text: /*
   * tmp007.c - Support for TI TMP007 IR thermopile sensor with integrated math engine
   *
   * Copyright (c) 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
   *
   * 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 Texas Instruments I2C 16-bit IR thermopile sensor
   *
   * (7-bit I2C slave address (0x40 - 0x47), changeable via ADR pins)
   *
   * Note:
   * 1. This driver assumes that the sensor has been calibrated beforehand
   * 2. Limit threshold events are enabled at the start
   * 3. Operating mode: INT
   *
   */
  
  #include <linux/err.h>
  #include <linux/i2c.h>
  #include <linux/delay.h>
  #include <linux/module.h>
  #include <linux/pm.h>
  #include <linux/bitops.h>
  #include <linux/of.h>
  #include <linux/irq.h>
  #include <linux/interrupt.h>
  
  #include <linux/iio/iio.h>
  #include <linux/iio/sysfs.h>
  #include <linux/iio/events.h>
  
  #define TMP007_TDIE 0x01
  #define TMP007_CONFIG 0x02
  #define TMP007_TOBJECT 0x03
  #define TMP007_STATUS 0x04
  #define TMP007_STATUS_MASK 0x05
  #define TMP007_TOBJ_HIGH_LIMIT 0x06
  #define TMP007_TOBJ_LOW_LIMIT 0x07
  #define TMP007_TDIE_HIGH_LIMIT 0x08
  #define TMP007_TDIE_LOW_LIMIT 0x09
  #define TMP007_MANUFACTURER_ID 0x1e
  #define TMP007_DEVICE_ID 0x1f
  
  #define TMP007_CONFIG_CONV_EN BIT(12)
  #define TMP007_CONFIG_TC_EN BIT(6)
  #define TMP007_CONFIG_CR_MASK GENMASK(11, 9)
  #define TMP007_CONFIG_ALERT_EN BIT(8)
  #define TMP007_CONFIG_CR_SHIFT 9
  
  /* Status register flags */
  #define TMP007_STATUS_ALERT BIT(15)
  #define TMP007_STATUS_CONV_READY BIT(14)
  #define TMP007_STATUS_OHF BIT(13)
  #define TMP007_STATUS_OLF BIT(12)
  #define TMP007_STATUS_LHF BIT(11)
  #define TMP007_STATUS_LLF BIT(10)
  #define TMP007_STATUS_DATA_VALID BIT(9)
  
  #define TMP007_MANUFACTURER_MAGIC 0x5449
  #define TMP007_DEVICE_MAGIC 0x0078
  
  #define TMP007_TEMP_SHIFT 2
  
  struct tmp007_data {
  	struct i2c_client *client;
  	struct mutex lock;
  	u16 config;
  	u16 status_mask;
  };
  
  static const int tmp007_avgs[5][2] = { {4, 0}, {2, 0}, {1, 0},
  					{0, 500000}, {0, 250000} };
  
  static int tmp007_read_temperature(struct tmp007_data *data, u8 reg)
  {
  	s32 ret;
  	int tries = 50;
  
  	while (tries-- > 0) {
  		ret = i2c_smbus_read_word_swapped(data->client,
  			TMP007_STATUS);
  		if (ret < 0)
  			return ret;
  		if ((ret & TMP007_STATUS_CONV_READY) &&
  			!(ret & TMP007_STATUS_DATA_VALID))
  				break;
  		msleep(100);
  	}
  
  	if (tries < 0)
  		return -EIO;
  
  	return i2c_smbus_read_word_swapped(data->client, reg);
  }
  
  static int tmp007_powerdown(struct tmp007_data *data)
  {
  	return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
  			data->config & ~TMP007_CONFIG_CONV_EN);
  }
  
  static int tmp007_read_raw(struct iio_dev *indio_dev,
  		struct iio_chan_spec const *channel, int *val,
  		int *val2, long mask)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	s32 ret;
  	int conv_rate;
  
  	switch (mask) {
  	case IIO_CHAN_INFO_RAW:
  		switch (channel->channel2) {
  		case IIO_MOD_TEMP_AMBIENT: /* LSB: 0.03125 degree Celsius */
  			ret = i2c_smbus_read_word_swapped(data->client, TMP007_TDIE);
  			if (ret < 0)
  				return ret;
  			break;
  		case IIO_MOD_TEMP_OBJECT:
  			ret = tmp007_read_temperature(data, TMP007_TOBJECT);
  			if (ret < 0)
  				return ret;
  			break;
  		default:
  			return -EINVAL;
  		}
  
