Please, try to avoid top posting in the future emails. On Fri, Jun 7, 2013 at 12:26 AM, Bin Gao <bin.gao@xxxxxxxxxxxxxxx> wrote: > With v4l2, the camera sensor i2c devices are taken over by v4l2 master > driver, i.e. ISP driver, and are not expected to be accessed from > user sapce by ioctl. So ISP driver has to register them by itself to > get all related information for further communication. Please check > v4l2_i2c_new_subdev_board() in drivers/media/video/v4l2-common.c for details. Yes, this is legacy approach for non-DT/non-ACPI5 platforms. > The platform code can definitely disallow calling i2c_register_board_info() > to register them but keep the i2c devices list and then let ISP driver register > them. But, problems come when a single kernel is going to run on two platforms > - one platform has ACPI5 and the other has SFI. You have to forget about SFI. Your ISP subdevices use plain platform data anyway. In ACPI 5 case v4l2 framework must be extended to cover that case. > The dynamic unregister and then > register based on this new helper will not have dependency on firmware interface - > the same platform code will work for all platforms. It's not a care of the ISP driver. I think you have to talk to Sakari about your issues. > On Thu, Jun 06, 2013 at 11:32:06PM +0300, Andy Shevchenko wrote: >> On Thu, Jun 6, 2013 at 9:33 PM, Bin Gao <bin.gao@xxxxxxxxxxxxxxx> wrote: >> > There is a requirement to get the i2c_client pointer dynamically without >> > knowing the bus and slave address. But we do know the client name, >> > i.e. the name in the i2c_board_info. This patch is to fit this requirement. >> > >> > A good example is that an ISP(Imaging Signal Processor) driver needs >> > register i2c camera sensor devices via v4l2, so it has to unregister >> > all i2c clients that were previously registered by calling >> > i2c_register_board_info(), and then re-register. For this case we >> > can use this helper to get i2c_client by passing the client name. >> >> Why ISP driver would like to register sensor drivers in the first place? >> That seems the task of platform code, or DT, or ACPI5 >> >> Why do you need to re-register them at run time? -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
