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2021-01-16fixp-arith: add a linear interpolation functionCraig Tatlor1-0/+19
Adds a function to interpolate against two points, this is carried arount as a helper function by tons of drivers. Signed-off-by: Craig Tatlor <ctatlor97@gmail.com> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20201204025509.1075506-3-dmitry.baryshkov@linaro.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-13/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-02[media] fixp-arith: replace sin/cos table by a better precision oneMauro Carvalho Chehab1-38/+107
The cos table used at fixp-arith.h has only 8 bits of precision. That causes problems if it is reused on other drivers. As some media drivers require a higher precision sin/cos implementation, replace the current implementation by one that will provide 32 bits precision. The values generated by the new implementation matches the 32 bit precision of glibc's sin for an angle measured in integer degrees. It also provides support for fractional angles via linear interpolation. On experimental calculus, when used a table with a 0.001 degree angle, the maximum error for sin is 0.000038, which is likely good enough for practical purposes. There are some logic there that seems to be specific to the usage inside ff-memless.c. Move those logic to there, as they're not needed elsewhere. Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Prashant Laddha <prladdha@cisco.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2012-05-14[media] Input: move drivers/input/fixp-arith.h to include/linuxAntonio Ospite1-0/+87
Move drivers/input/fixp-arith.h to include/linux so that the functions defined there can be used by other subsystems, for instance some video devices ISPs can control the output HUE value by setting registers for sin(HUE) and cos(HUE). Signed-off-by: Antonio Ospite <ospite@studenti.unina.it> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>