445 lines
12 KiB
C
445 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* Texas Instruments TMP108 SMBus temperature sensor driver
|
|
*
|
|
* Copyright (C) 2016 John Muir <john@jmuir.com>
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/hwmon.h>
|
|
#include <linux/hwmon-sysfs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/of.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/slab.h>
|
|
|
|
#define DRIVER_NAME "tmp108"
|
|
|
|
#define TMP108_REG_TEMP 0x00
|
|
#define TMP108_REG_CONF 0x01
|
|
#define TMP108_REG_TLOW 0x02
|
|
#define TMP108_REG_THIGH 0x03
|
|
|
|
#define TMP108_TEMP_MIN_MC -50000 /* Minimum millicelcius. */
|
|
#define TMP108_TEMP_MAX_MC 127937 /* Maximum millicelcius. */
|
|
|
|
/* Configuration register bits.
|
|
* Note: these bit definitions are byte swapped.
|
|
*/
|
|
#define TMP108_CONF_M0 0x0100 /* Sensor mode. */
|
|
#define TMP108_CONF_M1 0x0200
|
|
#define TMP108_CONF_TM 0x0400 /* Thermostat mode. */
|
|
#define TMP108_CONF_FL 0x0800 /* Watchdog flag - TLOW */
|
|
#define TMP108_CONF_FH 0x1000 /* Watchdog flag - THIGH */
|
|
#define TMP108_CONF_CR0 0x2000 /* Conversion rate. */
|
|
#define TMP108_CONF_CR1 0x4000
|
|
#define TMP108_CONF_ID 0x8000
|
|
#define TMP108_CONF_HYS0 0x0010 /* Hysteresis. */
|
|
#define TMP108_CONF_HYS1 0x0020
|
|
#define TMP108_CONF_POL 0x0080 /* Polarity of alert. */
|
|
|
|
/* Defaults set by the hardware upon reset. */
|
|
#define TMP108_CONF_DEFAULTS (TMP108_CONF_CR0 | TMP108_CONF_TM |\
|
|
TMP108_CONF_HYS0 | TMP108_CONF_M1)
|
|
/* These bits are read-only. */
|
|
#define TMP108_CONF_READ_ONLY (TMP108_CONF_FL | TMP108_CONF_FH |\
|
|
TMP108_CONF_ID)
|
|
|
|
#define TMP108_CONF_MODE_MASK (TMP108_CONF_M0|TMP108_CONF_M1)
|
|
#define TMP108_MODE_SHUTDOWN 0x0000
|
|
#define TMP108_MODE_ONE_SHOT TMP108_CONF_M0
|
|
#define TMP108_MODE_CONTINUOUS TMP108_CONF_M1 /* Default */
|
|
/* When M1 is set, M0 is ignored. */
|
|
|
|
#define TMP108_CONF_CONVRATE_MASK (TMP108_CONF_CR0|TMP108_CONF_CR1)
|
|
#define TMP108_CONVRATE_0P25HZ 0x0000
|
|
#define TMP108_CONVRATE_1HZ TMP108_CONF_CR0 /* Default */
|
|
#define TMP108_CONVRATE_4HZ TMP108_CONF_CR1
|
|
#define TMP108_CONVRATE_16HZ (TMP108_CONF_CR0|TMP108_CONF_CR1)
|
|
|
|
#define TMP108_CONF_HYSTERESIS_MASK (TMP108_CONF_HYS0|TMP108_CONF_HYS1)
|
|
#define TMP108_HYSTERESIS_0C 0x0000
|
|
#define TMP108_HYSTERESIS_1C TMP108_CONF_HYS0 /* Default */
|
|
#define TMP108_HYSTERESIS_2C TMP108_CONF_HYS1
|
|
#define TMP108_HYSTERESIS_4C (TMP108_CONF_HYS0|TMP108_CONF_HYS1)
|
|
|
|
#define TMP108_CONVERSION_TIME_MS 30 /* in milli-seconds */
|
|
|
|
struct tmp108 {
|
