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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham 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 A96CFC43381 for ; Mon, 1 Apr 2019 18:38:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 720F320896 for ; Mon, 1 Apr 2019 18:38:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PQJcwYuj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 720F320896 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OdeLaFV0stbbhsZyhuSk1al4xXiF33qM+iroJ+73WBs=; b=PQJcwYujGYIf75 kNqJGXfOI7swyfZMVqD1o5BXwwvPOC62d16qXa+VZo7PRdIp/J4zgVLQI4pHobBvrkqqCp7stKzcj NSzdlfYCZJNEg5TJiwmdwwUkxZsxJt/Layia/HSTUNxxMvQStCaNgUvKl96hB5j+IJIsJP1d+SOV9 ouMI2aKoz4p/4OSOXzyOpNMYUVAV46E6apsb7/gtDy6jOvw94LWVwzpxsEwUfuOZFTb4kQRBFOuzt LRgx84OyxmmnI9Yb4SUYuJN1EbjtzyhmP+al2VS3kXk/DfEVzgWi5A7gIhMoJA1QtPfLzmrA4e/nG IAvIIj0y3cBiNi4ITe7A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hB1pd-0006Ds-Uv; Mon, 01 Apr 2019 18:38:53 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hB1pa-0006DF-P0 for linux-amlogic@lists.infradead.org; Mon, 01 Apr 2019 18:38:52 +0000 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hB1pY-00030r-69; Mon, 01 Apr 2019 20:38:48 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1hB1pX-0007sB-Gf; Mon, 01 Apr 2019 20:38:47 +0200 Date: Mon, 1 Apr 2019 20:38:47 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Martin Blumenstingl Subject: Re: [PATCH 1/2] pwm: meson: consider 128 a valid pre-divider Message-ID: <20190401183847.7xhlgff63cvlzz2h@pengutronix.de> References: <20190401181817.11999-1-martin.blumenstingl@googlemail.com> <20190401181817.11999-2-martin.blumenstingl@googlemail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190401181817.11999-2-martin.blumenstingl@googlemail.com> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-amlogic@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190401_113850_977982_856C0F6F X-CRM114-Status: GOOD ( 11.27 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, narmstrong@baylibre.com, bichao.zheng@amlogic.com, linux-kernel@vger.kernel.org, thierry.reding@gmail.com, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, jbrunet@baylibre.com Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org Hello Martin, On Mon, Apr 01, 2019 at 08:18:16PM +0200, Martin Blumenstingl wrote: > diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c > index f6e738ad7bd9..4b708c1fcb1d 100644 > --- a/drivers/pwm/pwm-meson.c > +++ b/drivers/pwm/pwm-meson.c > @@ -188,7 +188,7 @@ static int meson_pwm_calc(struct meson_pwm *meson, > do_div(fin_ps, fin_freq); > = > /* Calc pre_div with the period */ > - for (pre_div =3D 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) { > + for (pre_div =3D 0; pre_div <=3D MISC_CLK_DIV_MASK; pre_div++) { > cnt =3D DIV_ROUND_CLOSEST_ULL((u64)period * 1000, > fin_ps * (pre_div + 1)); > dev_dbg(meson->chip.dev, "fin_ps=3D%llu pre_div=3D%u cnt=3D%u\n", You could even calculate pre_div without the loop. Something like: u64 pre_div =3D (u64)period * rate; do_div_round_up(pre_div, NSEC_PER_SEC * 0xffff); pre_div--; (I didn't check rounding and maybe its off by one and ...) This would also get rid of the strange 1000 that is currently used in the calculation without a real benefit (unless I missed something). Best regards Uwe -- = Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ | _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic