![Crt Mori](/assets/img/avatar_default.png)
Changed the offset to negative as usual equation is: (raw + offset)*scale and in this case offset should be negative (as we deduct 273.15 Kelvin to get temperature in Celsius). Signed-off-by: Crt Mori <cmo@melexis.com> Acked-by: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
567 lines
15 KiB
C
567 lines
15 KiB
C
/*
|
|
* mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
|
|
*
|
|
* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
|
|
* Copyright (c) 2015 Essensium NV
|
|
*
|
|
* This file is subject to the terms and conditions of version 2 of
|
|
* the GNU General Public License. See the file COPYING in the main
|
|
* directory of this archive for more details.
|
|
*
|
|
* Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
|
|
*
|
|
* (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
|
|
*
|
|
* To wake up from sleep mode, the SDA line must be held low while SCL is high
|
|
* for at least 33ms. This is achieved with an extra GPIO that can be connected
|
|
* directly to the SDA line. In normal operation, the GPIO is set as input and
|
|
* will not interfere in I2C communication. While the GPIO is driven low, the
|
|
* i2c adapter is locked since it cannot be used by other clients. The SCL line
|
|
* always has a pull-up so we do not need an extra GPIO to drive it high. If
|
|
* the "wakeup" GPIO is not given, power management will be disabled.
|
|
*
|
|
* TODO: filter configuration
|
|
*/
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/module.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/gpio/consumer.h>
|
|
#include <linux/pm_runtime.h>
|
|
|
|
#include <linux/iio/iio.h>
|
|
|
|
#define MLX90614_OP_RAM 0x00
|
|
#define MLX90614_OP_EEPROM 0x20
|
|
#define MLX90614_OP_SLEEP 0xff
|
|
|
|
/* RAM offsets with 16-bit data, MSB first */
|
|
#define MLX90614_RAW1 (MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
|
|
#define MLX90614_RAW2 (MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
|
|
#define MLX90614_TA (MLX90614_OP_RAM | 0x06) /* ambient temperature */
|
|
#define MLX90614_TOBJ1 (MLX90614_OP_RAM | 0x07) /* object 1 temperature */
|
|
#define MLX90614_TOBJ2 (MLX90614_OP_RAM | 0x08) /* object 2 temperature */
|
|
|
|
/* EEPROM offsets with 16-bit data, MSB first */
|
|
#define MLX90614_EMISSIVITY (MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
|
|
#define MLX90614_CONFIG (MLX90614_OP_EEPROM | 0x05) /* configuration register */
|
|
|
|
/* Control bits in configuration register */
|
|
#define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
|
|
#define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
|
|
#define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
|
|
#define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
|
|
#define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
|
|
#define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
|
|
#define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
|
|
#define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
|
|
|
|
/* Timings (in ms) */
|
|
#define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
|
|
#define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
|
|
#define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
|
|
|
|
#define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
|
|
|
|
struct mlx90614_data {
|
|
struct i2c_client *client;
|
|
struct mutex lock; /* for EEPROM access only */
|
|
struct gpio_desc *wakeup_gpio; /* NULL to disable sleep/wake-up */
|
|
unsigned long ready_timestamp; /* in jiffies */
|
|
};
|
|
|
|
/*
|
|
* Erase an address and write word.
|
|
* The mutex must be locked before calling.
|
|
*/
|
|
static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
|
|
u16 value)
|
|
{
|
|
/*
|
|
* Note: The mlx90614 requires a PEC on writing but does not send us a
|
|
* valid PEC on reading. Hence, we cannot set I2C_CLIENT_PEC in
|
|
* i2c_client.flags. As a workaround, we use i2c_smbus_xfer here.
