jc42.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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.
*/
#include <linux/bitops.h>
#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/err.h>
#include <linux/mutex.h>
#include <linux/of.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
#define JC42_REG_SMBUS 0x22 /* NXP and Atmel, possibly others? */
/* 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 */
#define GT_MANID 0x1c68 /* Giantec */
#define GT_MANID2 0x132d /* Giantec, 2nd mfg ID */
/* SMBUS register */
#define SMBUS_STMOUT BIT(7) /* SMBus time-out, active low */
/* 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
/* Giantec */
#define GT30TS00_DEVID 0x2200
#define GT30TS00_DEVID_MASK 0xff00
#define GT34TS02_DEVID 0x3300
#define GT34TS02_DEVID_MASK 0xff00
/* IDT */
#define TSE2004_DEVID 0x2200
#define TSE2004_DEVID_MASK 0xff00
#define TS3000_DEVID 0x2900 /* Also matches TSE2002 */
#define TS3000_DEVID_MASK 0xff00
#define TS3001_DEVID 0x3000
#define TS3001_DEVID_MASK 0xff00
/* Maxim */
#define MAX6604_DEVID 0x3e00
#define MAX6604_DEVID_MASK 0xffff
/* Microchip */
#define MCP9804_DEVID 0x0200
#define MCP9804_DEVID_MASK 0xfffc
#define MCP9808_DEVID 0x0400
#define MCP9808_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
#define CAT34TS02C_DEVID 0x0a00
#define CAT34TS02C_DEVID_MASK 0xfff0
#define CAT34TS04_DEVID 0x2200
#define CAT34TS04_DEVID_MASK 0xfff0
/* 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 },
{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
{ MCP_MANID, MCP9808_DEVID, MCP9808_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 },
{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_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;
}
static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct jc42_data *data = jc42_update_device(dev);
int temp, hyst;
if (IS_ERR(data))
return PTR_ERR(data);
switch (attr) {
case hwmon_temp_input:
*val = jc42_temp_from_reg(data->temp[t_input]);
return 0;
case hwmon_temp_min:
*val = jc42_temp_from_reg(data->temp[t_min]);
return 0;
case hwmon_temp_max:
*val = jc42_temp_from_reg(data->temp[t_max]);
return 0;
case hwmon_temp_crit:
*val = jc42_temp_from_reg(data->temp[t_crit]);
return 0;
case hwmon_temp_max_hyst:
temp = jc42_temp_from_reg(data->temp[t_max]);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
*val = temp - hyst;
return 0;
case hwmon_temp_crit_hyst:
temp = jc42_temp_from_reg(data->temp[t_crit]);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
*val = temp - hyst;
return 0;
case hwmon_temp_min_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1;
return 0;
case hwmon_temp_max_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1;
return 0;
case hwmon_temp_crit_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1;
return 0;
default:
return -EOPNOTSUPP;
}
}
static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct jc42_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int diff, hyst;
int ret;
mutex_lock(&data->update_lock);
switch (attr) {
case hwmon_temp_min:
data->temp[t_min] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min],
data->temp[t_min]);
break;
case hwmon_temp_max:
data->temp[t_max] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max],
data->temp[t_max]);
break;
case hwmon_temp_crit:
data->temp[t_crit] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit],
data->temp[t_crit]);
break;
case hwmon_temp_crit_hyst:
/*
* JC42.4 compliant chips only support four hysteresis values.
* Pick best choice and go from there.
*/
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 */
}
data->config = (data->config & ~JC42_CFG_HYST_MASK) |
(hyst << JC42_CFG_HYST_SHIFT);
ret = i2c_smbus_write_word_swapped(data->client,
JC42_REG_CONFIG,
data->config);
break;
default:
ret = -EOPNOTSUPP;
break;
}
mutex_unlock(&data->update_lock);
return ret;
}
static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct jc42_data *data = _data;
unsigned int config = data->config;
umode_t mode = 0444;
switch (attr) {
case hwmon_temp_min:
case hwmon_temp_max:
if (!(config & JC42_CFG_EVENT_LOCK))
mode |= 0200;
break;
case hwmon_temp_crit:
if (!(config & JC42_CFG_TCRIT_LOCK))
mode |= 0200;
break;
case hwmon_temp_crit_hyst:
if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
mode |= 0200;
break;
case hwmon_temp_input:
case hwmon_temp_max_hyst:
case hwmon_temp_min_alarm:
case hwmon_temp_max_alarm:
case hwmon_temp_crit_alarm:
break;
default:
mode = 0;
break;
}
return 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 const struct hwmon_channel_info *jc42_info[] = {
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
HWMON_T_CRIT | HWMON_T_MAX_HYST |
HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
NULL
};
static const struct hwmon_ops jc42_hwmon_ops = {
.is_visible = jc42_is_visible,
.read = jc42_read,
.write = jc42_write,
};
static const struct hwmon_chip_info jc42_chip_info = {
.ops = &jc42_hwmon_ops,
.info = jc42_info,
};
static int jc42_probe(struct i2c_client *client)
{
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);
if (device_property_read_bool(dev, "smbus-timeout-disable")) {
int smbus;
/*
* Not all chips support this register, but from a
* quick read of various datasheets no chip appears
* incompatible with the below attempt to disable
* the timeout. And the whole thing is opt-in...
*/
smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS);
if (smbus < 0)
return smbus;
i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS,
smbus | SMBUS_STMOUT);
}
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_info(dev, "jc42",
data, &jc42_chip_info,
NULL);
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);
#ifdef CONFIG_OF
static const struct of_device_id jc42_of_ids[] = {
{ .compatible = "jedec,jc-42.4-temp", },
{ }
};
MODULE_DEVICE_TABLE(of, jc42_of_ids);
#endif
static struct i2c_driver jc42_driver = {
.class = I2C_CLASS_SPD | I2C_CLASS_HWMON,
.driver = {
.name = "jc42",
.pm = JC42_DEV_PM_OPS,
.of_match_table = of_match_ptr(jc42_of_ids),
},
.probe_new = 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");