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 6A982C433F5 for ; Mon, 29 Nov 2021 23:06:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236346AbhK2XJt (ORCPT ); Mon, 29 Nov 2021 18:09:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236822AbhK2XJG (ORCPT ); Mon, 29 Nov 2021 18:09:06 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9826C043AF1 for ; Mon, 29 Nov 2021 12:52:42 -0800 (PST) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mrndF-0001H9-9a; Mon, 29 Nov 2021 21:52:13 +0100 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mrnd1-001nbP-Cy; Mon, 29 Nov 2021 21:51:58 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1mrnd0-0003gn-Bn; Mon, 29 Nov 2021 21:51:58 +0100 Date: Mon, 29 Nov 2021 21:51:54 +0100 From: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: Billy Tsai Cc: jdelvare@suse.com, linux@roeck-us.net, robh+dt@kernel.org, joel@jms.id.au, andrew@aj.id.au, lee.jones@linaro.org, thierry.reding@gmail.com, p.zabel@pengutronix.de, linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, BMC-SW@aspeedtech.com Subject: Re: [v13 2/2] pwm: Add Aspeed ast2600 PWM support Message-ID: <20211129205154.jtm4ehvvfo52toth@pengutronix.de> References: <20211129064329.27006-1-billy_tsai@aspeedtech.com> <20211129064329.27006-3-billy_tsai@aspeedtech.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ltrr7wjbtue7nf5u" Content-Disposition: inline In-Reply-To: <20211129064329.27006-3-billy_tsai@aspeedtech.com> X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 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: devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --ltrr7wjbtue7nf5u Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello Billy, just two minor thing left to criticise: On Mon, Nov 29, 2021 at 02:43:29PM +0800, Billy Tsai wrote: > + if (clk_en && duty_pt) { > + dividend =3D (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt > + << div_h; > + state->duty_cycle =3D DIV_ROUND_UP_ULL(dividend, rate); > + } else > + state->duty_cycle =3D clk_en ? state->period : 0; I wonder about checkpatch not criticising this construct. See Documentation/process/coding-style.rst: Do not unnecessarily use braces where a single statement will do. [...] This does not apply if only one branch of a conditional statement is a single statement; in the latter case use braces in both branches > [...] > +static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pw= m, > + const struct pwm_state *state) > +{ > + struct device *dev =3D chip->dev; > + struct aspeed_pwm_data *priv =3D aspeed_pwm_chip_to_data(chip); > + u32 hwpwm =3D pwm->hwpwm, duty_pt; > + unsigned long rate; > + u64 div_h, div_l, divisor, expect_period; > + bool clk_en; > + > + expect_period =3D state->period; > + dev_dbg(dev, "expect period: %lldns, duty_cycle: %lldns", expect_period, > + state->duty_cycle); > + > + rate =3D clk_get_rate(priv->clk); > + if (expect_period > div64_u64(ULLONG_MAX, (u64)rate)) > + expect_period =3D div64_u64(ULLONG_MAX, (u64)rate); If you write that as expect_period =3D min(div64_u64(ULLONG_MAX, (u64)rate), expect_period); you make sure that the division is only calculated once. Best regards Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | https://www.pengutronix.de/ | --ltrr7wjbtue7nf5u Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEfnIqFpAYrP8+dKQLwfwUeK3K7AkFAmGlPWcACgkQwfwUeK3K 7Ak8pwf/f38P/ANk72PoQ6XaxGN4JtL+YI2d3Fnkk/akQZog/rZXoqAqA+vpeUZN ZCP6kfvy1afZmpmJZ5/A7IcEVbx63vryrJDubwJBpEjW+XQ7zUEIkWviTmmfgtbf d4alL1S8iU6oPpM4ijAZi+AUbwOkzu0mLEW6Cvx/EPJaahmLxWTUjip+WVgEN3XW CbrXaQCNLjX2E+OE/ddOC2kCwGJjM8eOjoMl7xZ6gL0mEMyyQpReIxDKuUUK3PSA RhTGOVEP0CVoksgQaMf8X5aKQvbQqzlS0/Tpinpb2sPTeefRouahOsqb5aieNsbH qrCFLTc6x3uQByyGnIUj9364lD8/5A== =/Kh7 -----END PGP SIGNATURE----- --ltrr7wjbtue7nf5u--