diff options
| author | Gregor Boirie <gregor.boirie@parrot.com> | 2016-03-01 13:31:38 +0300 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-03-05 17:45:14 +0300 |
| commit | 033691a9a12f684c68f443f3676806dd64011295 (patch) | |
| tree | d35d94f3b5c6d90efd275b1d9d0248562c576347 /drivers/iio/pressure/ms5611_i2c.c | |
| parent | 7a948c5e05febd23ee8e61db95c3dc96737fe17f (diff) | |
| download | linux-033691a9a12f684c68f443f3676806dd64011295.tar.xz | |
iio:pressure:ms5611: oversampling rate support
Add support for setting and retrieving OverSampling Rate independently for
each of the temperature and pressure channels. This allows userspace to
fine tune hardware sampling process according to the following tradeoffs :
* the higher the OSR, the finer the resolution ;
* the higher the OSR, the lower the noise ;
BUT:
* the higher the OSR, the larger the drift ;
* the higher the OSR, the longer the response time, i.e. less samples per
unit of time.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.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 | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/iio/pressure/ms5611_i2c.c b/drivers/iio/pressure/ms5611_i2c.c index 57a8f2cfa235..55fb5fc0b6ea 100644 --- a/drivers/iio/pressure/ms5611_i2c.c +++ b/drivers/iio/pressure/ms5611_i2c.c @@ -63,23 +63,23 @@ static int ms5611_i2c_read_adc_temp_and_pressure(struct device *dev, { int ret; struct ms5611_state *st = iio_priv(dev_to_iio_dev(dev)); + const struct ms5611_osr *osr = st->temp_osr; - ret = i2c_smbus_write_byte(st->client, MS5611_START_TEMP_CONV); + ret = i2c_smbus_write_byte(st->client, osr->cmd); if (ret < 0) return ret; - usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); - + usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL)); ret = ms5611_i2c_read_adc(st, temp); if (ret < 0) return ret; - ret = i2c_smbus_write_byte(st->client, MS5611_START_PRESSURE_CONV); + osr = st->pressure_osr; + ret = i2c_smbus_write_byte(st->client, osr->cmd); if (ret < 0) return ret; - usleep_range(MS5611_CONV_TIME_MIN, MS5611_CONV_TIME_MAX); - + usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL)); return ms5611_i2c_read_adc(st, pressure); } |