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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 <masneyb@onstation.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
20 lines
859 B
Plaintext
20 lines
859 B
Plaintext
What: /sys/bus/iio/devices/iio:deviceX/proximity_on_chip_ambient_infrared_suppression
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Date: January 2011
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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From ISL29018 Data Sheet (FN6619.4, Oct 8, 2012) regarding the
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infrared suppression:
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Scheme 0, makes full n (4, 8, 12, 16) bits (unsigned) proximity
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detection. The range of Scheme 0 proximity count is from 0 to
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2^n. Logic 1 of this bit, Scheme 1, makes n-1 (3, 7, 11, 15)
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bits (2's complementary) proximity_less_ambient detection. The
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range of Scheme 1 proximity count is from -2^(n-1) to 2^(n-1).
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The sign bit is extended for resolutions less than 16. While
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Scheme 0 has wider dynamic range, Scheme 1 proximity detection
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is less affected by the ambient IR noise variation.
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0 Sensing IR from LED and ambient
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1 Sensing IR from LED with ambient IR rejection
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