On Sat, Jun 27, 2026 at 1:46 AM Charles Perry <[email protected]> wrote: > > Hello, > > This series adds support for RISC-V Platform Management Interface (RPMI) to > U-Boot. RPMI is an OS-agnostic protocol for communication between an > Application Processor (AP) and a Platform Microcontroller (PuC) [1]. The > goals and purpose of RPMI are similar to ARM's SCMI. > > This patchset first adds an abstraction layer for the transport > (UCLASS_RPMI), then adds two transport layer (SBI MPXY and shared memory) > and finally adds two client, or service group in RPMI jargon: Clock and > device power service groups. > > This series also include a sandbox mode for which the RPMI transport > doesn't attach to a firmware but contains a simulation of a firmware. This > reuses code from librpmi [2] to create the message responses. > > Apart from the spec [1], this series reuses code from the Linux SBI MPXY > driver [3], OpenSBI shared memory transport [4] and Linux RPMI clock driver > [5]. > > This was tested on a PIC64-HPSC SoC which features an application cluster > and a system controller with isolated address spaces, hence the need for > RPMI. I've tested the interoperability between RPMI clients and transports > with an S-Mode U-boot (using the MPXY transport) and M-Mode U-Boot (using > shared memory transport) and the following device tree fragment: > > ``` > firmware { > rpmi: mailbox@7000000000 { > compatible = "riscv,rpmi-shmem-mbox"; > reg = <0x70 0x00000000 0x0 0x3000>, > <0x70 0x00003000 0x0 0x3000>, > <0x70 0x00006000 0x0 0x1000>, > <0x70 0x00007000 0x0 0x1000>; > reg-names = "a2p-req", "p2a-ack", "p2a-req", > "a2p-ack"; > riscv,slot-size = <64>; > #mbox-cells = <1>; > }; > > ifndef CONFIG_RISCV_MMODE > clock-service { > compatible = "riscv,rpmi-mpxy-clock"; > mboxes = <&rpmi 0x8>; > riscv,sbi-mpxy-channel-id = <0x1000>; > }; > > device-power-service { > compatible = "riscv,rpmi-mpxy-device-power"; > mboxes = <&rpmi 0x9>; > riscv,sbi-mpxy-channel-id = <0x1001>; > }; > > mpxy_mbox: mailbox { > compatible = "riscv,sbi-mpxy-mbox"; > #mbox-cells = <2>; > }; > endif > > sysc_clk: clock-controller { > compatible = "riscv,rpmi-clock"; > ifdef CONFIG_RISCV_MMODE > mboxes = <&rpmi 0x8>; > else > mboxes = <&mpxy_mbox 0x1000 0x0>; > endif > #clock-cells = <1>; > }; > > sysc_dpwr: power-domain-controller { > compatible = "riscv,rpmi-device-power"; > ifdef CONFIG_RISCV_MMODE > mboxes = <&rpmi 0x9>; > else > mboxes = <&mpxy_mbox 0x1001 0x0>; > endif > #power-domain-cells = <1>; > }; > }; > ``` > > [1]: https://github.com/riscv-non-isa/riscv-rpmi > [2]: https://github.com/riscv-software-src/librpmi > [3]: > https://elixir.bootlin.com/linux/v7.0.10/source/drivers/mailbox/riscv-sbi-mpxy-mbox.c > [4]: > https://elixir.bootlin.com/opensbi/v1.8.1/source/lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c > [5]: https://elixir.bootlin.com/linux/v7.0.10/source/drivers/clk/clk-rpmi.c > > Cc: Rahul Pathak <[email protected]> > Cc: Anup Patel <[email protected]> > Cc: Paul Walmsley <[email protected]> > Cc: Palmer Dabbelt <[email protected]> > Cc: Albert Ou <[email protected]> > Cc: Alexandre Ghiti <[email protected]> > Cc: Romain Caritey <[email protected]> > Cc: Mame Maria Mbaye <[email protected]> > Cc: Tom Rini <[email protected]> > Cc: Heinrich Schuchardt <[email protected]> > Cc: Rick Chen <[email protected]> > Cc: Leo Yu-Chi Liang <[email protected]> > > Charles Perry (7): > firmware: add support for RPMI > firmware: rpmi: add support for the SBI MPXY transport > firmware: rpmi: add support for shared memory transport > drivers: clk: add support for RPMI clocks > drivers: power: add support for RPMI power domains > firmware: rpmi: add a test and a sandbox driver > firmware: rpmi: add a test and sandbox for device power
I have a more general question. Why add separate firmware framework for RPMI ? You can just extend the existing U-Boot mailbox framework and just like we have in Linux. The separate transport drivers will be mailbox-controller drivers and each service group will have a separate mailbox-client driver under appropriate driver subsystem. > > MAINTAINERS | 9 + > arch/riscv/include/asm/sbi.h | 57 +++ > arch/sandbox/dts/test.dts | 23 + > configs/sandbox_defconfig | 3 + > drivers/clk/Kconfig | 7 + > drivers/clk/Makefile | 1 + > drivers/clk/clk_rpmi.c | 346 +++++++++++++++ > drivers/firmware/Kconfig | 1 + > drivers/firmware/Makefile | 1 + > drivers/firmware/rpmi/Kconfig | 27 ++ > drivers/firmware/rpmi/Makefile | 4 + > drivers/firmware/rpmi/rpmi-sandbox-clock.c | 446 +++++++++++++++++++ > drivers/firmware/rpmi/rpmi-sandbox-power.c | 174 ++++++++ > drivers/firmware/rpmi/rpmi-sandbox.c | 158 +++++++ > drivers/firmware/rpmi/rpmi-sandbox.h | 48 +++ > drivers/firmware/rpmi/rpmi-sbi-mpxy.c | 449 +++++++++++++++++++ > drivers/firmware/rpmi/rpmi-shmem.c | 474 +++++++++++++++++++++ > drivers/firmware/rpmi/rpmi-uclass.c | 138 ++++++ > drivers/power/domain/Kconfig | 7 + > drivers/power/domain/Makefile | 1 + > drivers/power/domain/rpmi-power-domain.c | 229 ++++++++++ > include/dm/uclass-id.h | 1 + > include/rpmi-uclass.h | 79 ++++ > include/rpmi.h | 159 +++++++ > include/rpmi_proto.h | 143 +++++++ > test/dm/Makefile | 1 + > test/dm/rpmi.c | 69 +++ > 27 files changed, 3055 insertions(+) > create mode 100644 drivers/clk/clk_rpmi.c > create mode 100644 drivers/firmware/rpmi/Kconfig > create mode 100644 drivers/firmware/rpmi/Makefile > create mode 100644 drivers/firmware/rpmi/rpmi-sandbox-clock.c > create mode 100644 drivers/firmware/rpmi/rpmi-sandbox-power.c > create mode 100644 drivers/firmware/rpmi/rpmi-sandbox.c > create mode 100644 drivers/firmware/rpmi/rpmi-sandbox.h > create mode 100644 drivers/firmware/rpmi/rpmi-sbi-mpxy.c > create mode 100644 drivers/firmware/rpmi/rpmi-shmem.c > create mode 100644 drivers/firmware/rpmi/rpmi-uclass.c > create mode 100644 drivers/power/domain/rpmi-power-domain.c > create mode 100644 include/rpmi-uclass.h > create mode 100644 include/rpmi.h > create mode 100644 include/rpmi_proto.h > create mode 100644 test/dm/rpmi.c > > -- > 2.47.3 > Regards, Anup
