linux/include
Jonathan Cameron 5c64990b99 iio: core: Introduce _zeropoint for differential channels
Address an ABI gap for device where the offset of both lines in a
differential pair may be controlled so as to allow a wider range of
inputs, but without having any direct effect of the differential
measurement.

_offset cannot be used as to remain in line with existing usage,
userspace would be expected to apply it as (_raw + _offset) * _scale
whereas _zeropoint is not. i.e. If we were computing the differential
in software it would be.
((postive_raw + _zeropoint) - (negative_raw + zeropoint) + _offset) * _scale
= ((postive_raw - negative_raw) + _offset) * _scale
= (differential_raw + _offset) * _scale

Similarly calibbias is expected to tweak the measurement seen, not
the adjust the two lines of the differential pair.

Needed for in_capacitanceX-capacitanceY_zeropoint for the
AD7746 CDC driver.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220626122938.582107-12-jic23@kernel.org
2022-08-15 22:30:01 +01:00
..
acpi Merge branch 'acpi-properties' 2022-08-11 19:21:03 +02:00
asm-generic Bitmap patches for v6.0-rc1 2022-08-07 17:52:35 -07:00
clocksource
crypto for-5.20/block-2022-08-04 2022-08-04 20:00:14 -07:00
drm
dt-bindings dt-bindings: iio: adc: at91-sama5d2_adc: add id for temperature channel 2022-08-15 22:29:58 +01:00
keys
kunit
kvm
linux iio: core: Introduce _zeropoint for differential channels 2022-08-15 22:30:01 +01:00
math-emu
media SPDX changes for 6.0-rc1 2022-08-04 12:12:54 -07:00
memory
misc
net Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -07:00
pcmcia
ras mm, hwpoison: enable memory error handling on 1GB hugepage 2022-08-08 18:06:44 -07:00
rdma dma-mapping updates 2022-08-06 10:56:45 -07:00
rv
scsi SCSI misc on 20220813 2022-08-13 13:41:48 -07:00
soc Char / Misc driver changes for 6.0-rc1 2022-08-04 11:05:48 -07:00
sound
target
trace * Xen timer fixes 2022-08-11 12:10:08 -07:00
uapi virtio: fatures, fixes 2022-08-12 09:50:34 -07:00
ufs
vdso
video
xen x86/xen: Add support for HVMOP_set_evtchn_upcall_vector 2022-08-12 11:28:21 +02:00