  		*val = sign_extend32(ret, 15) >> TMP007_TEMP_SHIFT;
  
  		return IIO_VAL_INT;
  	case IIO_CHAN_INFO_SCALE:
  		*val = 31;
  		*val2 = 250000;
  
  		return IIO_VAL_INT_PLUS_MICRO;
  	case IIO_CHAN_INFO_SAMP_FREQ:
  		conv_rate = (data->config & TMP007_CONFIG_CR_MASK)
  				>> TMP007_CONFIG_CR_SHIFT;
  		*val = tmp007_avgs[conv_rate][0];
  		*val2 = tmp007_avgs[conv_rate][1];
  
  		return IIO_VAL_INT_PLUS_MICRO;
  	default:
  		return -EINVAL;
  	}
  }
  
  static int tmp007_write_raw(struct iio_dev *indio_dev,
  		struct iio_chan_spec const *channel, int val,
  		int val2, long mask)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	int i;
  	u16 tmp;
  
  	if (mask == IIO_CHAN_INFO_SAMP_FREQ) {
  		for (i = 0; i < ARRAY_SIZE(tmp007_avgs); i++) {
  			if ((val == tmp007_avgs[i][0]) &&
  			(val2 == tmp007_avgs[i][1])) {
  				tmp = data->config & ~TMP007_CONFIG_CR_MASK;
  				tmp |= (i << TMP007_CONFIG_CR_SHIFT);
  
  				return i2c_smbus_write_word_swapped(data->client,
  								TMP007_CONFIG,
  								data->config = tmp);
  			}
  		}
  	}
  
  	return -EINVAL;
  }
  
  static irqreturn_t tmp007_interrupt_handler(int irq, void *private)
  {
  	struct iio_dev *indio_dev = private;
  	struct tmp007_data *data = iio_priv(indio_dev);
  	int ret;
  
  	ret = i2c_smbus_read_word_swapped(data->client, TMP007_STATUS);
  	if ((ret < 0) || !(ret & (TMP007_STATUS_OHF | TMP007_STATUS_OLF |
  				TMP007_STATUS_LHF | TMP007_STATUS_LLF)))
  		return IRQ_NONE;
  
  	if (ret & TMP007_STATUS_OHF)
  		iio_push_event(indio_dev,
  				IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
  					IIO_MOD_TEMP_OBJECT,
  					IIO_EV_TYPE_THRESH,
  					IIO_EV_DIR_RISING),
  				iio_get_time_ns(indio_dev));
  
  	if (ret & TMP007_STATUS_OLF)
  		iio_push_event(indio_dev,
  				IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
  					IIO_MOD_TEMP_OBJECT,
  					IIO_EV_TYPE_THRESH,
  					IIO_EV_DIR_FALLING),
  				iio_get_time_ns(indio_dev));
  
  	if (ret & TMP007_STATUS_LHF)
  		iio_push_event(indio_dev,
  				IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
  					IIO_MOD_TEMP_AMBIENT,
  					IIO_EV_TYPE_THRESH,
  					IIO_EV_DIR_RISING),
  				iio_get_time_ns(indio_dev));
  
  	if (ret & TMP007_STATUS_LLF)
  		iio_push_event(indio_dev,
  				IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
  					IIO_MOD_TEMP_AMBIENT,
  					IIO_EV_TYPE_THRESH,
  					IIO_EV_DIR_FALLING),
  				iio_get_time_ns(indio_dev));
  
