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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 9CB92C43387 for ; Tue, 8 Jan 2019 07:43:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F77A20700 for ; Tue, 8 Jan 2019 07:43:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727473AbfAHHnh (ORCPT ); Tue, 8 Jan 2019 02:43:37 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:53179 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727295AbfAHHnh (ORCPT ); Tue, 8 Jan 2019 02:43:37 -0500 Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ggm2u-0008F8-NJ; Tue, 08 Jan 2019 08:43:32 +0100 Received: from ukl by ptx.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1ggm2t-0004hn-QE; Tue, 08 Jan 2019 08:43:31 +0100 Date: Tue, 8 Jan 2019 08:43:31 +0100 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Yoshihiro Shimoda Cc: thierry.reding@gmail.com, linux-pwm@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v2 1/4] pwm: rcar: Add support "atomic" API Message-ID: <20190108074331.lqwtex2pyumilfyn@pengutronix.de> References: <1546918094-13960-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> <1546918094-13960-2-git-send-email-yoshihiro.shimoda.uh@renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1546918094-13960-2-git-send-email-yoshihiro.shimoda.uh@renesas.com> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 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-renesas-soc@vger.kernel.org Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hello, On Tue, Jan 08, 2019 at 12:28:11PM +0900, Yoshihiro Shimoda wrote: > This patch adds support for "atomic" API. Behavior is the same as > when using legacy APIs. > > Signed-off-by: Yoshihiro Shimoda > --- > drivers/pwm/pwm-rcar.c | 37 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c > index a41812f..ba70e83 100644 > --- a/drivers/pwm/pwm-rcar.c > +++ b/drivers/pwm/pwm-rcar.c > @@ -192,12 +192,49 @@ static void rcar_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); > } > > +static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > + struct pwm_state *state) > +{ > + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); > + struct pwm_state cur_state; > + int div, ret; > + > + /* This HW doesn't support changing polarity */ > + pwm_get_state(pwm, &cur_state); > + if (state->polarity != cur_state.polarity) > + return -ENOTSUPP; Does the driver only support normal polarity or only inversed polarity? If so checking against that would be more clear here. > + > + div = rcar_pwm_get_clock_division(rp, state->period); > + if (div < 0) > + return div; > + > + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); > + > + ret = rcar_pwm_set_counter(rp, div, state->duty_cycle, state->period); > + if (!ret) > + rcar_pwm_set_clock_control(rp, div); > + > + /* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */ > + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR); > + > + if (!ret && state->enabled) > + ret = rcar_pwm_enable(chip, pwm); > + > + if (!state->enabled) { > + rcar_pwm_disable(chip, pwm); > + ret = 0; > + } Assume the PWM runs with duty cycle 33% when pwm_apply_state({ .enabled=0, .duty_cycle=66, .period=100 }) is called. Does this might result in a 66% wave form being emitted? If yes, this needs fixing. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |