The open-source and upstream Imagination Direct Rendering Manager (DRM) kernel graphics driver for supporting their modern graphics IP and pairing with their PowerVR Vulkan driver within Mesa is now being extended to work on the TI AM62P, AM67A, and J722S SoCs.
The Texas Instruments AM62P / AM67A / J722S SoCs aren’t too popular to the masses but there are some developer/evaluation boards based around them and these Arm Cortex powered SoCs end up being used in various automotive deployments and other application-specific uses. In any event the Imagination DRM driver is being extended to handle these additional SoCs with Imagination PowerVR graphics IP.
Linux developer Michael Walle sent out the patches this week for extending the Imagination driver support to these TI SoCs. Walle explained in the RFC patch series:
“The AM62P and AM67A/J722S feature the same BXS-4 GPU as the J721S2. In theory, one have to just add the DT node. But it turns out, that the clock handling is not working. If I understood Nishan Menon correct, it is working on the J721S2 because there, the clock is shared, while on the AM62P the GPU has its own PLL. In the latter case, the ‘#assigned-clocks’ property of the GPU node doesn’t work properly. Linux will try to set the clock frequency before probing the GPU. The clock handling firmware on the SoC won’t allow that if there is no user for it. To work around that limitation, set the clock again in the .probe() of the GPU driver after turning the device on.
This was tested on an AM67A.”
The Imagination DRM kernel driver continues advancing — along with the PowerVR Mesa Vulkan driver — albeit a decade later than most would have liked seeing this Imagination PowerVR open-source support.
