[PATCH V7 11/12] Documentation: bridge: Add documentation for ps8622 DT properties

[Thierry Reding]

On Tue, Sep 23, 2014 at 02:52:24PM +0300, Laurent Pinchart wrote:
> On Tuesday 23 September 2014 13:47:40 Andrzej Hajda wrote:
> > On 09/23/2014 01:23 PM, Laurent Pinchart wrote:
[...]
> > > This becomes an issue even on Linux when considering video-related devices
> > > that can be part of either a capture pipeline or a display pipeline. If
> > > the link always goes in the data flow direction, then it will be easy to
> > > locate the downstream device (bridge or panel) from the display controller
> > > driver, but it would be much more difficult to locate the same device from
> > > a camera driver as all of a sudden the device would become an upstream
> > > device.
> > 
> > Why?
> > 
> > If you have graph:
> > sensor --> camera
> > 
> > Then camera register itself in some framework as a destination device
> > and sensor looks in this framework for the device identified by remote
> > endpoint.
> > Then sensor tells camera it is connected to it and voila.
> 
> Except that both kernelspace and userspace deal with cameras the other way 
> around, the master device is the camera receiver, not the camera sensor. DRM 
> is architected the same way, with the component that performs DMA operations 
> being the master device.

I don't see what's wrong with having the camera reference the sensor by
phandle instead. That's much more natural in my opinion.

Thierry
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