基于 libgpiod v2.x 的 Linux GPIO 实现 Linux GPIO implementation using libgpiod v2.x More...

#include <linux_gpio.hpp>

Inheritance diagram for LibXR::LinuxGPIO:

Collaboration diagram for LibXR::LinuxGPIO:

Public Member Functions
	LinuxGPIO (const std::string &chip_path, unsigned int line_offset)
	构造 LinuxGPIO 对象。Constructs a LinuxGPIO instance.

	LinuxGPIO (const LinuxGPIO &)=delete

LinuxGPIO &	operator= (const LinuxGPIO &)=delete

bool	Read () override
	读取 GPIO 引脚状态。Reads the GPIO line level.

void	Write (bool value) override
	写入 GPIO 引脚状态。Writes a level to the GPIO line.

ErrorCode	EnableInterrupt () override
	使能 GPIO 中断处理状态。Enables GPIO interrupt handling state.

ErrorCode	DisableInterrupt () override
	禁用 GPIO 中断处理状态。Disables GPIO interrupt handling state.

int	GetFd () const
	获取 GPIO request 对应的文件描述符，用于 epoll/poll 注册。 Gets the request file descriptor for epoll/poll registration.

ErrorCode	HandleInterrupt ()
	非阻塞处理中断事件，排空队列并触发回调。 Handles GPIO interrupt events in non-blocking mode, drains queued events and dispatches callbacks.

ErrorCode	ReadEvent (GPIOEvent &event)
	读取单个中断事件。Reads a single interrupt edge event.

ErrorCode	SetConfig (Configuration config) override
	配置 GPIO 引脚参数。Configures GPIO line settings.

Public Member Functions inherited from LibXR::GPIO
	GPIO ()
	默认构造函数。Default constructor.

ErrorCode	RegisterCallback (Callback callback)
	注册 GPIO 事件回调函数。Registers a callback function for GPIO events.

Static Public Attributes
static constexpr size_t	EVENT_BUFFER_CAPACITY = 64

Private Member Functions
ErrorCode	ApplyDirection (Direction direction)
	根据 GPIO 方向配置 line settings。 Applies line settings according to GPIO direction.

ErrorCode	ApplyPull (Pull pull)
	根据 GPIO 上拉/下拉配置 line settings。 Applies line settings according to GPIO pull mode.

bool	EnsureConfigured () const
	确保 GPIO 已配置。Ensures GPIO has been configured.

ErrorCode	EnsureInterruptReady () const
	确保中断路径已启用。Ensures interrupt path is enabled and ready.

Static Private Member Functions
static bool	IsInterruptDirection (Direction direction)
	判断 direction 是否为中断方向。Checks whether direction is interrupt mode.

Private Attributes
std::string	chip_path_

unsigned int	line_offset_

gpiod_chip *	chip_ = nullptr

gpiod_edge_event_buffer *	event_buffer_
	持久化事件缓冲区。Persistent edge event buffer.

gpiod_line_settings *	settings_ = nullptr

gpiod_request_config *	req_cfg_ = nullptr

gpiod_line_config *	line_cfg_ = nullptr

gpiod_line_request *	request_ = nullptr

Configuration	current_config_ = {Direction::INPUT, Pull::NONE}

bool	has_config_ = false

bool	interrupt_enabled_ = false

Additional Inherited Members
Public Types inherited from LibXR::GPIO
enum class	Direction : uint8_t { INPUT , OUTPUT_PUSH_PULL , OUTPUT_OPEN_DRAIN , FALL_INTERRUPT , RISING_INTERRUPT , FALL_RISING_INTERRUPT }
	定义 GPIO 引脚的方向类型。Defines the direction types for GPIO pins. More...

enum class	Pull : uint8_t { NONE , UP , DOWN }
	定义 GPIO 引脚的上拉/下拉模式。Defines the pull-up/pull-down configurations for GPIO pins. More...

using	Callback = LibXR::Callback<>

Data Fields inherited from LibXR::GPIO
Callback	callback_
	GPIO 事件的回调函数。Callback function for GPIO events.

Detailed Description

基于 libgpiod v2.x 的 Linux GPIO 实现 Linux GPIO implementation using libgpiod v2.x

Definition at line 42 of file linux_gpio.hpp.

Constructor & Destructor Documentation

◆ LinuxGPIO()

LibXR::LinuxGPIO::LinuxGPIO	(	const std::string &	chip_path,
		unsigned int	line_offset )

inline

构造 LinuxGPIO 对象。Constructs a LinuxGPIO instance.

