From 4c73b809a99fc4df39fb18664288921b052f9649 Mon Sep 17 00:00:00 2001 From: Richard Lai Date: Wed, 14 Feb 2018 01:08:35 +0000 Subject: [PATCH] iio: chemical: ccs811: Renamed resistance member in ccs811_reading struct MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The resistance member in ccs811_reading struct is an unsigned 16-bit integer variable used to store RAW_DATA register bytes read from CCS811. It is kind of misleading to name this struct member as resistance. About the RAW_DATA register bytes, the CCS811 datasheet states that: ----- Two byte read only register which contains the latest readings from the sense resistor. The most significant 6 bits of the Byte 0 contain the value of the current through the sensor (0μA to 63μA). The lower 10 bits contain (as computed from the ADC) the readings of the voltage across the sensor with the selected current (1023 = 1.65V)" ----- Hence, the RAW_DATA register byte contains information about electric current and voltage of the CCS811 sensor. Calling this struct member 'resistance' is kind of misleading, although both electric current and voltage are needed to calculate the electrical resistance of the sensor using Ohm's law, V = I x R, in which a new channel type of IIO_RESISTANCE may be added to the driver in the future. Signed-off-by: Richard Lai Signed-off-by: Jonathan Cameron --- drivers/iio/chemical/ccs811.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c index cfaf86b248d9..e092ffe1431e 100644 --- a/drivers/iio/chemical/ccs811.c +++ b/drivers/iio/chemical/ccs811.c @@ -69,7 +69,7 @@ struct ccs811_reading { __be16 voc; u8 status; u8 error; - __be16 resistance; + __be16 raw_data; } __attribute__((__packed__)); struct ccs811_data { @@ -210,12 +210,12 @@ static int ccs811_read_raw(struct iio_dev *indio_dev, switch (chan->type) { case IIO_VOLTAGE: - *val = be16_to_cpu(data->buffer.resistance) & + *val = be16_to_cpu(data->buffer.raw_data) & CCS811_VOLTAGE_MASK; ret = IIO_VAL_INT; break; case IIO_CURRENT: - *val = be16_to_cpu(data->buffer.resistance) >> 10; + *val = be16_to_cpu(data->buffer.raw_data) >> 10; ret = IIO_VAL_INT; break; case IIO_CONCENTRATION: -- 2.30.2