From: Nylon Chen <nylon.chen@sifive.com>
To: aou@eecs.berkeley.edu, conor@kernel.org,
emil.renner.berthing@canonical.com, geert+renesas@glider.be,
heiko@sntech.de, krzysztof.kozlowski+dt@linaro.org,
palmer@dabbelt.com, paul.walmsley@sifive.com, robh+dt@kernel.org,
thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de,
devicetree@vger.kernel.org, linux-pwm@vger.kernel.org,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: nylon.chen@sifive.com, nylon7717@gmail.com, zong.li@sifive.com,
greentime.hu@sifive.com, vincent.chen@sifive.com
Subject: [PATCH v3 0/2] Change PWM-controlled LED pin active mode and algorithm
Date: Thu, 20 Apr 2023 17:34:55 +0800 [thread overview]
Message-ID: <20230420093457.18936-1-nylon.chen@sifive.com> (raw)
According to the circuit diagram of User LEDs - RGB described in the manual hifive-unleashed-a00.pdf[0] and hifive-unmatched-schematics-v3.pdf[1].
The behavior of PWM is acitve-high.
According to the descriptionof PWM for pwmcmp in SiFive FU740-C000 Manual[2].
The pwm algorithm is (PW) pulse active time = (D) duty * (T) period.
The `frac` variable is pulse "inactive" time so we need to invert it.
So this patchset removes active-low in DTS and adds reverse logic to the driver.
Updated patches: 2
New patches: (none)
Unchanged patches: 1
Links:
- [0]: https://sifive.cdn.prismic.io/sifive/c52a8e32-05ce-4aaf-95c8-7bf8453f8698_hifive-unleashed-a00-schematics-1.pdf
- [1]: https://sifive.cdn.prismic.io/sifive/6a06d6c0-6e66-49b5-8e9e-e68ce76f4192_hifive-unmatched-schematics-v3.pdf
- [2]: https://sifive.cdn.prismic.io/sifive/1a82e600-1f93-4f41-b2d8-86ed8b16acba_fu740-c000-manual-v1p6.pdf
Changed in v3:
- Convert the reference link to standard link.
- Move the inverted function before taking the minimum value.
- Change polarity check condition(high and low).
- Pick the biggest period length possible that is not bigger than the requested period.
Changed in v2:
- Convert the reference link to standard link.
- Fix typo: s/sifive unmatched:/sifive: unmatched:/.
- Remove active-low from hifive-unleashed-a00.dts.
- Include this reference link in the dts and pwm commit messages.
Nylon Chen (2):
riscv: dts: sifive: unleashed/unmatched: Remove PWM controlled LED's
active-low properties
pwm: sifive: change the PWM controlled LED algorithm
arch/riscv/boot/dts/sifive/hifive-unleashed-a00.dts | 4 ----
arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts | 4 ----
drivers/pwm/pwm-sifive.c | 9 ++++++---
3 files changed, 6 insertions(+), 11 deletions(-)
--
2.40.0
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2023-04-20 9:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-20 9:34 Nylon Chen [this message]
2023-04-20 9:34 ` [PATCH v3 1/2] riscv: dts: sifive: unleashed/unmatched: Remove PWM controlled LED's active-low properties Nylon Chen
2023-04-20 10:20 ` Conor Dooley
2023-04-20 9:34 ` [PATCH v3 2/2] pwm: sifive: change the PWM controlled LED algorithm Nylon Chen
2023-04-20 10:04 ` Emil Renner Berthing
[not found] ` <CAHh=Yk86AV542Y7wG6rkHTc4va1Gof3uXtj84zzK5m+khL_Aiw@mail.gmail.com>
2023-04-20 10:46 ` Emil Renner Berthing
2023-04-21 6:16 ` Nylon Chen
2023-04-21 10:09 ` Emil Renner Berthing
2023-04-20 10:28 ` Conor Dooley
2023-04-20 14:13 ` kernel test robot
2023-04-22 13:22 ` kernel test robot
2023-05-08 9:48 ` kernel test robot
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=20230420093457.18936-1-nylon.chen@sifive.com \
--to=nylon.chen@sifive.com \
--cc=aou@eecs.berkeley.edu \
--cc=conor@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=emil.renner.berthing@canonical.com \
--cc=geert+renesas@glider.be \
--cc=greentime.hu@sifive.com \
--cc=heiko@sntech.de \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=nylon7717@gmail.com \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=robh+dt@kernel.org \
--cc=thierry.reding@gmail.com \
--cc=u.kleine-koenig@pengutronix.de \
--cc=vincent.chen@sifive.com \
--cc=zong.li@sifive.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox