esp-idf/examples/cxx/experimental/experimental_cpp_component/include/gpio_cxx.hpp

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/*
* SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#if __cpp_exceptions
#include "esp_exception.hpp"
#include "system_cxx.hpp"
namespace idf {
/**
* @brief Exception thrown for errors in the GPIO C++ API.
*/
struct GPIOException : public ESPException {
/**
* @param error The IDF error representing the error class of the error to throw.
*/
GPIOException(esp_err_t error);
};
/**
* Check if the numeric pin number is valid on the current hardware.
*/
esp_err_t check_gpio_pin_num(uint32_t pin_num) noexcept;
/**
* Check if the numeric value of a drive strength is valid on the current hardware.
*/
esp_err_t check_gpio_drive_strength(uint32_t strength) noexcept;
/**
* This is a "Strong Value Type" class for GPIO. The GPIO pin number is checked during construction according to
* the hardware capabilities. This means that any GPIONumBase object is guaranteed to contain a valid GPIO number.
* See also the template class \c StrongValue.
*/
template<typename GPIONumFinalType>
class GPIONumBase final : public StrongValueComparable<uint32_t> {
public:
/**
* @brief Create a numerical pin number representation and make sure it's correct.
*
* @throw GPIOException if the number does not reflect a valid GPIO number on the current hardware.
*/
GPIONumBase(uint32_t pin) : StrongValueComparable<uint32_t>(pin)
{
esp_err_t pin_check_result = check_gpio_pin_num(pin);
if (pin_check_result != ESP_OK) {
throw GPIOException(pin_check_result);
}
}
using StrongValueComparable<uint32_t>::operator==;
using StrongValueComparable<uint32_t>::operator!=;
/**
* Retrieves the valid numerical representation of the GPIO number.
*/
uint32_t get_num() const { return get_value(); };
};
/**
* This is a TAG type whose sole purpose is to create a distinct type from GPIONumBase.
*/
class GPIONumType;
/**
* A GPIO number type used for general GPIOs, in contrast to specific GPIO pins like e.g. SPI_SCLK.
*/
using GPIONum = GPIONumBase<class GPIONumType>;
/**
* Level of an input GPIO.
*/
enum class GPIOLevel {
HIGH,
LOW
};
/**
* Represents a valid pull up configuration for GPIOs.
* It is supposed to resemble an enum type, hence it has static creation methods and a private constructor.
* This class is a "Strong Value Type", see also the template class \c StrongValue for more properties.
*/
class GPIOPullMode final : public StrongValueComparable<uint32_t> {
private:
/**
* Constructor is private since it should only be accessed by the static creation methods.
*
* @param pull_mode A valid numerical respresentation of the pull up configuration. Must be valid!
*/
GPIOPullMode(uint32_t pull_mode) : StrongValueComparable<uint32_t>(pull_mode) { }
public:
/**
* Create a representation of a floating pin configuration.
* For more information, check the driver and HAL files.
*/
static GPIOPullMode FLOATING();
/**
* Create a representation of a pullup configuration.
* For more information, check the driver and HAL files.
*/
static GPIOPullMode PULLUP();
/**
* Create a representation of a pulldown configuration.
* For more information, check the driver and HAL files.
*/
static GPIOPullMode PULLDOWN();
using StrongValueComparable<uint32_t>::operator==;
using StrongValueComparable<uint32_t>::operator!=;
/**
* Retrieves the valid numerical representation of the pull mode.
*/
uint32_t get_pull_mode() const { return get_value(); };
};
/**
* @brief Represents a valid wakup interrupt type for GPIO inputs.
*
* This class is a "Strong Value Type", see also the template class \c StrongValue for more properties.
* It is supposed to resemble an enum type, hence it has static creation methods and a private constructor.
* For a detailed mapping of interrupt types to numeric values, please refer to the driver types and implementation.
*/
class GPIOWakeupIntrType final: public StrongValueComparable<uint32_t> {
private:
/**
* Constructor is private since it should only be accessed by the static creation methods.
*
* @param pull_mode A valid numerical respresentation of a possible interrupt level to wake up. Must be valid!
*/
GPIOWakeupIntrType(uint32_t interrupt_level) : StrongValueComparable<uint32_t>(interrupt_level) { }
public:
static GPIOWakeupIntrType LOW_LEVEL();
static GPIOWakeupIntrType HIGH_LEVEL();
/**
* Retrieves the valid numerical representation of the pull mode.
*/
uint32_t get_level() const noexcept { return get_value(); };
};
/**
* Class representing a valid drive strength for GPIO outputs.
* This class is a "Strong Value Type", see also the template class \c StrongValue for more properties.
* For a detailed mapping for values to drive strengths, please refer to the datasheet of the chip you are using.
* E.g. for ESP32, the values in general are the following:
* - WEAK: 5mA
* - STRONGER: 10mA
* - DEFAULT/MEDIUM: 20mA
* - STRONGEST: 40mA
*/
class GPIODriveStrength final : public StrongValueComparable<uint32_t> {
public:
/**
* @brief Create a drive strength representation and checks its validity.
*
* After construction, this class should have a guaranteed valid strength representation.
*
* @param strength the numeric value mapping for a particular strength. For possible ranges, look at the
* static creation functions below.
* @throws GPIOException if the supplied number is out of the hardware capable range.
