From patchwork Wed Dec 22 03:46:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liam Beguin X-Patchwork-Id: 12690965 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60832C4321E for ; Wed, 22 Dec 2021 03:47:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242296AbhLVDrO (ORCPT ); Tue, 21 Dec 2021 22:47:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242208AbhLVDrB (ORCPT ); Tue, 21 Dec 2021 22:47:01 -0500 Received: from mail-qt1-x831.google.com (mail-qt1-x831.google.com [IPv6:2607:f8b0:4864:20::831]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FEEDC06173F; Tue, 21 Dec 2021 19:47:01 -0800 (PST) Received: by mail-qt1-x831.google.com with SMTP id p19so774117qtw.12; Tue, 21 Dec 2021 19:47:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BDkFtZR4GcVfPI2FAnt2gKNxJlGgIx5025z/PArQTSg=; b=hmhACLBVidwWeIBUvFwJTuDfbcxgEIfQ8CLsjIpb0uF8rLeVfPTFuDMLVeM2DWZjk2 Lg+iiOzUIYbM9pyjgCsghW7kSomnYChIKZQyhKYdhQlhYALaRGLNaD5YzaquzRqOLKXN WV7D+4zRyjJA1YhwemjuoIAacqpjhi3QYbuyH5/mCjLBKnA0Igczn9f1TyQNxXRiQl9h i836I5u3EacczEk+/HQn0EMcLAsIx4+oGZfNZxm2L2sD+jQKSX5J3DbJ47Ju1Fz3gHpu rv2NdLPp6VdJ8prdnGArhOMgLjXmUwnsmf84nj9UgA9afvw6dFarnQGo9i1Z/zVwMAxZ bqoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BDkFtZR4GcVfPI2FAnt2gKNxJlGgIx5025z/PArQTSg=; b=lYQTeM8Bpc5tmRZOHxvJ2ZUVR7Y8AdZjB3f5EybPCUQXoK1dr9cIVrrxF+siRdCYkP 4jYOuU2uNGeWBJL3SMh+wKutgXQme/0+OkGL2I+sEs/qgkmgRp49sdzcCPtslo6mrzWU 1SzRzXQk8pptRAWJInHcVyxr/xUUgZi/tqxwkjnlIlXtMPEgU+viKnI/g0w4lEqCXZmL xMQUFwLqbYsDidN2C1soX2adI0rpjes2j16ziaH8rvA9VirKkX6o9jxFpuW8A3Ynkcwq lqr+spBDsiyK7EcndKYb+oq9rXoFbdtFDZsGlK5/R6Bel9cCQFjeG7mA3ktvP9RJJmjX rUdQ== X-Gm-Message-State: AOAM530VtQwdycR1cOgUwt2DSyNdf5d335L4Y5gFqXTLnxEkuhZQfqGA OzV9dkYw/4bWir3tP3Kv24A= X-Google-Smtp-Source: ABdhPJzRqVp6q+2KRVioVVU+SUQ2i7jXZSiSONTaFZuIku/5yrQeFFIRowOwJt6WaIhyEBKkYGifyA== X-Received: by 2002:ac8:5a4a:: with SMTP id o10mr916786qta.91.1640144820596; Tue, 21 Dec 2021 19:47:00 -0800 (PST) Received: from shaak.xiphos.ca (69-165-204-82.cable.teksavvy.com. [69.165.204.82]) by smtp.gmail.com with ESMTPSA id f18sm918944qko.34.2021.12.21.19.46.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Dec 2021 19:47:00 -0800 (PST) From: Liam Beguin To: liambeguin@gmail.com, peda@axentia.se, jic23@kernel.org, andy.shevchenko@gmail.com, lars@metafoo.de Cc: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, robh+dt@kernel.org Subject: [PATCH v11 05/15] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support Date: Tue, 21 Dec 2021 22:46:36 -0500 Message-Id: <20211222034646.222189-6-liambeguin@gmail.com> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211222034646.222189-1-liambeguin@gmail.com> References: <20211222034646.222189-1-liambeguin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Liam Beguin Some ADCs use IIO_VAL_INT_PLUS_{NANO,MICRO} scale types. Add support for these to allow using the iio-rescaler with them. Signed-off-by: Liam Beguin Reviewed-by: Peter Rosin --- drivers/iio/afe/iio-rescale.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c index d0669fd8eac5..190a83e08008 100644 --- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -17,11 +17,15 @@ #include #include #include +#include int rescale_process_scale(struct rescale *rescale, int scale_type, int *val, int *val2) { unsigned long long tmp; + s32 rem; + u32 mult; + u32 neg; switch (scale_type) { case IIO_VAL_FRACTIONAL: @@ -40,6 +44,37 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, tmp *= rescale->numerator; do_div(tmp, 1000000000LL); *val = tmp; + return scale_type; + case IIO_VAL_INT_PLUS_NANO: + case IIO_VAL_INT_PLUS_MICRO: + mult = scale_type == IIO_VAL_INT_PLUS_NANO ? NANO : MICRO; + + /* + * For IIO_VAL_INT_PLUS_{MICRO,NANO} scale types if either *val + * OR *val2 is negative the schan scale is negative, i.e. + * *val = 1 and *val2 = -0.5 yields -1.5 not -0.5. + */ + neg = *val < 0 || *val2 < 0; + + tmp = (s64)abs(*val) * abs(rescale->numerator); + *val = div_s64_rem(tmp, abs(rescale->denominator), &rem); + + tmp = (s64)rem * mult + (s64)abs(*val2) * abs(rescale->numerator); + tmp = div_s64(tmp, abs(rescale->denominator)); + + *val += div_s64_rem(tmp, mult, val2); + + /* + * If only one of the rescaler elements or the schan scale is + * negative, the combined scale is negative. + */ + if (neg ^ ((rescale->numerator < 0) ^ (rescale->denominator < 0))) { + if (*val) + *val = -*val; + else + *val2 = -*val2; + } + return scale_type; default: return -EOPNOTSUPP;