hid: Import iichid - I2C transport backend for HID subsystem

[wulf]

Summary

This implements hid_if.m methods for HID-over-I2C protocol [1].

Following kernel options are added:

IICHID_SAMPLING - Enable support for a sampling mode as interrupt
                  resource acquisition is not always possible in a case
                  of GPIO interrupts.
IICHID_DEBUG    - Enable debug output.

The module is substantially based on Marc Priggemeyer's work (D16698).

[1] http://download.microsoft.com/download/7/d/d/7dd44bb7-2a7a-4505-ac1c-7227d3d96d5b/hid-over-i2c-protocol-spec-v1-0.docx

[• hselasky]

sys/dev/iicbus/iichid.c

78

You can change:
DPRINTFN((sc), 1, VA_ARGS)
Into:
DPRINTFN(sc, 1, VA_ARGS)

At this level, the macro arguments are already comma separated.

80

please use do {} while (0) for these!

[wulf]

sys/dev/iicbus/iichid.c

78

Done

80

Done