概览

odrive对stm32的gpio和gpio中断进行了自己的封装，故对其进行分析

Gpio对象

class Stm32Gpio {public:static const Stm32Gpio none;Stm32Gpio() : port_(nullptr), pin_mask_(0) {}Stm32Gpio(GPIO_TypeDef* port, uint16_t pin) : port_(port), pin_mask_(pin) {}operator bool() const { return port_ && pin_mask_; }/*** @brief Configures the GPIO with the specified parameters.* * This can be done regardless of the current state of the GPIO.* * If any subscription is in place, it is not disabled by this function.*/bool config(uint32_t mode, uint32_t pull, uint32_t speed = GPIO_SPEED_FREQ_LOW);void write(bool state) {if (port_) {HAL_GPIO_WritePin(port_, pin_mask_, state ? GPIO_PIN_SET : GPIO_PIN_RESET);}}bool read() {return port_ && (port_->IDR & pin_mask_);}/*** @brief Subscribes to external interrupts on the specified GPIO.* * Before calling this function the gpio should most likely be configured as* input (however this is not mandatory, the interrupt works in output mode* too).* Also you need to enable the EXTIx_IRQn interrupt vectors in the NVIC,* otherwise the subscription won't have any effect.* * Only one subscription is allowed per pin number. I.e. it is not possible* to set up a subscription for both PA0 and PB0 at the same time.* * This function is thread-safe with respect to all other public functions* of this class.* * Returns true if the subscription was set up successfully or false otherwise.*/bool subscribe(bool rising_edge, bool falling_edge, void (*callback)(void*), void* ctx);/*** @brief Unsubscribes from external interrupt on the specified GPIO.* * If no subscription was active for this GPIO, calling this function has no* effect.** This function is thread-safe with respect to all other public functions* of this class, however it must not be called from an interrupt routine* running at a higher priority than the interrupt that is being unsubscribed.** After this function returns the callback given to subscribe() will no* longer be invoked.*/void unsubscribe();uint16_t get_pin_number() {uint16_t pin_number = 0;uint16_t pin_mask = pin_mask_ >> 1;while (pin_mask) {pin_mask >>= 1;pin_number++;}return pin_number;}GPIO_TypeDef* port_;uint16_t pin_mask_; // TODO: store pin_number_ instead of pin_mask_
};

pin_mask_ 用于将gpio的序号改写成便于位操作的形式
eg ： pin3 ，pin_mask_ = 0000000000001000
pin0 ，pin_mask_ = 0000000000000001
于是get_pin_number()即为逆向操作

bool read() {return port_ && (port_->IDR & pin_mask_);}

read函数使用直接读取寄存器的方法
write是直接调用HAL库

`config`函数

bool Stm32Gpio::config(uint32_t mode, uint32_t pull, uint32_t speed) {if (port_ == GPIOA) {__HAL_RCC_GPIOA_CLK_ENABLE();} else if (port_ == GPIOB) {__HAL_RCC_GPIOB_CLK_ENABLE();} else if (port_ == GPIOC) {__HAL_RCC_GPIOC_CLK_ENABLE();} else if (port_ == GPIOD) {__HAL_RCC_GPIOD_CLK_ENABLE();} else if (port_ == GPIOE) {__HAL_RCC_GPIOE_CLK_ENABLE();} else if (port_ == GPIOF) {__HAL_RCC_GPIOF_CLK_ENABLE();} else if (port_ == GPIOG) {__HAL_RCC_GPIOG_CLK_ENABLE();} else if (port_ == GPIOH) {__HAL_RCC_GPIOH_CLK_ENABLE();} else {return false;}size_t position = get_pin_number();// The following code is mostly taken from HAL_GPIO_Init/* Configure IO Direction mode (Input, Output, Alternate or Analog) */uint32_t temp = port_->MODER;temp &= ~(GPIO_MODER_MODER0 << (position * 2U));temp |= ((mode & GPIO_MODE) << (position * 2U));port_->MODER = temp;/* In case of Output or Alternate function mode selection */if((mode == GPIO_MODE_OUTPUT_PP) || (mode == GPIO_MODE_AF_PP) ||(mode == GPIO_MODE_OUTPUT_OD) || (mode == GPIO_MODE_AF_OD)){/* Check the Speed parameter */assert_param(IS_GPIO_SPEED(speed));/* Configure the IO Speed */temp = port_->OSPEEDR; temp &= ~(GPIO_OSPEEDER_OSPEEDR0 << (position * 2U));temp |= (speed << (position * 2U));port_->OSPEEDR = temp;/* Configure the IO Output Type */temp = port_->OTYPER;temp &= ~(GPIO_OTYPER_OT_0 << position) ;temp |= (((mode & GPIO_OUTPUT_TYPE) >> 4U) << position);port_->OTYPER = temp;}/* Activate the Pull-up or Pull down resistor for the current IO */temp = port_->PUPDR;temp &= ~(GPIO_PUPDR_PUPDR0 << (position * 2U));temp |= ((pull) << (position * 2U));port_->PUPDR = temp;return true;
}

