// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.hardware.registers;

using zx;

protocol Device {
    /// Reads from the register from the specified MMIO offset in register width equal to 8, 16, 32, and
    /// 64 bit variants.
    /// |offset| : Offset from base of MMIO to read from. Offset must be aligned to beginning of register. For
    ///             example, for 32 bits, offset must be divisible by 4, and for 64 bits, offset
    ///             must be divisible by 8. If this is not satisfied, read will fail.
    /// |mask| : Mask of bits to read. For example, to read the lower 2 bytes of data in a 32 bit
    ///          register, mask should be 0x0000FFFF.
    /// @Returns: |value| : Value of register at the specified address.
    ReadRegister8(uint64 offset, uint8 mask) -> (uint8 value) error zx.status;
    ReadRegister16(uint64 offset, uint16 mask) -> (uint16 value) error zx.status;
    ReadRegister32(uint64 offset, uint32 mask) -> (uint32 value) error zx.status;
    ReadRegister64(uint64 offset, uint64 mask) -> (uint64 value) error zx.status;

    /// Writes to the register at the specified MMIO offset in register width equal to 8, 16, 32, and
    /// 64 bit variants
    /// |offset| : Offset from base of MMIO to write to. Offset must be aligned to beginning of register. For
    ///             example, for 32 bits, offset must be divisible by 4, and for 64 bits, offset
    ///             must be divisible by 8. If this is not satisfied, write will fail.
    /// |mask| : Mask of bits to write. For example, to write to the lower 2 bytes of data in a 32
    ///          bit register, mask should be 0x0000FFFF.
    /// |value| : Value of register at the specified address.
    WriteRegister8(uint64 offset, uint8 mask, uint8 value) -> () error zx.status;
    WriteRegister16(uint64 offset, uint16 mask, uint16 value) -> () error zx.status;
    WriteRegister32(uint64 offset, uint32 mask, uint32 value) -> () error zx.status;
    WriteRegister64(uint64 offset, uint64 mask, uint64 value) -> () error zx.status;
};