  	return IRQ_HANDLED;
  }
  
  static int tmp007_write_event_config(struct iio_dev *indio_dev,
  		const struct iio_chan_spec *chan, enum iio_event_type type,
  		enum iio_event_direction dir, int state)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	unsigned int status_mask;
  	int ret;
  
  	switch (chan->channel2) {
  	case IIO_MOD_TEMP_AMBIENT:
  	if (dir == IIO_EV_DIR_RISING)
  			status_mask = TMP007_STATUS_LHF;
  		else
  			status_mask = TMP007_STATUS_LLF;
  		break;
  	case IIO_MOD_TEMP_OBJECT:
  		if (dir == IIO_EV_DIR_RISING)
  			status_mask = TMP007_STATUS_OHF;
  		else
  			status_mask = TMP007_STATUS_OLF;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	mutex_lock(&data->lock);
  	ret = i2c_smbus_read_word_swapped(data->client, TMP007_STATUS_MASK);
  	mutex_unlock(&data->lock);
  	if (ret < 0)
  		return ret;
  
  	if (state)
  		ret |= status_mask;
  	else
  		ret &= ~status_mask;
  
  	return i2c_smbus_write_word_swapped(data->client, TMP007_STATUS_MASK,
  					data->status_mask = ret);
  }
  
  static int tmp007_read_event_config(struct iio_dev *indio_dev,
  		const struct iio_chan_spec *chan, enum iio_event_type type,
  		enum iio_event_direction dir)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	unsigned int mask;
  
  	switch (chan->channel2) {
  	case IIO_MOD_TEMP_AMBIENT:
  		if (dir == IIO_EV_DIR_RISING)
  			mask = TMP007_STATUS_LHF;
  		else
  			mask = TMP007_STATUS_LLF;
  		break;
  	case IIO_MOD_TEMP_OBJECT:
  		if (dir == IIO_EV_DIR_RISING)
  			mask = TMP007_STATUS_OHF;
  		else
  			mask = TMP007_STATUS_OLF;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return !!(data->status_mask & mask);
  }
  
  static int tmp007_read_thresh(struct iio_dev *indio_dev,
  		const struct iio_chan_spec *chan, enum iio_event_type type,
  		enum iio_event_direction dir, enum iio_event_info info,
  		int *val, int *val2)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	int ret;
  	u8 reg;
  
  	switch (chan->channel2) {
  	case IIO_MOD_TEMP_AMBIENT: /* LSB: 0.5 degree Celsius */
  		if (dir == IIO_EV_DIR_RISING)
  			reg = TMP007_TDIE_HIGH_LIMIT;
  		else
  			reg = TMP007_TDIE_LOW_LIMIT;
  		break;
  	case IIO_MOD_TEMP_OBJECT:
  		if (dir == IIO_EV_DIR_RISING)
  			reg = TMP007_TOBJ_HIGH_LIMIT;
  	else
  			reg = TMP007_TOBJ_LOW_LIMIT;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	ret = i2c_smbus_read_word_swapped(data->client, reg);
  	if (ret < 0)
  		return ret;
  
  	/* Shift length 7 bits = 6(15:6) + 1(0.5 LSB) */
  	*val = sign_extend32(ret, 15) >> 7;
  
  	return IIO_VAL_INT;
  }
  
  static int tmp007_write_thresh(struct iio_dev *indio_dev,
  		const struct iio_chan_spec *chan, enum iio_event_type type,
  		enum iio_event_direction dir, enum iio_event_info info,
  		int val, int val2)
  {
  	struct tmp007_data *data = iio_priv(indio_dev);
  	u8 reg;
  
  	switch (chan->channel2) {
  	case IIO_MOD_TEMP_AMBIENT:
  		if (dir == IIO_EV_DIR_RISING)
  			reg = TMP007_TDIE_HIGH_LIMIT;
  		else
  			reg = TMP007_TDIE_LOW_LIMIT;
  		break;
  	case IIO_MOD_TEMP_OBJECT:
  		if (dir == IIO_EV_DIR_RISING)
  			reg = TMP007_TOBJ_HIGH_LIMIT;
  		else
  			reg = TMP007_TOBJ_LOW_LIMIT;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	/* Full scale threshold value is +/- 256 degree Celsius */
  	if (val < -256 || val > 255)
  		return -EINVAL;
  
