[PATCH 10/11] Staging: iio: accel: Add comments about units in data read function

From: Himanshu Jha
Date: Mon Mar 05 2018 - 02:51:08 EST


Clarify the conversion and formation of resultant data in the
adis16201_read_raw() with sufficient comments.

Signed-off-by: Himanshu Jha <himanshujha199640@xxxxxxxxx>
---
drivers/staging/iio/accel/adis16201.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/staging/iio/accel/adis16201.c b/drivers/staging/iio/accel/adis16201.c
index 8d795e2..946c7b1 100644
--- a/drivers/staging/iio/accel/adis16201.c
+++ b/drivers/staging/iio/accel/adis16201.c
@@ -130,6 +130,11 @@ static int adis16201_read_raw(struct iio_dev *indio_dev,
*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);
return IIO_VAL_INT_PLUS_NANO;
@@ -142,6 +147,11 @@ static int adis16201_read_raw(struct iio_dev *indio_dev,
}
break;
case IIO_CHAN_INFO_OFFSET:
+ /*
+ * The raw ADC value is 0x4FE 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:
--
2.7.4