Quelle  hdc100x.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
 *
 * Copyright (C) 2015, 2018
 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
 *
 * Datasheets:
 * https://www.ti.com/product/HDC1000/datasheet
 * https://www.ti.com/product/HDC1008/datasheet
 * https://www.ti.com/product/HDC1010/datasheet
 * https://www.ti.com/product/HDC1050/datasheet
 * https://www.ti.com/product/HDC1080/datasheet
 */

#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/init.h>
#include <linux/i2c.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#include <linux/time.h>

#define HDC100X_REG_TEMP   0x00
#define HDC100X_REG_HUMIDITY   0x01

#define HDC100X_REG_CONFIG   0x02
#define HDC100X_REG_CONFIG_ACQ_MODE  BIT(12)
#define HDC100X_REG_CONFIG_HEATER_EN  BIT(13)

struct hdc100x_data {
 struct i2c_client *client;
 struct mutex lock;
 u16 config;

 /* integration time of the sensor */
 int adc_int_us[2];
 /* Ensure natural alignment of timestamp */
 struct {
  __be16 channels[2];
  aligned_s64 ts;
 } scan;
};

/* integration time in us */
static const int hdc100x_int_time[][3] = {
 { 6350, 3650, 0 }, /* IIO_TEMP channel*/
 { 6500, 3850, 2500 }, /* IIO_HUMIDITYRELATIVE channel */
};

/* HDC100X_REG_CONFIG shift and mask values */
static const struct {
 int shift;
 int mask;
} hdc100x_resolution_shift[2] = {
 { /* IIO_TEMP channel */
  .shift = 10,
  .mask = 1
 },
 { /* IIO_HUMIDITYRELATIVE channel */
  .shift = 8,
  .mask = 3,
 },
};

static IIO_CONST_ATTR(temp_integration_time_available,
  "0.00365 0.00635");

static IIO_CONST_ATTR(humidityrelative_integration_time_available,
  "0.0025 0.00385 0.0065");

static IIO_CONST_ATTR(out_current_heater_raw_available,
  "0 1");

static struct attribute *hdc100x_attributes[] = {
 &iio_const_attr_temp_integration_time_available.dev_attr.attr,
 &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
 &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
 NULL
};

static const struct attribute_group hdc100x_attribute_group = {
 .attrs = hdc100x_attributes,
};

static const struct iio_chan_spec hdc100x_channels[] = {
 {
  .type = IIO_TEMP,
  .address = HDC100X_REG_TEMP,
  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
   BIT(IIO_CHAN_INFO_SCALE) |
   BIT(IIO_CHAN_INFO_INT_TIME) |
   BIT(IIO_CHAN_INFO_OFFSET),
  .scan_index = 0,
  .scan_type = {
   .sign = 's',
   .realbits = 16,
   .storagebits = 16,
   .endianness = IIO_BE,
  },
 },
 {
  .type = IIO_HUMIDITYRELATIVE,
  .address = HDC100X_REG_HUMIDITY,
  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
   BIT(IIO_CHAN_INFO_SCALE) |
   BIT(IIO_CHAN_INFO_INT_TIME),
  .scan_index = 1,
  .scan_type = {
   .sign = 'u',
   .realbits = 16,
   .storagebits = 16,
   .endianness = IIO_BE,
  },
 },
 {
  .type = IIO_CURRENT,
  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  .extend_name = "heater",
  .output = 1,
  .scan_index = -1,
 },
 IIO_CHAN_SOFT_TIMESTAMP(2),
};

static const unsigned long hdc100x_scan_masks[] = {0x3, 0};

static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
{
 int tmp = (~mask & data->config) | val;
 int ret;

 ret = i2c_smbus_write_word_swapped(data->client,
      HDC100X_REG_CONFIG, tmp);
 if (!ret)
  data->config = tmp;

 return ret;
}

static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
{
 int shift = hdc100x_resolution_shift[chan].shift;
 int ret = -EINVAL;
 int i;

 for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
  if (val2 && val2 == hdc100x_int_time[chan][i]) {
   ret = hdc100x_update_config(data,
    hdc100x_resolution_shift[chan].mask << shift,
    i << shift);
   if (!ret)
    data->adc_int_us[chan] = val2;
   break;
  }
 }

 return ret;
}

static int hdc100x_get_measurement(struct hdc100x_data *data,
       struct iio_chan_spec const *chan)
{
 struct i2c_client *client = data->client;
 int delay = data->adc_int_us[chan->address] + 1*USEC_PER_MSEC;
 int ret;
 __be16 val;

 /* start measurement */
 ret = i2c_smbus_write_byte(client, chan->address);
 if (ret < 0) {
  dev_err(&client->dev, "cannot start measurement");
  return ret;
 }

 /* wait for integration time to pass */
 usleep_range(delay, delay + 1000);

