144 lines
3.2 KiB
C
144 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* MS5611 pressure and temperature sensor driver (SPI bus)
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*
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* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
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*
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*/
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/spi/spi.h>
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#include <linux/mod_devicetable.h>
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#include <asm/unaligned.h>
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#include "ms5611.h"
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static int ms5611_spi_reset(struct ms5611_state *st)
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{
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u8 cmd = MS5611_RESET;
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return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
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}
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static int ms5611_spi_read_prom_word(struct ms5611_state *st, int index,
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u16 *word)
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{
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int ret;
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ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
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if (ret < 0)
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return ret;
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*word = ret;
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return 0;
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}
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static int ms5611_spi_read_adc(struct ms5611_state *st, s32 *val)
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{
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int ret;
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u8 buf[3] = { MS5611_READ_ADC };
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ret = spi_write_then_read(st->client, buf, 1, buf, 3);
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if (ret < 0)
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return ret;
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*val = get_unaligned_be24(&buf[0]);
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return 0;
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}
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static int ms5611_spi_read_adc_temp_and_pressure(struct ms5611_state *st,
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s32 *temp, s32 *pressure)
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{
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int ret;
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const struct ms5611_osr *osr = st->temp_osr;
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/*
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* Warning: &osr->cmd MUST be aligned on a word boundary since used as
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* 2nd argument (void*) of spi_write_then_read.
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*/
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ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
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if (ret < 0)
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return ret;
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usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
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ret = ms5611_spi_read_adc(st, temp);
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if (ret < 0)
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return ret;
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osr = st->pressure_osr;
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ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
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if (ret < 0)
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return ret;
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usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
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return ms5611_spi_read_adc(st, pressure);
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}
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static int ms5611_spi_probe(struct spi_device *spi)
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{
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int ret;
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struct ms5611_state *st;
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struct iio_dev *indio_dev;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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spi_set_drvdata(spi, indio_dev);
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spi->mode = SPI_MODE_0;
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spi->max_speed_hz = min(spi->max_speed_hz, 20000000U);
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spi->bits_per_word = 8;
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ret = spi_setup(spi);
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if (ret < 0)
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return ret;
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st = iio_priv(indio_dev);
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st->reset = ms5611_spi_reset;
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st->read_prom_word = ms5611_spi_read_prom_word;
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st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
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st->client = spi;
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return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
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spi_get_device_id(spi)->driver_data);
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}
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static void ms5611_spi_remove(struct spi_device *spi)
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{
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ms5611_remove(spi_get_drvdata(spi));
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}
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static const struct of_device_id ms5611_spi_matches[] = {
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{ .compatible = "meas,ms5611" },
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{ .compatible = "meas,ms5607" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
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static const struct spi_device_id ms5611_id[] = {
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{ "ms5611", MS5611 },
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{ "ms5607", MS5607 },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, ms5611_id);
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static struct spi_driver ms5611_driver = {
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.driver = {
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.name = "ms5611",
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.of_match_table = ms5611_spi_matches
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},
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.id_table = ms5611_id,
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.probe = ms5611_spi_probe,
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.remove = ms5611_spi_remove,
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};
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module_spi_driver(ms5611_driver);
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MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
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MODULE_DESCRIPTION("MS5611 spi driver");
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MODULE_LICENSE("GPL v2");
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MODULE_IMPORT_NS(IIO_MS5611);
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