打开时钟
获取pin_number
后面进行gpio的初始化（官方注释：基本从HAL库复制）

`subscribe`函数

bool Stm32Gpio::subscribe(bool rising_edge, bool falling_edge, void (*callback)(void*), void* ctx) {uint32_t pin_number = get_pin_number();if (pin_number >= N_EXTI) {return false; // invalid pin number}struct subscription_t& subscription = subscriptions[pin_number];GPIO_TypeDef* no_port = nullptr;if (!__atomic_compare_exchange_n(&subscription.port, &no_port, port_, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {return false; // already in use}// The following code is mostly taken from HAL_GPIO_Init__HAL_RCC_SYSCFG_CLK_ENABLE();uint32_t temp = SYSCFG->EXTICR[pin_number >> 2U];temp &= ~(0x0FU << (4U * (pin_number & 0x03U)));temp |= ((uint32_t)(GPIO_GET_INDEX(port_)) << (4U * (pin_number & 0x03U)));SYSCFG->EXTICR[pin_number >> 2U] = temp;if (rising_edge) {EXTI->RTSR |= (uint32_t)pin_mask_;} else {EXTI->RTSR &= ~((uint32_t)pin_mask_);}if (falling_edge) {EXTI->FTSR |= (uint32_t)pin_mask_;} else {EXTI->FTSR &= ~((uint32_t)pin_mask_);}EXTI->EMR &= ~((uint32_t)pin_mask_);EXTI->IMR |= (uint32_t)pin_mask_;// Clear any previous triggers__HAL_GPIO_EXTI_CLEAR_IT(pin_mask_);subscription.ctx = ctx;subscription.callback = callback;return true;
}

该函数是配置相关gpio的中断的它没有进行gpio input或output的配置，也没有开中断
同时还有一个结构体数组保存相应的中断线信息


#define N_EXTI 16struct subscription_t {GPIO_TypeDef* port = nullptr;void (*callback)(void*) = nullptr;void* ctx = nullptr;
} subscriptions[N_EXTI];

未知ctx是干啥的，上下文？求教 ctx作为输入参数传入calllback

`unsubscribe`函数

即取消gpio的中断线和deinit subscriptions中的配置

杂项函数

void maybe_handle(uint16_t exti_number) {if(__HAL_GPIO_EXTI_GET_IT(1 << exti_number) == RESET) {return; // This interrupt source did not trigger the interrupt line}__HAL_GPIO_EXTI_CLEAR_IT(1 << exti_number);if (exti_number >= N_EXTI) {return;}subscription_t& subscription = subscriptions[exti_number];if (subscription.callback) {(*subscription.callback)(subscription.ctx);}
}

这是gpio的中断线处理程序，首先判断是不是这个gpio的中断请求，然后清标志位，防溢出，调用callback，ctx作为参数传入

main.cpp中的gpio相关

在main.hpp中还有个函数

static Stm32Gpio get_gpio(size_t gpio_num) {return (gpio_num < GPIO_COUNT) ? gpios[gpio_num] : GPIO_COUNT ? gpios[0] : Stm32Gpio::none;
}

它将gpio_num转换成Stm32Gpio 而有个Stm32Gpio gpios[]保存着每个gpio的参数，它被存在board.c文件中
本文完，To be countinue…

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Odrive_0.5.5运行代码分析_(三)_GPIO详解

开始

概览

Gpio对象

`config`函数

`subscribe`函数

`unsubscribe`函数

杂项函数

main.cpp中的gpio相关

Odrive_0.5.5运行代码分析_(三)_GPIO详解相关推荐

最新文章

热门文章

Odrive_0.5.5运行代码分析_(三)_GPIO详解

开始

概览

Gpio对象

config函数

subscribe函数

unsubscribe函数

杂项函数

main.cpp中的gpio相关

Odrive_0.5.5运行代码分析_(三)_GPIO详解相关推荐

最新文章

热门文章

`config`函数

`subscribe`函数

`unsubscribe`函数