Audit log functionality for user roles (& PII viewer enablement)

Have an audit log report for user roles (permisison changes and teh admin responsible for the change) and allow for us to report when 'PII viewer' has been turned on/off for a certain user. We would like to see when 'PII Viewer' permissions are granted (date/time), when the permission is revoked (date/time), and who edited the 'PII Viewer' access (user field).