As an alcoholic in recovery, this is my advice to you:
Go to a bookstore and pick up a book called Alcoholics Anonymous (do not accept a substitute!). You can also find this book, sometimes for free, at any AA meeting.
Place this book by your father's bedside. If he asks, tell him you were just lingering around a bookstore one day when inspiration struck and you saw this book on the shelf. Leafing through its pages, you read some of the stories in it and thought it would be something your father would like to read.
Tell him that as fellow alcoholics, the authors of the book understand.
If you're certain he wants to stop, you may bring the book to him as joyfully as though you just struck oil; you will find him reading this book almost obsessively. He will likely go for the Program in the book (the "12-Steps" Program)at once. If you're not certain he wants to stop, then you likely won't have long to wait. Cheerfully see him through more sprees. Do not urge him to follow the Program. The more you hurry him, the more he will resent it, and his recovery may be delayed. The point is that you already planted the seed. Repeated suffering and stumbling will drive him back to the book. Talk about his alcoholism and this book only if he brings the issue up!
Since this book was first published, the Program of AA has released millions of alcoholics from asylums and hospitals of all kinds.
You may not think that a simple book has the power to bring your father into recovery, but here you'd be mistaken. This book was written by people just like your dad who have found a solution to their alcoholism. And because of this, your dad will relate to just about everything written in this book.
If your father wants what we have, and is willing to go to any lengths to get it, then he will be ready.