Would this ordinance be unconstitutional?

Because he is soliciting children outside a school, an ordinance could be drafted stating that it is illegal to pass out literature or advertisements to minors, or to approach or solicit hem without written consent of parents, within 100 feet of a school entrance, during certain specified hours that would coincide within say, 30 minutes of school opening or closing and during the normal specified school hours. The ordinance might stand up in court, and just because this guy claims it is legally protected speech, doesn't mean an ordinance could not be passed. Speech to minors on or adjacent to a school might not have the same protection as speech to adults. However, I think such an ordinance would have a high risk of being found unconstitutional. There is no proved harm in giving bibles to children or pornography, for that matter, even though there are laws against the latter. If porn is illegal for kids, religion should be too, as it is in just as ugly.