From: Pavel Machek <pavel@ucw.cz>
To: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
linux-leds@vger.kernel.org, linux-media@vger.kernel.org,
niklas.soderlund@ragnatech.se, robh@kernel.org,
hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com,
devicetree@vger.kernel.org, sre@kernel.org
Subject: Re: as3645a flash userland interface
Date: Thu, 14 Sep 2017 12:07:18 +0200 [thread overview]
Message-ID: <20170914100718.GA3843@amd> (raw)
In-Reply-To: <4bf12e8e-beff-0199-cdee-4a52ebe7cdaf@samsung.com>
[-- Attachment #1: Type: text/plain, Size: 1990 bytes --]
Hi!
> >>>>What directory are the flash controls in?
> >>>>
> >>>>/sys/class/leds/led-controller:flash ?
> >>>>
> >>>>Could we arrange for something less generic, like
> >>>>
> >>>>/sys/class/leds/main-camera:flash ?
> >>>
> >>>I'd rather avoid overcomplicating this. LED class device name pattern
> >>>is well defined to devicename:colour:function
> >>>(see Documentation/leds/leds-class.txt, "LED Device Naming" section).
> >>>
> >>>In this case "flash" in place of the "function" segment makes the
> >>>things clear enough I suppose.
> >>
> >>It does not.
> >>
> >>Phones usually have two cameras, front and back, and these days both
> >>cameras have their flash.
> >>
> >>And poor userspace flashlight application can not know if as3645
> >>drivers front LED or back LED. Thus, I'd set devicename to
> >>front-camera or main-camera -- because that's what it is associated
> >>with. Userspace does not care what hardware drives the LED, but needs
> >>to know if it is front or back camera.
> >
> >The name of a LED flash class device isn't fixed and is derived
> >from DT label property. Name in the example of some DT bindings
> >will not force people to apply similar pattern for the other
> >drivers and even for the related one. No worry about having
> >to keep anything forever basing on that.
>
> Isn't the V4L2 subdev/Media Controller API supposed to provide means
> for associating flash LEDs with camera sensors? You seem to be insisting
> on using the sysfs leds interface for that, which is not a primary
> interface for camera flash AFAICT.
a) subdev/media controller API currently does not provide such means.
b) if we have /sys/class/leds interface to userland, it should be
useful.
c) having flashlight application going through media controller API is
a bad joke.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
next prev parent reply other threads:[~2017-09-14 10:07 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-12 8:42 [PATCH v11 00/24] Unified fwnode endpoint parser, async sub-device notifier support, N9 flash DTS Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 01/24] v4l: fwnode: Move KernelDoc documentation to the header Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 02/24] v4l: async: Remove re-probing support Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 03/24] v4l: async: Use more intuitive names for internal functions Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 04/24] v4l: async: Add V4L2 async documentation to the documentation build Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 05/24] v4l: fwnode: Support generic parsing of graph endpoints in a device Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 06/24] omap3isp: Use generic parser for parsing fwnode endpoints Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 07/24] rcar-vin: " Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 08/24] omap3isp: Fix check for our own sub-devices Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 09/24] omap3isp: Print the name of the entity where no source pads could be found Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 10/24] v4l: async: Move async subdev notifier operations to a separate structure Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 11/24] v4l: async: Introduce helpers for calling async ops callbacks Sakari Ailus
2017-09-12 9:39 ` Hans Verkuil
2017-09-12 8:42 ` [PATCH v11 12/24] v4l: async: Register sub-devices before calling bound callback Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 13/24] v4l: async: Allow async notifier register call succeed with no subdevs Sakari Ailus
2017-09-12 9:38 ` Hans Verkuil
2017-09-12 8:42 ` [PATCH v11 14/24] v4l: async: Allow binding notifiers to sub-devices Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 15/24] dt: bindings: Add a binding for flash LED devices associated to a sensor Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 16/24] dt: bindings: Add lens-focus binding for image sensors Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 17/24] v4l: fwnode: Add a helper function for parsing generic references Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 18/24] v4l: fwnode: Add a helper function to obtain device / interger references Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 19/24] v4l: fwnode: Add convenience function for parsing common external refs Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 20/24] dt: bindings: smiapp: Document lens-focus and flash-leds properties Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 21/24] smiapp: Add support for flash and lens devices Sakari Ailus
2017-09-12 10:31 ` Pavel Machek
2017-09-12 8:42 ` [PATCH v11 22/24] ov5670: " Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 23/24] ov13858: " Sakari Ailus
2017-09-12 8:42 ` [PATCH v11 24/24] arm: dts: omap3: N9/N950: Add flash references to the camera Sakari Ailus
2017-09-12 10:36 ` as3645a flash userland interface Pavel Machek
2017-09-12 10:47 ` Sakari Ailus
2017-09-12 11:40 ` Pavel Machek
2017-09-12 12:04 ` Sakari Ailus
2017-09-12 18:53 ` Jacek Anaszewski
2017-09-12 21:55 ` Pavel Machek
2017-09-13 17:53 ` Jacek Anaszewski
2017-09-14 9:24 ` Sylwester Nawrocki
2017-09-14 10:07 ` Pavel Machek [this message]
2017-09-14 10:28 ` Sakari Ailus
2017-09-14 11:01 ` Sylwester Nawrocki
2017-09-14 11:53 ` Pavel Machek
2017-09-14 13:16 ` Sylwester Nawrocki
2017-09-18 9:12 ` Sakari Ailus
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=20170914100718.GA3843@amd \
--to=pavel@ucw.cz \
--cc=devicetree@vger.kernel.org \
--cc=hverkuil@xs4all.nl \
--cc=jacek.anaszewski@gmail.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-leds@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=niklas.soderlund@ragnatech.se \
--cc=robh@kernel.org \
--cc=s.nawrocki@samsung.com \
--cc=sakari.ailus@linux.intel.com \
--cc=sre@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox