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=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 4B7B3C49ED7 for ; Mon, 23 Sep 2019 08:27:50 +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 20BC420835 for ; Mon, 23 Sep 2019 08:27:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="WLhrtVMl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20BC420835 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-arm-kernel-bounces+infradead-linux-arm-kernel=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=6uq8IQBx1YxP+VuNkTjmNOUSiUOPVsiop4Dj2kn1sIk=; b=WLhrtVMlnUQDiA zg8XVHD1BfjpXsLVB36nsdEkqHfnqEdBLTpRUC3kn+5SkamMkcYCAr5z4Jd9d8c7Pd3Eo14Aiwfk0 PEIzM98p1Z5J6n3lSHK5x7DSO+iECJUVtHkU21mv3X6OWAQzrUAMbLh6ObbfVguMcTF1zpt7RGsQ6 fjNZaxPJ9BpzcsGJ19WBinZwQ9o1x9yP3FHQCdwGPKuvfgtGXSyFlumf7hjSoGIxss1LSbifoLryG O7yed0fbsjOX1ZSD9i+0WWxg8P/jHQyfFZxha0ESMT4aAaDKQaxwk7bhbmHgdqKoJor1Yr2/eDzk+ wIAAgVTXyX0sYE0QdgKg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCJhB-0004LX-Tk; Mon, 23 Sep 2019 08:27:45 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCJh8-0004Km-DC for linux-arm-kernel@lists.infradead.org; Mon, 23 Sep 2019 08:27:43 +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 4.92) (envelope-from ) id 1iCJh2-0007k8-EV; Mon, 23 Sep 2019 10:27:36 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1iCJh1-0000Cf-Vo; Mon, 23 Sep 2019 10:27:35 +0200 Date: Mon, 23 Sep 2019 10:27:35 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Rasmus Villemoes Subject: Re: [PATCH 3/4] pwm: mxs: add support for inverse polarity Message-ID: <20190923082735.tzxyhvjlnztsxhsc@pengutronix.de> References: <20190923081348.6843-1-linux@rasmusvillemoes.dk> <20190923081348.6843-4-linux@rasmusvillemoes.dk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190923081348.6843-4-linux@rasmusvillemoes.dk> 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-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190923_012742_449234_E56B9EDA X-CRM114-Status: GOOD ( 17.91 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, linux-pwm@vger.kernel.org, Shawn Guo , Sascha Hauer , linux-kernel@vger.kernel.org, Rob Herring , Thierry Reding , NXP Linux Team , Pengutronix Kernel Team , Fabio Estevam , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Sep 23, 2019 at 10:13:47AM +0200, Rasmus Villemoes wrote: > If I'm reading of_pwm_xlate_with_flags() right, existing device trees > that set #pwm-cells =3D 2 will continue to work. > = > Signed-off-by: Rasmus Villemoes > --- > drivers/pwm/pwm-mxs.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > = > diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c > index 284107784dad..c46697acaf11 100644 > --- a/drivers/pwm/pwm-mxs.c > +++ b/drivers/pwm/pwm-mxs.c > @@ -25,8 +25,11 @@ > #define PERIOD_PERIOD(p) ((p) & 0xffff) > #define PERIOD_PERIOD_MAX 0x10000 > #define PERIOD_ACTIVE_HIGH (3 << 16) > +#define PERIOD_ACTIVE_LOW (2 << 16) > +#define PERIOD_INACTIVE_HIGH (3 << 18) > #define PERIOD_INACTIVE_LOW (2 << 18) > #define PERIOD_POLARITY_NORMAL (PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LO= W) > +#define PERIOD_POLARITY_INVERSE (PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HI= GH) > #define PERIOD_CDIV(div) (((div) & 0x7) << 20) > #define PERIOD_CDIV_MAX 8 > = > @@ -50,9 +53,7 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct = pwm_device *pwm, > unsigned int period_cycles, duty_cycles; > unsigned long rate; > unsigned long long c; > - > - if (state->polarity !=3D PWM_POLARITY_NORMAL) > - return -ENOTSUPP; > + unsigned int pol_bits; > = > rate =3D clk_get_rate(mxs->clk); > while (1) { > @@ -81,9 +82,12 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct= pwm_device *pwm, > return ret; > } > = > + pol_bits =3D state->polarity =3D=3D PWM_POLARITY_NORMAL ? > + PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE; > + > writel(duty_cycles << 16, > mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); > - writel(PERIOD_PERIOD(period_cycles) | PERIOD_POLARITY_NORMAL | PERIOD_C= DIV(div), > + writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div), When will this affect the output? Only on the next start of a period, or immediatly? Can it happen that this results in a mixed output (i.e. a period that has already the new duty cycle from the line above but not the new polarity (or period)? Best regards Uwe -- = Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel