On Tuesday 16 June 2009 16:45:04 Jonathan Cameron wrote: > Guennadi Liakhovetski wrote: > > On Mon, 15 Jun 2009, Jonathan Cameron wrote: > >> From: Jonathan Cameron <jic23@xxxxxxxxx> > >> > >> OV7670 soc-camera driver. Merge of drivers from Jonathan Corbet, > >> Darius Augulis and Jonathan Cameron > > > > Could you please, describe in more detail how you merged them? > > Mostly by combining the various register sets and then adding pretty much > all the functionality in each of them, testing pretty much everything. > > Note that a lot of what was in those drivers (usually labeled as > untested) simply doesn't work and is based on 'magic' register sets > provided by omnivision. > > > However, I am not sure this is the best way to go. I think, a better > > approach would be to take a driver currently in the mainline, perhaps, > > the most feature-complete one if there are several of them there, > > That is more or less what I've done (it's based on Jonathan Corbet's > driver). Darius' driver and mine have never been in mainline. Darius' was > a complete rewrite based on doc's he has under NDA. Mine was based on > Jonathan Corbet's one with a few bits leveraged from a working tinyos > driver for the platform I'm using (principally because Omnivision are > ignoring both myself and the board supplier). > > > convert > > it and its user(s) to v4l2-subdev, extend it with any features missing > > in it and present in other drivers, then switch users of all other > > ov7670 drivers over to this one, > > That's the problem. The only mainlined driver is specifically for an OLPC > machine. The driver is tied to specific i2c device and doesn't use > anything anywhere near soc-camera or v4l2-subdev. Yes, it does. ov7670.c was converted to v4l2-subdev in 2.6.30. > While it would be nice to get a single driver working > for this hardware as well as more conventional soc-camera devices, it > isn't going to happen without a lot of input from someone with an olpc. > The chip is interfaced through a Marvell 88alp101 'cafe' chip which does > a whole host of random things alongside being video processor and taking > a quick look at that would be written in a completely different fashion > if it were done now (mfd with subdevices etc, v4l2-sudev) > > So basically in the ideal world it would happen exactly as you've > suggested, but I doubt it'll happen any time soon and in the meantime > there is no in kernel support for those of us using the chip on other > platforms. > > *looks hopefully in the direction of Jonathan Corbet and other olpc > owners* I have an olpc, but I still haven't had the time to setup a proper test environment on it. However, I managed to clear my backlog of reviews in the past few days so hopefully I can find some time this weekend to set it up. > > and finally make it work with soc-camera. This > > way you get a series of smaller and reviewable patches, instead of a > > completely new driver, that reproduces a lot of existing code but has > > to be reviewed anew. How does this sound? > > Would be fine if the original driver (or anything terribly close to it) > were useable on a platform I actually have without more or less being > rewritten. > > I can back track the driver to be as close to that as possible and still > functional, but I'm not entirely sure it will make the code any easier to > review and you'll loose a lot the functionality lifted from Darius' as > my original drivers. > > The original posting I made was as close as you can reasonably get to > Jonathan's original driver. > > http://patchwork.kernel.org/patch/12192/ > > At the time it wasn't really reviewed (beyond a few comments) > as you were just commencing the soc-camera conversion and it made > sense to wait for after that. > > I'm not really sure how we should proceed with this. I'm particularly > loath to touch the olpc driver unless we have a reasonable number of > people willing to test. The current ov7670.c driver in the 2.6.30 tree (and the v4l-dvb repository) is already v4l2_subdev based and should be reusable in other platforms, including soc-camera once that has also been converted to use v4l2_subdev. Regards, Hans -- Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
