From af06437dae78cc61d89f528fa4a121c27c50bc55 Mon Sep 17 00:00:00 2001 From: Brian Masney Date: Mon, 10 Oct 2016 03:20:01 -0400 Subject: [PATCH] staging: iio: isl29018: add ABI documentation for infrared suppression Add ABI documentation from the ISL29018 Data Sheet (FN6619.4, Oct 8, 2012) about the infrared suppression that can be controlled with the proximity_on_chip_ambient_infrared_suppression sysfs attribute. Signed-off-by: Brian Masney Signed-off-by: Jonathan Cameron --- .../ABI/testing/sysfs-bus-iio-light-isl29018 | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-light-isl29018 diff --git a/Documentation/ABI/testing/sysfs-bus-iio-light-isl29018 b/Documentation/ABI/testing/sysfs-bus-iio-light-isl29018 new file mode 100644 index 000000000000..f0ce0a0476ea --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-light-isl29018 @@ -0,0 +1,19 @@ +What: /sys/bus/iio/devices/iio:deviceX/proximity_on_chip_ambient_infrared_suppression +Date: January 2011 +KernelVersion: 2.6.37 +Contact: linux-iio@vger.kernel.org +Description: + From ISL29018 Data Sheet (FN6619.4, Oct 8, 2012) regarding the + infrared suppression: + + Scheme 0, makes full n (4, 8, 12, 16) bits (unsigned) proximity + detection. The range of Scheme 0 proximity count is from 0 to + 2^n. Logic 1 of this bit, Scheme 1, makes n-1 (3, 7, 11, 15) + bits (2's complementary) proximity_less_ambient detection. The + range of Scheme 1 proximity count is from -2^(n-1) to 2^(n-1). + The sign bit is extended for resolutions less than 16. While + Scheme 0 has wider dynamic range, Scheme 1 proximity detection + is less affected by the ambient IR noise variation. + + 0 Sensing IR from LED and ambient + 1 Sensing IR from LED with ambient IR rejection -- 2.11.0