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kernel/linux-rt-4.4.41/drivers/iio/pressure/ms5611_spi.c 2.87 KB
5113f6f70   김현기   kernel add
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  /*
   * MS5611 pressure and temperature sensor driver (SPI bus)
   *
   * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #include <linux/delay.h>
  #include <linux/module.h>
  #include <linux/spi/spi.h>
  
  #include "ms5611.h"
  
  static int ms5611_spi_reset(struct device *dev)
  {
  	u8 cmd = MS5611_RESET;
  	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  
  	return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  }
  
  static int ms5611_spi_read_prom_word(struct device *dev, int index, u16 *word)
  {
  	int ret;
  	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  
  	ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
  	if (ret < 0)
  		return ret;
  
  	*word = ret;
  
  	return 0;
  }
  
  static int ms5611_spi_read_adc(struct device *dev, s32 *val)
  {
  	int ret;
  	u8 buf[3] = { MS5611_READ_ADC };
  	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  
  	ret = spi_write_then_read(st->client, buf, 1, buf, 3);
  	if (ret < 0)
  		return ret;
  
  	*val = (buf[0] << 16) | (buf[1] << 8) | buf[2];
  
  	return 0;
  }
  
  static int ms5611_spi_read_adc_temp_and_pressure(struct device *dev,
  						 s32 *temp, s32 *pressure)
  {
  	u8 cmd;
  	int ret;
  	struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  
  	cmd = MS5611_START_TEMP_CONV;
  	ret = spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  	if (ret < 0)
  		return ret;
  
  	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
  
  	ret = ms5611_spi_read_adc(dev, temp);
  	if (ret < 0)
  		return ret;
  
  	cmd = MS5611_START_PRESSURE_CONV;
  	ret = spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  	if (ret < 0)
  		return ret;
  
  	usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX);
  
  	return ms5611_spi_read_adc(dev, pressure);
  }
  
  static int ms5611_spi_probe(struct spi_device *spi)
  {
  	int ret;
  	struct ms5611_state *st;
  	struct iio_dev *indio_dev;
  
  	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
  	if (!indio_dev)
  		return -ENOMEM;
  
  	spi->mode = SPI_MODE_0;
  	spi->max_speed_hz = 20000000;
  	spi->bits_per_word = 8;
  	ret = spi_setup(spi);
  	if (ret < 0)
  		return ret;
  
  	st = iio_priv(indio_dev);
  	st->reset = ms5611_spi_reset;
  	st->read_prom_word = ms5611_spi_read_prom_word;
  	st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
  	st->client = spi;
  
  	return ms5611_probe(indio_dev, &spi->dev,
  			    spi_get_device_id(spi)->driver_data);
  }
  
  static const struct spi_device_id ms5611_id[] = {
  	{ "ms5611", MS5611 },
  	{ "ms5607", MS5607 },
  	{ }
  };
  MODULE_DEVICE_TABLE(spi, ms5611_id);
  
  static struct spi_driver ms5611_driver = {
  	.driver = {
  		.name = "ms5611",
  	},
  	.id_table = ms5611_id,
  	.probe = ms5611_spi_probe,
  };
  module_spi_driver(ms5611_driver);
  
  MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
  MODULE_DESCRIPTION("MS5611 spi driver");
  MODULE_LICENSE("GPL v2");