Generally speaking, Adobe stops updating older versions to be able to read raw files from newer cameras when they release a newer version of Photoshop.
First you need to determine whether Adobe has released support for your new camera in your version of Photoshop. To do that, look at these two pages. You'll want to find out the earliest version of Camera Raw that can support your camera, then what version of Photoshop can run that version of Camera Raw.
Camera Raw plug-in | Supported cameras
Camera Raw-compatible Adobe applications
If you find your camera is supported by your version of Photoshop, you need to download the latest update for Camera Raw. There's more information on how to do that here:
If your version of Photoshop cannot support your camera, you can download and install the latest version of the free Adobe DNG Converter, which can take your raw files as input and put out DNG format files, which your version of Photoshop can open.
Photoshop Help | Digital Negative (DNG)
The DNG converter DOES work, but if you want maximal quality from your raw files (not to mention the convenience and ease of use of directly opening your raw files) you'll want the latest version of Photoshop. Adobe has made substantial improvements in raw conversion quality in recent years.
-Noel