From patchwork Fri Dec 4 02:54:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 11950473 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 DF42EC433FE for ; Fri, 4 Dec 2020 02:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91B72224D4 for ; Fri, 4 Dec 2020 02:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725960AbgLDC4p (ORCPT ); Thu, 3 Dec 2020 21:56:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726670AbgLDC4o (ORCPT ); Thu, 3 Dec 2020 21:56:44 -0500 Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64BACC08E860 for ; Thu, 3 Dec 2020 18:55:21 -0800 (PST) Received: by mail-lj1-x244.google.com with SMTP id f24so4885542ljk.13 for ; Thu, 03 Dec 2020 18:55:21 -0800 (PST) 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=4MAQUsN9uWY5ajUEroZxi+OKqjFgmfYZZ4/Px2YZkiI=; b=qQ92WvbLHygA9tYFlW/qVMiJlnWK1Okf7PjhTjzbbiNH8IuTFRwQkmHVZNHzoBywFz SbqTzuqyPUkNO5jGVBicTIQ+VJ0+PYpVbQtPeQRwm6vLgJCH66/gg/lwr+GUOogiGL7G bhKNRn1+/hq2u4CntZ7xKj+Y9/jC3W0x0VLbMrFgiwBIFimYsJKLdXXaAG8swhyAADOt 0ruXuZRs5uGuJOZlN8t6PHIe2P5OQh8iZ9QTRhTNQQAx3JhsNJWO762LHND9Zd3z/k/I 6SdZFaVZHuHG4Yq6SL1FpypMyIFW+zDiq7tf5HClBe7lqWHO65/1CbvEEW3TX+azVzGS HL6A== 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=4MAQUsN9uWY5ajUEroZxi+OKqjFgmfYZZ4/Px2YZkiI=; b=ifzEvE11kf7Pg8sP88WrqZTr9fv+t3K0dp6qDIAn67NZ333l4PWmcF8ksOXYKaUhqc aJGhpsLKzs8Fcw8/HcKDM5/jDvT92BycpOWVORNs1XoEybvGqj4oQoVt7yediLa9OG/R jFOJB6E/9PUqlBEQT0GVqYtsoO+ZOqS/YS5D5TXVD3Dp9489JTDA8Z4rOHspFO4BC8iT gRcq6KncAPSapPfupeZJSwpV4Du5VMjacknR1CeVuD/a8cOhydjg8yVh2NkJetHaIkvB CJpZu9ZbNgAeifdgGoJAEIoaEEskdw6xdgnAGIBZWrAyKcU6vAttH3TkGEVG4fkIPoEC xhww== X-Gm-Message-State: AOAM532VkujZzw1kb7eGd9TkzvsNDfim1/EDkwJ0XIezMbeB/HS6569q 2AId11Wf7KuJIrDOlqBaQklioA== X-Google-Smtp-Source: ABdhPJzhROS7VX4f30wwhjmSfuiX+tj6hkBERlUAa04UXeta/A5TNU+d8/z2jLiqKbzKPJiKLFFmdQ== X-Received: by 2002:a2e:2286:: with SMTP id i128mr2446984lji.396.1607050519844; Thu, 03 Dec 2020 18:55:19 -0800 (PST) Received: from eriador.lumag.spb.ru ([188.162.64.117]) by smtp.gmail.com with ESMTPSA id b8sm1131667ljo.68.2020.12.03.18.55.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Dec 2020 18:55:19 -0800 (PST) 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 v10 02/15] fixp-arith: add a linear interpolation function Date: Fri, 4 Dec 2020 05:54:56 +0300 Message-Id: <20201204025509.1075506-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201204025509.1075506-1-dmitry.baryshkov@linaro.org> References: <20201204025509.1075506-1-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