LXR linux/drivers/iio/pressure/ms5611

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * MS5611 pressure and temperature sensor driver (SPI bus)
   4 *
   5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
   6 *
   7 */
   8
   9#include <linux/delay.h>
  10#include <linux/module.h>
  11#include <linux/spi/spi.h>
  12#include <linux/mod_devicetable.h>
  13
  14#include <asm/unaligned.h>
  15
  16#include "ms5611.h"
  17
  18static int ms5611_spi_reset(struct device *dev)
  19{
  20        u8 cmd = MS5611_RESET;
  21        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  22
  23        return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  24}
  25
  26static int ms5611_spi_read_prom_word(struct device *dev, int index, u16 *word)
  27{
  28        int ret;
  29        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  30
  31        ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
  32        if (ret < 0)
  33                return ret;
  34
  35        *word = ret;
  36
  37        return 0;
  38}
  39
  40static int ms5611_spi_read_adc(struct device *dev, s32 *val)
  41{
  42        int ret;
  43        u8 buf[3] = { MS5611_READ_ADC };
  44        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  45
  46        ret = spi_write_then_read(st->client, buf, 1, buf, 3);
  47        if (ret < 0)
  48                return ret;
  49
  50        *val = get_unaligned_be24(&buf[0]);
  51
  52        return 0;
  53}
  54
  55static int ms5611_spi_read_adc_temp_and_pressure(struct device *dev,
  56                                                 s32 *temp, s32 *pressure)
  57{
  58        int ret;
  59        struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev));
  60        const struct ms5611_osr *osr = st->temp_osr;
  61
  62        /*
  63         * Warning: &osr->cmd MUST be aligned on a word boundary since used as
  64         * 2nd argument (void*) of spi_write_then_read.
  65         */
  66        ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  67        if (ret < 0)
  68                return ret;
  69
  70        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  71        ret = ms5611_spi_read_adc(dev, temp);
  72        if (ret < 0)
  73                return ret;
  74
  75        osr = st->pressure_osr;
  76        ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  77        if (ret < 0)
  78                return ret;
  79
  80        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  81        return ms5611_spi_read_adc(dev, pressure);
  82}
  83
  84static int ms5611_spi_probe(struct spi_device *spi)
  85{
  86        int ret;
  87        struct ms5611_state *st;
  88        struct iio_dev *indio_dev;
  89
  90        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
  91        if (!indio_dev)
  92                return -ENOMEM;
  93
  94        spi_set_drvdata(spi, indio_dev);
  95
  96        spi->mode = SPI_MODE_0;
  97        spi->max_speed_hz = 20000000;
  98        spi->bits_per_word = 8;
  99        ret = spi_setup(spi);
 100        if (ret < 0)
 101                return ret;
 102
 103        st = iio_priv(indio_dev);
 104        st->reset = ms5611_spi_reset;
 105        st->read_prom_word = ms5611_spi_read_prom_word;
 106        st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
 107        st->client = spi;
 108
 109        return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
 110                            spi_get_device_id(spi)->driver_data);
 111}
 112
 113static int ms5611_spi_remove(struct spi_device *spi)
 114{
 115        return ms5611_remove(spi_get_drvdata(spi));
 116}
 117
 118static const struct of_device_id ms5611_spi_matches[] = {
 119        { .compatible = "meas,ms5611" },
 120        { .compatible = "meas,ms5607" },
 121        { }
 122};
 123MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
 124
 125static const struct spi_device_id ms5611_id[] = {
 126        { "ms5611", MS5611 },
 127        { "ms5607", MS5607 },
 128        { }
 129};
 130MODULE_DEVICE_TABLE(spi, ms5611_id);
 131
 132static struct spi_driver ms5611_driver = {
 133        .driver = {
 134                .name = "ms5611",
 135                .of_match_table = ms5611_spi_matches
 136        },
 137        .id_table = ms5611_id,
 138        .probe = ms5611_spi_probe,
 139        .remove = ms5611_spi_remove,
 140};
 141module_spi_driver(ms5611_driver);
 142
 143MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 144MODULE_DESCRIPTION("MS5611 spi driver");
 145MODULE_LICENSE("GPL v2");
 146