#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#define DRIVER_NAME "tmp102"
#define TMP102_TEMP_REG 0x00
#define TMP102_CONF_REG 0x01
#define TMP102_CONF_SD 0x0100
#define TMP102_CONF_TM 0x0200
#define TMP102_CONF_POL 0x0400
#define TMP102_CONF_F0 0x0800
#define TMP102_CONF_F1 0x1000
#define TMP102_CONF_R0 0x2000
#define TMP102_CONF_R1 0x4000
#define TMP102_CONF_OS 0x8000
#define TMP102_CONF_EM 0x0010
#define TMP102_CONF_AL 0x0020
#define TMP102_CONF_CR0 0x0040
#define TMP102_CONF_CR1 0x0080
#define TMP102_TLOW_REG 0x02
#define TMP102_THIGH_REG 0x03
#define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \
TMP102_CONF_POL | TMP102_CONF_F0 | \
TMP102_CONF_F1 | TMP102_CONF_OS | \
TMP102_CONF_EM | TMP102_CONF_AL | \
TMP102_CONF_CR0 | TMP102_CONF_CR1)
#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \
TMP102_CONF_CR0)
#define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \
TMP102_CONF_CR1)
#define CONVERSION_TIME_MS 35
struct tmp102 {
const char *label;
struct regmap *regmap;
u16 config_orig;
unsigned long ready_time;
};
static inline int tmp102_reg_to_mC(s16 val)
{
return ((val & ~0x01) * 1000) / 128;
}
static inline u16 tmp102_mC_to_reg(int val)
{
return (val * 128) / 1000;
}
static int tmp102_read_string(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, const char **str)
{
struct tmp102 *tmp102 = dev_get_drvdata(dev);
*str = tmp102->label;
return 0;
}
static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
{
struct tmp102 *tmp102 = dev_get_drvdata(dev);
unsigned int regval;
int err, reg;
switch (attr) {
case hwmon_temp_input:
if (time_before(jiffies, tmp102->ready_time)) {
dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
return -EAGAIN;
}
reg = TMP102_TEMP_REG;
break;
case hwmon_temp_max_hyst:
reg = TMP102_TLOW_REG;
break;
case hwmon_temp_max:
reg = TMP102_THIGH_REG;
break;
default:
return -EOPNOTSUPP;
}
err = regmap_read(tmp102->regmap, reg, ®val);
if (err < 0)
return err;
*temp = tmp102_reg_to_mC(regval);
return 0;
}
static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long temp)
{
struct tmp102 *tmp102 = dev_get_drvdata(dev);
int reg;
switch (attr) {
case hwmon_temp_max_hyst:
reg = TMP102_TLOW_REG;
break;
case hwmon_temp_max:
reg = TMP102_THIGH_REG;
break;
default:
return -EOPNOTSUPP;
}
temp = clamp_val(temp, -256000, 255000);
return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));
}
static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct tmp102 *tmp102 = data;
if (type != hwmon_temp)
return 0;
switch (attr) {
case hwmon_temp_input:
return 0444;
case hwmon_temp_label:
if (tmp102->label)
return 0444;
return 0;
case hwmon_temp_max_hyst:
case hwmon_temp_max:
return 0644;
default:
return 0;
}
}
static const struct hwmon_channel_info * const tmp102_info[] = {
HWMON_CHANNEL_INFO(chip,
HWMON_C_REGISTER_TZ),
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_MAX | HWMON_T_MAX_HYST),
NULL
};
static const struct hwmon_ops tmp102_hwmon_ops = {
.is_visible = tmp102_is_visible,
.read_string = tmp102_read_string,
.read = tmp102_read,
.write = tmp102_write,
};
static const struct hwmon_chip_info tmp102_chip_info = {
.ops = &tmp102_hwmon_ops,
.info = tmp102_info,
};
static void tmp102_restore_config(void *data)
{
struct tmp102 *tmp102 = data;
regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
}
static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
{
return reg != TMP102_TEMP_REG;
}
static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
{
return reg == TMP102_TEMP_REG;
}
static const struct regmap_config tmp102_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.max_register = TMP102_THIGH_REG,
.writeable_reg = tmp102_is_writeable_reg,
.volatile_reg = tmp102_is_volatile_reg,
.val_format_endian = REGMAP_ENDIAN_BIG,
.cache_type = REGCACHE_MAPLE,
.use_single_read = true,
.use_single_write = true,
};
static int tmp102_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct tmp102 *tmp102;
unsigned int regval;
int err;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_err(dev,
"adapter doesn't support SMBus word transactions\n");
return -ENODEV;
}
err = devm_regulator_get_enable_optional(dev, "vcc");
if (err < 0 && err != -ENODEV)
return dev_err_probe(dev, err, "Failed to enable regulator\n");
tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
if (!tmp102)
return -ENOMEM;
of_property_read_string(dev->of_node, "label", &tmp102->label);
i2c_set_clientdata(client, tmp102);
tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
if (IS_ERR(tmp102->regmap))
return PTR_ERR(tmp102->regmap);
err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val);
if (err < 0) {
dev_err(dev, "error reading config register\n");
return err;
}
if ((regval & ~TMP102_CONFREG_MASK) !=
(TMP102_CONF_R0 | TMP102_CONF_R1)) {
dev_err(dev, "unexpected config register value\n");
return -ENODEV;
}
tmp102->config_orig = regval;
err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
if (err)
return err;
regval &= ~TMP102_CONFIG_CLEAR;
regval |= TMP102_CONFIG_SET;
err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
if (err < 0) {
dev_err(dev, "error writing config register\n");
return err;
}
tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
tmp102,
&tmp102_chip_info,
NULL);
if (IS_ERR(hwmon_dev)) {
dev_dbg(dev, "unable to register hwmon device\n");
return PTR_ERR(hwmon_dev);
}
dev_info(dev, "initialized\n");
return 0;
}
static int tmp102_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tmp102 *tmp102 = i2c_get_clientdata(client);
return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
TMP102_CONF_SD, TMP102_CONF_SD);
}
static int tmp102_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tmp102 *tmp102 = i2c_get_clientdata(client);
int err;
err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
TMP102_CONF_SD, 0);
tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
return err;
}
static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
static const struct i2c_device_id tmp102_id[] = {
{ "tmp102" },
{ }
};
MODULE_DEVICE_TABLE(i2c, tmp102_id);
static const struct of_device_id __maybe_unused tmp102_of_match[] = {
{ .compatible = "ti,tmp102" },
{ },
};
MODULE_DEVICE_TABLE(of, tmp102_of_match);
static struct i2c_driver tmp102_driver = {
.driver.name = DRIVER_NAME,
.driver.of_match_table = of_match_ptr(tmp102_of_match),
.driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops),
.probe = tmp102_probe,
.id_table = tmp102_id,
};
module_i2c_driver(tmp102_driver);
MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
MODULE_LICENSE("GPL");
