[RFC]Question regrading TODO list for bcm2835 camera and bcm2835-audio

Michael Zoran mzoran at crowfest.net
Sun Feb 26 11:56:04 PST 2017


I noticed that the TODO list for the RPI camera and the audio driver
have fixing the issue of the runtime load order dependency between
vchiq and the function driver(camera/audio). The TODO list mentions
making the camera driver a platform driver.

I've been toying for awhile with the concept of making vchiq a bus
driver that function drivers register with rather the making the camera
a platform driver.  Meaning when vchiq loads, it walks the registered
functions drivers and using the standard driver methods and bus
matching methods it calls the probe function on the function drivers.

Taking this farther, one could also change vchiq to be a non-platform
driver with the raspberrypi firmware driver also being a bus driver.  I
have prototyped converting the firmware driver to be a bus driver, but
perhaps it would be better to start from the other direction and
convert the camera and audio drivers first.

I mentioned all this as an issue on the downstream github page, but I
didn't get much feedback.  I'm thinking the downstream guys don't want
to break something that sort of works now, and that they thought I was
looking for a downstream only solution.

Does anybody have any feedback/comments/opinions about taking an
approach like this?  Any feedback would be good including negative
feedback just so I know this isn't something I should put any effort
into.

What got me started on this path was that the platform driver model
doesn't really fit well with firmware and vchiq based drivers and that
documenting the DT nodes would require the need to treat
vchiq/camera/audio as multiplatform when they clearly are not.

Thanks.


  





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