 /* read measurement */
 ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
 if (ret < 0) {
  dev_err(&client->dev, "cannot read sensor data\n");
  return ret;
 }
 return be16_to_cpu(val);
}

static int hdc100x_get_heater_status(struct hdc100x_data *data)
{
 return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
}

static int hdc100x_read_raw(struct iio_dev *indio_dev,
       struct iio_chan_spec const *chan, int *val,
       int *val2, long mask)
{
 struct hdc100x_data *data = iio_priv(indio_dev);

 switch (mask) {
 case IIO_CHAN_INFO_RAW: {
  int ret;

  guard(mutex)(&data->lock);
  if (chan->type == IIO_CURRENT) {
   *val = hdc100x_get_heater_status(data);
   return IIO_VAL_INT;
  }
  if (!iio_device_claim_direct(indio_dev))
   return -EBUSY;

  ret = hdc100x_get_measurement(data, chan);
  iio_device_release_direct(indio_dev);
  if (ret < 0)
   return ret;
  *val = ret;
  return IIO_VAL_INT;
 }
 case IIO_CHAN_INFO_INT_TIME:
  *val = 0;
  *val2 = data->adc_int_us[chan->address];
  return IIO_VAL_INT_PLUS_MICRO;
 case IIO_CHAN_INFO_SCALE:
  if (chan->type == IIO_TEMP) {
   *val = 165000;
   *val2 = 65536;
   return IIO_VAL_FRACTIONAL;
  } else {
   *val = 100000;
   *val2 = 65536;
   return IIO_VAL_FRACTIONAL;
  }
  break;
 case IIO_CHAN_INFO_OFFSET:
  *val = -15887;
  *val2 = 515151;
  return IIO_VAL_INT_PLUS_MICRO;
 default:
  return -EINVAL;
 }
}

static int hdc100x_write_raw(struct iio_dev *indio_dev,
        struct iio_chan_spec const *chan,
        int val, int val2, long mask)
{
 struct hdc100x_data *data = iio_priv(indio_dev);

 switch (mask) {
 case IIO_CHAN_INFO_INT_TIME: {
  if (val != 0)
   return -EINVAL;

  guard(mutex)(&data->lock);
  return hdc100x_set_it_time(data, chan->address, val2);
 }
 case IIO_CHAN_INFO_RAW: {
  if (chan->type != IIO_CURRENT || val2 != 0)
   return -EINVAL;

  guard(mutex)(&data->lock);
  return hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
          val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
 }
 default:
  return -EINVAL;
 }
}

static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
{
 struct hdc100x_data *data = iio_priv(indio_dev);

 /* Buffer is enabled. First set ACQ Mode, then attach poll func */
 guard(mutex)(&data->lock);
 return hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
         HDC100X_REG_CONFIG_ACQ_MODE);
}

static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
{
 struct hdc100x_data *data = iio_priv(indio_dev);

 guard(mutex)(&data->lock);
 return hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
}

static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
 .postenable  = hdc100x_buffer_postenable,
 .predisable  = hdc100x_buffer_predisable,
};

static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
{
 struct iio_poll_func *pf = p;
 struct iio_dev *indio_dev = pf->indio_dev;
 struct hdc100x_data *data = iio_priv(indio_dev);
 struct i2c_client *client = data->client;
 int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC;
 int ret;

 /* dual read starts at temp register */
 mutex_lock(&data->lock);
 ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
 if (ret < 0) {
  dev_err(&client->dev, "cannot start measurement\n");
  goto err;
 }
 usleep_range(delay, delay + 1000);

 ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4);
 if (ret < 0) {
  dev_err(&client->dev, "cannot read sensor data\n");
  goto err;
 }

 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
        iio_get_time_ns(indio_dev));
err:
 mutex_unlock(&data->lock);
 iio_trigger_notify_done(indio_dev->trig);

 return IRQ_HANDLED;
}

static const struct iio_info hdc100x_info = {
 .read_raw = hdc100x_read_raw,
 .write_raw = hdc100x_write_raw,
 .attrs = &hdc100x_attribute_group,
};

static int hdc100x_probe(struct i2c_client *client)
{
 struct iio_dev *indio_dev;
 struct hdc100x_data *data;
 int ret;

 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
         I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
  return -EOPNOTSUPP;

 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->name = dev_name(&client->dev);
 indio_dev->modes = INDIO_DIRECT_MODE;
 indio_dev->info = &hdc100x_info;

 indio_dev->channels = hdc100x_channels;
 indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
 indio_dev->available_scan_masks = hdc100x_scan_masks;

 /* be sure we are in a known state */
 hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
 hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
 hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);

 ret = devm_iio_triggered_buffer_setup(&client->dev,
      indio_dev, NULL,
      hdc100x_trigger_handler,
      &hdc_buffer_setup_ops);
 if (ret < 0) {
  dev_err(&client->dev, "iio triggered buffer setup failed\n");
  return ret;
 }

 return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct i2c_device_id hdc100x_id[] = {
 { "hdc100x" },
 { "hdc1000" },
 { "hdc1008" },
 { "hdc1010" },
 { "hdc1050" },
 { "hdc1080" },
 { }
};
MODULE_DEVICE_TABLE(i2c, hdc100x_id);

static const struct of_device_id hdc100x_dt_ids[] = {
 { .compatible = "ti,hdc1000" },
 { .compatible = "ti,hdc1008" },
 { .compatible = "ti,hdc1010" },
 { .compatible = "ti,hdc1050" },
 { .compatible = "ti,hdc1080" },
 { }
};
MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);

static const struct acpi_device_id hdc100x_acpi_match[] = {
 { "TXNW1010" },
 { }
};
MODULE_DEVICE_TABLE(acpi, hdc100x_acpi_match);

static struct i2c_driver hdc100x_driver = {
 .driver = {
  .name = "hdc100x",
  .of_match_table = hdc100x_dt_ids,
  .acpi_match_table = hdc100x_acpi_match,
 },
 .probe = hdc100x_probe,
 .id_table = hdc100x_id,
};
module_i2c_driver(hdc100x_driver);

MODULE_AUTHOR("Matt Ranostay ");
MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
MODULE_LICENSE("GPL");