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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 CF6ADC76190 for ; Mon, 22 Jul 2019 19:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD4C120838 for ; Mon, 22 Jul 2019 19:35:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731542AbfGVTfF (ORCPT ); Mon, 22 Jul 2019 15:35:05 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:38431 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726380AbfGVTfE (ORCPT ); Mon, 22 Jul 2019 15:35:04 -0400 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 1hpe5K-0001BK-4k; Mon, 22 Jul 2019 21:34:58 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1hpe5I-0005kZ-2C; Mon, 22 Jul 2019 21:34:56 +0200 Date: Mon, 22 Jul 2019 21:34:56 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Paul Cercueil Cc: Thierry Reding , Rob Herring , Mark Rutland , od@zcrc.me, linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/6] pwm: jz4740: Apply configuration atomically Message-ID: <20190722193456.h4hfte5cczucermd@pengutronix.de> References: <20190607154410.10633-1-paul@crapouillou.net> <20190607154410.10633-4-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190607154410.10633-4-paul@crapouillou.net> 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-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Paul, On Fri, Jun 07, 2019 at 05:44:07PM +0200, Paul Cercueil wrote: > -static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > - int duty_ns, int period_ns) > +static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > + struct pwm_state *state) > { > struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip); > unsigned long long tmp; > unsigned long period, duty; > unsigned int prescaler = 0; > uint16_t ctrl; > - bool is_enabled; > > - tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns; > + tmp = (unsigned long long)clk_get_rate(jz4740->clk) * state->period; > do_div(tmp, 1000000000); > period = tmp; > > @@ -96,16 +95,14 @@ static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > if (prescaler == 6) > return -EINVAL; > > - tmp = (unsigned long long)period * duty_ns; > - do_div(tmp, period_ns); > + tmp = (unsigned long long)period * state->duty_cycle; > + do_div(tmp, state->period); > duty = period - tmp; > > if (duty >= period) > duty = period - 1; > > - is_enabled = jz4740_timer_is_enabled(pwm->hwpwm); > - if (is_enabled) > - jz4740_pwm_disable(chip, pwm); > + jz4740_pwm_disable(chip, pwm); I assume this stops the PWM. Does this complete the currently running period? How does the PWM behave then? (Does it still drive the output? If so, on which level?) > > jz4740_timer_set_count(pwm->hwpwm, 0); > jz4740_timer_set_duty(pwm->hwpwm, duty); Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |