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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Vinod <vkoul@kernel.org>
Cc: linux-media@vger.kernel.org,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans Verkuil <hverkuil@xs4all.nl>,
	Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: Re: camera control interface
Date: Wed, 30 May 2018 10:04:29 +0300	[thread overview]
Message-ID: <2593976.2pOKjEb3EO@avalon> (raw)
In-Reply-To: <20180529082932.GH5666@vkoul-mobl>

Hi Vinod,

On Tuesday, 29 May 2018 11:29:32 EEST Vinod wrote:
> Hi folks,
> 
> I am writing a driver for camera control inteface which is an i2c
> controller. So looking up the code I think it can be a v4l subdev,
> right? Can it be an independent i2c master and not v4l subdev?

What do you mean by "camera control interface" here ? A hardware device 
handling communication with camera sensors ? I assume the communication bus is 
I2C ? Is that "camera control interface" plain I2C or does it have additional 
features ?

If we're talking about an I2C controller a V4L2 subdev is not only unneeded, 
but it wouldn't help. You need an I2C master.

> Second the control sports GPIOs. It can support  a set of
> synchronization primitives so it's possible to drive I2C clients and
> GPIOs with hardware controlled timing to allow for sync control of
> sensors hooked and also for fancy strobe. How would we represent these
> gpios in v4l2 and allow the control, any ideas on that.

Even if your main use case it related to camera, synchronization of I2C and 
GPIO doesn't seem to be a V4L2 feature to me. It sounds that you need to 
implement that int he I2C and GPIO subsystems.

-- 
Regards,

Laurent Pinchart

  reply	other threads:[~2018-05-30  7:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-29  8:29 camera control interface Vinod
2018-05-30  7:04 ` Laurent Pinchart [this message]
2018-05-30  7:28   ` Vinod
2018-05-30  7:31     ` Laurent Pinchart
2018-05-30  7:40       ` Vinod
2018-05-30  7:52         ` Laurent Pinchart

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