From 8f114acd4e1a9cfa05b70bcc4219bc88197b5c9b Mon Sep 17 00:00:00 2001
From: Narcisa Ana Maria Vasile <narcisaanamaria12@gmail.com>
Date: Wed, 6 Dec 2017 18:57:58 +0200
Subject: iio: chemical: ccs811: Fix output of IIO_CONCENTRATION channels
in_concentration_raw should report, according to sysfs-bus-iio documentation,
a "Raw (unscaled no offset etc.) percentage reading of a substance."
Modify scale to convert from ppm/ppb to percentage:
1 ppm = 0.0001%
1 ppb = 0.0000001%
There is no offset needed to convert the ppm/ppb to percentage,
so remove offset from IIO_CONCENTRATION (IIO_MOD_CO2) channel.
Cc'd stable to reduce chance of userspace breakage in the long
run as we fix this wrong bit of ABI usage.
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@gmail.com>
Cc: <Stable@vger.kernel.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/chemical/ccs811.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
(limited to 'drivers/iio')
diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
index 97bce8345c6a..fbe2431f5b81 100644
--- a/drivers/iio/chemical/ccs811.c
+++ b/drivers/iio/chemical/ccs811.c
@@ -96,7 +96,6 @@ static const struct iio_chan_spec ccs811_channels[] = {
.channel2 = IIO_MOD_CO2,
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
@@ -255,24 +254,18 @@ static int ccs811_read_raw(struct iio_dev *indio_dev,
switch (chan->channel2) {
case IIO_MOD_CO2:
*val = 0;
- *val2 = 12834;
+ *val2 = 100;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_MOD_VOC:
*val = 0;
- *val2 = 84246;
- return IIO_VAL_INT_PLUS_MICRO;
+ *val2 = 100;
+ return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
- case IIO_CHAN_INFO_OFFSET:
- if (!(chan->type == IIO_CONCENTRATION &&
- chan->channel2 == IIO_MOD_CO2))
- return -EINVAL;
- *val = -400;
- return IIO_VAL_INT;
default:
return -EINVAL;
}
--
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