[deliverable/linux.git] / drivers / iio / temperature / mlx90614.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");
Commit	Line	Data
474fe212 PM	1	/*
	2	* mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
	3	*
	4	* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
bad4d1a0	5	* Copyright (c) 2015 Essensium NV
474fe212 PM	6	*
	7	* This file is subject to the terms and conditions of version 2 of
	8	* the GNU General Public License. See the file COPYING in the main
	9	* directory of this archive for more details.
	10	*
	11	* Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
	12	*
	13	* (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
	14	*
eb4b07da VCSM	15	* To wake up from sleep mode, the SDA line must be held low while SCL is high
	16	* for at least 33ms. This is achieved with an extra GPIO that can be connected
	17	* directly to the SDA line. In normal operation, the GPIO is set as input and
	18	* will not interfere in I2C communication. While the GPIO is driven low, the
	19	* i2c adapter is locked since it cannot be used by other clients. The SCL line
	20	* always has a pull-up so we do not need an extra GPIO to drive it high. If
	21	* the "wakeup" GPIO is not given, power management will be disabled.
	22	*
	23	* TODO: filter configuration
474fe212 PM	24	*/
	25
	26	#include <linux/err.h>
	27	#include <linux/i2c.h>
	28	#include <linux/module.h>
fad65a8f	29	#include <linux/delay.h>
eb4b07da VCSM	30	#include <linux/jiffies.h>
	31	#include <linux/gpio/consumer.h>
	32	#include <linux/pm_runtime.h>
474fe212 PM	33
	34	#include <linux/iio/iio.h>
	35
209c0069 VCSM	36	#define MLX90614_OP_RAM 0x00
	37	#define MLX90614_OP_EEPROM 0x20
	38	#define MLX90614_OP_SLEEP 0xff
474fe212 PM	39
474fe212 PM	40	/* RAM offsets with 16-bit data, MSB first */
209c0069 VCSM	41	#define MLX90614_RAW1 (MLX90614_OP_RAM \| 0x04) /* raw data IR channel 1 */
209c0069 VCSM	42	#define MLX90614_RAW2 (MLX90614_OP_RAM \| 0x05) /* raw data IR channel 2 */
c7586584 VCSM	43	#define MLX90614_TA (MLX90614_OP_RAM \| 0x06) /* ambient temperature */
c7586584 VCSM	44	#define MLX90614_TOBJ1 (MLX90614_OP_RAM \| 0x07) /* object 1 temperature */
209c0069 VCSM	45	#define MLX90614_TOBJ2 (MLX90614_OP_RAM \| 0x08) /* object 2 temperature */
	46
	47	/* EEPROM offsets with 16-bit data, MSB first */
	48	#define MLX90614_EMISSIVITY (MLX90614_OP_EEPROM \| 0x04) /* emissivity correction coefficient */
	49	#define MLX90614_CONFIG (MLX90614_OP_EEPROM \| 0x05) /* configuration register */
	50
	51	/* Control bits in configuration register */
	52	#define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
	53	#define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
	54	#define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
	55	#define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
	56	#define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
	57	#define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
	58	#define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
	59	#define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
	60
	61	/* Timings (in ms) */
	62	#define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
	63	#define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
	64	#define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
474fe212	65
eb4b07da VCSM	66	#define MLX90614_AUTOSLEEP_DELAY 5000 /* default autosleep delay */
eb4b07da VCSM	67
474fe212 PM	68	struct mlx90614_data {
474fe212 PM	69	struct i2c_client *client;
fad65a8f	70	struct mutex lock; /* for EEPROM access only */
eb4b07da VCSM	71	struct gpio_desc wakeup_gpio; / NULL to disable sleep/wake-up */
eb4b07da VCSM	72	unsigned long ready_timestamp; /* in jiffies */
474fe212 PM	73	};
474fe212 PM	74
fad65a8f VCSM	75	/*
	76	* Erase an address and write word.
	77	* The mutex must be locked before calling.
	78	*/
	79	static s32 mlx90614_write_word(const struct i2c_client *client, u8 command,
	80	u16 value)
	81	{
	82	/*
	83	* Note: The mlx90614 requires a PEC on writing but does not send us a
	84	* valid PEC on reading. Hence, we cannot set I2C_CLIENT_PEC in
	85	* i2c_client.flags. As a workaround, we use i2c_smbus_xfer here.
