Filling form with Datamapper ORM object - Codeigniter

I'm trying to get a form populated by data coming from a Datamapper object.

Here's my controller code:

function find()
 {       
     $sub_list = new Subject(); 
     $data['s'] = $sub_list->all;
 
     $this->load->view('professors/find', $data);
 
 }
 

In my view I'd want to show a dropdown form with the data coming from that object but I can't make it work.
This code:

<?php echo form_dropdown('accesso', $s);?>
 

Just show me "Subject" for every field in the db.

Many thanks for the help! I'm sorry for the silly issue!

EDIT: Problem solved!

<?php foreach ($s as $a):?>
 <?php $options[$a->name] = $a->name; ?>
 <?php endforeach ?>
 <?php echo form_dropdown('accesso', $options);?>
 

Thanks!

---