If the brain can give rise to consciousness, then any matter can give rise to consciousness, because for any material system, there is some frame of reference, however arbitrary and complex and twisted (and all frames of reference are ultimately arbitrary), under which the physical system appears to behave exactly as a brain does.
All it takes is a possible frame of reference, because even the frame of reference that observes a brain behaving with the dynamic that it seems to is arbitrary, unless you want to say that a conscious being has to occupy the frame of reference, but then an argument that consciousness is an emergent property of material would be an infinite regress.
That is, if you assume that our frame of reference is the one necessarily by which a conscious dynamic must operate, then you are assuming that a consciousness must exist having that reference frame of observation, and that consciousness must in turn have a consciousness that exists to validate the frame of reference by which its internal dynamics render a phenomenology, ad infinitum.
(It cannot be the consciousness in question that validates its own reference frame, because that would be to cause oneself to exist, and also we do not observe the submolecular motion involved in our own brains, so it must be another’s consciousness that validates the reference frame. (Granted, the conscious entities (humans) that make the reference frame in which conscious humans are recognized don’t observe consciousness by observing submolecular action either, but by observing the physical dynamic on a more macroscopic scale—looking at faces, etc. However, reductionist theory does not say that consciousness is made up of the dynamic of observable motor command, which is why I appeal to a dynamic of subatomic particles wrt what composes consciousness.))
Of course, one could say that, in some equally strangely arranged frame of reference, a stereo system is a can opener. And yes, this would have little meaning because the stereo system could be anything from any arbitrarily arranged frame of reference, and we, in our frame of reference, cannot possibly use it as a can opener, or garage door opener, or whatever. However, when we say that this item can (according to some reference frame) act as a brain, we are saying (when we suppose that consciousness is an emergent property of the brain) that there is a phenomenology—a self—an experiencing entity—hidden in that stereo system—actually, a countless number of phenomenologies, and they don’t need relative observers to feel, know, desire, perceive, etc. (whereas, e.g. a fork can be defined completely on a functionalistic basis).
Conclusion: either consciousness is everywhere, or consciousness is not a function of the brain.
More specifically, it would not be a function of the brain because it would not be reducible at all.
Admittedly, I don’t know what the implications would be in regard to a non-reductionistic theory of mind being a function of the brain.