LXR linux/drivers/iio/pressure/ms5611

   1/*
   2 * MS5611 pressure and temperature sensor driver (SPI bus)
   3 *
   4 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 *
  10 */
  11
  12#include <linux/delay.h>
  13#include <linux/module.h>
  14#include <linux/spi/spi.h>
  15#include <linux/of_device.h>
  16
  17#include "ms5611.h"
  18
  19static int ms5611_spi_reset(struct device *dev)
  20{
  21        u8 cmd = MS5611_RESET;
  22        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  23
  24        return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  25}
  26
  27static int ms5611_spi_read_prom_word(struct device *dev, int index, u16 *word)
  28{
  29        int ret;
  30        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  31
  32        ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
  33        if (ret < 0)
  34                return ret;
  35
  36        *word = ret;
  37
  38        return 0;
  39}
  40
  41static int ms5611_spi_read_adc(struct device *dev, s32 *val)
  42{
  43        int ret;
  44        u8 buf[3] = { MS5611_READ_ADC };
  45        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  46
  47        ret = spi_write_then_read(st->client, buf, 1, buf, 3);
  48        if (ret < 0)
  49                return ret;
  50
  51        *val = (buf[0] << 16) | (buf[1] << 8) | buf[2];
  52
  53        return 0;
  54}
  55
  56static int ms5611_spi_read_adc_temp_and_pressure(struct device *dev,
  57                                                 s32 *temp, s32 *pressure)
  58{
  59        int ret;
  60        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  61        const struct ms5611_osr *osr = st->temp_osr;
  62
  63        /*
  64         * Warning: &osr->cmd MUST be aligned on a word boundary since used as
  65         * 2nd argument (void*) of spi_write_then_read.
  66         */
  67        ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  68        if (ret < 0)
  69                return ret;
  70
  71        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  72        ret = ms5611_spi_read_adc(dev, temp);
  73        if (ret < 0)
  74                return ret;
  75
  76        osr = st->pressure_osr;
  77        ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  78        if (ret < 0)
  79                return ret;
  80
  81        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  82        return ms5611_spi_read_adc(dev, pressure);
  83}
  84
  85static int ms5611_spi_probe(struct spi_device *spi)
  86{
  87        int ret;
  88        struct ms5611_state *st;
  89        struct iio_dev *indio_dev;
  90
  91        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
  92        if (!indio_dev)
  93                return -ENOMEM;
  94
  95        spi_set_drvdata(spi, indio_dev);
  96
  97        spi->mode = SPI_MODE_0;
  98        spi->max_speed_hz = 20000000;
  99        spi->bits_per_word = 8;
 100        ret = spi_setup(spi);
 101        if (ret < 0)
 102                return ret;
 103
 104        st = iio_priv(indio_dev);
 105        st->reset = ms5611_spi_reset;
 106        st->read_prom_word = ms5611_spi_read_prom_word;
 107        st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
 108        st->client = spi;
 109
 110        return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
 111                            spi_get_device_id(spi)->driver_data);
 112}
 113
 114static int ms5611_spi_remove(struct spi_device *spi)
 115{
 116        return ms5611_remove(spi_get_drvdata(spi));
 117}
 118
 119#if defined(CONFIG_OF)
 120static const struct of_device_id ms5611_spi_matches[] = {
 121        { .compatible = "meas,ms5611" },
 122        { .compatible = "ms5611" },
 123        { .compatible = "meas,ms5607" },
 124        { .compatible = "ms5607" },
 125        { }
 126};
 127MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
 128#endif
 129
 130static const struct spi_device_id ms5611_id[] = {
 131        { "ms5611", MS5611 },
 132        { "ms5607", MS5607 },
 133        { }
 134};
 135MODULE_DEVICE_TABLE(spi, ms5611_id);
 136
 137static struct spi_driver ms5611_driver = {
 138        .driver = {
 139                .name = "ms5611",
 140                .of_match_table = of_match_ptr(ms5611_spi_matches)
 141        },
 142        .id_table = ms5611_id,
 143        .probe = ms5611_spi_probe,
 144        .remove = ms5611_spi_remove,
 145};
 146module_spi_driver(ms5611_driver);
 147
 148MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 149MODULE_DESCRIPTION("MS5611 spi driver");
 150MODULE_LICENSE("GPL v2");
 151