From: Boris Brezillon <boris.brezillon@free-electrons.com> To: Brian Norris <briannorris@chromium.org> Cc: Thierry Reding <thierry.reding@gmail.com>, linux-pwm@vger.kernel.org, Mark Brown <broonie@kernel.org>, Liam Girdwood <lgirdwood@gmail.com>, Heiko Stuebner <heiko@sntech.de>, linux-rockchip@lists.infradead.org, Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim <milo.kim@ti.com>, Doug Anderson <dianders@google.com>, Caesar Wang <wxt@rock-chips.com>, Stephen Barber <smbarber@chromium.org>, Srinivas Kandagatla <srinivas.kandagatla@gmail.com>, Maxime Coquelin <maxime.coquelin@st.com>, Patrice Chotard <patrice.chotard@st.com>, kernel@stlinux.com, Laxman Dewangan <ldewangan@nvidia.com> Subject: Re: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API Date: Sat, 4 Jun 2016 08:28:48 +0200 [thread overview] Message-ID: <20160604082848.0b897b14@bbrezillon> (raw) In-Reply-To: <20160603205028.GH124478@google.com> On Fri, 3 Jun 2016 13:50:28 -0700 Brian Norris <briannorris@chromium.org> wrote: > + 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 <boris.brezillon@free-electrons.com> > > --- > > 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. Oops, forgot to comment on that in the commit message. Indeed, the use of pwm_set_relative_duty_cycle() solves the problem Laxman was seeing. > > > > > - 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 <briannorris@chromium.org> > Tested-by: Brian Norris <briannorris@chromium.org> -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: boris.brezillon@free-electrons.com (Boris Brezillon) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API Date: Sat, 4 Jun 2016 08:28:48 +0200 [thread overview] Message-ID: <20160604082848.0b897b14@bbrezillon> (raw) In-Reply-To: <20160603205028.GH124478@google.com> On Fri, 3 Jun 2016 13:50:28 -0700 Brian Norris <briannorris@chromium.org> wrote: > + 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 <boris.brezillon@free-electrons.com> > > --- > > 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. Oops, forgot to comment on that in the commit message. Indeed, the use of pwm_set_relative_duty_cycle() solves the problem Laxman was seeing. > > > > > - 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 <briannorris@chromium.org> > Tested-by: Brian Norris <briannorris@chromium.org> -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
next prev parent reply other threads:[~2016-06-04 6:28 UTC|newest] Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-03 8:22 [PATCH 00/14] regulator: pwm: various improvements Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon 2016-06-03 8:22 ` [PATCH 01/14] pwm: Add new helpers to create/manipulate PWM states Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 02/14] regulator: pwm: Drop unneeded pwm_enable() call Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 11:08 ` Applied "regulator: pwm: Drop unneeded pwm_enable() call" to the regulator tree Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 8:23 ` [PATCH 03/14] pwm: rockchip: Fix period and duty_cycle approximation Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:03 ` Brian Norris 2016-06-03 20:03 ` Brian Norris 2016-06-04 6:19 ` Boris Brezillon 2016-06-04 6:19 ` Boris Brezillon 2016-06-07 17:25 ` Brian Norris 2016-06-07 17:25 ` Brian Norris 2016-06-03 8:23 ` [PATCH 04/14] pwm: rockchip: Add support for hardware readout Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:07 ` Brian Norris 2016-06-03 20:07 ` Brian Norris 2016-06-03 20:20 ` Brian Norris 2016-06-03 20:20 ` Brian Norris 2016-06-04 6:24 ` Boris Brezillon 2016-06-04 6:24 ` Boris Brezillon 2016-06-07 17:26 ` Brian Norris 2016-06-07 17:26 ` Brian Norris 2016-06-03 8:23 ` [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:28 ` Brian Norris 2016-06-03 20:28 ` Brian Norris 2016-06-04 6:26 ` Boris Brezillon 2016-06-04 6:26 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 06/14] pwm: rockchip: Add support for atomic update Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:37 ` Brian Norris 2016-06-03 20:37 ` Brian Norris 2016-06-03 20:37 ` Brian Norris 2016-06-03 8:23 ` [PATCH 07/14] pwm: sti: Add support for hardware readout Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 08/14] pwm: sti: Avoid glitches on already running PWMs Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:38 ` Brian Norris 2016-06-03 20:38 ` Brian Norris 2016-06-03 20:38 ` Brian Norris 2016-06-03 8:23 ` [PATCH 09/14] regulator: pwm: Adjust PWM config at probe time Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:41 ` Brian Norris 2016-06-03 20:41 ` Brian Norris 2016-06-03 8:23 ` [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:50 ` Brian Norris 2016-06-03 20:50 ` Brian Norris 2016-06-03 20:50 ` Brian Norris 2016-06-04 6:28 ` Boris Brezillon [this message] 2016-06-04 6:28 ` Boris Brezillon 2016-06-06 6:14 ` Laxman Dewangan 2016-06-06 6:14 ` Laxman Dewangan 2016-06-06 6:14 ` Laxman Dewangan 2016-06-03 8:23 ` [PATCH 11/14] regulator: pwm: properly initialize the ->state field Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:51 ` Brian Norris 2016-06-03 20:51 ` Brian Norris 2016-06-03 8:23 ` [PATCH 12/14] regulator: pwm: Retrieve correct voltage Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:55 ` Brian Norris 2016-06-03 20:55 ` Brian Norris 2016-06-03 8:23 ` [PATCH 13/14] regulator: pwm: Support extra continuous mode cases Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 21:03 ` Brian Norris 2016-06-03 21:03 ` Brian Norris 2016-06-04 6:30 ` Boris Brezillon 2016-06-04 6:30 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 14/14] regulator: pwm: Document pwm-dutycycle-unit and pwm-dutycycle-range Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 21:04 ` Brian Norris 2016-06-03 21:04 ` Brian Norris 2016-06-03 21:04 ` Brian Norris 2016-06-06 14:09 ` Rob Herring 2016-06-06 14:09 ` Rob Herring
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