	86	*/
	87	union i2c_smbus_data data;
	88	s32 ret;
	89
	90	dev_dbg(&client->dev, "Writing 0x%x to address 0x%x", value, command);
	91
	92	data.word = 0x0000; /* erase command */
	93	ret = i2c_smbus_xfer(client->adapter, client->addr,
	94	client->flags \| I2C_CLIENT_PEC,
	95	I2C_SMBUS_WRITE, command,
	96	I2C_SMBUS_WORD_DATA, &data);
	97	if (ret < 0)
	98	return ret;
	99
	100	msleep(MLX90614_TIMING_EEPROM);
	101
	102	data.word = value; /* actual write */
	103	ret = i2c_smbus_xfer(client->adapter, client->addr,
	104	client->flags \| I2C_CLIENT_PEC,
	105	I2C_SMBUS_WRITE, command,
	106	I2C_SMBUS_WORD_DATA, &data);
	107
	108	msleep(MLX90614_TIMING_EEPROM);
	109
	110	return ret;
	111	}
	112
eb4b07da VCSM	113	#ifdef CONFIG_PM
	114	/*
	115	* If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since
	116	* the last wake-up. This is normally only needed to get a valid temperature
	117	* reading. EEPROM access does not need such delay.
	118	* Return 0 on success, <0 on error.
	119	*/
	120	static int mlx90614_power_get(struct mlx90614_data *data, bool startup)
	121	{
	122	unsigned long now;
	123
	124	if (!data->wakeup_gpio)
	125	return 0;
	126
	127	pm_runtime_get_sync(&data->client->dev);
	128
	129	if (startup) {
	130	now = jiffies;
	131	if (time_before(now, data->ready_timestamp) &&
	132	msleep_interruptible(jiffies_to_msecs(
	133	data->ready_timestamp - now)) != 0) {
	134	pm_runtime_put_autosuspend(&data->client->dev);
	135	return -EINTR;
	136	}
	137	}
	138
	139	return 0;
	140	}
	141
	142	static void mlx90614_power_put(struct mlx90614_data *data)
	143	{
	144	if (!data->wakeup_gpio)
	145	return;
	146
	147	pm_runtime_mark_last_busy(&data->client->dev);
	148	pm_runtime_put_autosuspend(&data->client->dev);
	149	}
	150	#else
	151	static inline int mlx90614_power_get(struct mlx90614_data *data, bool startup)
	152	{
	153	return 0;
	154	}
	155
	156	static inline void mlx90614_power_put(struct mlx90614_data *data)
	157	{
	158	}
	159	#endif
	160
474fe212 PM	161	static int mlx90614_read_raw(struct iio_dev *indio_dev,
	162	struct iio_chan_spec const channel, int val,
	163	int *val2, long mask)
	164	{
	165	struct mlx90614_data *data = iio_priv(indio_dev);
bad4d1a0	166	u8 cmd;
474fe212 PM	167	s32 ret;
	168
	169	switch (mask) {
	170	case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
	171	switch (channel->channel2) {
	172	case IIO_MOD_TEMP_AMBIENT:
bad4d1a0	173	cmd = MLX90614_TA;
474fe212 PM	174	break;
474fe212 PM	175	case IIO_MOD_TEMP_OBJECT:
bad4d1a0 VCSM	176	switch (channel->channel) {
	177	case 0:
	178	cmd = MLX90614_TOBJ1;
	179	break;
	180	case 1:
	181	cmd = MLX90614_TOBJ2;
	182	break;
	183	default:
	184	return -EINVAL;
	185	}
474fe212 PM	186	break;
	187	default:
	188	return -EINVAL;
	189	}
bad4d1a0	190
eb4b07da VCSM	191	ret = mlx90614_power_get(data, true);
	192	if (ret < 0)
	193	return ret;
bad4d1a0	194	ret = i2c_smbus_read_word_data(data->client, cmd);
eb4b07da VCSM	195	mlx90614_power_put(data);
eb4b07da VCSM	196
bad4d1a0 VCSM	197	if (ret < 0)
bad4d1a0 VCSM	198	return ret;
d02e0f8f VCSM	199
	200	/* MSB is an error flag */
	201	if (ret & 0x8000)
	202	return -EIO;
	203
474fe212 PM	204	*val = ret;
	205	return IIO_VAL_INT;
	206	case IIO_CHAN_INFO_OFFSET:
c68a67b7	207	*val = -13657;
474fe212 PM	208	*val2 = 500000;
	209	return IIO_VAL_INT_PLUS_MICRO;
	210	case IIO_CHAN_INFO_SCALE:
	211	*val = 20;
	212	return IIO_VAL_INT;
fad65a8f	213	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