*/
GPIODriveStrength(uint32_t strength) : StrongValueComparable<uint32_t>(strength)
{
esp_err_t strength_check_result = check_gpio_drive_strength(strength);
if (strength_check_result != ESP_OK) {
throw GPIOException(strength_check_result);
}
}
/**
* Create a representation of the default drive strength.
* For more information, check the datasheet and driver and HAL files.
*/
static GPIODriveStrength DEFAULT();
/**
* Create a representation of the weak drive strength.
* For more information, check the datasheet and driver and HAL files.
*/
static GPIODriveStrength WEAK();
/**
* Create a representation of the less weak drive strength.
* For more information, check the datasheet and driver and HAL files.
*/
static GPIODriveStrength LESS_WEAK();
/**
* Create a representation of the medium drive strength.
* For more information, check the datasheet and driver and HAL files.
*/
static GPIODriveStrength MEDIUM();
/**
* Create a representation of the strong drive strength.
*/
static GPIODriveStrength STRONGEST();
using StrongValueComparable<uint32_t>::operator==;
using StrongValueComparable<uint32_t>::operator!=;
/**
* Retrieves the valid numerical representation of the drive strength.
*/
uint32_t get_strength() const { return get_value(); };
};
/**
* @brief Implementations commonly used functionality for all GPIO configurations.
*
* Some functionality is only for specific configurations (set and get drive strength) but is necessary here
* to avoid complicating the inheritance hierarchy of the GPIO classes.
* Child classes implementing any GPIO configuration (output, input, etc.) are meant to intherit from this class
* and possibly make some of the functionality publicly available.
*/
class GPIOBase {
protected:
/**
* @brief Construct a GPIO.
*
* This constructor will only reset the GPIO but leaves the actual configuration (input, output, etc.) to
* the sub class.
*
* @param num GPIO pin number of the GPIO to be configured.
*
* @throws GPIOException
* - if the underlying driver function fails
*/
GPIOBase(GPIONum num);
/**
* @brief Enable gpio pad hold function.
*
* The gpio pad hold function works in both input and output modes, but must be output-capable gpios.
* If pad hold enabled:
* in output mode: the output level of the pad will be force locked and can not be changed.
* in input mode: the input value read will not change, regardless the changes of input signal.
*
* @throws GPIOException if the underlying driver function fails.
*/
void hold_en();
/**
* @brief Disable gpio pad hold function.
*
* @throws GPIOException if the underlying driver function fails.
*/
void hold_dis();
/**
* @brief Configure the drive strength of the GPIO.
*
* @param strength The drive strength. Refer to \c GPIODriveStrength for more details.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_drive_strength(GPIODriveStrength strength);
/**
* @brief Return the current drive strength of the GPIO.
*
* @return The currently configured drive strength. Refer to \c GPIODriveStrength for more details.
*
* @throws GPIOException if the underlying driver function fails.
*/
GPIODriveStrength get_drive_strength();
/**
* @brief The number of the configured GPIO pin.
*/
GPIONum gpio_num;
};
/**
* @brief This class represents a GPIO which is configured as output.
*/
class GPIO_Output : public GPIOBase {
public:
/**
* @brief Construct and configure a GPIO as output.
*
* @param num GPIO pin number of the GPIO to be configured.
*
* @throws GPIOException
* - if the underlying driver function fails
*/
GPIO_Output(GPIONum num);
/**
* @brief Set GPIO to high level.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_high();
/**
* @brief Set GPIO to low level.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_low();
using GPIOBase::set_drive_strength;
using GPIOBase::get_drive_strength;
};
/**
* @brief This class represents a GPIO which is configured as input.
*/
class GPIOInput : public GPIOBase {
public:
/**
* @brief Construct and configure a GPIO as input.
*
* @param num GPIO pin number of the GPIO to be configured.
*
* @throws GPIOException
* - if the underlying driver function fails
*/
GPIOInput(GPIONum num);
/**
* @brief Read the current level of the GPIO.
*
* @return The GPIO current level of the GPIO.
*/
GPIOLevel get_level() const noexcept;
/**
* @brief Configure the internal pull-up and pull-down restors.
*
* @param mode The pull-up/pull-down configuration see \c GPIOPullMode.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_pull_mode(GPIOPullMode mode);
/**
* @brief Configure the pin as wake up pin.
*
* @throws GPIOException if the underlying driver function fails.
*/
void wakeup_enable(GPIOWakeupIntrType interrupt_type);
/**
* @brief Disable wake up functionality for this pin if it was enabled before.
*
* @throws GPIOException if the underlying driver function fails.
*/
void wakeup_disable();
};
/**
* @brief This class represents a GPIO which is configured as open drain output and input at the same time.
*
* This class facilitates bit-banging for single wire protocols.
*/
class GPIO_OpenDrain : public GPIOInput {
public:
/**
* @brief Construct and configure a GPIO as open drain output as well as input.
*
* @param num GPIO pin number of the GPIO to be configured.
*
* @throws GPIOException
* - if the underlying driver function fails
*/
GPIO_OpenDrain(GPIONum num);
/**
* @brief Set GPIO to floating level.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_floating();
/**
* @brief Set GPIO to low level.
*
* @throws GPIOException if the underlying driver function fails.
*/
void set_low();
using GPIOBase::set_drive_strength;
using GPIOBase::get_drive_strength;
};
}
#endif