diff options
| author | Himanshu Jha <himanshujha199640@gmail.com> | 2018-03-17 01:36:22 +0530 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2018-03-18 08:31:40 +0000 |
| commit | 57f9386405a2ec7617d4d3b4cd1dc6c7fe299565 (patch) | |
| tree | 7d38d8e40fe962631d4b9d121cc8d7826aaf114e /drivers/staging/iio/accel/adis16201.c | |
| parent | 0d0f97d896d7813bfbc19c4650d797f938c4c198 (diff) | |
Staging: iio: accel: adis16201: Add comments about units in read_raw()
Clarify the conversion and formation of resultant data in the
adis16201_read_raw() with sufficient comments and remove the unnecessary
comments.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/staging/iio/accel/adis16201.c')
| -rw-r--r-- | drivers/staging/iio/accel/adis16201.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/staging/iio/accel/adis16201.c b/drivers/staging/iio/accel/adis16201.c index 4a65e9a3a775..87ad3d421c12 100644 --- a/drivers/staging/iio/accel/adis16201.c +++ b/drivers/staging/iio/accel/adis16201.c @@ -120,31 +120,43 @@ static int adis16201_read_raw(struct iio_dev *indio_dev, switch (chan->type) { case IIO_VOLTAGE: if (chan->channel == 0) { + /* Voltage base units are mV hence 1.22 mV */ *val = 1; - *val2 = 220000; /* 1.22 mV */ + *val2 = 220000; } else { + /* Voltage base units are mV hence 0.61 mV */ *val = 0; - *val2 = 610000; /* 0.610 mV */ + *val2 = 610000; } return IIO_VAL_INT_PLUS_MICRO; case IIO_TEMP: - *val = -470; /* 0.47 C */ + *val = -470; *val2 = 0; return IIO_VAL_INT_PLUS_MICRO; case IIO_ACCEL: + /* + * IIO base unit for sensitivity of accelerometer + * is milli g. + * 1 LSB represents 0.244 mg. + */ *val = 0; - *val2 = IIO_G_TO_M_S_2(462400); /* 0.4624 mg */ + *val2 = IIO_G_TO_M_S_2(462400); return IIO_VAL_INT_PLUS_NANO; case IIO_INCLI: *val = 0; - *val2 = 100000; /* 0.1 degree */ + *val2 = 100000; return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } break; case IIO_CHAN_INFO_OFFSET: - *val = 25000 / -470 - 1278; /* 25 C = 1278 */ + /* + * The raw ADC value is 1278 when the temperature + * is 25 degrees and the scale factor per milli + * degree celcius is -470. + */ + *val = 25000 / -470 - 1278; return IIO_VAL_INT; case IIO_CHAN_INFO_CALIBBIAS: switch (chan->type) { @@ -252,13 +264,11 @@ static int adis16201_probe(struct spi_device *spi) struct adis *st; struct iio_dev *indio_dev; - /* setup the industrialio driver allocated elements */ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); - /* this is only used for removal purposes */ spi_set_drvdata(spi, indio_dev); indio_dev->name = spi->dev.driver->name; @@ -277,7 +287,6 @@ static int adis16201_probe(struct spi_device *spi) if (ret) return ret; - /* Get the device into a sane initial state */ ret = adis_initial_startup(st); if (ret) goto error_cleanup_buffer_trigger; |