/* * 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); } static const struct spi_device_id ms5611_id[] = { { "ms5611", 0 }, { } }; MODULE_DEVICE_TABLE(spi, ms5611_id); static struct spi_driver ms5611_driver = { .driver = { .name = "ms5611", .owner = THIS_MODULE, }, .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");