[PATCH 1/3] lib: utils: Add MPXY RPMI mailbox driver for voltage
Anup Patel
anup at brainfault.org
Mon Nov 3 21:12:00 PST 2025
On Mon, Oct 13, 2025 at 9:02 PM Joshua Yeong
<joshua.yeong at starfivetech.com> wrote:
>
> Add voltage service group for RPMI/MPXY support
>
> Signed-off-by: Joshua Yeong <joshua.yeong at starfivetech.com>
I have marked the driver as experimental until the DT compatible
string is accepted on LKML.
Applied this patch to the riscv/opensbi repo.
Thanks,
Anup
> ---
> include/sbi_utils/mailbox/rpmi_msgprot.h | 81 ++++++++++++++++++++++++
> lib/utils/mpxy/Kconfig | 4 ++
> lib/utils/mpxy/fdt_mpxy_rpmi_voltage.c | 76 ++++++++++++++++++++++
> lib/utils/mpxy/objects.mk | 3 +
> platform/generic/configs/defconfig | 1 +
> 5 files changed, 165 insertions(+)
> create mode 100644 lib/utils/mpxy/fdt_mpxy_rpmi_voltage.c
>
> diff --git a/include/sbi_utils/mailbox/rpmi_msgprot.h b/include/sbi_utils/mailbox/rpmi_msgprot.h
> index a761b560..6b5a553c 100644
> --- a/include/sbi_utils/mailbox/rpmi_msgprot.h
> +++ b/include/sbi_utils/mailbox/rpmi_msgprot.h
> @@ -216,6 +216,7 @@ enum rpmi_servicegroup_id {
> RPMI_SRVGRP_SYSTEM_SUSPEND = 0x0004,
> RPMI_SRVGRP_HSM = 0x0005,
> RPMI_SRVGRP_CPPC = 0x0006,
> + RPMI_SRVGRP_VOLTAGE = 0x00007,
> RPMI_SRVGRP_CLOCK = 0x0008,
> RPMI_SRVGRP_ID_MAX_COUNT,
>
> @@ -611,6 +612,86 @@ struct rpmi_cppc_hart_list_resp {
> u32 hartid[(RPMI_MSG_DATA_SIZE(RPMI_SLOT_SIZE_MIN) - (sizeof(u32) * 3)) / sizeof(u32)];
> };
>
> +/** RPMI Voltage ServiceGroup Service IDs */
> +enum rpmi_voltage_service_id {
> + RPMI_VOLTAGE_SRV_ENABLE_NOTIFICATION = 0x01,
> + RPMI_VOLTAGE_SRV_GET_NUM_DOMAINS = 0x02,
> + RPMI_VOLTAGE_SRV_GET_ATTRIBUTES = 0x03,
> + RPMI_VOLTAGE_SRV_GET_SUPPORTED_LEVELS = 0x04,
> + RPMI_VOLTAGE_SRV_SET_CONFIG = 0x05,
> + RPMI_VOLTAGE_SRV_GET_CONFIG = 0x06,
> + RPMI_VOLTAGE_SRV_SET_LEVEL = 0x07,
> + RPMI_VOLTAGE_SRV_GET_LEVEL = 0x08,
> + RPMI_VOLTAGE_SRV_MAX_COUNT,
> +};
> +
> +struct rpmi_voltage_get_num_domains_resp {
> + s32 status;
> + u32 num_domains;
> +};
> +
> +struct rpmi_voltage_get_attributes_req {
> + u32 domain_id;
> +};
> +
> +struct rpmi_voltage_get_attributes_resp {
> + s32 status;
> + u32 flags;
> + u32 num_levels;
> + u32 transition_latency;
> + u8 name[16];
> +};
> +
> +struct rpmi_voltage_get_supported_rate_req {
> + u32 domain_id;
> + u32 index;
> +};
> +
> +struct rpmi_voltage_get_supported_rate_resp {
> + s32 status;
> + u32 flags;
> + u32 remaining;
> + u32 returned;
> + u32 level[0];
> +};
> +
> +struct rpmi_voltage_set_config_req {
> + u32 domain_id;
> +#define RPMI_CLOCK_CONFIG_ENABLE (1U << 0)
> + u32 config;
> +};
> +
> +struct rpmi_voltage_set_config_resp {
> + s32 status;
> +};
> +
> +struct rpmi_voltage_get_config_req {
> + u32 domain_id;
> +};
> +
> +struct rpmi_voltage_get_config_resp {
> + s32 status;
> + u32 config;
> +};
> +
> +struct rpmi_voltage_set_level_req {
> + u32 domain_id;
> + s32 level;
> +};
> +
> +struct rpmi_voltage_set_level_resp {
> + s32 status;
> +};
> +
> +struct rpmi_voltage_get_level_req {
> + u32 domain_id;
> +};
> +
> +struct rpmi_voltage_get_level_resp {
> + s32 status;
> + s32 level;
> +};
> +
> /** RPMI Clock ServiceGroup Service IDs */
> enum rpmi_clock_service_id {
> RPMI_CLOCK_SRV_ENABLE_NOTIFICATION = 0x01,
> diff --git a/lib/utils/mpxy/Kconfig b/lib/utils/mpxy/Kconfig
> index 8d1f5183..f720af2c 100644
> --- a/lib/utils/mpxy/Kconfig
> +++ b/lib/utils/mpxy/Kconfig
> @@ -22,6 +22,10 @@ config FDT_MPXY_RPMI_SYSMSI
> bool "MPXY driver for RPMI system MSI service group"
> default n
>
> +config FDT_MPXY_RPMI_VOLTAGE
> + bool "MPXY driver for RPMI voltage service group"
> + default n
> +
> endif
>
> endmenu
> diff --git a/lib/utils/mpxy/fdt_mpxy_rpmi_voltage.c b/lib/utils/mpxy/fdt_mpxy_rpmi_voltage.c
> new file mode 100644
> index 00000000..a281924e
> --- /dev/null
> +++ b/lib/utils/mpxy/fdt_mpxy_rpmi_voltage.c
> @@ -0,0 +1,76 @@
> +#include <sbi_utils/mpxy/fdt_mpxy_rpmi_mbox.h>
> +
> +static struct mpxy_rpmi_service_data voltage_services[] = {
