用HAL库写一个输出PWM的驱动

好的，下面是一个使用 HAL 库编写的 PWM 驱动的示例：

#include "stm32f4xx_hal.h"

// 定义 PWM 输出的引脚
#define PWM_OUTPUT_PIN GPIO_PIN_9

// 定义 PWM 输出的端口
#define PWM_OUTPUT_PORT GPIOC

// 定义 PWM 输出的频率
#define PWM_FREQUENCY 1000

int main(void)
{
    // 初始化 HAL 库
    HAL_Init();

    // 初始化 PWM 输出的引脚
    __HAL_RCC_GPIOC_CLK_ENABLE();
    GPIO_InitTypeDef gpio_init;
    gpio_init.Pin = PWM_OUTPUT_PIN;
    gpio_init.Mode = GPIO_MODE_AF_PP;
    gpio_init.Pull = GPIO_PULLUP;
    gpio_init.Speed = GPIO_SPEED_FREQ_HIGH;
    gpio_init.Alternate = GPIO_AF2_TIM3;
    HAL_GPIO_Init(PWM_OUTPUT_PORT, &gpio_init);

    // 初始化 PWM
    __HAL_RCC_TIM3_CLK_ENABLE();
    TIM_HandleTypeDef tim_handle;
    tim_handle.Instance = TIM3;
    tim_handle.Init.Period = (SystemCoreClock / PWM_FREQUENCY) - 1;
    tim_handle.Init.Prescaler = 0;
    tim_handle.Init.ClockDivision = 0;
    tim_handle.Init.CounterMode = TIM_COUNTERMODE_UP;
    tim_handle.Init.RepetitionCounter = 0;
    HAL_TIM_PWM_Init(&tim_handle);

    // 配置 PWM 输出
    TIM_OC_InitTypeDef tim_oc_init;
    tim_oc_init.OCMode = TIM_OCMODE_PWM1;
    tim_oc_init.Pulse = (tim_handle.Init.Period + 1) / 2;
    tim_oc_init.OCPolarity = TIM_OCPOLARITY_HIGH;
    tim_oc_init.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&tim_handle, &tim_oc_init, TIM_CHANNEL_1);

    // 启动 PWM
    HAL_TIM_PWM_Start(&tim_handle, TIM_CHANNEL_1);

    // 循环
    while (1)
    {
        // 在这里可以修改 PWM 占空比，例如