Different server vendors have different system management. Some are more complex than other but typical vSphere admin is using vSphere Update Manager (VUM) so would not it be cool to do firmware management directly from VUM? Yes, of course, so how it could be done?
Well, there is a chapter in vSphere documentation covering "Updating Firmware in vSAN Clusters", however, there is no information what hardware is supported. I did some internal research and colleagues have pointed me to VMware KB 60382 "IO Controllers that vSAN supports firmware updating" where supported IO Controllers are listed.
At the time of writing this post, there are plenty of Dell IO Controllers, two Lenovo, two SuperMicro and one Fujitsu.
At the moment, you can update only IO Controllers but it may or may not change in the future.