initiator.h

// Copyright 2023 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#pragma once
 
#include "pw_bytes/span.h"
#include "pw_chrono/system_clock.h"
#include "pw_i2c/address.h"
#include "pw_i2c/initiator.h"
#include "pw_result/result.h"
#include "pw_status/status.h"
#include "pw_sync/lock_annotations.h"
#include "pw_sync/timed_mutex.h"
 
namespace pw::i2c {
 
class LinuxInitiator final : public Initiator {
 public:
  static Result<int> OpenI2cBus(const char* bus_path);
 
  LinuxInitiator(int fd);
 
  LinuxInitiator(const LinuxInitiator&) = delete;
  LinuxInitiator& operator=(const LinuxInitiator&) = delete;
 
  ~LinuxInitiator() override;
 
 private:
  Status DoWriteReadFor(Address device_address,
                        ConstByteSpan tx_buffer,
                        ByteSpan rx_buffer,
                        chrono::SystemClock::duration timeout) override
      PW_LOCKS_EXCLUDED(mutex_);
 
  Status DoWriteReadForLocked(uint8_t address,
                              ConstByteSpan tx_buffer,
                              ByteSpan rx_buffer,
                              chrono::SystemClock::duration timeout)
      PW_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
  const int fd_;
 
  sync::TimedMutex mutex_;
};
 
}  // namespace pw::i2c