From patchwork Wed Oct 7 13:54:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 11820695 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 E24B0139F for ; Wed, 7 Oct 2020 13:55:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDF9921582 for ; Wed, 7 Oct 2020 13:55:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="J0HrgTP+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728560AbgJGNzT (ORCPT ); Wed, 7 Oct 2020 09:55:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728554AbgJGNys (ORCPT ); Wed, 7 Oct 2020 09:54:48 -0400 Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C77AC061755 for ; Wed, 7 Oct 2020 06:54:46 -0700 (PDT) Received: by mail-lf1-x144.google.com with SMTP id r127so2357806lff.12 for ; Wed, 07 Oct 2020 06:54:46 -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=J0HrgTP+bdsiziFzBLAU3bFhSgcehD3IjjAumE61noLFhq70j+LNfR4NnX9nqFCeYT 9UzC/oIh1asAvqg3J1HbStk6aoQvGIml1fTYox6KJwNkqPYffm9bRoXCmhtTWRaPGKn2 frh2vEiA+bp3euj+YWZkmRgGB3eWHDrQm4rz/v2xTKxMaQqFVTGc/dOpqkHfLjTinLrP P/vBvbdIKr7GsDQcujkJcb6C8lJGAjyDtTT3+825JbMEi55QG6E3PlO4k7A+OQDiaLXK wnWF0Kv61acAbziZX7YQ8cbcIX9o1MKNT5k5C8bNeBtt8mJC9nCLMSlXJ6nYEW+au3Io oc7Q== 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=Crq4plFrgO0XF+9ktVzd6dzozcOxdyNSIW626IGvjwG4ndKbBWA3F8iHDSQP7kyb13 UBaFnjd9wqwHY9o7rq7CRh0batzbKu82Hvn+mS24jtoEAIW6sVWHVj4jqC5c19jCuuCI apHIU1HgBZ6WoShdMDGBeft7GnK2qRlWpXv15e5NsWizOQiZoR6NOR5yLqCknu63kpaD pH01T4vERnwKs96MrRl0jTcO7sCIWx0p+8XZ0ClXee8EQDg2wANyxxXdPWbjEJ63iIBo Ff1vV2h1acyuUZ9UV6hqGtTEHGZAPsrHdyKn5V1LVuejpJREng/zQiDkQS5AHUeKlOKb S4QQ== X-Gm-Message-State: AOAM530xOYJgMC1O0qm37t+j2+ad9u9WX1rCl+1Jucm9mVEn5N/7cHbp MfP6NB7yFi5JSVodGsMsBewaGQ== X-Google-Smtp-Source: ABdhPJzbdFLj0KVV5TfCbDkOYOXQF8BsCmIn/MeBPuzERCQJAPmCUR3WfIMSzkUI75efgUaNtyDVRg== X-Received: by 2002:ac2:53a5:: with SMTP id j5mr922652lfh.253.1602078884614; Wed, 07 Oct 2020 06:54:44 -0700 (PDT) Received: from localhost.localdomain ([188.162.65.250]) by smtp.gmail.com with ESMTPSA id n3sm339768lfq.274.2020.10.07.06.54.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 06:54:43 -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 v7 02/10] fixp-arith: add a linear interpolation function Date: Wed, 7 Oct 2020 16:54:25 +0300 Message-Id: <20201007135433.1041979-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201007135433.1041979-1-dmitry.baryshkov@linaro.org> References: <20201007135433.1041979-1-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