18c2ecf20Sopenharmony_ciWhat: /sys/bus/iio/devices/iio:deviceX/proximity_on_chip_ambient_infrared_suppression 28c2ecf20Sopenharmony_ciDate: January 2011 38c2ecf20Sopenharmony_ciKernelVersion: 2.6.37 48c2ecf20Sopenharmony_ciContact: linux-iio@vger.kernel.org 58c2ecf20Sopenharmony_ciDescription: 68c2ecf20Sopenharmony_ci From ISL29018 Data Sheet (FN6619.4, Oct 8, 2012) regarding the 78c2ecf20Sopenharmony_ci infrared suppression: 88c2ecf20Sopenharmony_ci 98c2ecf20Sopenharmony_ci Scheme 0, makes full n (4, 8, 12, 16) bits (unsigned) proximity 108c2ecf20Sopenharmony_ci detection. The range of Scheme 0 proximity count is from 0 to 118c2ecf20Sopenharmony_ci 2^n. Logic 1 of this bit, Scheme 1, makes n-1 (3, 7, 11, 15) 128c2ecf20Sopenharmony_ci bits (2's complementary) proximity_less_ambient detection. The 138c2ecf20Sopenharmony_ci range of Scheme 1 proximity count is from -2^(n-1) to 2^(n-1). 148c2ecf20Sopenharmony_ci The sign bit is extended for resolutions less than 16. While 158c2ecf20Sopenharmony_ci Scheme 0 has wider dynamic range, Scheme 1 proximity detection 168c2ecf20Sopenharmony_ci is less affected by the ambient IR noise variation. 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci == ============================================= 198c2ecf20Sopenharmony_ci 0 Sensing IR from LED and ambient 208c2ecf20Sopenharmony_ci 1 Sensing IR from LED with ambient IR rejection 218c2ecf20Sopenharmony_ci == ============================================= 22