In a clause with passive voice, the grammatical subject expresses the theme or patient of the main verb – that is, the person or thing that undergoes the action or has its state changed. -My homework is done
The passive form of causative is used when the focus is on the thing instead of the person. When you combine them together, you are essentially saying someone caused something to be done . -I have my homework done. Does the difference lie in the performance of an action?