Samsung just took a load of code and dumped it on the company's open source repository this afternoon, a la the Galaxy Tab Pro 8.4 in both Wi-Fi and LTE trims. There are a total of 5 kernel source files here, 2 for North American Wi-Fi variants (SM-T320_NA), 2 for global Wi-Fi variants (SM-T320), and one for the global LTE variant (SM-T325).
This follows the release of kernel source code for both the Tab Pro 10.1 and Note Pro 12.2 a month ago. The Tab Pro 12.2 remains the only one of the new Pro-level Samsung tablets without published kernel source at this point, though that's likely because it's not actually available for purchase until next week.
Hit up the link below to get downloading.