Parameters

chip_path	GPIO chip 设备路径（如 "/dev/gpiochip0"）。 GPIO chip device path (e.g. "/dev/gpiochip0").
line_offset	GPIO line 偏移量。GPIO line offset.

Definition at line 53 of file linux_gpio.hpp.

      : chip_path_(chip_path),
        line_offset_(line_offset),
        chip_(gpiod_chip_open(chip_path.c_str()))
  {
    if (!chip_)
    {
      XR_LOG_ERROR("Failed to open GPIO chip: %s", chip_path.c_str());
      ASSERT(false);
      return;
    }
 
    settings_ = gpiod_line_settings_new();
    if (!settings_)
    {
      XR_LOG_ERROR("Failed to create GPIO line settings");
      ASSERT(false);
      return;
    }
 
    line_cfg_ = gpiod_line_config_new();
    if (!line_cfg_)
    {
      XR_LOG_ERROR("Failed to create GPIO line config");
      ASSERT(false);
      return;
    }
 
    req_cfg_ = gpiod_request_config_new();
    if (!req_cfg_)
    {
      XR_LOG_ERROR("Failed to create GPIO request config");
      ASSERT(false);
      return;
    }
 
    gpiod_request_config_set_consumer(req_cfg_, "LinuxGPIO");
    gpiod_request_config_set_event_buffer_size(req_cfg_, EVENT_BUFFER_CAPACITY);
 
    event_buffer_ = gpiod_edge_event_buffer_new(EVENT_BUFFER_CAPACITY);
    if (!event_buffer_)
    {
      XR_LOG_ERROR("Failed to allocate GPIO edge event buffer");
      ASSERT(false);
      return;
    }
  }

Member Function Documentation

◆ ApplyDirection()

ErrorCode LibXR::LinuxGPIO::ApplyDirection ( Direction direction )

inlineprivate

根据 GPIO 方向配置 line settings。 Applies line settings according to GPIO direction.

Returns: 操作结果。Operation result.

Definition at line 382 of file linux_gpio.hpp.

  {
    if (!settings_)
    {
      return ErrorCode::FAILED;
    }
 
    switch (direction)
    {
      case Direction::INPUT:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_INPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_NONE) < 0)
        {
          return ErrorCode::FAILED;
        }
        break;
 
      case Direction::OUTPUT_PUSH_PULL:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_OUTPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_drive(settings_, GPIOD_LINE_DRIVE_PUSH_PULL) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_NONE) < 0)
        {
          return ErrorCode::FAILED;
        }
        break;
 
      case Direction::OUTPUT_OPEN_DRAIN:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_OUTPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_drive(settings_, GPIOD_LINE_DRIVE_OPEN_DRAIN) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_NONE) < 0)
        {
          return ErrorCode::FAILED;
        }
        break;
 
      case Direction::RISING_INTERRUPT:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_INPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_RISING) < 0)
        {
          return ErrorCode::FAILED;
        }
        break;
 
      case Direction::FALL_INTERRUPT:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_INPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_FALLING) <
            0)
        {
          return ErrorCode::FAILED;
        }
        break;
 
      case Direction::FALL_RISING_INTERRUPT:
        if (gpiod_line_settings_set_direction(settings_, GPIOD_LINE_DIRECTION_INPUT) < 0)
        {
          return ErrorCode::FAILED;
        }
        if (gpiod_line_settings_set_edge_detection(settings_, GPIOD_LINE_EDGE_BOTH) < 0)
        {
          return ErrorCode::FAILED;
        }
        break;
    }
 
    return ErrorCode::OK;
  }

◆ ApplyPull()

ErrorCode LibXR::LinuxGPIO::ApplyPull ( Pull pull )

inlineprivate

根据 GPIO 上拉/下拉配置 line settings。 Applies line settings according to GPIO pull mode.

Returns: 操作结果。Operation result.

Definition at line 475 of file linux_gpio.hpp.

  {
    if (!settings_)
    {
      return ErrorCode::FAILED;
    }
 
    int ret = 0;
    switch (pull)
    {
      case Pull::NONE:
        ret = gpiod_line_settings_set_bias(settings_, GPIOD_LINE_BIAS_DISABLED);
        break;
      case Pull::UP:
        ret = gpiod_line_settings_set_bias(settings_, GPIOD_LINE_BIAS_PULL_UP);
        break;
      case Pull::DOWN:
        ret = gpiod_line_settings_set_bias(settings_, GPIOD_LINE_BIAS_PULL_DOWN);
        break;
    }
 
    return ret < 0 ? ErrorCode::FAILED : ErrorCode::OK;
  }

◆ DisableInterrupt()

ErrorCode LibXR::LinuxGPIO::DisableInterrupt ( )

inlineoverridevirtual

禁用 GPIO 中断处理状态。Disables GPIO interrupt handling state.

Returns: 操作结果。Operation result.

Implements LibXR::GPIO.

Definition at line 169 of file linux_gpio.hpp.

  {
    interrupt_enabled_ = false;
    return ErrorCode::OK;
  }

◆ EnableInterrupt()

ErrorCode LibXR::LinuxGPIO::EnableInterrupt ( )

inlineoverridevirtual

使能 GPIO 中断处理状态。Enables GPIO interrupt handling state.

Returns: 操作结果。Operation result.

Implements LibXR::GPIO.

Definition at line 149 of file linux_gpio.hpp.

  {
    if (!has_config_ || !request_)
    {
      return ErrorCode::STATE_ERR;
    }
 
    if (!IsInterruptDirection(current_config_.direction))
    {
      return ErrorCode::ARG_ERR;
    }
 
    interrupt_enabled_ = true;
    return ErrorCode::OK;
  }

◆ EnsureConfigured()

bool LibXR::LinuxGPIO::EnsureConfigured ( ) const

inlineprivate

确保 GPIO 已配置。Ensures GPIO has been configured.

Definition at line 513 of file linux_gpio.hpp.

  {
    if (!has_config_ || !request_)
    {
      XR_LOG_ERROR("GPIO is not configured");
      ASSERT(false);
      return false;
    }
 
    return true;
  }

◆ EnsureInterruptReady()

ErrorCode LibXR::LinuxGPIO::EnsureInterruptReady ( ) const

inlineprivate

确保中断路径已启用。Ensures interrupt path is enabled and ready.

Definition at line 528 of file linux_gpio.hpp.

  {
    if (!EnsureConfigured())
    {
      return ErrorCode::STATE_ERR;
    }
 
    if (!IsInterruptDirection(current_config_.direction))
    {
      XR_LOG_ERROR("GPIO is not configured for interrupt mode");
      ASSERT(false);
      return ErrorCode::ARG_ERR;
    }
 
    if (!interrupt_enabled_)
    {
      XR_LOG_ERROR("GPIO interrupt is not enabled");
      return ErrorCode::STATE_ERR;
    }
 
    return ErrorCode::OK;
  }

◆ GetFd()

int LibXR::LinuxGPIO::GetFd ( ) const

inline

获取 GPIO request 对应的文件描述符，用于 epoll/poll 注册。 Gets the request file descriptor for epoll/poll registration.

Returns: request 文件描述符。Request file descriptor.

Definition at line 180 of file linux_gpio.hpp.

  {
    if (EnsureInterruptReady() != ErrorCode::OK)
    {
      return -1;
    }
 
    return gpiod_line_request_get_fd(request_);
  }

◆ HandleInterrupt()

ErrorCode LibXR::LinuxGPIO::HandleInterrupt ( )

inline

非阻塞处理中断事件，排空队列并触发回调。 Handles GPIO interrupt events in non-blocking mode, drains queued events and dispatches callbacks.

Returns: ErrorCode::OK 表示处理了至少一个事件，ErrorCode::EMPTY 表示无事件。 ErrorCode::OK means at least one event was handled; ErrorCode::EMPTY means no pending event.

Definition at line 198 of file linux_gpio.hpp.

  {
    const ErrorCode READY = EnsureInterruptReady();
    if (READY != ErrorCode::OK)
    {
      return READY;
    }
 
    bool handled = false;
    while (true)
    {
      int ready = gpiod_line_request_wait_edge_events(request_, 0);
      if (ready < 0)
      {
        XR_LOG_ERROR("Failed to poll GPIO edge events: %s", std::strerror(errno));
        return ErrorCode::FAILED;
      }
 
      if (ready == 0)
      {
        break;
      }
 
      int read = gpiod_line_request_read_edge_events(request_, event_buffer_,
                                                     EVENT_BUFFER_CAPACITY);
      if (read < 0)
      {
        XR_LOG_ERROR("Failed to read GPIO edge events: %s", std::strerror(errno));
        return ErrorCode::FAILED;
      }
 
      if (read == 0)
      {
        break;
      }
 
      handled = true;
      if (!callback_.Empty())
      {
        for (int i = 0; i < read; ++i)
        {
          callback_.Run(false);
        }
      }
    }
 
    return handled ? ErrorCode::OK : ErrorCode::EMPTY;
  }

◆ IsInterruptDirection()

static bool LibXR::LinuxGPIO::IsInterruptDirection ( Direction direction )

inlinestaticprivate

判断 direction 是否为中断方向。Checks whether direction is interrupt mode.

