kueckermann
commented
2 months ago Having some issues with this one. It seems that while libgpiod does have the functionality for pull up/down and debounce, it doesn't seem to be exposed in the development headers from libgpiod-dev. The headers for the core cpp library do clearly have these parameters available. You'll notice in this file that internal bias for pull up/down is there: https://github.com/brgl/libgpiod/blob/master/bindings/cxx/gpiodcxx/line.hpp
But the header file that comes from libgpiod-dev doesn't have any availability for this, as reference here the section from the header file for line:
class line
{
public:
/**
* @brief Default constructor. Creates an empty line object.
*/
GPIOD_API line(void);
/**
* @brief Copy constructor.
* @param other Other line object.
*/
GPIOD_API line(const line& other) = default;
/**
* @brief Move constructor.
* @param other Other line object.
*/
GPIOD_API line(line&& other) = default;
/**
* @brief Assignment operator.
* @param other Other line object.
* @return Reference to this object.
*/
GPIOD_API line& operator=(const line& other) = default;
/**
* @brief Move assignment operator.
* @param other Other line object.
* @return Reference to this object.
*/
GPIOD_API line& operator=(line&& other) = default;
/**
* @brief Destructor.
*/
GPIOD_API ~line(void) = default;
/**
* @brief Get the offset of this line.
* @return Offet of this line.
*/
GPIOD_API unsigned int offset(void) const;
/**
* @brief Get the name of this line (if any).
* @return Name of this line or an empty string if it is unnamed.
*/
GPIOD_API ::std::string name(void) const;
/**
* @brief Get the consumer of this line (if any).
* @return Name of the consumer of this line or an empty string if it
* is unused.
*/
GPIOD_API ::std::string consumer(void) const;
/**
* @brief Get current direction of this line.
* @return Current direction setting.
*/
GPIOD_API int direction(void) const noexcept;
/**
* @brief Get current active state of this line.
* @return Current active state setting.
*/
GPIOD_API int active_state(void) const noexcept;
/**
* @brief Check if this line is used by the kernel or other user space
* process.
* @return True if this line is in use, false otherwise.
*/
GPIOD_API bool is_used(void) const;
/**
* @brief Check if this line represents an open-drain GPIO.
* @return True if the line is an open-drain GPIO, false otherwise.
*/
GPIOD_API bool is_open_drain(void) const;
/**
* @brief Check if this line represents an open-source GPIO.
* @return True if the line is an open-source GPIO, false otherwise.
*/
GPIOD_API bool is_open_source(void) const;
/**
* @brief Request this line.
* @param config Request config (see gpiod::line_request).
* @param default_val Default value - only matters for OUTPUT direction.
*/
GPIOD_API void request(const line_request& config, int default_val = 0) const;
/**
* @brief Release the line if it was previously requested.
*/
GPIOD_API void release(void) const;
/**
* @brief Check if this user has ownership of this line.
* @return True if the user has ownership of this line, false otherwise.
*/
GPIOD_API bool is_requested(void) const;
/**
* @brief Read the line value.
* @return Current value (0 or 1).
*/
GPIOD_API int get_value(void) const;
/**
* @brief Set the value of this line.
* @param val New value (0 or 1).
*/
GPIOD_API void set_value(int val) const;
/**
* @brief Wait for an event on this line.
* @param timeout Time to wait before returning if no event occurred.
* @return True if an event occurred and can be read, false if the wait
* timed out.
*/
GPIOD_API bool event_wait(const ::std::chrono::nanoseconds& timeout) const;
/**
* @brief Read a line event.
* @return Line event object.
*/
GPIOD_API line_event event_read(void) const;
/**
* @brief Get the event file descriptor associated with this line.
* @return File descriptor number.
*/
GPIOD_API int event_get_fd(void) const;
/**
* @brief Get the reference to the parent chip.
* @return Reference to the parent chip object.
*/
GPIOD_API const chip& get_chip(void) const;
/**
* @brief Reset the state of this object.
*
* This is useful when the user needs to e.g. keep the line_event object
* but wants to drop the reference to the GPIO chip indirectly held by
* the line being the source of the event.
*/
GPIOD_API void reset(void);
/**
* @brief Check if two line objects reference the same GPIO line.
* @param rhs Right-hand side of the equation.
* @return True if both objects reference the same line, fale otherwise.
*/
GPIOD_API bool operator==(const line& rhs) const noexcept;
/**
* @brief Check if two line objects reference different GPIO lines.
* @param rhs Right-hand side of the equation.
* @return False if both objects reference the same line, true otherwise.
*/
GPIOD_API bool operator!=(const line& rhs) const noexcept;
/**
* @brief Check if this object holds a reference to any GPIO line.
* @return True if this object references a GPIO line, false otherwise.
*/
GPIOD_API explicit operator bool(void) const noexcept;
/**
* @brief Check if this object doesn't reference any GPIO line.
* @return True if this object doesn't reference any GPIO line, true
* otherwise.
*/
GPIOD_API bool operator!(void) const noexcept;
/**
* @brief Possible direction settings.
*/
enum : int {
DIRECTION_INPUT = 1,
/**< Line's direction setting is input. */
DIRECTION_OUTPUT,
/**< Line's direction setting is output. */
};
/**
* @brief Possible active state settings.
*/
enum : int {
ACTIVE_LOW = 1,
/**< Line's active state is low. */
ACTIVE_HIGH,
/**< Line's active state is high. */
};Not sure why, but can only think that this is newer functionality that isn't exposed in libgpiod-dev yet. But that's just a guess. Will see if it's possible to directly reference the header files from the core library instead of from libgpiod-dev.
Tom-Hirschberger
Hi, switched to your library recently as Kernel 6.6 broke one of my MagicMirror modules. Would be grate to be able to set pull-up or pull-down for pins while registering them.