Function sbi_rt::cppc_read_hi

source ·

pub fn cppc_read_hi(cppc_reg_id: u32) -> SbiRet

Expand description

Read the upper 32-bit value of the CPPC register identified by cppc_reg_id.

§Parameters

The cppc_reg_id parameter specifies the CPPC register ID.

§Return value

SbiRet.value will contain the upper 32 bits of the register value. This function always returns zero in SbiRet.value when supervisor mode XLEN is 64 or higher.

The possible error codes returned in SbiRet.error are shown in the table below:

Return code	Description
`SbiRet::success()`	Read completed successfully.
`SbiRet::invalid_param()`	`cppc_reg_id` is reserved.
`SbiRet::not_supported()`	`cppc_reg_id` is not implemented by the platform.
`SbiRet::denied()`	`cppc_reg_id` is a write-only register.
`SbiRet::failed()`	The read operation request failed for unspecified or unknown other reasons.

This function is defined in RISC-V SBI Specification chapter 14.3.