From: Denis Bodor Subject: Re: add iic_detach() to iic driver, for USB/IIC adapters To: Mark Kettenis Cc: tech@openbsd.org Date: Thu, 12 Sep 2024 05:58:38 +0200 On Wed, Sep 11, 2024 at 04:57:41PM +0200, Mark Kettenis wrote: > > This impacts a lot more code than I had originally thought. > > I wonder if this is a good idea after all... > Yes, not sure about this one. The iic(4) bus itself does not support > hotplugging and USB iic(4) controllers are somewhat of a rare toy I > guess. I know of two, the I2C-Tiny-USB project and the CP2112 controller... I think this is only really useful if a /dev/iic-n is made available to allow the buses to be used from user space. There is the beginnings of such an implementation in i2c_io.h (JI2C_IOCTL_EXEC behind a ‘#ifdef notyet’ ) but this code has been around since 2004. Is this something desirable (notyet == tobedone) or is the OpenBSD philosophy to keep access to i2c devices strictly in kernel space? -- Denis