Returns: true 表示中断方向。True if direction is interrupt mode.

Definition at line 503 of file linux_gpio.hpp.

  {
    return direction == Direction::RISING_INTERRUPT ||
           direction == Direction::FALL_INTERRUPT ||
           direction == Direction::FALL_RISING_INTERRUPT;
  }

◆ Read()

bool LibXR::LinuxGPIO::Read ( )

inlineoverridevirtual

读取 GPIO 引脚状态。Reads the GPIO line level.

Returns: true 高电平，false 低电平。True for high level, false for low level.

Implements LibXR::GPIO.

Definition at line 108 of file linux_gpio.hpp.

  {
    if (!EnsureConfigured())
    {
      return false;
    }
 
    enum gpiod_line_value value = gpiod_line_request_get_value(request_, line_offset_);
    if (value == GPIOD_LINE_VALUE_ERROR)
    {
      XR_LOG_ERROR("Failed to read GPIO value: %s", std::strerror(errno));
      return false;
    }
 
    return value == GPIOD_LINE_VALUE_ACTIVE;
  }

◆ ReadEvent()

ErrorCode LibXR::LinuxGPIO::ReadEvent ( GPIOEvent & event )

inline

读取单个中断事件。Reads a single interrupt edge event.

Parameters

event 输出事件结构体。Output edge event structure.

Returns: 操作结果。Operation result.

Definition at line 252 of file linux_gpio.hpp.

  {
    const ErrorCode READY_STATUS = EnsureInterruptReady();
    if (READY_STATUS != ErrorCode::OK)
    {
      return READY_STATUS;
    }
 
    int ready = gpiod_line_request_wait_edge_events(request_, 0);
    if (ready < 0)
    {
      XR_LOG_ERROR("Failed to poll GPIO edge events: %s", std::strerror(errno));
      return ErrorCode::FAILED;
    }
 
    if (ready == 0)
    {
      return ErrorCode::EMPTY;
    }
 
    int ret = gpiod_line_request_read_edge_events(request_, event_buffer_, 1);
 
    if (ret < 0)
    {
      XR_LOG_ERROR("Failed to read GPIO edge event: %s", std::strerror(errno));
      return ErrorCode::FAILED;
    }
 
    if (ret == 0)
    {
      return ErrorCode::EMPTY;
    }
 
    struct gpiod_edge_event* edge_event =
        gpiod_edge_event_buffer_get_event(event_buffer_, ret - 1);
    if (!edge_event)
    {
      XR_LOG_ERROR("Failed to access GPIO edge event from buffer");
      return ErrorCode::FAILED;
    }
 
    const uint64_t TIMESTAMP_NS = gpiod_edge_event_get_timestamp_ns(edge_event);
    if (TIMESTAMP_NS > static_cast<uint64_t>(std::numeric_limits<int64_t>::max()))
    {
      XR_LOG_ERROR("GPIO edge event timestamp out of int64 range");
      return ErrorCode::OUT_OF_RANGE;
    }
 
    event.timestamp = static_cast<int64_t>(TIMESTAMP_NS);
    event.type =
        (gpiod_edge_event_get_event_type(edge_event) == GPIOD_EDGE_EVENT_RISING_EDGE)
            ? GPIOEventType::RISING_EDGE
            : GPIOEventType::FALLING_EDGE;
 
    return ErrorCode::OK;
  }

◆ SetConfig()

ErrorCode LibXR::LinuxGPIO::SetConfig ( Configuration config )

inlineoverridevirtual

配置 GPIO 引脚参数。Configures GPIO line settings.

Parameters

config GPIO 配置。GPIO configuration.

Returns: 操作结果。Operation result.

Implements LibXR::GPIO.

Definition at line 314 of file linux_gpio.hpp.

