runtime_probe/functions/ectool_i2cread.h

/* Copyright 2018 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#ifndef RUNTIME_PROBE_FUNCTIONS_ECTOOL_I2CREAD_H_
#define RUNTIME_PROBE_FUNCTIONS_ECTOOL_I2CREAD_H_

#include <memory>
#include <string>

#include <base/values.h>

#include "runtime_probe/probe_function.h"

namespace runtime_probe {

/* Execute "ectool i2cread" command.
 * TODO(b/120826467) : Access /dev/cros_ec directly.
 *
 * This probe function takes the following arguments:
 *   size: Return bits, it can be either 8 or 16.
 *   port: The port of the I2C connected to EC.
 *   addr: The I2C address
 *   offset: The register offset.
 *   key: The key of saved output. Output will be saved in string.
 *
 * More details can be found under command "ectool i2cread help"
 */
class EctoolI2Cread : public ProbeFunction {
 public:
  static constexpr auto function_name = "ectool_i2cread";

  /* Define a parser for this function.
   *
   * @args dict_value: a JSON dictionary to parse arguments from.
   *
   * @return pointer to new `EctoolI2Cread` instance on success, nullptr
   *   otherwise.
   */
  static std::unique_ptr<ProbeFunction> FromDictionaryValue(
      const base::DictionaryValue& dict_value) {
    std::unique_ptr<EctoolI2Cread> instance{new EctoolI2Cread()};

    if (dict_value.size() != 5) {
      LOG(ERROR) << function_name << " expect 5 arguments.";
      return nullptr;
    }

    bool result = true;

    result &= PARSE_ARGUMENT(size);
    result &= PARSE_ARGUMENT(port);
    result &= PARSE_ARGUMENT(addr);
    result &= PARSE_ARGUMENT(offset);
    result &= PARSE_ARGUMENT(key);

    if (result)
      return instance;
    return nullptr;
  }

  DataType Eval() const override;

 private:
  int addr_;
  std::string key_;
  int offset_;
  int port_;
  int size_;

  static ProbeFunction::Register<EctoolI2Cread> register_;
};

/* Register the EctoolI2Cread */
REGISTER_PROBE_FUNCTION(EctoolI2Cread);

}  // namespace runtime_probe

#endif  // RUNTIME_PROBE_FUNCTIONS_ECTOOL_I2CREAD_H_