From: Pavel Machek <pavel@ucw.cz>
To: David Lechner <david@lechnology.com>
Cc: Jacek Anaszewski <j.anaszewski@samsung.com>,
Richard Purdie <rpurdie@rpsys.net>,
linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org,
Marcel Holtmann <marcel@holtmann.org>
Subject: Re: [PATCH v3] leds: Introduce userspace leds driver
Date: Fri, 16 Sep 2016 07:59:27 +0200 [thread overview]
Message-ID: <20160916055927.GC13205@amd> (raw)
In-Reply-To: <d3f1810c-e97a-4460-1415-f54e8501cf64@lechnology.com>
Hi!
+The current brightness is found by reading a single byte from the
character
+device. Values are unsigned: 0 to 255. Reading does not block and
always returns
+the most recent brightness value. The device node can also be polled
to notify
+when the brightness value changes.
What is going on there? We have O_NONBLOCK, user should be able to
select if he wants blocking behaviour or not.
And yes, there's interface for creating a LED, but not one for
deleting it?
And... how is it going to work with multiple LEDs? Userspace gets
single bytes with brightness. How does it know to which LED the
brightness belongs?
Thanks,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2016-09-16 5:59 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-09 16:49 [PATCH v3] leds: Introduce userspace leds driver David Lechner
[not found] ` <alpine.LRH.2.20.1609091525060.22407@federalhill.net>
2016-09-09 20:44 ` David Lechner
[not found] ` <CGME20160912081846eucas1p255044e49034685ad44400d6830ef0b95@eucas1p2.samsung.com>
2016-09-12 8:18 ` Jacek Anaszewski
2016-09-12 14:58 ` David Lechner
2016-09-15 13:08 ` Pavel Machek
2016-09-15 13:35 ` Pavel Machek
2016-09-15 14:54 ` Jacek Anaszewski
2016-09-16 6:09 ` Pavel Machek
2016-09-15 14:54 ` Jacek Anaszewski
2016-09-15 15:31 ` David Lechner
2016-09-15 15:35 ` David Lechner
2016-09-16 5:51 ` Pavel Machek
2016-09-16 15:18 ` David Lechner
2016-09-16 5:59 ` Pavel Machek [this message]
2016-09-16 15:32 ` David Lechner
2016-09-16 6:07 ` Pavel Machek
2016-09-16 15:41 ` David Lechner
2016-09-15 16:34 ` David Lechner
2016-09-16 5:50 ` Pavel Machek
2016-09-16 7:07 ` Jacek Anaszewski
2016-09-16 15:09 ` David Lechner
2016-09-16 19:29 ` Pavel Machek
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