|
struct regmap *regmap;
|
|
u16 orig_config;
|
|
unsigned long ready_time;
|
|
};
|
|
|
|
/* convert 12-bit TMP108 register value to milliCelsius */
|
|
static inline int tmp108_temp_reg_to_mC(s16 val)
|
|
{
|
|
return (val & ~0x0f) * 1000 / 256;
|
|
}
|
|
|
|
/* convert milliCelsius to left adjusted 12-bit TMP108 register value */
|
|
static inline u16 tmp108_mC_to_temp_reg(int val)
|
|
{
|
|
return (val * 256) / 1000;
|
|
}
|
|
|
|
static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,
|
|
u32 attr, int channel, long *temp)
|
|
{
|
|
struct tmp108 *tmp108 = dev_get_drvdata(dev);
|
|
unsigned int regval;
|
|
int err, hyst;
|
|
|
|
if (type == hwmon_chip) {
|
|
if (attr == hwmon_chip_update_interval) {
|
|
err = regmap_read(tmp108->regmap, TMP108_REG_CONF,
|
|
®val);
|
|
if (err < 0)
|
|
return err;
|
|
switch (regval & TMP108_CONF_CONVRATE_MASK) {
|
|
case TMP108_CONVRATE_0P25HZ:
|
|
default:
|
|
*temp = 4000;
|
|
break;
|
|
case TMP108_CONVRATE_1HZ:
|
|
*temp = 1000;
|
|
break;
|
|
case TMP108_CONVRATE_4HZ:
|
|
*temp = 250;
|
|
break;
|
|
case TMP108_CONVRATE_16HZ:
|
|
*temp = 63;
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
switch (attr) {
|
|
case hwmon_temp_input:
|
|
/* Is it too early to return a conversion ? */
|
|
if (time_before(jiffies, tmp108->ready_time)) {
|
|
dev_dbg(dev, "%s: Conversion not ready yet..\n",
|
|
__func__);
|
|
return -EAGAIN;
|
|
}
|
|
err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, ®val);
|
|
if (err < 0)
|
|
return err;
|
|
*temp = tmp108_temp_reg_to_mC(regval);
|
|
break;
|
|
case hwmon_temp_min:
|
|
case hwmon_temp_max:
|
|
err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?
|
|
TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);
|
|
if (err < 0)
|
|
return err;
|
|
*temp = tmp108_temp_reg_to_mC(regval);
|
|
break;
|
|
case hwmon_temp_min_alarm:
|
|
case hwmon_temp_max_alarm:
|
|
err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);
|
|
if (err < 0)
|
|
return err;
|
|
*temp = !!(regval & (attr == hwmon_temp_min_alarm ?
|
|
TMP108_CONF_FL : TMP108_CONF_FH));
|
|
break;
|
|
case hwmon_temp_min_hyst:
|
|
case hwmon_temp_max_hyst:
|
|
err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);
|
|
if (err < 0)
|
|
return err;
|
|
switch (regval & TMP108_CONF_HYSTERESIS_MASK) {
|
|
case TMP108_HYSTERESIS_0C:
|
|
default:
|
|
hyst = 0;
|
|
break;
|
|
case TMP108_HYSTERESIS_1C:
|
|
hyst = 1000;
|
|
break;
|
|
case TMP108_HYSTERESIS_2C:
|
|
hyst = 2000;
|
|
break;
|
|
case TMP108_HYSTERESIS_4C:
|
|
hyst = 4000;
|
|
break;
|
|
}
|
|
err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?
