attr_temp1_input.attr,
&dev_attr_temp1_crit.attr,
&dev_attr_temp1_min.attr,
&dev_attr_temp1_max.attr,
&dev_attr_temp1_crit_hyst.attr,
&dev_attr_temp1_max_hyst.attr,
&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
NULL
};
static umode_t jc42_attribute_mode(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct i2c_client *client = to_i2c_client(dev);
struct jc42_data *data = i2c_get_clientdata(client);
unsigned int config = data->config;
bool readonly;
if (attr == &dev_attr_temp1_crit.attr)
readonly = config & JC42_CFG_TCRIT_LOCK;
else if (attr == &dev_attr_temp1_min.attr ||
attr == &dev_attr_temp1_max.attr)
readonly = config & JC42_CFG_EVENT_LOCK;
else if (attr == &dev_attr_temp1_crit_hyst.attr)
readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
else
readonly = true;
return S_IRUGO | (readonly ? 0 : S_IWUSR);
}
static const struct attribute_group jc42_group = {
.attrs = jc42_attributes,
.is_visible = jc42_attribute_mode,
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int i, config, cap, manid, devid;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
if (cap < 0 || config < 0 || manid < 0 || devid < 0)
return -ENODEV;
if ((cap & 0xff00) || (config & 0xf800))
return -ENODEV;
for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
struct jc42_chips *chip = &jc42_chips[i];
if (manid == chip->manid &&
(devid & chip->devid_mask) == chip->devid) {
strlcpy(info->type, "jc42", I2C_NAME_SIZE);
return 0;
}
}
return -ENODEV;
}
static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
struct jc42_data *data;
int config, cap, err;
struct device *dev = &client->dev;
data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
if (cap < 0)
return cap;
data->extended = !!(cap & JC42_CAP_RANGE);
config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
if (config < 0)
return config;
data->orig_config = config;
if (config & JC42_CFG_SHUTDOWN) {
config &= ~JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
}
data->config = config;
/* Register sysfs hooks */
err = sysfs_create_group(&dev->kobj, &jc42_group);
if (err)
return err;
data->hwmon_dev = hwmon_device_register(dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
return 0;
exit_remove:
sysfs_remove_group(&dev->kobj, &jc42_group);
return err;
}
static int jc42_remove(struct i2c_client *client)
{
struct jc42_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &jc42_group);
/* Restore original configuration except hysteresis */
if ((data->config & ~JC42_CFG_HYST_MASK) !=
(data->orig_config & ~JC42_CFG_HYST_MASK)) {
int config;
config = (data->orig_config & ~JC42_CFG_HYST_MASK)
| (data->config & JC42_CFG_HYST_MASK);
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
}
return 0;
}
static struct jc42_data *jc42_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct jc42_data *data = i2c_get_clientdata(client);
struct jc42_data *ret = data;
int val;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp_input = val;
val = i2c_smbus_read_word_swapped(client,
JC42_REG_TEMP_CRITICAL);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp_crit = val;
val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp_min = val;
val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp_max = val;
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
module_i2c_driver(jc42_driver);
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("JC42 driver");
MODULE_LICENSE("GPL");
