linux-zen-server/drivers/iio/pressure/ms5611_i2c.c

136 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* MS5611 pressure and temperature sensor driver (I2C bus)
*
* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
*
* 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 <linux/mod_devicetable.h>
#include <asm/unaligned.h>
#include "ms5611.h"
static int ms5611_i2c_reset(struct ms5611_state *st)
{
return i2c_smbus_write_byte(st->client, MS5611_RESET);
}
static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
u16 *word)
{
int ret;
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 = get_unaligned_be24(&buf[0]);
return 0;
}
static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
s32 *temp, s32 *pressure)
{
int ret;
const struct ms5611_osr *osr = st->temp_osr;
ret = i2c_smbus_write_byte(st->client, osr->cmd);
if (ret < 0)
return ret;
usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
ret = ms5611_i2c_read_adc(st, temp);
if (ret < 0)
return ret;
osr = st->pressure_osr;
ret = i2c_smbus_write_byte(st->client, osr->cmd);
if (ret < 0)
return ret;
usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
return ms5611_i2c_read_adc(st, pressure);
}
static int ms5611_i2c_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
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 -EOPNOTSUPP;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
i2c_set_clientdata(client, 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, id->name, id->driver_data);
}
static const struct of_device_id ms5611_i2c_matches[] = {
{ .compatible = "meas,ms5611" },
{ .compatible = "meas,ms5607" },
{ }
};
MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
static const struct i2c_device_id ms5611_id[] = {
{ "ms5611", MS5611 },
{ "ms5607", MS5607 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ms5611_id);
static struct i2c_driver ms5611_driver = {
.driver = {
.name = "ms5611",
.of_match_table = ms5611_i2c_matches,
},
.id_table = ms5611_id,
.probe_new = ms5611_i2c_probe,
};
module_i2c_driver(ms5611_driver);
MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 i2c driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(IIO_MS5611);