|
|
TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);
|
|
if (err < 0)
|
|
return err;
|
|
*temp = tmp108_temp_reg_to_mC(regval);
|
|
if (attr == hwmon_temp_min_hyst)
|
|
*temp += hyst;
|
|
else
|
|
*temp -= hyst;
|
|
break;
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,
|
|
u32 attr, int channel, long temp)
|
|
{
|
|
struct tmp108 *tmp108 = dev_get_drvdata(dev);
|
|
u32 regval, mask;
|
|
int err;
|
|
|
|
if (type == hwmon_chip) {
|
|
if (attr == hwmon_chip_update_interval) {
|
|
if (temp < 156)
|
|
mask = TMP108_CONVRATE_16HZ;
|
|
else if (temp < 625)
|
|
mask = TMP108_CONVRATE_4HZ;
|
|
else if (temp < 2500)
|
|
mask = TMP108_CONVRATE_1HZ;
|
|
else
|
|
mask = TMP108_CONVRATE_0P25HZ;
|
|
return regmap_update_bits(tmp108->regmap,
|
|
TMP108_REG_CONF,
|
|
TMP108_CONF_CONVRATE_MASK,
|
|
mask);
|
|
}
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
switch (attr) {
|
|
case hwmon_temp_min:
|
|
case hwmon_temp_max:
|
|
temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
|
|
return regmap_write(tmp108->regmap,
|
|
attr == hwmon_temp_min ?
|
|
TMP108_REG_TLOW : TMP108_REG_THIGH,
|
|
tmp108_mC_to_temp_reg(temp));
|
|
case hwmon_temp_min_hyst:
|
|
case hwmon_temp_max_hyst:
|
|
temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
|
|
err = regmap_read(tmp108->regmap,
|
|
attr == hwmon_temp_min_hyst ?
|
|
TMP108_REG_TLOW : TMP108_REG_THIGH,
|
|
®val);
|
|
if (err < 0)
|
|
return err;
|
|
if (attr == hwmon_temp_min_hyst)
|
|
temp -= tmp108_temp_reg_to_mC(regval);
|
|
else
|
|
temp = tmp108_temp_reg_to_mC(regval) - temp;
|
|
if (temp < 500)
|
|
mask = TMP108_HYSTERESIS_0C;
|
|
else if (temp < 1500)
|
|
mask = TMP108_HYSTERESIS_1C;
|
|
else if (temp < 3000)
|
|
mask = TMP108_HYSTERESIS_2C;
|
|
else
|
|
mask = TMP108_HYSTERESIS_4C;
|
|
return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
|
|
TMP108_CONF_HYSTERESIS_MASK, mask);
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
|
|
static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,
|
|
u32 attr, int channel)
|
|
{
|
|
if (type == hwmon_chip && attr == hwmon_chip_update_interval)
|
|
return 0644;
|
|
|
|
if (type != hwmon_temp)
|
|
return 0;
|
|
|
|
switch (attr) {
|
|
case hwmon_temp_input:
|
|
case hwmon_temp_min_alarm:
|
|
case hwmon_temp_max_alarm:
|
|
return 0444;
|
|
case hwmon_temp_min:
|
|
case hwmon_temp_max:
|
|
case hwmon_temp_min_hyst:
|
|
case hwmon_temp_max_hyst:
|
|
return 0644;
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static const struct hwmon_channel_info *tmp108_info[] = {
|
|
HWMON_CHANNEL_INFO(chip,
|
|
HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
|
|
HWMON_CHANNEL_INFO(temp,
|
|
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
|
|
HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
|
|
HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),
|
|
NULL
|
|
};
|
|
|
|
static const struct hwmon_ops tmp108_hwmon_ops = {
|
|
.is_visible = tmp108_is_visible,
|
|
.read = tmp108_read,
|
|
.write = tmp108_write,
|
|
};
|
|
|
|
static const struct hwmon_chip_info tmp108_chip_info = {
|
|
.ops = &tmp108_hwmon_ops,
|
|
.info = tmp108_info,
|
|
};
|
|
|
|
static void tmp108_restore_config(void *data)
|
|
{
|
|
struct tmp108 *tmp108 = data;
|
|
|
|
regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);
|
|
}
|
|
|
|
static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)
|
|
{
|
|
return reg != TMP108_REG_TEMP;
|
|
}
|
|
|
|
static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)
|
|
{
|
|
/* Configuration register must be volatile to enable FL and FH. */
|
|
return reg == TMP108_REG_TEMP || reg == TMP108_REG_CONF;
