stm32l1xx_nucleo_led.c

[詳解]

/** @file
    @brief      STM32L152RE-Nucleo LEDドライバ

    @date       2018.08.13
    @author     Takashi SHUDO
*/

#include "device.h"

#define RCC_AHB1ENR     (*(volatile unsigned long *)0x40023830)
#define RCC_AHB1LPENR   (*(volatile unsigned long *)0x40023850)
#define RCC_AHB1_BIT_GPIOD      (1<<3)

/*
  GPIOレジスタ
*/
typedef struct st_reg_gpio {
        unsigned long   MODER;
        unsigned long   OTYPE;
        unsigned long   OSPEEDR;
        unsigned long   PUPDR;
        unsigned long   IDR;
        unsigned long   ODR;
        unsigned long   BSRR;
        unsigned long   LCKR;
        unsigned long   AFRL;
        unsigned long   AFRH;
} st_reg_gpio;

#define GPIOA_BASE      (0x40020000 + 0x000)

#define GPIOA   ((st_reg_gpio *)GPIOA_BASE)

#define GPIO_MODE_BIT_IN        0x00    // Input Mode
#define GPIO_MODE_BIT_OUT       0x01    // Output Mode
#define GPIO_MODE_BIT_AF        0x02    // Alternate functions Mode
#define GPIO_MODE_BIT_AN        0x03    // Analog Mode
#define GPIO_MODE_BIT_ALL       0x03

#define GPIO_OTYPE_BIT_PP       0x00    // push-pull
#define GPIO_OTYPE_BIT_OD       0x01    // open-drain

#define GPIO_OSPEED_BIT_ALL     0x03
#define GPIO_OSPEED_BIT_50MHz   0x02
#define GPIO_OSPEED_BIT_100MHz  0x03

#define GPIO_PUPDR_BIT_NOPULL   0x00    // No pull-up, pull-down
#define GPIO_PUPDR_BIT_PUP      0x01    // pull-up
#define GPIO_PUPDR_BIT_PDOWN    0x02    // pull-down
#define GPIO_PUPDR_BIT_ALL      0x03

#define GPIO_AFR_BIT_I2C123     0x04
#define GPIO_AFR_BIT_USART123   0x07
#define GPIO_AFR_BIT_ALL        0x0F

static void init_pin(st_reg_gpio *gpio, int pin)
{
        volatile st_reg_gpio *gpiox = gpio;

        gpiox->MODER &= ~(((unsigned long)GPIO_MODE_BIT_ALL) << (2*pin));
        gpiox->MODER |= (((unsigned long)GPIO_MODE_BIT_OUT) << (2*pin));
        gpiox->OSPEEDR &= ~(((unsigned long)GPIO_OSPEED_BIT_ALL) << (2*pin));
        gpiox->OSPEEDR |= (((unsigned long)GPIO_OSPEED_BIT_50MHz) << (2*pin));
        gpiox->OTYPE &= ~(((unsigned long)1) << pin);
        gpiox->OTYPE |= (((unsigned long)GPIO_OTYPE_BIT_PP) << pin);
        gpiox->PUPDR &= ~(((unsigned long)GPIO_PUPDR_BIT_ALL) << (2*pin));
        gpiox->PUPDR |= (((unsigned long)GPIO_PUPDR_BIT_NOPULL) << (2*pin));
//      gpiox->PUPDR |= (((unsigned long)GPIO_PUPDR_BIT_PUP) << (2*pin));

        if(pin < 8) {
                gpiox->AFRL &= ~(((unsigned long)GPIO_AFR_BIT_ALL) << (4*pin));
                gpiox->AFRL |= (((unsigned long)GPIO_AFR_BIT_I2C123) << (4*pin));
        } else {
                gpiox->AFRH &= ~(((unsigned long)GPIO_AFR_BIT_ALL) << (4*(pin-8)));
                gpiox->AFRH |= (((unsigned long)GPIO_AFR_BIT_I2C123) << (4*(pin-8)));
        }
}

#define POS_LD2 5       // Green
#define BIT_LD2         (1 << POS_LD2)

static unsigned long flg_led_on;

static int led_register(struct st_device *dev, char *param)
{
        flg_led_on = 0;

        RCC_AHB1ENR |= RCC_AHB1_BIT_GPIOD;

        init_pin(GPIOA, POS_LD2);

        return 0;
}

static int led_getc(struct st_device *dev, unsigned char *rd)
{
        *rd = ((GPIOA->ODR & BIT_LD2) >> POS_LD2);

        return 1;
}

static int led_putc(struct st_device *dev, unsigned char ch)
{
        flg_led_on = ((ch << POS_LD2) & BIT_LD2);
        GPIOA->ODR = flg_led_on;

        return 1;
}

static int led_suspend(struct st_device *dev)
{
        GPIOA->ODR &= ~(BIT_LD2);

        return 0;
}

static int led_resume(struct st_device *dev)
{
        GPIOA->ODR = flg_led_on;

        return 0;
}

const struct st_device led_device = {
        .name           = DEF_DEV_NAME_LED,
        .explan         = "STM32L152RE-Nucleo LED",
        .register_dev   = led_register,
        .getc           = led_getc,
        .putc           = led_putc,
        .suspend        = led_suspend,
        .resume         = led_resume,
}; //!< LEDドライバ