AMDGPU DRM Driver Adds CGS Interface, ACP Driver

Written by Michael Larabel in Radeon on 9 July 2015 at 12:34 PM EDT. 7 Comments
Alex Deucher sent out twelve new patches just minutes ago for the AMDGPU DRM driver. The AMDGPU driver was merged for Linux 4.2 while these patches provide new features/functionality and thus will not be merged until Linux 4.3.

The new patches were authored by various AMD developers and add amd_gnb_bus support, CGS interfaces, and a new ACP driver.

CGS is described by the patches as being Common Graphics Services. "CGS (Common Graphics Services) is an AMD cross component abstraction layer to designed to better encapsulate specific IP block drivers so different teams can effectively work on differnet IP block drivers independently. It provides a common interface for things like accessing registers, allocating GPU memory, and registering interrupt sources. The plan is to eventually move more and more IP drivers to this interface. The first user is the ACP IP driver."

This new ACP driver is for an audio co-processor, which is just found on new AMD APU/SoCs. "This adds the ACP (Audio CoProcessor) IP driver and wires it up to the amdgpu driver. The ACP block provides the DMA engine and bus for the i2s codec which is supported by an alsa driver. This is required for audio on APUs that utilize an i2s codec."
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week