|
|
}
|
|
|
|
static const struct regmap_config tmp108_regmap_config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 16,
|
|
.max_register = TMP108_REG_THIGH,
|
|
.writeable_reg = tmp108_is_writeable_reg,
|
|
.volatile_reg = tmp108_is_volatile_reg,
|
|
.val_format_endian = REGMAP_ENDIAN_BIG,
|
|
.cache_type = REGCACHE_RBTREE,
|
|
.use_single_read = true,
|
|
.use_single_write = true,
|
|
};
|
|
|
|
static int tmp108_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct device *dev = &client->dev;
|
|
struct device *hwmon_dev;
|
|
struct tmp108 *tmp108;
|
|
int err;
|
|
u32 config;
|
|
|
|
if (!i2c_check_functionality(client->adapter,
|
|
I2C_FUNC_SMBUS_WORD_DATA)) {
|
|
dev_err(dev,
|
|
"adapter doesn't support SMBus word transactions\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);
|
|
if (!tmp108)
|
|
return -ENOMEM;
|
|
|
|
dev_set_drvdata(dev, tmp108);
|
|
|
|
tmp108->regmap = devm_regmap_init_i2c(client, &tmp108_regmap_config);
|
|
if (IS_ERR(tmp108->regmap)) {
|
|
err = PTR_ERR(tmp108->regmap);
|
|
dev_err(dev, "regmap init failed: %d", err);
|
|
return err;
|
|
}
|
|
|
|
err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);
|
|
if (err < 0) {
|
|
dev_err(dev, "error reading config register: %d", err);
|
|
return err;
|
|
}
|
|
tmp108->orig_config = config;
|
|
|
|
/* Only continuous mode is supported. */
|
|
config &= ~TMP108_CONF_MODE_MASK;
|
|
config |= TMP108_MODE_CONTINUOUS;
|
|
|
|
/* Only comparator mode is supported. */
|
|
config &= ~TMP108_CONF_TM;
|
|
|
|
err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);
|
|
if (err < 0) {
|
|
dev_err(dev, "error writing config register: %d", err);
|
|
return err;
|
|
}
|
|
|
|
tmp108->ready_time = jiffies;
|
|
if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==
|
|
TMP108_MODE_SHUTDOWN)
|
|
tmp108->ready_time +=
|
|
msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
|
|
|
|
err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);
|
|
if (err) {
|
|
dev_err(dev, "add action or reset failed: %d", err);
|
|
return err;
|
|
}
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
|
|
tmp108,
|
|
&tmp108_chip_info,
|
|
NULL);
|
|
return PTR_ERR_OR_ZERO(hwmon_dev);
|
|
}
|
|
|
|
static int __maybe_unused tmp108_suspend(struct device *dev)
|
|
{
|
|
struct tmp108 *tmp108 = dev_get_drvdata(dev);
|
|
|
|
return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
|
|
TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);
|
|
}
|
|
|
|
static int __maybe_unused tmp108_resume(struct device *dev)
|
|
{
|
|
struct tmp108 *tmp108 = dev_get_drvdata(dev);
|
|
int err;
|
|
|
|
err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
|
|
TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);
|
|
tmp108->ready_time = jiffies +
|
|
msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
|
|
return err;
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);
|
|
|
|
static const struct i2c_device_id tmp108_i2c_ids[] = {
|
|
{ "tmp108", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id tmp108_of_ids[] = {
|
|
{ .compatible = "ti,tmp108", },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, tmp108_of_ids);
|
|
#endif
|
|
|
|
static struct i2c_driver tmp108_driver = {
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.pm = &tmp108_dev_pm_ops,
|
|
.of_match_table = of_match_ptr(tmp108_of_ids),
|
|
},
|
|
.probe = tmp108_probe,
|
|
.id_table = tmp108_i2c_ids,
|
|
};
|
|
|
|
module_i2c_driver(tmp108_driver);
|
|
|
|
MODULE_AUTHOR("John Muir <john@jmuir.com>");
|
|
MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
|
|
MODULE_LICENSE("GPL");
|