eb4b07da	214	mlx90614_power_get(data, false);
fad65a8f VCSM	215	mutex_lock(&data->lock);
	216	ret = i2c_smbus_read_word_data(data->client,
	217	MLX90614_EMISSIVITY);
	218	mutex_unlock(&data->lock);
eb4b07da	219	mlx90614_power_put(data);
fad65a8f VCSM	220
	221	if (ret < 0)
	222	return ret;
	223
	224	if (ret == 65535) {
	225	*val = 1;
	226	*val2 = 0;
	227	} else {
	228	*val = 0;
	229	val2 = ret 15259; /* 1/65535 ~ 0.000015259 */
	230	}
	231	return IIO_VAL_INT_PLUS_NANO;
	232	default:
	233	return -EINVAL;
	234	}
	235	}
	236
	237	static int mlx90614_write_raw(struct iio_dev *indio_dev,
	238	struct iio_chan_spec const *channel, int val,
	239	int val2, long mask)
	240	{
	241	struct mlx90614_data *data = iio_priv(indio_dev);
	242	s32 ret;
	243
	244	switch (mask) {
	245	case IIO_CHAN_INFO_CALIBEMISSIVITY: /* 1/65535 / LSB */
	246	if (val < 0 \|\| val2 < 0 \|\| val > 1 \|\| (val == 1 && val2 != 0))
	247	return -EINVAL;
	248	val = val * 65535 + val2 / 15259; /* 1/65535 ~ 0.000015259 */
	249
eb4b07da	250	mlx90614_power_get(data, false);
fad65a8f VCSM	251	mutex_lock(&data->lock);
	252	ret = mlx90614_write_word(data->client, MLX90614_EMISSIVITY,
	253	val);
	254	mutex_unlock(&data->lock);
eb4b07da	255	mlx90614_power_put(data);
fad65a8f	256
f2c714a0	257	return ret;
fad65a8f VCSM	258	default:
	259	return -EINVAL;
	260	}
	261	}
	262
	263	static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev,
6069f47f	264	struct iio_chan_spec const *channel,
fad65a8f VCSM	265	long mask)
	266	{
	267	switch (mask) {
	268	case IIO_CHAN_INFO_CALIBEMISSIVITY:
	269	return IIO_VAL_INT_PLUS_NANO;
474fe212 PM	270	default:
	271	return -EINVAL;
	272	}
	273	}
	274
	275	static const struct iio_chan_spec mlx90614_channels[] = {
	276	{
	277	.type = IIO_TEMP,
	278	.modified = 1,
	279	.channel2 = IIO_MOD_TEMP_AMBIENT,
	280	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	281	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	282	BIT(IIO_CHAN_INFO_SCALE),
	283	},
	284	{
	285	.type = IIO_TEMP,
	286	.modified = 1,
	287	.channel2 = IIO_MOD_TEMP_OBJECT,
fad65a8f VCSM	288	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
fad65a8f VCSM	289	BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
474fe212 PM	290	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	291	BIT(IIO_CHAN_INFO_SCALE),
	292	},
bad4d1a0 VCSM	293	{
	294	.type = IIO_TEMP,
	295	.indexed = 1,
	296	.modified = 1,
	297	.channel = 1,
	298	.channel2 = IIO_MOD_TEMP_OBJECT,
fad65a8f VCSM	299	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
fad65a8f VCSM	300	BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
bad4d1a0 VCSM	301	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) \|
	302	BIT(IIO_CHAN_INFO_SCALE),
	303	},
474fe212 PM	304	};
	305
	306	static const struct iio_info mlx90614_info = {
	307	.read_raw = mlx90614_read_raw,
fad65a8f VCSM	308	.write_raw = mlx90614_write_raw,
fad65a8f VCSM	309	.write_raw_get_fmt = mlx90614_write_raw_get_fmt,
474fe212 PM	310	.driver_module = THIS_MODULE,
	311	};
	312
eb4b07da VCSM	313	#ifdef CONFIG_PM
	314	static int mlx90614_sleep(struct mlx90614_data *data)
	315	{
	316	s32 ret;
	317
	318	if (!data->wakeup_gpio) {
	319	dev_dbg(&data->client->dev, "Sleep disabled");
	320	return -ENOSYS;
	321	}
	322
	323	dev_dbg(&data->client->dev, "Requesting sleep");
	324
	325	mutex_lock(&data->lock);
	326	ret = i2c_smbus_xfer(data->client->adapter, data->client->addr,