|
|
*/
|
|
union i2c_smbus_data data;
|
|
s32 ret;
|
|
|
|
dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
|
|
|
|
data.word = 0x0000; /* erase command */
|
|
ret = i2c_smbus_xfer(client->adapter, client->addr,
|
|
client->flags | I2C_CLIENT_PEC,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_WORD_DATA, &data);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
msleep(MLX90614_TIMING_EEPROM);
|
|
|
|
data.word = value; /* actual write */
|
|
ret = i2c_smbus_xfer(client->adapter, client->addr,
|
|
client->flags | I2C_CLIENT_PEC,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_WORD_DATA, &data);
|
|
|
|
msleep(MLX90614_TIMING_EEPROM);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
/*
|
|
* If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
|
|
* the last wake-up. This is normally only needed to get a valid temperature
|
|
* reading. EEPROM access does not need such delay.
|
|
* Return 0 on success, <0 on error.
|
|
*/
|
|
static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
|
|
{
|
|
unsigned long now;
|
|
|
|
if (!data->wakeup_gpio)
|
|
return 0;
|
|
|
|
pm_runtime_get_sync(&data->client->dev);
|
|
|
|
if (startup) {
|
|
now = jiffies;
|
|
if (time_before(now, data->ready_timestamp) &&
|
|
msleep_interruptible(jiffies_to_msecs(
|
|
data->ready_timestamp - now)) != 0) {
|
|
pm_runtime_put_autosuspend(&data->client->dev);
|
|
return -EINTR;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mlx90614_power_put(struct mlx90614_data *data)
|
|
{
|
|
if (!data->wakeup_gpio)
|
|
return;
|
|
|
|
pm_runtime_mark_last_busy(&data->client->dev);
|
|
pm_runtime_put_autosuspend(&data->client->dev);
|
|
}
|
|
#else
|
|
static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void mlx90614_power_put(struct mlx90614_data *data)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int mlx90614_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *channel, int *val,
|
|
int *val2, long mask)
|
|
{
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
u8 cmd;
|
|
s32 ret;
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
|
|
switch (channel->channel2) {
|
|
case IIO_MOD_TEMP_AMBIENT:
|
|
cmd = MLX90614_TA;
|
|
break;
|
|
case IIO_MOD_TEMP_OBJECT:
|
|
switch (channel->channel) {
|
|
case 0:
|
|
cmd = MLX90614_TOBJ1;
|
|
break;
|
|
case 1:
|
|
cmd = MLX90614_TOBJ2;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = mlx90614_power_get(data, true);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = i2c_smbus_read_word_data(data->client, cmd);
|
|
mlx90614_power_put(data);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* MSB is an error flag */
|
|
if (ret & 0x8000)
|
|
return -EIO;
|
|
|
|
*val = ret;
|
|
return IIO_VAL_INT;
|
|
case IIO_CHAN_INFO_OFFSET:
|
|
*val = -13657;
|
|
*val2 = 500000;
|
|
return IIO_VAL_INT_PLUS_MICRO;
|
|
case IIO_CHAN_INFO_SCALE:
|
|
*val = 20;
|
|
return IIO_VAL_INT;
|
|
case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
|
|
mlx90614_power_get(data, false);
|
|
mutex_lock(&data->lock);
|
|
ret = i2c_smbus_read_word_data(data->client,
|
|
MLX90614_EMISSIVITY);
|
|
mutex_unlock(&data->lock);
|
|
mlx90614_power_put(data);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ret == 65535) {
|
|
*val = 1;
|
|
*val2 = 0;
|
|
} else {
|
|
*val = 0;
|
|
