From: Sven Van Asbroeck <thesven73@gmail.com>
To: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-pwm@vger.kernel.org
Subject: Re: [PATCH v5 2/7] pwm: pca9685: Support hardware readout
Date: Fri, 29 Jan 2021 13:05:14 -0500 [thread overview]
Message-ID: <CAGngYiWd0u=+DPhvK+8v9FT8Y1Evn1brWRheMNDXWFVVL-wNFw@mail.gmail.com> (raw)
In-Reply-To: <YBQ4c2cYYPDMjkeH@workstation.tuxnet>
Hi Clemens,
On Fri, Jan 29, 2021 at 11:31 AM Clemens Gruber
<clemens.gruber@pqgruber.com> wrote:
>
> Ok, so you suggest we extend our get_state logic to deal with cases
> like the following:
Kind of. We can't control how other actors (bootloaders etc) program the
chip. As far as I know, there are many, many different register settings that
result in the same physical chip outputs. So if .probe() wants to preserve the
existing chip settings, .get_state() has to be able to deal with every possible
setting. Even invalid ones.
In addition, .apply() cannot make any assumptions as to which bits are
already set/cleared on the chip. Including preserved, invalid settings.
This might get quite complex.
However if we reset the chip in .probe() to a known state (a normalized state,
in the mathematical sense), then both .get_state() and .apply() become
much simpler. because they only need to deal with known, normalized states.
In short, it's a tradeoff between code complexity, and user friendliness/
features.
Sven
next prev parent reply other threads:[~2021-01-29 18:06 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20201216125320.5277-1-clemens.gruber@pqgruber.com>
[not found] ` <20201216125320.5277-2-clemens.gruber@pqgruber.com>
2020-12-17 4:00 ` [PATCH v5 2/7] pwm: pca9685: Support hardware readout Sven Van Asbroeck
2020-12-17 17:43 ` Clemens Gruber
2020-12-17 17:52 ` Sven Van Asbroeck
2021-01-03 17:04 ` Clemens Gruber
2021-01-07 14:18 ` Sven Van Asbroeck
2021-01-11 20:43 ` Uwe Kleine-König
2021-03-22 8:34 ` Thierry Reding
2021-03-31 10:25 ` Uwe Kleine-König
2021-03-31 15:52 ` Thierry Reding
2021-04-06 6:33 ` Uwe Kleine-König
2021-04-06 13:47 ` Thierry Reding
2021-04-06 20:44 ` Uwe Kleine-König
2021-03-22 8:15 ` Thierry Reding
2021-01-11 20:35 ` Uwe Kleine-König
2021-01-14 17:16 ` Clemens Gruber
2021-01-14 18:05 ` Uwe Kleine-König
2021-03-22 8:53 ` Thierry Reding
[not found] ` <CAGngYiW=KhCOZX3tPMFykXzpWLpj3qusN2OXVPSfHLRcyts+wA@mail.gmail.com>
2021-01-29 16:31 ` Clemens Gruber
2021-01-29 18:05 ` Sven Van Asbroeck [this message]
2021-01-29 20:37 ` Clemens Gruber
2021-01-29 21:24 ` Sven Van Asbroeck
2021-01-29 22:16 ` Sven Van Asbroeck
2021-02-01 17:24 ` Clemens Gruber
2021-03-01 21:52 ` Uwe Kleine-König
2021-03-04 13:22 ` Clemens Gruber
2021-02-14 14:46 ` Clemens Gruber
2021-03-22 9:19 ` Thierry Reding
[not found] ` <CAHp75Ve2FFEMsAv8S18bUDFsH2UkiQ5UvgcRtZ=j30syQtEirw@mail.gmail.com>
2021-03-22 11:22 ` Uwe Kleine-König
2021-03-22 11:40 ` Andy Shevchenko
2021-03-22 11:48 ` Uwe Kleine-König
2021-03-22 12:15 ` Andy Shevchenko
2021-03-22 13:25 ` Uwe Kleine-König
2021-03-27 16:05 ` Clemens Gruber
2021-03-22 9:14 ` Thierry Reding
2021-03-22 8:47 ` Thierry Reding
2020-12-15 21:22 [PATCH v5 1/7] pwm: pca9685: Switch to atomic API Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 2/7] pwm: pca9685: Support hardware readout Clemens Gruber
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='CAGngYiWd0u=+DPhvK+8v9FT8Y1Evn1brWRheMNDXWFVVL-wNFw@mail.gmail.com' \
--to=thesven73@gmail.com \
--cc=clemens.gruber@pqgruber.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=thierry.reding@gmail.com \
--cc=u.kleine-koenig@pengutronix.de \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).