First it was WebGL for Android 4.0 and later the Sensor HAL for 2011 Xperia Phones was also made open source. Sony is showing great concern to the developers out there who love the Xperia range of smartphones that they are releasing the FM radio module for 2011 Xperia smartphones also as open source. This means, for a custom ROM developer it’s much easier to configure custom ROMs to use the FM chip and FM radio app.
The FM radio module for 2011 Xperia was built on Texas Instrument’s FM chip with some minor tweaks to improve FM radio handling . So the company decided to release the FM radio module as open source to close the gap between the TI open source FM radio solution and company's own implementation.
Also the previously released Sensor HAL have been updated. Now there are options to configure the magnetometer sensor.
So if you are an open community developer you can download FM radio module and the updated Sensor HAL to make your own ROM!
Also Sony has assured that you'll see more giveaways:
"Our ambition is to support the open dev community as much as we can, and we hope you find the FM radio and the updated sensor HAL useful. What else do you wish to see open sourced?"
- From the blog post
Source : Developer World