The T-head TH1520 SoC supports a hardware mailbox that enables two cores within the SoC to communicate and coordinate [1]. One example of such coordination would be cooperation with the T-Head E902 core, which is responsible for power, clock, and resource management. For example, in the specific case of the BXM-4-64 GPU, it needs to be powered on by the E902 core, and the kernel running on the E910 needs to 'ask' the firmware running on the E902 core to enable power to the GPU island. Given recent advancements in work on the upstream GPU driver [2], there is an emerging need to get this code in the mainline kernel. Link: https://openbeagle.org/beaglev-ahead/beaglev-ahead/-/blob/main/docs/TH1520%20System%20User%20Manual.pdf [1] Link: https://gitlab.freedesktop.org/imagination/linux-firmware/-/issues/1 [2] Michal Wilczynski (3): mailbox: Introduce support for T-head TH1520 Mailbox driver dt-bindings: mailbox: Add thead,th1520-mailbox bindings riscv: dts: thead: Add mailbox node .../bindings/mailbox/thead,th1520-mbox.yaml | 84 +++ MAINTAINERS | 2 + arch/riscv/boot/dts/thead/th1520.dtsi | 13 + drivers/mailbox/Kconfig | 10 + drivers/mailbox/Makefile | 2 + drivers/mailbox/mailbox-th1520.c | 551 ++++++++++++++++++ 6 files changed, 662 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml create mode 100644 drivers/mailbox/mailbox-th1520.c -- 2.34.1