*val2 = ret * 15259; /* 1/65535 ~ 0.000015259 */
|
|
}
|
|
return IIO_VAL_INT_PLUS_NANO;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int mlx90614_write_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *channel, int val,
|
|
int val2, long mask)
|
|
{
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
s32 ret;
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
|
|
if (val < 0 || val2 < 0 || val > 1 || (val == 1 && val2 != 0))
|
|
return -EINVAL;
|
|
val = val * 65535 + val2 / 15259; /* 1/65535 ~ 0.000015259 */
|
|
|
|
mlx90614_power_get(data, false);
|
|
mutex_lock(&data->lock);
|
|
ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
|
|
val);
|
|
mutex_unlock(&data->lock);
|
|
mlx90614_power_put(data);
|
|
|
|
return ret;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *channel,
|
|
long mask)
|
|
{
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_CALIBEMISSIVITY:
|
|
return IIO_VAL_INT_PLUS_NANO;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static const struct iio_chan_spec mlx90614_channels[] = {
|
|
{
|
|
.type = IIO_TEMP,
|
|
.modified = 1,
|
|
.channel2 = IIO_MOD_TEMP_AMBIENT,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
|
|
BIT(IIO_CHAN_INFO_SCALE),
|
|
},
|
|
{
|
|
.type = IIO_TEMP,
|
|
.modified = 1,
|
|
.channel2 = IIO_MOD_TEMP_OBJECT,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
|
BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
|
|
BIT(IIO_CHAN_INFO_SCALE),
|
|
},
|
|
{
|
|
.type = IIO_TEMP,
|
|
.indexed = 1,
|
|
.modified = 1,
|
|
.channel = 1,
|
|
.channel2 = IIO_MOD_TEMP_OBJECT,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
|
BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
|
|
BIT(IIO_CHAN_INFO_SCALE),
|
|
},
|
|
};
|
|
|
|
static const struct iio_info mlx90614_info = {
|
|
.read_raw = mlx90614_read_raw,
|
|
.write_raw = mlx90614_write_raw,
|
|
.write_raw_get_fmt = mlx90614_write_raw_get_fmt,
|
|
.driver_module = THIS_MODULE,
|
|
};
|
|
|
|
#ifdef CONFIG_PM
|
|
static int mlx90614_sleep(struct mlx90614_data *data)
|
|
{
|
|
s32 ret;
|
|
|
|
if (!data->wakeup_gpio) {
|
|
dev_dbg(&data->client->dev, "Sleep disabled");
|
|
return -ENOSYS;
|
|
}
|
|
|
|
dev_dbg(&data->client->dev, "Requesting sleep");
|
|
|
|
mutex_lock(&data->lock);
|
|
ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
|
|
data->client->flags | I2C_CLIENT_PEC,
|
|
I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
|
|
I2C_SMBUS_BYTE, NULL);
|
|
mutex_unlock(&data->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mlx90614_wakeup(struct mlx90614_data *data)
|
|
{
|
|
if (!data->wakeup_gpio) {
|
|
dev_dbg(&data->client->dev, "Wake-up disabled");
|
|
return -ENOSYS;
|
|
}
|
|
|
|
dev_dbg(&data->client->dev, "Requesting wake-up");
|
|
|
|
i2c_lock_adapter(data->client->adapter);
|
|
gpiod_direction_output(data->wakeup_gpio, 0);
|
|
msleep(MLX90614_TIMING_WAKEUP);
|
|
gpiod_direction_input(data->wakeup_gpio);
|
|
i2c_unlock_adapter(data->client->adapter);
|
|
|
|
data->ready_timestamp = jiffies +
|
|
msecs_to_jiffies(MLX90614_TIMING_STARTUP);
|
|
|
|
/*
|
|
* Quirk: the i2c controller may get confused right after the
|
|
* wake-up signal has been sent. As a workaround, do a dummy read.
|
|
* If the read fails, the controller will probably be reset so that
|
|
* further reads will work.
