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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 <linux/of_device.h>
#include "ms5611.h"
static int ms5611_spi_reset(struct ms5611_state *st)
{
u8 cmd = MS5611_RESET;
return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
}
static int ms5611_spi_read_prom_word(struct ms5611_state *st, int index,
u16 *word)
{
int ret;
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 ms5611_state *st, s32 *val)
{
int ret;
u8 buf[3] = { MS5611_READ_ADC };
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 ms5611_state *st,
s32 *temp, s32 *pressure)
{
int ret;
const struct ms5611_osr *osr = st->temp_osr;
/*
* Warning: &osr->cmd MUST be aligned on a word boundary since used as
* 2nd argument (void*) of spi_write_then_read.
*/
ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
if (ret < 0)
return ret;
usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
ret = ms5611_spi_read_adc(st, temp);
if (ret < 0)
return ret;
osr = st->pressure_osr;
ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
if (ret < 0)
return ret;
usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
return ms5611_spi_read_adc(st, 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_set_drvdata(spi, indio_dev);
spi->mode = SPI_MODE_0;
spi->max_speed_hz = min(spi->max_speed_hz, 20000000U);
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)->name,
spi_get_device_id(spi)->driver_data);
}
static int ms5611_spi_remove(struct spi_device *spi)
{
return ms5611_remove(spi_get_drvdata(spi));
}
#if defined(CONFIG_OF)
static const struct of_device_id ms5611_spi_matches[] = {
{ .compatible = "meas,ms5611" },
{ .compatible = "ms5611" },
{ .compatible = "meas,ms5607" },
{ .compatible = "ms5607" },
{ }
};
MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
#endif
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",
.of_match_table = of_match_ptr(ms5611_spi_matches)
},
.id_table = ms5611_id,
.probe = ms5611_spi_probe,
.remove = ms5611_spi_remove,
};
module_spi_driver(ms5611_driver);
MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 spi driver");
MODULE_LICENSE("GPL v2");
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