	327	data->client->flags \| I2C_CLIENT_PEC,
	328	I2C_SMBUS_WRITE, MLX90614_OP_SLEEP,
	329	I2C_SMBUS_BYTE, NULL);
	330	mutex_unlock(&data->lock);
	331
	332	return ret;
	333	}
	334
	335	static int mlx90614_wakeup(struct mlx90614_data *data)
	336	{
	337	if (!data->wakeup_gpio) {
	338	dev_dbg(&data->client->dev, "Wake-up disabled");
	339	return -ENOSYS;
	340	}
	341
	342	dev_dbg(&data->client->dev, "Requesting wake-up");
	343
	344	i2c_lock_adapter(data->client->adapter);
	345	gpiod_direction_output(data->wakeup_gpio, 0);
	346	msleep(MLX90614_TIMING_WAKEUP);
	347	gpiod_direction_input(data->wakeup_gpio);
	348	i2c_unlock_adapter(data->client->adapter);
	349
	350	data->ready_timestamp = jiffies +
	351	msecs_to_jiffies(MLX90614_TIMING_STARTUP);
	352
	353	/*
	354	* Quirk: the i2c controller may get confused right after the
	355	* wake-up signal has been sent. As a workaround, do a dummy read.
	356	* If the read fails, the controller will probably be reset so that
	357	* further reads will work.
	358	*/
	359	i2c_smbus_read_word_data(data->client, MLX90614_CONFIG);
	360
	361	return 0;
	362	}
	363
	364	/* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
	365	static struct gpio_desc mlx90614_probe_wakeup(struct i2c_client client)
	366	{
	367	struct gpio_desc *gpio;
	368
	369	if (!i2c_check_functionality(client->adapter,
	370	I2C_FUNC_SMBUS_WRITE_BYTE)) {
	371	dev_info(&client->dev,
	372	"i2c adapter does not support SMBUS_WRITE_BYTE, sleep disabled");
	373	return NULL;
	374	}
	375
	376	gpio = devm_gpiod_get_optional(&client->dev, "wakeup", GPIOD_IN);
377
378	if (IS_ERR(gpio)) {
379	dev_warn(&client->dev,
380	"gpio acquisition failed with error %ld, sleep disabled",
381	PTR_ERR(gpio));
382	return NULL;
383	} else if (!gpio) {
384	dev_info(&client->dev,
385	"wakeup-gpio not found, sleep disabled");
386	}
387
388	return gpio;
389	}
390	#else
391	static inline int mlx90614_sleep(struct mlx90614_data *data)
392	{
393	return -ENOSYS;
394	}
395	static inline int mlx90614_wakeup(struct mlx90614_data *data)
396	{
397	return -ENOSYS;
398	}
399	static inline struct gpio_desc mlx90614_probe_wakeup(struct i2c_client client)
400	{
401	return NULL;
402	}
403	#endif
404
bad4d1a0 VCSM	405	/* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
	406	static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
	407	{
	408	s32 ret;
	409
	410	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
	411
	412	if (ret < 0)
	413	return ret;
	414
	415	return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
	416	}
	417
474fe212 PM	418	static int mlx90614_probe(struct i2c_client *client,
	419	const struct i2c_device_id *id)
	420	{
	421	struct iio_dev *indio_dev;
	422	struct mlx90614_data *data;
bad4d1a0	423	int ret;
474fe212 PM	424
	425	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
	426	return -ENODEV;
	427
	428	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	429	if (!indio_dev)
	430	return -ENOMEM;
	431
	432	data = iio_priv(indio_dev);
	433	i2c_set_clientdata(client, indio_dev);
	434	data->client = client;
fad65a8f	435	mutex_init(&data->lock);
eb4b07da VCSM	436	data->wakeup_gpio = mlx90614_probe_wakeup(client);
	437
	438	mlx90614_wakeup(data);
474fe212 PM	439
	440	indio_dev->dev.parent = &client->dev;
	441	indio_dev->name = id->name;
	442	indio_dev->modes = INDIO_DIRECT_MODE;
	443	indio_dev->info = &mlx90614_info;
	444
bad4d1a0 VCSM	445	ret = mlx90614_probe_num_ir_sensors(client);
	446	switch (ret) {
