diff options
Diffstat (limited to 'drivers/iio/pressure/ms5611_spi.c')
-rw-r--r-- | drivers/iio/pressure/ms5611_spi.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/drivers/iio/pressure/ms5611_spi.c b/drivers/iio/pressure/ms5611_spi.c new file mode 100644 index 000000000000..976726fd4e6c --- /dev/null +++ b/drivers/iio/pressure/ms5611_spi.c @@ -0,0 +1,127 @@ +/* + * 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"); |