11-01-2015 09:27 PM
I am seeing two drivers for vtc in petalinux. drivers/media/platform/xilinx/xilinx-vtc.c and drivers/gpu/drm/xilinx/xilinx_vtc.c. I am using vivado 2015.2(vtc 6.1). Which one I should use. What are the differences between them?
11-01-2015 10:58 PM
11-03-2015 07:46 PM
The difference would be in the API - use the driver which matches the API the rest of your pipeline and software uses, or will use. If you're starting from scratch, DRM/KMS is newer.
drivers/gpu/drm/xilinx/xilinx_vtc.c would be the DRM/KMS API
drivers/media/platform/xilinx/xilinx-vtc.c would be the (older) v4l API.
08-18-2018 08:27 AM
Be careful, when you use vtc driver.
When the clk(for video timing) is not running, don't access register.
It causes kernel fault to access register due to axi bus error
You should enable clock before you access vtc register.
page 20 describes
"If the clk signal is not running, the AXI4-Lite interface asserts the slave error response (0x2) for all addresses."