  {
    if (!settings_ || !line_cfg_ || !req_cfg_ || !chip_)
    {
      return ErrorCode::INIT_ERR;
    }
 
    interrupt_enabled_ = false;
 
    gpiod_line_settings_reset(settings_);
    gpiod_line_config_reset(line_cfg_);
 
    if (ApplyDirection(config.direction) != ErrorCode::OK)
    {
      return ErrorCode::ARG_ERR;
    }
 
    if (ApplyPull(config.pull) != ErrorCode::OK)
    {
      return ErrorCode::ARG_ERR;
    }
 
    if (gpiod_line_config_add_line_settings(line_cfg_, &line_offset_, 1, settings_) < 0)
    {
      return ErrorCode::FAILED;
    }
 
    if (!request_)
    {
      request_ = gpiod_chip_request_lines(chip_, req_cfg_, line_cfg_);
      if (!request_)
      {
        return ErrorCode::FAILED;
      }
    }
    else
    {
      if (gpiod_line_request_reconfigure_lines(request_, line_cfg_) < 0)
      {
        return ErrorCode::FAILED;
      }
    }
 
    current_config_ = config;
    has_config_ = true;
 
    return ErrorCode::OK;
  }

◆ Write()

void LibXR::LinuxGPIO::Write ( bool value )

inlineoverridevirtual

写入 GPIO 引脚状态。Writes a level to the GPIO line.

Parameters

value true 高电平，false 低电平。True for high level, false for low level.

Implements LibXR::GPIO.

Definition at line 129 of file linux_gpio.hpp.

  {
    if (!EnsureConfigured())
    {
      return;
    }
 
    enum gpiod_line_value line_value =
        value ? GPIOD_LINE_VALUE_ACTIVE : GPIOD_LINE_VALUE_INACTIVE;
 
    if (gpiod_line_request_set_value(request_, line_offset_, line_value) < 0)
    {
      XR_LOG_WARN("Failed to write GPIO value: %s", std::strerror(errno));
    }
  }

Field Documentation

◆ chip_

gpiod_chip* LibXR::LinuxGPIO::chip_ = nullptr

private

Definition at line 366 of file linux_gpio.hpp.

◆ chip_path_

std::string LibXR::LinuxGPIO::chip_path_

private

Definition at line 364 of file linux_gpio.hpp.

◆ current_config_

Configuration LibXR::LinuxGPIO::current_config_ = {Direction::INPUT, Pull::NONE}

private

Definition at line 373 of file linux_gpio.hpp.

373{Direction::INPUT, Pull::NONE};

◆ event_buffer_

gpiod_edge_event_buffer* LibXR::LinuxGPIO::event_buffer_

private

Initial value:

=

nullptr

持久化事件缓冲区。Persistent edge event buffer.

Definition at line 367 of file linux_gpio.hpp.

◆ EVENT_BUFFER_CAPACITY

size_t LibXR::LinuxGPIO::EVENT_BUFFER_CAPACITY = 64

staticconstexpr

Definition at line 45 of file linux_gpio.hpp.

◆ has_config_

bool LibXR::LinuxGPIO::has_config_ = false

private

Definition at line 374 of file linux_gpio.hpp.

◆ interrupt_enabled_

bool LibXR::LinuxGPIO::interrupt_enabled_ = false

private

Definition at line 375 of file linux_gpio.hpp.

◆ line_cfg_

gpiod_line_config* LibXR::LinuxGPIO::line_cfg_ = nullptr

private

Definition at line 371 of file linux_gpio.hpp.

◆ line_offset_

unsigned int LibXR::LinuxGPIO::line_offset_

private

Definition at line 365 of file linux_gpio.hpp.

◆ req_cfg_

gpiod_request_config* LibXR::LinuxGPIO::req_cfg_ = nullptr

private

Definition at line 370 of file linux_gpio.hpp.

◆ request_

gpiod_line_request* LibXR::LinuxGPIO::request_ = nullptr

private

Definition at line 372 of file linux_gpio.hpp.

◆ settings_

gpiod_line_settings* LibXR::LinuxGPIO::settings_ = nullptr

private

Definition at line 369 of file linux_gpio.hpp.

The documentation for this class was generated from the following file:

driver/Linux/linux_gpio.hpp

Public Member Functions

Static Public Attributes

Private Member Functions

Static Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ LinuxGPIO()

Member Function Documentation

◆ ApplyDirection()

◆ ApplyPull()

◆ DisableInterrupt()

◆ EnableInterrupt()

◆ EnsureConfigured()

◆ EnsureInterruptReady()

◆ GetFd()

◆ HandleInterrupt()

◆ IsInterruptDirection()

◆ Read()

◆ ReadEvent()

◆ SetConfig()

◆ Write()

Field Documentation

◆ chip_

◆ chip_path_

◆ current_config_

◆ event_buffer_

◆ EVENT_BUFFER_CAPACITY

◆ has_config_

◆ interrupt_enabled_

◆ line_cfg_

◆ line_offset_

◆ req_cfg_

◆ request_

◆ settings_