diff options
author | Tomasz Duszynski <tduszyns@gmail.com> | 2015-03-14 21:29:31 +0100 |
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committer | Jonathan Cameron <jic23@kernel.org> | 2015-03-15 11:47:46 +0000 |
commit | c0644160a8b5e56b3c3896d77ac3d50d41fa9336 (patch) | |
tree | 9cd8486122d69d05455b20b7e831758e55917514 /drivers/iio/pressure/ms5611_i2c.c | |
parent | 8b0544263761adbc7308f6910cdcc0d601782cb1 (diff) |
iio: pressure: add support for MS5611 pressure and temperature sensor
Add support for Measurement Specialities MS5611 pressure
and temperature sensor.
Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/pressure/ms5611_i2c.c')
-rw-r--r-- | drivers/iio/pressure/ms5611_i2c.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/iio/pressure/ms5611_i2c.c b/drivers/iio/pressure/ms5611_i2c.c new file mode 100644 index 000000000000..748fd9acaad8 --- /dev/null +++ b/drivers/iio/pressure/ms5611_i2c.c @@ -0,0 +1,128 @@ +/* + * MS5611 pressure and temperature sensor driver (I2C 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. + * + * 7-bit I2C slave addresses: + * + * 0x77 (CSB pin low) + * 0x76 (CSB pin high) + * + */ + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/module.h> + +#include "ms5611.h" + +static int ms5611_i2c_reset(struct device *dev) +{ + struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); + + return i2c_smbus_write_byte(st->client, MS5611_RESET); +} + +static int ms5611_i2c_read_prom_word(struct device *dev, int index, u16 *word) +{ + int ret; + struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); + + ret = i2c_smbus_read_word_swapped(st->client, + MS5611_READ_PROM_WORD + (index << 1)); + if (ret < 0) + return ret; + + *word = ret; + + return 0; +} + +static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val) +{ + int ret; + u8 buf[3]; + + ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC, + 3, buf); + if (ret < 0) + return ret; + + *val = (buf[0] << 16) | (buf[1] << 8) | buf[2]; + + return 0; +} + +static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev, + s32 *temp, s32 *pressure) +{ + int ret; + struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); + + ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV); + if (ret < 0) + return ret; + + usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); + + ret = ms5611_i2c_read_adc(st, temp); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV); + if (ret < 0) + return ret; + + usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); + + return ms5611_i2c_read_adc(st, pressure); +} + +static int ms5611_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ms5611_state *st; + struct iio_dev *indio_dev; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_BYTE | + I2C_FUNC_SMBUS_READ_WORD_DATA | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) + return -ENODEV; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->reset = ms5611_i2c_reset; + st->read_prom_word = ms5611_i2c_read_prom_word; + st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure; + st->client = client; + + return ms5611_probe(indio_dev, &client->dev); +} + +static const struct i2c_device_id ms5611_id[] = { + { "ms5611", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ms5611_id); + +static struct i2c_driver ms5611_driver = { + .driver = { + .name = "ms5611", + .owner = THIS_MODULE, + }, + .id_table = ms5611_id, + .probe = ms5611_i2c_probe, +}; +module_i2c_driver(ms5611_driver); + +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); +MODULE_DESCRIPTION("MS5611 i2c driver"); +MODULE_LICENSE("GPL v2"); |