Hans Verkuil wrote: > 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. Ah! thanks for the heads up on that. Some how I missed that entirely. > >> 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. Cool. > >>> 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. Excellent, I'll look at moving the functionality patches based on this driver and Darius' on to that then. Sorry for repeating some of your work, I somehow completely forgot your original email saying this was on it's way! Jonathan -- 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
