From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422723AbcFCUum (ORCPT ); Fri, 3 Jun 2016 16:50:42 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:36793 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161078AbcFCUuc (ORCPT ); Fri, 3 Jun 2016 16:50:32 -0400 Date: Fri, 3 Jun 2016 13:50:28 -0700 From: Brian Norris To: Boris Brezillon Cc: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood , Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim , Doug Anderson , Caesar Wang , Stephen Barber , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com, Laxman Dewangan Subject: Re: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API Message-ID: <20160603205028.GH124478@google.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> <1464942192-25967-11-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464942192-25967-11-git-send-email-boris.brezillon@free-electrons.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Laxman Hi, On Fri, Jun 03, 2016 at 10:23:08AM +0200, Boris Brezillon wrote: > Use the atomic API wherever appropriate and get rid of pwm_apply_args() > call (the reference period and polarity are now explicitly set when > calling pwm_apply_state()). > > We also make use of the pwm_set_relative_duty_cycle() helper to ease > relative to absolute duty_cycle conversion. > > Signed-off-by: Boris Brezillon > --- > drivers/regulator/pwm-regulator.c | 38 ++++++++++---------------------------- > 1 file changed, 10 insertions(+), 28 deletions(-) > > diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c > index 524b43f..bf033fd 100644 > --- a/drivers/regulator/pwm-regulator.c > +++ b/drivers/regulator/pwm-regulator.c > @@ -59,16 +59,14 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, > unsigned selector) > { > struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); > - struct pwm_args pargs; > - int dutycycle; > + struct pwm_state pstate; > int ret; > > - pwm_get_args(drvdata->pwm, &pargs); > + pwm_prepare_new_state(drvdata->pwm, &pstate); > + pwm_set_relative_duty_cycle(&pstate, > + drvdata->duty_cycle_table[selector].dutycycle, 100); > > - dutycycle = (pargs.period * > - drvdata->duty_cycle_table[selector].dutycycle) / 100; > - > - ret = pwm_config(drvdata->pwm, dutycycle, pargs.period); > + ret = pwm_apply_state(drvdata->pwm, &pstate); > if (ret) { > dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); > return ret; > @@ -126,34 +124,18 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, > { > struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); > unsigned int ramp_delay = rdev->constraints->ramp_delay; > - struct pwm_args pargs; > unsigned int req_diff = min_uV - rdev->constraints->min_uV; > + struct pwm_state pstate; > unsigned int diff; > - unsigned int duty_pulse; > - u64 req_period; > - u32 rem; > int ret; > > - pwm_get_args(drvdata->pwm, &pargs); > + pwm_prepare_new_state(drvdata->pwm, &pstate); > diff = rdev->constraints->max_uV - rdev->constraints->min_uV; > > - /* First try to find out if we get the iduty cycle time which is > - * factor of PWM period time. If (request_diff_to_min * pwm_period) > - * is perfect divided by voltage_range_diff then it is possible to > - * get duty cycle time which is factor of PWM period. This will help > - * to get output voltage nearer to requested value as there is no > - * calculation loss. > - */ > - req_period = req_diff * pargs.period; > - div_u64_rem(req_period, diff, &rem); > - if (!rem) { > - do_div(req_period, diff); > - duty_pulse = (unsigned int)req_period; > - } else { > - duty_pulse = (pargs.period / 100) * ((req_diff * 100) / diff); > - } > + /* We pass diff as the scale to get a uV precision. */ > + pwm_set_relative_duty_cycle(&pstate, req_diff, diff); Notably, you're dropping much of Laxman's commit fd786fb0276a ("regulator: pwm: Try to avoid voltage error in duty cycle calculation"), but I believe the DIV_ROUND_CLOSEST_ULL() in pwm_set_relative_duty_cycle() solves his problem better. > > - ret = pwm_config(drvdata->pwm, duty_pulse, pargs.period); > + ret = pwm_apply_state(drvdata->pwm, &pstate); > if (ret) { > dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); > return ret; Reviewed-by: Brian Norris Tested-by: Brian Norris