  	/* Shift length 7 bits = 6(15:6) + 1(0.5 LSB) */
  	return i2c_smbus_write_word_swapped(data->client, reg, (val << 7));
  }
  
  static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
  
  static struct attribute *tmp007_attributes[] = {
  	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group tmp007_attribute_group = {
  	.attrs = tmp007_attributes,
  };
  
  static const struct iio_event_spec tmp007_obj_event[] = {
  	{
  		.type = IIO_EV_TYPE_THRESH,
  		.dir = IIO_EV_DIR_RISING,
  		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
  			BIT(IIO_EV_INFO_ENABLE),
  	},
  	{
  		.type = IIO_EV_TYPE_THRESH,
  		.dir = IIO_EV_DIR_FALLING,
  		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
  			BIT(IIO_EV_INFO_ENABLE),
  	},
  };
  
  static const struct iio_event_spec tmp007_die_event[] = {
  	{
  		.type = IIO_EV_TYPE_THRESH,
  		.dir = IIO_EV_DIR_RISING,
  		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
  			BIT(IIO_EV_INFO_ENABLE),
  	},
  	{
  		.type = IIO_EV_TYPE_THRESH,
  		.dir = IIO_EV_DIR_FALLING,
  		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
  			BIT(IIO_EV_INFO_ENABLE),
  	},
  };
  
  static const struct iio_chan_spec tmp007_channels[] = {
  	{
  		.type = IIO_TEMP,
  		.modified = 1,
  		.channel2 = IIO_MOD_TEMP_AMBIENT,
  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  				BIT(IIO_CHAN_INFO_SCALE),
  		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  		.event_spec = tmp007_die_event,
  		.num_event_specs = ARRAY_SIZE(tmp007_die_event),
  	},
  	{
  		.type = IIO_TEMP,
  		.modified = 1,
  		.channel2 = IIO_MOD_TEMP_OBJECT,
  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  				BIT(IIO_CHAN_INFO_SCALE),
  		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  		.event_spec = tmp007_obj_event,
  		.num_event_specs = ARRAY_SIZE(tmp007_obj_event),
  	}
  };
  
  static const struct iio_info tmp007_info = {
  	.read_raw = tmp007_read_raw,
  	.write_raw = tmp007_write_raw,
  	.read_event_config = tmp007_read_event_config,
  	.write_event_config = tmp007_write_event_config,
  	.read_event_value = tmp007_read_thresh,
  	.write_event_value = tmp007_write_thresh,
  	.attrs = &tmp007_attribute_group,
  	.driver_module = THIS_MODULE,
  };
  
  static bool tmp007_identify(struct i2c_client *client)
  {
  	int manf_id, dev_id;
  
  	manf_id = i2c_smbus_read_word_swapped(client, TMP007_MANUFACTURER_ID);
  	if (manf_id < 0)
  		return false;
  
  	dev_id = i2c_smbus_read_word_swapped(client, TMP007_DEVICE_ID);
  	if (dev_id < 0)
  		return false;
  
  	return (manf_id == TMP007_MANUFACTURER_MAGIC && dev_id == TMP007_DEVICE_MAGIC);
  }
  
  static int tmp007_probe(struct i2c_client *client,
  			const struct i2c_device_id *tmp007_id)
  {
  	struct tmp007_data *data;
  	struct iio_dev *indio_dev;
  	int ret;
  
