From patchwork Fri Oct 9 15:44:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 11826331 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 0971F139F for ; Fri, 9 Oct 2020 15:45:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0CEE222BA for ; Fri, 9 Oct 2020 15:45:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="bwohXV3Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389395AbgJIPpM (ORCPT ); Fri, 9 Oct 2020 11:45:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389252AbgJIPpL (ORCPT ); Fri, 9 Oct 2020 11:45:11 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71B7EC0613D2 for ; Fri, 9 Oct 2020 08:45:11 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id a5so10038227ljj.11 for ; Fri, 09 Oct 2020 08:45:11 -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=bwohXV3YZo5cTz0TyNBCL/bMBJIwuPprPvrhOn48oBFgGvgBiXBPol+T7jzXJBlYAA jUNORplCm8Wgt6R/yIDhzByfIanKQaRWKUsdeKHBlp9j7NJay5EhVgnn4OsBJuW8J5rT 4jY1ipSBsKUbbkCAHXDVjb+xgwIl+w8giDNkvPSQH/N1orSMRnrH/odd77upToDSb/tZ C9bDTxulmJAh7cAMvpxWd8JWMXHySlcOgA90BBBcPtxqwOC2vrjeGvdHFEiwn/cJ+x5H pLGtSKf/BZvDTvSJ6pjLxBWYBYY0TaULkbUVShYJDXk5SqlJa8+bv3Sdc2ab16TnE7Em 2sgw== 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=IH9l0HYtHaAGkQbZuVdWcUm7lQobgOtkRQ7mzpWrKMi0FGMrE5c3BgsNaY2adift2L zDF4WlCCzLT0K8+kQLRmt/CXiuZk/rLw5mtShuiuOv5aVQYzairbYIXfKkYRuKDN8Bup IyeE0VvaS/Cn4ETCG1Xt8mv8zvU7A9NOltSha/+VgpOxNPgsvSqGdwofQdyd3qmYogiV EpCydddNi3uLOdFOSqwjEdB8k27Nyr2TVq5vEYETPweq5NyHbbhlcmEqb8i/jPgXHrdv 2Oq39B79cBC9hKtIXegx+x0neapMUY7dtVyIHgb8ltq7uMgbOIx/dsHiwBQAuJgWzwib UpOQ== X-Gm-Message-State: AOAM530plfLX73dap+vVXEbn4gTdCgodilCXw2gRZ8SbETzWa/FVpcee o2jxG03xtJlDjwWgM17pcuTQiM3OpXe5XneH X-Google-Smtp-Source: ABdhPJx4YT06cf8vN3nDNG3Uu3PKq6LBvxoVB37Y6nn3qXNuVpxuivte4YhuJX4KuTYrszCj94VHFw== X-Received: by 2002:a2e:8042:: with SMTP id p2mr4336774ljg.90.1602258309858; Fri, 09 Oct 2020 08:45:09 -0700 (PDT) Received: from eriador.lan ([188.162.65.231]) by smtp.gmail.com with ESMTPSA id r4sm1505597lfc.162.2020.10.09.08.45.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2020 08:45:09 -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 v8 02/11] fixp-arith: add a linear interpolation function Date: Fri, 9 Oct 2020 18:44:50 +0300 Message-Id: <20201009154459.106189-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201009154459.106189-1-dmitry.baryshkov@linaro.org> References: <20201009154459.106189-1-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