I hike with cameras a lot, most DSLRs are much more robust than most people think, and providing you protect the lens surfaces you normally don't need much to keep it safe.
Padding
Put the camera away from hard edged items, most hiking gear is soft, there's no point in carrying extra weight for padding, when you'll already have some spare clothes in you bag.
Waterproofing
You'll already be aiming to keep your spare clothing dry, so just pack the camera in the waterproof container you already have.
Accessibility
Make sure you keep your camera accessible otherwise you'll just be carrying the weight for no reason.
Weight
Seriously consider what camera gear you need and what you can leave behind. I'm very selective with the gear I carry normally trying to keep it less than 1.5kg, if you don't hike regularly, don't underestimate how much the extra weight will make your life hard when walking