tree 1d946ba2bb7c0323df8b2cc5266016de1dbc4ff5
parent 7a36d36fd987e1a3b2cc67839755481f25e9ebbf
author Andrew Geissler <geissonator@yahoo.com> 1595608895 -0500
committer Andrew Geissler <geissonator@yahoo.com> 1595608895 -0500

cfam-reset: utilize new sysfs interface if avaialble

The kernel introduced support on some systems for a sysfs based
mechanism to issue cfam resets. See the following commit for more
information:
https://github.com/openbmc/linux/commit/0298c9857e284aae7841a31c2a6cd3954afec6c9

Userspace software should first look to utilize the new sysfs based
mechanism and if not available, fall back to the libgpiod mechanism.

Currently only witherspoon-tacoma and rainier support this new sysfs
based cfam reset mechanism.

Tested:
- Built a witherspoon image and verified libgpiod path was used
- Built a witherspoon-tacoma and verified new sysfs path was used

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I3a99899cb7d46a878a62c93954c59b7853c2b759