From: Pavel Machek <pavel@ucw.cz>
To: David Laight <David.Laight@ACULAB.COM>
Cc: 'Linus Walleij' <linus.walleij@linaro.org>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Linux LED Subsystem <linux-leds@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Rob Herring <robh@kernel.org>, Dmitry Torokhov <dtor@google.com>,
Guenter Roeck <linux@roeck-us.net>, Dan Murphy <dmurphy@ti.com>,
Baolin Wang <baolin.wang@linaro.org>,
Daniel Mack <daniel@zonque.org>,
Oleh Kravchenko <oleg@kaa.org.ua>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Simon Shields <simon@lineageos.org>
Subject: Various LED complexities was Re: [PATCH v5 05/26] leds: core: Add support for composing LED class device names
Date: Thu, 4 Jul 2019 00:05:26 +0200 [thread overview]
Message-ID: <20190703220526.GB876@amd> (raw)
In-Reply-To: <643e3b10fe9d45b59ed063ffc6d578ff@AcuMS.aculab.com>
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On Fri 2019-06-28 13:30:30, David Laight wrote:
> From: Linus Walleij
> > Sent: 28 June 2019 09:46
> ...
> > A problem with LEDs is that it invites bikeshedding because it is too
> > relateable.
>
> Bikeshedding leds :-)
>
> It also isn't at all clear how to handle bi-colour and tri-colour leds.
> ISTR the usual interface lets you set the brightness, but more often
> leds are single brightness but multi-colour.
> Eg the ethernet 'speed' led which is (usually) off/orange/green.
>
> Changing the brightness either means changing the current or using PWM.
> Both really require more hardware support than changing colours.
>
> I've done some led driving (for a front panel) from a PLD (small FPGA).
> As well as the obvious things I did:
> - dim: 1/8th on at 80Hz.
> - flash: 1/8th on at 4Hz.
> - orange: 50-50 red-green at 80Hz on an RGB led.
>
> There was also the 'ethernet activity' led which could either be driven
> by the hardware, or forced on/off/flash by the driver.
> If driven by the hardware, the software could read the current state.
>
> None of this really fitted the Linux leds interface.
Well, we are working on some of those :-). But lets discuss that in
separate threads.
In particular we are working on triggers and RGB LEDs.
bi-color LEDs seem to handled as two separate LEDs. Not much expected
to change there.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2019-07-03 22:05 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-09 19:07 [PATCH v5 00/26] Add generic support for composing LED class device name Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 01/26] leds: class: Improve LED and LED flash class registration API Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 02/26] dt-bindings: leds: Add LED_COLOR_ID definitions Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 03/26] dt-bindings: leds: Add LED_FUNCTION definitions Jacek Anaszewski
2019-11-15 13:01 ` Geert Uytterhoeven
2019-11-15 20:14 ` Jacek Anaszewski
2019-11-25 15:17 ` Pavel Machek
2019-06-09 19:07 ` [PATCH v5 04/26] dt-bindings: leds: Add properties for LED name construction Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 05/26] leds: core: Add support for composing LED class device names Jacek Anaszewski
2019-06-26 19:05 ` Jacek Anaszewski
2019-06-26 20:07 ` Oleh Kravchenko
2019-06-27 18:28 ` Jacek Anaszewski
2019-06-28 8:46 ` Linus Walleij
2019-06-28 13:30 ` David Laight
2019-07-03 22:05 ` Pavel Machek [this message]
2019-07-03 22:00 ` Pavel Machek
2019-07-17 21:03 ` Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 06/26] dt-bindings: sc27xx-blt: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 07/26] leds: sc27xx-blt: Use generic support for composing LED names Jacek Anaszewski
2019-06-10 2:52 ` Baolin Wang
2019-06-09 19:07 ` [PATCH v5 08/26] dt-bindings: lt3593: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 09/26] leds: lt3593: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 10/26] dt-bindings: lp8860: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 11/26] leds: lp8860: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 12/26] dt-bindings: lm3692x: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 13/26] leds: lm3692x: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 14/26] dt-bindings: lm36010: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 15/26] leds: lm3601x: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 16/26] dt-bindings: cr0014114: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 17/26] leds: cr0014114: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 18/26] dt-bindings: aat1290: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 19/26] leds: aat1290: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 20/26] dt-bindings: as3645a: Add function and color properties Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 21/26] leds: as3645a: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:07 ` [PATCH v5 22/26] dt-bindings: leds-gpio: Add function and color properties Jacek Anaszewski
2019-06-09 19:08 ` [PATCH v5 23/26] leds: gpio: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:08 ` [PATCH v5 24/26] dt-bindings: an30259a: Add function and color properties Jacek Anaszewski
2019-06-09 19:08 ` [PATCH v5 25/26] leds: an30259a: Use generic support for composing LED names Jacek Anaszewski
2019-06-09 19:08 ` [PATCH v5 26/26] leds: Document standard LED functions Jacek Anaszewski
2019-07-18 11:03 ` Pavel Machek
2019-07-18 13:31 ` Jacek Anaszewski
2019-07-17 21:14 ` [PATCH v5 00/26] Add generic support for composing LED class device name Jacek Anaszewski
2019-07-18 10:52 ` Pavel Machek
2019-07-24 21:02 ` Jacek Anaszewski
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