From patchwork Wed Sep 30 10:01:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 11808665 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 86606618 for ; Wed, 30 Sep 2020 10:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66F302076B for ; Wed, 30 Sep 2020 10:02:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="L7JpW8e4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728938AbgI3KCZ (ORCPT ); Wed, 30 Sep 2020 06:02:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729225AbgI3KCY (ORCPT ); Wed, 30 Sep 2020 06:02:24 -0400 Received: from mail-lf1-x142.google.com (mail-lf1-x142.google.com [IPv6:2a00:1450:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0196BC061755 for ; Wed, 30 Sep 2020 03:02:24 -0700 (PDT) Received: by mail-lf1-x142.google.com with SMTP id z19so1410849lfr.4 for ; Wed, 30 Sep 2020 03:02:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=u+ec5e/iUjJ8qDBtGE9xKBCADcm1RI8srVHT5OLXlvU=; b=L7JpW8e41pdQIDs7XVntiDjzE5Whj9TdpeqexPl106qK8irLfsBgPwN+J/IgEe/GWB 8CvCZf6TL20ekgQj5nkrKaJQN9Scd8FnmVP0FlvOHGD3ZMp1WZVPCAstpY1i3ejR2Ow/ RUGykcuatohUzP5y8wZA7Hh4EvItbSX3bc+wJfw9+KLldbCWOOc1H0I2/w53H1DSLlks kLCF9lZUFdpCHrk04/77Pto7W1TUf1IhMqJnighA1lIn+PilH9NXLam0F085MiAwSNuH MilmtAaB5f0ibptA12QDDQ1J+hz38YKS9dHqV7Wrvq5sGAZaMO6I6yb2utuP/s9ObxGX z4Qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=u+ec5e/iUjJ8qDBtGE9xKBCADcm1RI8srVHT5OLXlvU=; b=REfpJpa496Ove3pG8FQkvRnmrkdbhIqJVfoB4gQWo0css8ZZpBq/13jyKJWEj3ehME 5Dkq4JWGRBZF+2bxKV8/Eb+OQrPHNtavk7UfyVkFvpRADGTSRRt+cP1OjdLWNU/DJTkg K+VdemSe0nHgyMBrFZgJNXjngAuAkKyTzDylT4JUWGUarv18Y0uWxsFJiiO2YzRq8rcp kkD2RAYejiq6ZxHGKWERct8q3N7Xle1YEflAel7VO33560SSJk2ajmzWMAu2rpc/Fmsc FP9zX1T/6IdQ85FzsrRoDTkiR9ryyocujRu94jFUVzDXMaHO4QRFeH5beFxHC6YR9zaZ u/Wg== X-Gm-Message-State: AOAM531k6BICnvbpNmjxgYEUW0bcTpd16KPuRhoJWJ5xn1CURcOfnfWa SsV2T0N+TKfy1TwBXte1zgx7Cw== X-Google-Smtp-Source: ABdhPJzwwTX5w1ZQGgCsH5flM1GdwUDPzLgUTf5zIUJ76ZzgPt5znCt8OgR/hp2NsMNJkCGhBPk5Cg== X-Received: by 2002:ac2:418c:: with SMTP id z12mr645897lfh.231.1601460142445; Wed, 30 Sep 2020 03:02:22 -0700 (PDT) Received: from eriador.lan ([188.162.64.138]) by smtp.gmail.com with ESMTPSA id w4sm132479lff.231.2020.09.30.03.02.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Sep 2020 03:02:21 -0700 (PDT) From: Dmitry Baryshkov To: Andy Gross , Bjorn Andersson , Rob Herring , Zhang Rui , Daniel Lezcano , Amit Kucheria , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler Cc: linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, Manivannan Sadhasivam , Jishnu Prakash , Craig Tatlor , Jonathan Cameron Subject: [PATCH v6 02/10] fixp-arith: add a linear interpolation function Date: Wed, 30 Sep 2020 13:01:55 +0300 Message-Id: <20200930100203.1988374-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200930100203.1988374-1-dmitry.baryshkov@linaro.org> References: <20200930100203.1988374-1-dmitry.baryshkov@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Craig Tatlor 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 Signed-off-by: Dmitry Baryshkov Acked-by: Jonathan Cameron --- include/linux/fixp-arith.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/fixp-arith.h b/include/linux/fixp-arith.h index 8396013785ef..281cb4f83dbe 100644 --- a/include/linux/fixp-arith.h +++ b/include/linux/fixp-arith.h @@ -141,4 +141,23 @@ static inline s32 fixp_sin32_rad(u32 radians, u32 twopi) #define fixp_cos32_rad(rad, twopi) \ fixp_sin32_rad(rad + twopi / 4, twopi) +/** + * fixp_linear_interpolate() - interpolates a value from two known points + * + * @x0: x value of point 0 + * @y0: y value of point 0 + * @x1: x value of point 1 + * @y1: y value of point 1 + * @x: the linear interpolant + */ +static inline int fixp_linear_interpolate(int x0, int y0, int x1, int y1, int x) +{ + if (y0 == y1 || x == x0) + return y0; + if (x1 == x0 || x == x1) + return y1; + + return y0 + ((y1 - y0) * (x - x0) / (x1 - x0)); +} + #endif