linux/drivers/hwmon/jc42.c
Jean Delvare 9130880a1c hwmon: (jc42) Allow negative hysteresis temperatures
The driver supports negative high and critical limits, it can return
negative hysteresis values, so there is no good reason to not let the
user write negative hysteresis values.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2015-01-25 21:24:00 -08:00

554 lines
15 KiB
C

/*
* 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 ATMEL_MANID2 0x1114 /* 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
#define AT30TSE004_DEVID 0x2200
#define AT30TSE004_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 MCP98244_DEVID 0x2200
#define MCP98244_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 STTS2004_DEVID 0x2201
#define STTS2004_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 },
{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_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, MCP98244_DEVID, MCP98244_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, STTS2004_DEVID, STTS2004_DEVID_MASK },
{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
};
enum temp_index {
t_input = 0,
t_crit,
t_min,
t_max,
t_num_temp
};
static const u8 temp_regs[t_num_temp] = {
[t_input] = JC42_REG_TEMP,
[t_crit] = JC42_REG_TEMP_CRITICAL,
[t_min] = JC42_REG_TEMP_LOWER,
[t_max] = JC42_REG_TEMP_UPPER,
};
/* Each client has this additional data */
struct jc42_data {
struct i2c_client *client;
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[t_num_temp];/* Temperatures */
};
#define JC42_TEMP_MIN_EXTENDED (-40000)
#define JC42_TEMP_MIN 0
#define JC42_TEMP_MAX 125000
static u16 jc42_temp_to_reg(long 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 = sign_extend32(reg, 12);
/* convert from 0.0625 to 0.001 resolution */
return reg * 125 / 2;
}
static struct jc42_data *jc42_update_device(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
struct jc42_data *ret = data;
int i, val;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
for (i = 0; i < t_num_temp; i++) {
val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp[i] = val;
}
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
/* sysfs functions */
static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
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->temp[attr->index]));
}
static ssize_t show_temp_hyst(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
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[attr->index]);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
return sprintf(buf, "%d\n", temp - hyst);
}
static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct jc42_data *data = dev_get_drvdata(dev);
int err, ret = count;
int nr = attr->index;
long val;
if (kstrtol(buf, 10, &val) < 0)
return -EINVAL;
mutex_lock(&data->update_lock);
data->temp[nr] = jc42_temp_to_reg(val, data->extended);
err = i2c_smbus_write_word_swapped(data->client, temp_regs[nr],
data->temp[nr]);
if (err < 0)
ret = err;
mutex_unlock(&data->update_lock);
return ret;
}
/*
* 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 jc42_data *data = dev_get_drvdata(dev);
long val;
int diff, hyst;
int err;
int ret = count;
if (kstrtol(buf, 10, &val) < 0)
return -EINVAL;
val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED :
JC42_TEMP_MIN) - 6000, JC42_TEMP_MAX);
diff = jc42_temp_from_reg(data->temp[t_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(data->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[t_input];
if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
val = 0;
return sprintf(buf, "%u\n", (val >> bit) & 1);
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, set_temp, t_crit);
static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp, set_temp, t_min);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, set_temp, t_max);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_hyst,
set_temp_crit_hyst, t_crit);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
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[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_crit.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_max_hyst.dev_attr.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 jc42_data *data = dev_get_drvdata(dev);
unsigned int config = data->config;
bool readonly;
if (attr == &sensor_dev_attr_temp1_crit.dev_attr.attr)
readonly = config & JC42_CFG_TCRIT_LOCK;
else if (attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
attr == &sensor_dev_attr_temp1_max.dev_attr.attr)
readonly = config & JC42_CFG_EVENT_LOCK;
else if (attr == &sensor_dev_attr_temp1_crit_hyst.dev_attr.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,
};
__ATTRIBUTE_GROUPS(jc42);
/* 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 device *dev = &client->dev;
struct device *hwmon_dev;
struct jc42_data *data;
int config, cap;
data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
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;
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data,
jc42_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static int jc42_remove(struct i2c_client *client)
{
struct jc42_data *data = i2c_get_clientdata(client);
/* 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;
}
#ifdef CONFIG_PM
static int jc42_suspend(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
data->config |= JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
data->config);
return 0;
}
static int jc42_resume(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
data->config &= ~JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(data->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 */
static const struct i2c_device_id jc42_id[] = {
{ "jc42", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, jc42_id);
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,
};
module_i2c_driver(jc42_driver);
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("JC42 driver");
MODULE_LICENSE("GPL");