blob: 2af494d1e664a1bf41fe6243f541ab2754a83082 [file] [log] [blame]
// Copyright 2017 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.
#pragma once
#include <zircon/assert.h>
#include <fbl/type_support.h>
#include <fbl/unique_ptr.h>
// DDK tpm protocol support
//
// :: Mixins ::
//
// ddk::TpmProtocol is a mixin class that simplifies writing DDK drivers that
// interact with the TPM protocol. It takes care of implementing the function pointer tables and
// calling into the object that wraps it.
//
// :: Examples ::
//
// // A driver that implements a ZX_PROTOCOL_TPM device
// class TpmDevice;
// using TpmDeviceType = ddk::Device<TpmDevice, /* ddk mixins */>;
//
// class TpmDevice : public TpmDeviceType,
// public ddk::TpmProtocol<TpmDevice> {
// public:
// TpmDevice(zx_device_t* parent)
// : TpmDeviceType("my-tpm-device", parent) {}
//
// zx_status_t Bind() {
// DdkAdd();
// }
//
// void DdkRelease() {
// // Clean up
// }
//
// ...
// private:
// ...
// };
namespace ddk {
template <typename D>
class TpmProtocol : public internal::base_protocol {
public:
TpmProtocol() {
// Can only inherit from one base_protocol implemenation
ZX_ASSERT(ddk_proto_id_ == 0);
ddk_proto_id_ = ZX_PROTOCOL_TPM;
ddk_proto_ops_ = &ops_;
}
private:
// Empty struct to use for ops, so that we do not break the invariant that ddk_proto_ops_ is
// non-null for devices with a protocol.
struct {
} ops_;
};
} // namespace ddk