From: Jean-Jacques Hiblot <jjhiblot@ti.com>
To: Pavel Machek <pavel@ucw.cz>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: <daniel.thompson@linaro.org>, <linux-leds@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <dmurphy@ti.com>,
<tomi.valkeinen@ti.com>
Subject: Re: [PATCH v5 3/3] leds: Add control of the voltage/current regulator to the LED core
Date: Mon, 14 Oct 2019 12:49:07 +0200 [thread overview]
Message-ID: <eb8c0df1-0d5b-11d0-9965-3192fa5675f3@ti.com> (raw)
In-Reply-To: <20191013120937.GK5653@amd>
On 13/10/2019 14:09, Pavel Machek wrote:
> Hi!
>
>> I must say I'm not a big fan of this change.
>> It adds a bunch of code to the LED core and gives small
>> functionality in a reward. It may also influence maximum
>> software blinking rate, so I'd rather avoid calling
>> regulator_enable/disable when timer trigger is set.
>>
>> It will of course require more code.
>>
>> Since AFAIR Pavel was original proponent of this change then
>> I'd like to see his opinion before we move on to discussing
>> possible improvements to this patch.
> Was I?
>
> Okay, this series looks quite confusing to me. First, 1/3 looks
> "interesting" (would have to analyze it way more).
>
> Second, 3/3... So we have a LED driver _and_ a regulator? So yes, the
> chip driving a LED is usually ... voltage/current regulator. What is
> second regulator doing there? Is that a common setup?
This is quite common with current-sink LED drivers.
The setup looks like this:
+-----------+
| |
| Regulator |
| +------------------------+
| | |
+-----------+ __|__
\ /
+---------------------+ \ / led
| | V
| Led Driver | --+--
| | |
| | |
| +----------+
| \ |
| \ |
| + |
| | |
+---------------------+
|
+--+--+
///////
Only the regulator usually does not supply only one LED.
JJ
>
> Best regards,
> Pavel
>
next prev parent reply other threads:[~2019-10-14 10:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 10:20 [PATCH v5 0/3] " Jean-Jacques Hiblot
2019-09-23 10:20 ` [PATCH v5 1/3] led: make led_set_brightness_sync() use led_set_brightness_nosleep() Jean-Jacques Hiblot
2019-09-23 10:20 ` [PATCH v5 2/3] dt-bindings: leds: document the "power-supply" property Jean-Jacques Hiblot
2019-09-23 10:20 ` [PATCH v5 3/3] leds: Add control of the voltage/current regulator to the LED core Jean-Jacques Hiblot
2019-09-24 18:58 ` Jacek Anaszewski
2019-09-25 8:41 ` Jean-Jacques Hiblot
2019-10-13 12:09 ` Pavel Machek
2019-10-13 16:40 ` Jacek Anaszewski
2019-10-14 10:49 ` Jean-Jacques Hiblot [this message]
2019-10-14 12:38 ` Daniel Thompson
2019-10-14 18:48 ` Jacek Anaszewski
2019-10-16 8:13 ` Jean-Jacques Hiblot
2019-10-17 19:05 ` Jacek Anaszewski
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=eb8c0df1-0d5b-11d0-9965-3192fa5675f3@ti.com \
--to=jjhiblot@ti.com \
--cc=daniel.thompson@linaro.org \
--cc=dmurphy@ti.com \
--cc=jacek.anaszewski@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-leds@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=tomi.valkeinen@ti.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
all inboxes | Powered by JetHome®