From: Laxman Dewangan <ldewangan@nvidia.com>
To: Boris Brezillon <boris.brezillon@free-electrons.com>,
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>
Subject: Re: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API
Date: Mon, 6 Jun 2016 11:44:59 +0530 [thread overview]
Message-ID: <575514E3.7050802@nvidia.com> (raw)
In-Reply-To: <20160604082848.0b897b14@bbrezillon>
On Saturday 04 June 2016 11:58 AM, Boris Brezillon wrote:
> 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:
>>> - * 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.
>
Yaah, the issue which I was seeing and had fix will be resolved with
this also.
I wanted to do req_diff * period first before any scaling/division.
Function pwm_set_relative_duty_cycle() does the same, and hence it is fine.
state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)val * state->period,
+ scale);
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Thanks,
Laxman
WARNING: multiple messages have this Message-ID (diff)
From: Laxman Dewangan <ldewangan@nvidia.com>
To: Boris Brezillon <boris.brezillon@free-electrons.com>,
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
Subject: Re: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API
Date: Mon, 6 Jun 2016 11:44:59 +0530 [thread overview]
Message-ID: <575514E3.7050802@nvidia.com> (raw)
In-Reply-To: <20160604082848.0b897b14@bbrezillon>
On Saturday 04 June 2016 11:58 AM, Boris Brezillon wrote:
> 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:
>>> - * 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.
>
Yaah, the issue which I was seeing and had fix will be resolved with
this also.
I wanted to do req_diff * period first before any scaling/division.
Function pwm_set_relative_duty_cycle() does the same, and hence it is fine.
state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)val * state->period,
+ scale);
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Thanks,
Laxman
WARNING: multiple messages have this Message-ID (diff)
From: ldewangan@nvidia.com (Laxman Dewangan)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API
Date: Mon, 6 Jun 2016 11:44:59 +0530 [thread overview]
Message-ID: <575514E3.7050802@nvidia.com> (raw)
In-Reply-To: <20160604082848.0b897b14@bbrezillon>
On Saturday 04 June 2016 11:58 AM, Boris Brezillon wrote:
> 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:
>>> - * 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.
>
Yaah, the issue which I was seeing and had fix will be resolved with
this also.
I wanted to do req_diff * period first before any scaling/division.
Function pwm_set_relative_duty_cycle() does the same, and hence it is fine.
state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)val * state->period,
+ scale);
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Thanks,
Laxman
next prev parent reply other threads:[~2016-06-06 6:27 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
2016-06-04 6:28 ` Boris Brezillon
2016-06-06 6:14 ` Laxman Dewangan [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=575514E3.7050802@nvidia.com \
--to=ldewangan@nvidia.com \
--cc=boris.brezillon@free-electrons.com \
--cc=briannorris@chromium.org \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=dianders@google.com \
--cc=galak@codeaurora.org \
--cc=heiko@sntech.de \
--cc=ijc+devicetree@hellion.org.uk \
--cc=kernel@stlinux.com \
--cc=lgirdwood@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=maxime.coquelin@st.com \
--cc=milo.kim@ti.com \
--cc=patrice.chotard@st.com \
--cc=pawel.moll@arm.com \
--cc=robh+dt@kernel.org \
--cc=smbarber@chromium.org \
--cc=srinivas.kandagatla@gmail.com \
--cc=thierry.reding@gmail.com \
--cc=wxt@rock-chips.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.