The passive form of "Do it." is "Let it be done (by you)."
Please do your homework regularly is an imperative sentence and has no subject but the subject (you) is implied. So to make a passive sentence from an imperative sentence you can use the subject - you. You have been told to do your homework regularly. or you could say: Let your homework be done regularly.
This sentence can not be changed in passive form.
The passive voice is possible only with a transitive verb. "Come" is intransitive, and so can't form a passive voice.
An imperative sentence is a sentence that gives a command. An example of an imperative sentence would be: Hand me those pamphlets, please.
To change a sentence into passive the sentence must be active. 'Shut the door please' is not an active sentence, it is an imperative sentence, it has no subject. You could write something like this - You are asked to shut the door - but this is a bit awkward.
This sentence already is in passive form. When you see variations of the verb "to be," you're usually looking at passive voice. The active form would be "The criminal cut the electric wires" (or whoever cut them).
Imperative
Music is listened to by them.
He told it to us. = active sentence.It was told to us by him. = passive sentence.
To change an active sentence to passive, identify the object in the active sentence and make it the subject in the passive sentence. Move the subject of the active sentence to the phrase with "by" and change the verb to its past participle form. To change a passive sentence to active, identify the subject in the passive sentence and make it the subject in the active sentence. Use an appropriate active verb to describe the subject's action and add the original object of the passive sentence as the direct object in the active sentence.
It is an imperative sentence. The pronoun "you" is implied, which happens in imperative sentences.
You are very imperative.