> +{
> + .id = RPMI_VOLTAGE_SRV_ENABLE_NOTIFICATION,
> + .min_tx_len = sizeof(struct rpmi_enable_notification_req),
> + .max_tx_len = sizeof(struct rpmi_enable_notification_req),
> + .min_rx_len = sizeof(struct rpmi_enable_notification_resp),
> + .max_rx_len = sizeof(struct rpmi_enable_notification_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_GET_NUM_DOMAINS,
> + .min_tx_len = 0,
> + .max_tx_len = 0,
> + .min_rx_len = sizeof(struct rpmi_voltage_get_num_domains_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_get_num_domains_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_GET_ATTRIBUTES,
> + .min_tx_len = sizeof(struct rpmi_voltage_get_attributes_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_get_attributes_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_get_attributes_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_get_attributes_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_GET_SUPPORTED_LEVELS,
> + .min_tx_len = sizeof(struct rpmi_voltage_get_supported_rate_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_get_supported_rate_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_get_supported_rate_resp),
> + .max_rx_len = -1U,
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_SET_CONFIG,
> + .min_tx_len = sizeof(struct rpmi_voltage_set_config_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_set_config_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_set_config_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_set_config_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_GET_CONFIG,
> + .min_tx_len = sizeof(struct rpmi_voltage_get_config_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_get_config_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_get_config_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_get_config_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_SET_LEVEL,
> + .min_tx_len = sizeof(struct rpmi_voltage_set_level_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_set_level_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_set_level_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_set_level_resp),
> +},
> +{
> + .id = RPMI_VOLTAGE_SRV_GET_LEVEL,
> + .min_tx_len = sizeof(struct rpmi_voltage_get_level_req),
> + .max_tx_len = sizeof(struct rpmi_voltage_get_level_req),
> + .min_rx_len = sizeof(struct rpmi_voltage_get_level_resp),
> + .max_rx_len = sizeof(struct rpmi_voltage_get_level_resp),
> +},
> +};
> +
> +static const struct mpxy_rpmi_mbox_data voltage_data = {
> + .servicegrp_id = RPMI_SRVGRP_VOLTAGE,
> + .num_services = RPMI_VOLTAGE_SRV_MAX_COUNT,
> + .service_data = voltage_services,
> +};
> +
> +static const struct fdt_match voltage_match[] = {
> + { .compatible = "riscv,rpmi-mpxy-voltage", .data = &voltage_data },
> + { },
> +};
> +
> +const struct fdt_driver fdt_mpxy_rpmi_voltage = {
> + .match_table = voltage_match,
> + .init = mpxy_rpmi_mbox_init,
> +};
> diff --git a/lib/utils/mpxy/objects.mk b/lib/utils/mpxy/objects.mk
> index 5b6e9bdf..a71c56af 100644
> --- a/lib/utils/mpxy/objects.mk
> +++ b/lib/utils/mpxy/objects.mk
> @@ -17,3 +17,6 @@ libsbiutils-objs-$(CONFIG_FDT_MPXY_RPMI_CLOCK) += mpxy/fdt_mpxy_rpmi_clock.o
>
> carray-fdt_mpxy_drivers-$(CONFIG_FDT_MPXY_RPMI_SYSMSI) += fdt_mpxy_rpmi_sysmsi
> libsbiutils-objs-$(CONFIG_FDT_MPXY_RPMI_SYSMSI) += mpxy/fdt_mpxy_rpmi_sysmsi.o
> +
> +carray-fdt_mpxy_drivers-$(CONFIG_FDT_MPXY_RPMI_VOLTAGE) += fdt_mpxy_rpmi_voltage
> +libsbiutils-objs-$(CONFIG_FDT_MPXY_RPMI_VOLTAGE) += mpxy/fdt_mpxy_rpmi_voltage.o
> diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig
> index fb90bb3e..10992619 100644
> --- a/platform/generic/configs/defconfig
> +++ b/platform/generic/configs/defconfig
> @@ -59,4 +59,5 @@ CONFIG_FDT_TIMER_PLMT=y
> CONFIG_FDT_MPXY=y
> CONFIG_FDT_MPXY_RPMI_MBOX=y
> CONFIG_FDT_MPXY_RPMI_CLOCK=y
> +CONFIG_FDT_MPXY_RPMI_VOLTAGE=y
> CONFIG_FDT_MPXY_RPMI_SYSMSI=y
> --
> 2.43.0
>
>
> --
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