Limited support
This feature is only present in Portal 2: Community Edition. press_x360_button
press_x360_button
Press the specified Xbox 360 controller button (lt, rt, st[art], ba[ck], lb, rb, a, b, x, y, l[eft], r[right], u[p], d[own])
Press the specified Xbox 360 controller button (lt, rt, st[art], ba[ck], lb, rb, a, b, x, y, l[eft], r[right], u[p], d[own])