All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: linux-leds@vger.kernel.org
Subject: leds-pwm: issue in  __led_pwm_set()
Date: Wed, 25 Sep 2013 22:00:13 +0200	[thread overview]
Message-ID: <524340CD.4060403@free-electrons.com> (raw)

Hi,

I'm using leds-pwm on an atmel sama5d31 based board. I have one
question/issue. In __led_pwm_set(), if the duty cycle is 0,
pwm_disable() is called. This won't work fine on that platform. What
happens is that pwm_config() correctly sets the duty cycle to 0 which is
behaving correctly with that controller (and in my case, putting the
line low). But the call to pwm_disable() is making the pwm controller
release the line and then it is set to high.

I've tried various configurations, like configuring a pull-down on the
pin but I still observe the same behavior. For now, I have a workaround
in atmel-pwm (I activate the output overdrive when duty cycle is 0). But
I believe, we should find another way to do that.

Any input is appreciated.

Regards,

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com


             reply	other threads:[~2013-09-25 20:00 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-25 20:00 Alexandre Belloni [this message]
2013-09-26  0:28 ` leds-pwm: issue in __led_pwm_set() Milo Kim
2013-09-26  7:13   ` Alexandre Belloni
2013-09-26  7:34     ` Milo Kim
2013-09-26  7:48       ` Alexandre Belloni
2013-09-27 15:51         ` Milo Kim
2013-09-27 16:15           ` Alexandre Belloni
2013-09-27 17:23             ` Milo Kim
2013-09-27 17:33               ` Milo Kim
2013-09-27 18:34                 ` Alexandre Belloni
2013-09-27 19:46                   ` Alexandre Belloni
2013-09-28 13:29                     ` Milo Kim

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=524340CD.4060403@free-electrons.com \
    --to=alexandre.belloni@free-electrons.com \
    --cc=linux-leds@vger.kernel.org \
    /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.