From mboxrd@z Thu Jan 1 00:00:00 1970 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 7952FC54EED for ; Mon, 30 Jan 2023 09:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236048AbjA3Jer (ORCPT ); Mon, 30 Jan 2023 04:34:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236243AbjA3JeQ (ORCPT ); Mon, 30 Jan 2023 04:34:16 -0500 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 231E19EDC for ; Mon, 30 Jan 2023 01:32:56 -0800 (PST) Received: by mail-pj1-x1036.google.com with SMTP id w6-20020a17090ac98600b0022c58cc7a18so6009547pjt.1 for ; Mon, 30 Jan 2023 01:32:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=w06XLuTGv42ExA7kvsEzi3HmqNn0e+XIKH+7gH1xWFk=; b=PPfshnuneZVuaGMsWsf0abmeP49jp4AxSkkBj/mh1QI/DzHKXdaR6hl+H+ItCxqyBK 8EvW4xXW6VegaasREhK2bUhShb9wvty8UOLr3wp/rbISnmKVHRVvA0rpCOSUt0MCj0ZR oPhRoLukyOzJLiU4C/lp/aLdGjZGUoPkShPRj19HLGlGJVneY/5JrOxKgYSDAs+kHckA ZbAar3Gjnh03WMx7A3k5Ncx3kq8vJdKp0fzptQZusU7UMj0/chZLjSo/ClNBAAPUYkSd 8bm/XpTxdY/MmYvytxFvGcJV04KPmAG08wqBrYkaeFcuRA8URaK7P1WcmVaJR2IZIpdw jMhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=w06XLuTGv42ExA7kvsEzi3HmqNn0e+XIKH+7gH1xWFk=; b=xou/XueX+yBWROXl/BQP9XD+8h7FN5nBPp5EljOnwEqQiBsorURDfHonrmt2EoBG91 Bv07gfkISIlBr10eTc1Bs5LuveM2TZUQFYVm6kxaAFm7WhhdUoE3OchU7d7+tsDXz+8C U6btT5/kuxVyJXd+S6JX7gGBw7tAjf9IT0bqzhIFQ1hmPmS0CkAEiJMgJy3ISDyh00zM AUk/zFMqS1hRDdpALNiNMU6LVfRQlH/bLPvGKENDHyJAgUn+pkotoqfkS8uP32V44LoV X4QYOUbr2VBlBoDfcg25osiB0gP5qSndT2PV68ap/ztoUFoW7s7l8t1X465jwxt/FR8f 961A== X-Gm-Message-State: AFqh2koHSf12AyJh7e6Lobienj8rHO+ATpHhC7m8eJMztod3n/Po6pgd P56tkdWHj2g8rD/sJ0+oRMkvpA== X-Google-Smtp-Source: AMrXdXtS3CCualmkzbk7XdCqctKx3U6p6dFg1oHURin04Tlb0OJZb8OfiFW6kp53r9/H5XL1owCXrw== X-Received: by 2002:a05:6a20:1596:b0:b8:7905:b6c4 with SMTP id h22-20020a056a20159600b000b87905b6c4mr62293777pzj.61.1675071165340; Mon, 30 Jan 2023 01:32:45 -0800 (PST) Received: from hsinchu15.internal.sifive.com (59-124-168-89.hinet-ip.hinet.net. [59.124.168.89]) by smtp.gmail.com with ESMTPSA id t13-20020a6564cd000000b004db2b310f95sm6245704pgv.16.2023.01.30.01.32.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Jan 2023 01:32:44 -0800 (PST) From: Nylon Chen To: aou@eecs.berkeley.edu, conor@kernel.org, emil.renner.berthing@canonical.com, geert+renesas@glider.be, heiko@sntech.de, krzysztof.kozlowski+dt@linaro.org, palmer@dabbelt.com, paul.walmsley@sifive.com, robh+dt@kernel.org, thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de, devicetree@vger.kernel.org, linux-pwm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: nylon.chen@sifive.com, nylon7717@gmail.com, zong.li@sifive.com, greentime.hu@sifive.com, vincent.chen@sifive.com Subject: [PATCH v2 2/2] pwm: sifive: change the PWM controlled LED algorithm Date: Mon, 30 Jan 2023 17:32:29 +0800 Message-Id: <20230130093229.27489-3-nylon.chen@sifive.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20230130093229.27489-1-nylon.chen@sifive.com> References: <20230130093229.27489-1-nylon.chen@sifive.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org The `frac` variable represents the pulse inactive time, and the result of this algorithm is the pulse active time. Therefore, we must reverse the result. The reference is SiFive FU740-C000 Manual[0]. [0]: https://sifive.cdn.prismic.io/sifive/1a82e600-1f93-4f41-b2d8-86ed8b16acba_fu740-c000-manual-v1p6.pdf Signed-off-by: Nylon Chen --- drivers/pwm/pwm-sifive.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index 62b6acc6373d..a5eda165d071 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -158,6 +158,7 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, frac = DIV64_U64_ROUND_CLOSEST(num, state->period); /* The hardware cannot generate a 100% duty cycle */ frac = min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1); + frac = (1U << PWM_SIFIVE_CMPWIDTH) - 1 - frac; mutex_lock(&ddata->lock); if (state->period != ddata->approx_period) { -- 2.36.1