while (
  m/
    (?:                # non-capturing braces
      "(?<val>[^"]*)"  # Find either string delimited by '"'
      |                # or
      (?<val>[^,]*)    # string up to next ','
    )
    (?:,|$)            # After which there is either , or end of line
  /gx
) {
  push @input, $+{val};
}