	447	case 0:
	448	dev_dbg(&client->dev, "Found single sensor");
	449	indio_dev->channels = mlx90614_channels;
	450	indio_dev->num_channels = 2;
	451	break;
	452	case 1:
	453	dev_dbg(&client->dev, "Found dual sensor");
	454	indio_dev->channels = mlx90614_channels;
	455	indio_dev->num_channels = 3;
	456	break;
	457	default:
	458	return ret;
	459	}
474fe212	460
eb4b07da VCSM	461	if (data->wakeup_gpio) {
	462	pm_runtime_set_autosuspend_delay(&client->dev,
	463	MLX90614_AUTOSLEEP_DELAY);
	464	pm_runtime_use_autosuspend(&client->dev);
	465	pm_runtime_set_active(&client->dev);
	466	pm_runtime_enable(&client->dev);
	467	}
	468
474fe212 PM	469	return iio_device_register(indio_dev);
	470	}
	471
	472	static int mlx90614_remove(struct i2c_client *client)
	473	{
eb4b07da VCSM	474	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	475	struct mlx90614_data *data = iio_priv(indio_dev);
	476
	477	iio_device_unregister(indio_dev);
	478
	479	if (data->wakeup_gpio) {
	480	pm_runtime_disable(&client->dev);
	481	if (!pm_runtime_status_suspended(&client->dev))
	482	mlx90614_sleep(data);
	483	pm_runtime_set_suspended(&client->dev);
	484	}
474fe212 PM	485
	486	return 0;
	487	}
	488
	489	static const struct i2c_device_id mlx90614_id[] = {
	490	{ "mlx90614", 0 },
	491	{ }
	492	};
	493	MODULE_DEVICE_TABLE(i2c, mlx90614_id);
	494
eb4b07da VCSM	495	#ifdef CONFIG_PM_SLEEP
	496	static int mlx90614_pm_suspend(struct device *dev)
	497	{
	498	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	499	struct mlx90614_data *data = iio_priv(indio_dev);
	500
	501	if (data->wakeup_gpio && pm_runtime_active(dev))
	502	return mlx90614_sleep(data);
	503
	504	return 0;
	505	}
	506
	507	static int mlx90614_pm_resume(struct device *dev)
	508	{
	509	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	510	struct mlx90614_data *data = iio_priv(indio_dev);
	511	int err;
	512
	513	if (data->wakeup_gpio) {
	514	err = mlx90614_wakeup(data);
	515	if (err < 0)
	516	return err;
	517
	518	pm_runtime_disable(dev);
	519	pm_runtime_set_active(dev);
	520	pm_runtime_enable(dev);
	521	}
	522
	523	return 0;
	524	}
	525	#endif
	526
	527	#ifdef CONFIG_PM
	528	static int mlx90614_pm_runtime_suspend(struct device *dev)
	529	{
	530	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	531	struct mlx90614_data *data = iio_priv(indio_dev);
	532
	533	return mlx90614_sleep(data);
	534	}
	535
	536	static int mlx90614_pm_runtime_resume(struct device *dev)
	537	{
	538	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	539	struct mlx90614_data *data = iio_priv(indio_dev);
	540
	541	return mlx90614_wakeup(data);
	542	}
	543	#endif
	544
	545	static const struct dev_pm_ops mlx90614_pm_ops = {
	546	SET_SYSTEM_SLEEP_PM_OPS(mlx90614_pm_suspend, mlx90614_pm_resume)
	547	SET_RUNTIME_PM_OPS(mlx90614_pm_runtime_suspend,
	548	mlx90614_pm_runtime_resume, NULL)
	549	};
	550
474fe212 PM	551	static struct i2c_driver mlx90614_driver = {
	552	.driver = {
	553	.name = "mlx90614",
	554	.owner = THIS_MODULE,
eb4b07da	555	.pm = &mlx90614_pm_ops,
474fe212 PM	556	},
	557	.probe = mlx90614_probe,
	558	.remove = mlx90614_remove,
	559	.id_table = mlx90614_id,
	560	};
	561	module_i2c_driver(mlx90614_driver);
	562
	563	MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
bad4d1a0	564	MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
474fe212 PM	565	MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
474fe212 PM	566	MODULE_LICENSE("GPL");