  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
  		return -EOPNOTSUPP;
  
  	if (!tmp007_identify(client)) {
  		dev_err(&client->dev, "TMP007 not found\n");
  		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);
  
  	indio_dev->dev.parent = &client->dev;
  	indio_dev->name = "tmp007";
  	indio_dev->modes = INDIO_DIRECT_MODE;
  	indio_dev->info = &tmp007_info;
  
  	indio_dev->channels = tmp007_channels;
  	indio_dev->num_channels = ARRAY_SIZE(tmp007_channels);
  
  	/*
  	 * Set Configuration register:
  	 * 1. Conversion ON
  	 * 2. ALERT enable
  	 * 3. Transient correction enable
  	 */
  
  	ret = i2c_smbus_read_word_swapped(data->client, TMP007_CONFIG);
  	if (ret < 0)
  		return ret;
  
  	data->config = ret;
  	data->config |= (TMP007_CONFIG_CONV_EN | TMP007_CONFIG_ALERT_EN | TMP007_CONFIG_TC_EN);
  
  	ret = i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
  					data->config);
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * Only the following flags can activate ALERT pin. Data conversion/validity flags
  	 * flags can still be polled for getting temperature data
  	 *
  	 * Set Status Mask register:
  	 * 1. Object temperature high limit enable
  	 * 2. Object temperature low limit enable
  	 * 3. TDIE temperature high limit enable
  	 * 4. TDIE temperature low limit enable
  	 */
  
  	ret = i2c_smbus_read_word_swapped(data->client, TMP007_STATUS_MASK);
  	if (ret < 0)
  		goto error_powerdown;
  
  	data->status_mask = ret;
  	data->status_mask |= (TMP007_STATUS_OHF | TMP007_STATUS_OLF
  				| TMP007_STATUS_LHF | TMP007_STATUS_LLF);
  
  	ret = i2c_smbus_write_word_swapped(data->client, TMP007_STATUS_MASK, data->status_mask);
  	if (ret < 0)
  		goto error_powerdown;
  
  	if (client->irq) {
  		ret = devm_request_threaded_irq(&client->dev, client->irq,
  				NULL, tmp007_interrupt_handler,
  				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
  				tmp007_id->name, indio_dev);
  		if (ret) {
  			dev_err(&client->dev, "irq request error %d\n", -ret);
  			goto error_powerdown;
  		}
  	}
  
  	return iio_device_register(indio_dev);
  
  error_powerdown:
  	tmp007_powerdown(data);
  
  	return ret;
  }
  
  static int tmp007_remove(struct i2c_client *client)
  {
  	struct iio_dev *indio_dev = i2c_get_clientdata(client);
  	struct tmp007_data *data = iio_priv(indio_dev);
  
  	iio_device_unregister(indio_dev);
  	tmp007_powerdown(data);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int tmp007_suspend(struct device *dev)
  {
  	struct tmp007_data *data = iio_priv(i2c_get_clientdata(
  			to_i2c_client(dev)));
  
  	return tmp007_powerdown(data);
  }
  
  static int tmp007_resume(struct device *dev)
  {
  	struct tmp007_data *data = iio_priv(i2c_get_clientdata(
  			to_i2c_client(dev)));
  
  	return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
  			data->config | TMP007_CONFIG_CONV_EN);
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(tmp007_pm_ops, tmp007_suspend, tmp007_resume);
  
  static const struct of_device_id tmp007_of_match[] = {
  	{ .compatible = "ti,tmp007", },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, tmp007_of_match);
  
  static const struct i2c_device_id tmp007_id[] = {
  	{ "tmp007", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, tmp007_id);
  
  static struct i2c_driver tmp007_driver = {
  	.driver = {
  		.name	= "tmp007",
  		.of_match_table = of_match_ptr(tmp007_of_match),
  		.pm	= &tmp007_pm_ops,
  	},
  	.probe		= tmp007_probe,
  	.remove		= tmp007_remove,
  	.id_table	= tmp007_id,
  };
  module_i2c_driver(tmp007_driver);
  
  MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
  MODULE_DESCRIPTION("TI TMP007 IR thermopile sensor driver");
  MODULE_LICENSE("GPL");
  