> > > I'm very interested in how easy it is for you to convert cx18 to > > > v4l2_subdev. Please let me know anything that is unclear or that can be > > > improved in the documentation or code! Hans, Converting cx18 to use a v4l2_device object was easy enough. There's not a lot to do, because on it's own it doesn't do to much. At this early stage, without the v4l2_subdev work done, it's simply one more piece of kernel rigamarole with which to deal, along with struct pci_dev, struct device, struct video_dev. As I begin the conversion process to v4l2_subdev, I realize it's not the straightforward hack for which I was hoping. A clear first step in the porting process needs to be to answer design questions: 1. What are the v4l2_subdev's for this family of capture devices? (This is actually harder to answer than I thought.) 2. Do I need to write any bridge specific v42l_subdev's? 3. What functions do all the needed v4l2_subdev's perform? 4. What functions will I need from all the functions a chip/v4l2_subdev provides? 5. How will I manage the subdevs to get at just the particular subdev functions I need for any given task? 6. Do I try to deal with the DTV subdevices on my hybrid cards now, or wait until later? These are all up front design questions that I would have done on a professional project with a full up front design. What I found with trying to iteratively hack was that decisions come up at many junctures with porting this framework to cx18. I suspect the framework will be great for maintenance activities once in place, but initial porting of existing drivers probably requires an above average level of discipline. I will elaborate on how I encountered the design questions above, later today (I've got to head to out soon). I'll also propose what I think is some guidance to answer question 1 at least. (For highly integrated devices with loose internal couplings in places, like CX23418, it's not as simple as a "chip" or "something connected to I2C, GPIO or other bus lines".) Regards, Andy -- 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
