Hi all, FYI, I'm a participating kernel device driver developer (i2c, w1, uio) but a complete USB noob. I want to make a proper in-kernel i2c master driver for the Silabs CP2112 usb to smbus bridge (actually i2c compliant). The device is presented as HID and uses reports for operation. (see http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf ) Silabs expects it's customers to drive the chip from userspace using hiddev in the kernel. This prevents users from harnessing all of the i2c client drivers in the kernel, hence this effort. (unless I am missing something?) I have my CP2112 eval kit with me and I'm ready to get started but I'd like some pointers to get on the right track ASAP. - as per device driver customs, which existing driver (patch or already merged) should be used as template? - where does such a driver belong? I'm guessing drivers/i2c/busses/i2c-cp2112.c - would I use the same internal APIs that the IOCTLs of hiddev use for example? - what else should I read/look-at/consider? Note that aside from i2c, the chip has GPIOs. I want to properly register those with the GPIO subsystem and implement an interrupt controller (like gpio-adp5588.c) with these GPIOs. I know it's going to have latency, but this would be acceptable for the i2c slaves we would put on it. Problem it, the CP2112 doesn't have any described feature in it's API which suggests this would be possible. Being a USB noob, my hardware guy told me something like "the USB host controller can poll the chip for what you want and report if there's a change". I still have some generic USB homework to do obviously, but can anyone push me in the right direction for this? Thanks for all the help! Looking forward to submitting a patch! /jfd-- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
