From patchwork Thu Sep 3 13:21:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 256860 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C9B8C43461 for ; Thu, 3 Sep 2020 14:32:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 217CA20BED for ; Thu, 3 Sep 2020 14:32:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="iZLw1CfU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729347AbgICOcK (ORCPT ); Thu, 3 Sep 2020 10:32:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729303AbgICO1m (ORCPT ); Thu, 3 Sep 2020 10:27:42 -0400 Received: from mail-lj1-x241.google.com (mail-lj1-x241.google.com [IPv6:2a00:1450:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5064C06121A for ; Thu, 3 Sep 2020 06:21:22 -0700 (PDT) Received: by mail-lj1-x241.google.com with SMTP id k25so3629172ljg.9 for ; Thu, 03 Sep 2020 06:21:22 -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=wcVYXgQ5pttw1IKCDgQFlSKYdGXdwjbBjMlIEbUjqiQ=; b=iZLw1CfUpf3zao1xXVpOnJTFOmznOoCWLAU15PeWwd16NwdTP2lGXLKN4iSi6eR0i6 x+zv7dQuz4X0lGxw64dYnfTCDF3jXrFctSGJ1Qb+QeNWWJToXF/bayDRh0USlB20xWU2 xcYHy9v+xKy8bizid6TCyu1VQ/i1vAn+ZYkZk2cstVoPua/zC/DG9cLE91kpZAc022QI inCfL8jDqhQIVS0+/YW/M0U5Dr2hs/eG2r2Kgrzagdw+hTG4alTmxvysUoOrDg9TsXa1 hV4inadOBaQVDQGWmHe6zE2vy9Oz36Hyl8Nt+CDAvzGQefDphw08x4xz00sppiHbMINu t76w== 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=wcVYXgQ5pttw1IKCDgQFlSKYdGXdwjbBjMlIEbUjqiQ=; b=rlM8Rj/s8yoQnii6tsaSH8Eun/1XdYhkpvH5KKB8CV8di5DH7e2rE146xqvPo+kps0 8C1H+yHPXuBDz7rG58PY84zIc7Zbr+blUjRFkFDuaXCXTFTz1rjN9/BpXBUAH8Y76CyF fjITCHkd7qN4SutUB5kGIGzndCPiO7YGRhtkI4rVU3p0mPHLAski2kKmWvd+uNbU68wn zKckD4y3aSzLLRZtpg87yX0miqZzmryKQMXXu5m8ar2gPE3JgFiCKz6FZi6qh+EH5vVx f2lqwoKLTfwk8OhgCyv3+t8si22PsEGvwE1cXYbV8yCkb/gBFewufSmcRmcIj7TfNqeK WQGA== X-Gm-Message-State: AOAM532ruhgyejUvot8ICsOUh35YCsrGB1IeKMKXdtOnlwfnIspuRkf7 yJ6yDccIwSE8tnEzvqP9dR0TuA== X-Google-Smtp-Source: ABdhPJwoWGc8Hxt5nyEATXELirHjbXfeqr2xI0d9g+TZMjeBMrNFljP+NwuSNqU1v5CsQS8IgUQ2yg== X-Received: by 2002:a2e:8215:: with SMTP id w21mr1246122ljg.43.1599139280959; Thu, 03 Sep 2020 06:21:20 -0700 (PDT) Received: from eriador.lan ([188.162.64.138]) by smtp.gmail.com with ESMTPSA id e23sm584220lfj.80.2020.09.03.06.21.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2020 06:21:20 -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, Craig Tatlor Subject: [PATCH v2 2/9] fixp-arith: add a linear interpolation function Date: Thu, 3 Sep 2020 16:21:02 +0300 Message-Id: <20200903132109.1914011-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903132109.1914011-1-dmitry.baryshkov@linaro.org> References: <20200903132109.1914011-1-dmitry.baryshkov@linaro.org> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@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 --- 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