|
|
*/
|
|
i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
|
|
static struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
|
|
{
|
|
struct gpio_desc *gpio;
|
|
|
|
if (!i2c_check_functionality(client->adapter,
|
|
I2C_FUNC_SMBUS_WRITE_BYTE)) {
|
|
dev_info(&client->dev,
|
|
"i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
|
|
return NULL;
|
|
}
|
|
|
|
gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
|
|
|
|
if (IS_ERR(gpio)) {
|
|
dev_warn(&client->dev,
|
|
"gpio acquisition failed with error %ld, sleep disabled",
|
|
PTR_ERR(gpio));
|
|
return NULL;
|
|
} else if (!gpio) {
|
|
dev_info(&client->dev,
|
|
"wakeup-gpio not found, sleep disabled");
|
|
}
|
|
|
|
return gpio;
|
|
}
|
|
#else
|
|
static inline int mlx90614_sleep(struct mlx90614_data *data)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
static inline int mlx90614_wakeup(struct mlx90614_data *data)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
static inline struct gpio_desc *mlx90614_probe_wakeup(struct i2c_client *client)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
/* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
|
|
static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
|
|
{
|
|
s32 ret;
|
|
|
|
ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
|
|
}
|
|
|
|
static int mlx90614_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct mlx90614_data *data;
|
|
int ret;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
|
|
return -ENODEV;
|
|
|
|
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
data = iio_priv(indio_dev);
|
|
i2c_set_clientdata(client, indio_dev);
|
|
data->client = client;
|
|
mutex_init(&data->lock);
|
|
data->wakeup_gpio = mlx90614_probe_wakeup(client);
|
|
|
|
mlx90614_wakeup(data);
|
|
|
|
indio_dev->dev.parent = &client->dev;
|
|
indio_dev->name = id->name;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->info = &mlx90614_info;
|
|
|
|
ret = mlx90614_probe_num_ir_sensors(client);
|
|
switch (ret) {
|
|
case 0:
|
|
dev_dbg(&client->dev, "Found single sensor");
|
|
indio_dev->channels = mlx90614_channels;
|
|
indio_dev->num_channels = 2;
|
|
break;
|
|
case 1:
|
|
dev_dbg(&client->dev, "Found dual sensor");
|
|
indio_dev->channels = mlx90614_channels;
|
|
indio_dev->num_channels = 3;
|
|
break;
|
|
default:
|
|
return ret;
|
|
}
|
|
|
|
if (data->wakeup_gpio) {
|
|
pm_runtime_set_autosuspend_delay(&client->dev,
|
|
MLX90614_AUTOSLEEP_DELAY);
|
|
pm_runtime_use_autosuspend(&client->dev);
|
|
pm_runtime_set_active(&client->dev);
|
|
pm_runtime_enable(&client->dev);
|
|
}
|
|
|
|
return iio_device_register(indio_dev);
|
|
}
|
|
|
|
static int mlx90614_remove(struct i2c_client *client)
|
|
{
|
|
struct iio_dev *indio_dev = i2c_get_clientdata(client);
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
|
|
if (data->wakeup_gpio) {
|
|
pm_runtime_disable(&client->dev);
|
|
if (!pm_runtime_status_suspended(&client->dev))
|
|
mlx90614_sleep(data);
|
|
pm_runtime_set_suspended(&client->dev);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id mlx90614_id[] = {
|
|
{ "mlx90614", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, mlx90614_id);
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int mlx90614_pm_suspend(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
|
|
if (data->wakeup_gpio && pm_runtime_active(dev))
|
|
return mlx90614_sleep(data);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mlx90614_pm_resume(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
int err;
|
|
|
|
if (data->wakeup_gpio) {
|
|
err = mlx90614_wakeup(data);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
pm_runtime_disable(dev);
|
|
pm_runtime_set_active(dev);
|
|
pm_runtime_enable(dev);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_PM
|
|
static int mlx90614_pm_runtime_suspend(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
|
|
return mlx90614_sleep(data);
|
|
}
|
|
|
|
static int mlx90614_pm_runtime_resume(struct device *dev)
|
|
{
|
|
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
|
|
struct mlx90614_data *data = iio_priv(indio_dev);
|
|
|
|
return mlx90614_wakeup(data);
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops mlx90614_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
|
|
SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
|
|
mlx90614_pm_runtime_resume, NULL)
|
|
};
|
|
|
|
static struct i2c_driver mlx90614_driver = {
|
|
.driver = {
|
|
.name = "mlx90614",
|
|
.owner = THIS_MODULE,
|
|
.pm = &mlx90614_pm_ops,
|
|
},
|
|
.probe = mlx90614_probe,
|
|
.remove = mlx90614_remove,
|
|
.id_table = mlx90614_id,
|
|
};
|
|
module_i2c_driver(mlx90614_driver);
|
|
|
|
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
|
|
MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
|
|
MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
|
|
MODULE_LICENSE("GPL");
|