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[23.128.96.18]) by mx.google.com with ESMTP id l12si7523298edt.99.2020.09.14.08.57.49; Mon, 14 Sep 2020 08:57:49 -0700 (PDT) Received-SPF: pass (google.com: domain of devicetree-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=Ah7wZk7H; spf=pass (google.com: domain of devicetree-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726420AbgINP5p (ORCPT + 6 others); Mon, 14 Sep 2020 11:57:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbgINPsY (ORCPT ); Mon, 14 Sep 2020 11:48:24 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A1E2C061354 for ; Mon, 14 Sep 2020 08:48:24 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id k25so132477ljk.0 for ; Mon, 14 Sep 2020 08:48:24 -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=Ah7wZk7H4a1YXb3siR+1ZjnwbjtSkXQdarNonG4apXmKK1RU7RgA3q5ffNCULhdZvv szBF+ywo3gSiAmVakhVSgrzGXibgJEBf0zLpay43DWkEfJks/Sxn9RKntWuRWYaevQev lg3aSW2BNqdhGyZe/JNz3NltDhgf8++D85FQcp14KLyjLf7D4vi1YLxZTZvklHXZ9T8Y Un2iIgaxXMW8MTzeluqSCr7BmwGpo0sk+04aycaYPhknOLHiqpydFmz5ZYsXOE0v/Gbs S1YPClKB3VqmlDYAnn14//BI+/N1syiPKkvqMZDzc7xAJueJPfZwiiaWpHxrUtoA2par bnCQ== 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=D1ef4SAyhjpLsEAxO5Ro6Ys7Fr6GGzGvMi6iax1JmstlVHaLRla9v+AQU35M2rsX8Z Z+Vd2g2udqFFeBR3WS4JB3exGzASBvxf55aWwByv8uDOthZHK1icFHd/YsMZBMm6s8aX T8fkGa4bu+zjHkIbl4W9xp+vNFB7JZ3p245h/J2BbwaIWBUhCdYb+cqRu/o5KpVPb651 JVxt+BcK7CmoZDPizCGLdw404iPtxr/bhhzLtThcWQJrsBF/ihSJjODur3V1M8bT3/9U 9fsm5Pc7JtTYWT0yUs8sB0tTi1xPNSDT5NBFVGPIA/krfG4pWFnOn28VcEU6bp7y2rsw 5fIA== X-Gm-Message-State: AOAM532yOgefoxvfwUqk8S2z/Qnx5ILEUB+SK3CS2pnR85Ha4xSnWXV6 tpyrJ0fFOPnINwfvmX10GohvoQ== X-Received: by 2002:a2e:780d:: with SMTP id t13mr5681189ljc.324.1600098502656; Mon, 14 Sep 2020 08:48:22 -0700 (PDT) Received: from eriador.lan ([188.162.64.187]) by smtp.gmail.com with ESMTPSA id f19sm3834650lfs.85.2020.09.14.08.48.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2020 08:48:22 -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 , Craig Tatlor , Jonathan Cameron Subject: [PATCH v5 2/9] fixp-arith: add a linear interpolation function Date: Mon, 14 Sep 2020 18:48:02 +0300 Message-Id: <20200914154809.192174-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200914154809.192174-1-dmitry.baryshkov@linaro.org> References: <20200914154809.192174-1-dmitry.baryshkov@linaro.org> MIME-Version: 1.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@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(+) -- 2.28.0 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