Hi Davide,
Linking home page to logo is not unusual but there are still very many users who will not think to click the logo. This means the rest of your navigation has to be very obvious to the user. When I have done this for clients we always have a footer menu that includes the 'Home' link.
The logo should also be provided with a 'Title' either on the image code or the link code. The title would ideally be in the link code and read...
<a href="index.php" title="Link to home page" alt="home page">
<img src="link/to/your/image.png" alt="name of company or site" title="name of company or site" />
</a>
The title will be displayed when people mouse over the link. This helps those who get lost and also assists with SEO.
Hope this helps