usart.c

/*
 * File      : usart.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006-2013, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2013-11-15     bright       the first version
 */

#include <stm32f0xx.h>
#include <rtdevice.h>
#include "usart.h"

/* USART1 */
#define UART1_GPIO_TX			GPIO_Pin_9
#define UART1_GPIO_TX_SOURCE	GPIO_PinSource9
#define UART1_GPIO_RX			GPIO_Pin_10
#define UART1_GPIO_RX_SOURCE	GPIO_PinSource10
#define UART1_GPIO_AF			GPIO_AF_1
#define UART1_GPIO				GPIOA

/* USART2 */
#define UART2_GPIO_TX			GPIO_Pin_2
#define UART2_GPIO_TX_SOURCE	GPIO_PinSource2
#define UART2_GPIO_RX			GPIO_Pin_3
#define UART2_GPIO_RX_SOURCE	GPIO_PinSource3
#define UART2_GPIO_AF			GPIO_AF_1
#define UART2_GPIO				GPIOA

/* STM32 uart driver */
struct stm32_uart
{
    USART_TypeDef* uart_device;
    IRQn_Type irq;
};

static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
{
    struct stm32_uart* uart;
    USART_InitTypeDef USART_InitStructure;

    RT_ASSERT(serial != RT_NULL);
    RT_ASSERT(cfg != RT_NULL);

    uart = (struct stm32_uart *)serial->parent.user_data;

    USART_InitStructure.USART_BaudRate = cfg->baud_rate;

    if (cfg->data_bits == DATA_BITS_8)
        USART_InitStructure.USART_WordLength = USART_WordLength_8b;

    if (cfg->stop_bits == STOP_BITS_1)
        USART_InitStructure.USART_StopBits = USART_StopBits_1;
    else if (cfg->stop_bits == STOP_BITS_2)
        USART_InitStructure.USART_StopBits = USART_StopBits_2;

    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(uart->uart_device, &USART_InitStructure);

    /* Enable USART */
    USART_Cmd(uart->uart_device, ENABLE);
    /* enable interrupt */
    USART_ITConfig(uart->uart_device, USART_IT_RXNE, ENABLE);

    return RT_EOK;
}

static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *arg)
{
    struct stm32_uart* uart;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;

    switch (cmd)
    {
    case RT_DEVICE_CTRL_CLR_INT:
        /* disable rx irq */
        UART_DISABLE_IRQ(uart->irq);
        break;
    case RT_DEVICE_CTRL_SET_INT:
        /* enable rx irq */
        UART_ENABLE_IRQ(uart->irq);
        break;
    }

    return RT_EOK;
}

static int stm32_putc(struct rt_serial_device *serial, char c)
{
    struct stm32_uart* uart;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;

    while (!(uart->uart_device->ISR & USART_FLAG_TXE));
    uart->uart_device->TDR = c;

    return 1;
}

static int stm32_getc(struct rt_serial_device *serial)
{
    int ch;
    struct stm32_uart* uart;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct stm32_uart *)serial->parent.user_data;

    ch = -1;
    if (uart->uart_device->ISR & USART_FLAG_RXNE)
    {
        ch = uart->uart_device->RDR & 0xff;
    }

    return ch;
}

static const struct rt_uart_ops stm32_uart_ops =
{
    stm32_configure,
    stm32_control,
    stm32_putc,
    stm32_getc,
};

#if defined(RT_USING_UART1)
/* UART1 device driver structure */
struct stm32_uart uart1 =
{
    USART1,
    USART1_IRQn,
};
struct rt_serial_device serial1;

void USART1_IRQHandler(void)
{
    struct stm32_uart* uart;

    uart = &uart1;

    /* enter interrupt */
    rt_interrupt_enter();
    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
    {
        rt_hw_serial_isr(&serial1, RT_SERIAL_EVENT_RX_IND);
        /* clear interrupt */
        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
    }
    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
    {
        /* clear interrupt */
        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
    }

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* RT_USING_UART1 */

#if defined(RT_USING_UART2)
/* UART2 device driver structure */
struct stm32_uart uart2 =
{
    USART2,
    USART2_IRQn,
};
struct rt_serial_device serial2;

void USART2_IRQHandler(void)
{
    struct stm32_uart* uart;

    uart = &uart2;

    /* enter interrupt */
    rt_interrupt_enter();
    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
    {
        rt_hw_serial_isr(&serial2, RT_SERIAL_EVENT_RX_IND);
        /* clear interrupt */
        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
    }
    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
    {
        /* clear interrupt */
        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
    }

    /* leave interrupt */
    rt_interrupt_leave();
}
#endif /* RT_USING_UART2 */

static void RCC_Configuration(void)
{
#ifdef RT_USING_UART1
    /* Enable GPIO clock */
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
    /* Enable USART clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
#endif /* RT_USING_UART1 */

#ifdef RT_USING_UART2
    /* Enable GPIO clock */
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
    /* Enable USART clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
#endif /* RT_USING_UART2 */

}

static void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

#ifdef RT_USING_UART1
	/* Connect PXx to USARTx_Tx */
	GPIO_PinAFConfig(UART1_GPIO, UART1_GPIO_TX_SOURCE, UART1_GPIO_AF);

	/* Connect PXx to USARTx_Rx */
	GPIO_PinAFConfig(UART1_GPIO, UART1_GPIO_RX_SOURCE, UART1_GPIO_AF);

	/* Configure USART Tx, Rx as alternate function push-pull */
	GPIO_InitStructure.GPIO_Pin = UART1_GPIO_TX | UART1_GPIO_RX;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
	GPIO_Init(UART1_GPIO, &GPIO_InitStructure);
#endif /* RT_USING_UART1 */

#ifdef RT_USING_UART2
	/* Connect PXx to USARTx_Tx */
	GPIO_PinAFConfig(UART2_GPIO, UART2_GPIO_TX_SOURCE, UART2_GPIO_AF);

	/* Connect PXx to USARTx_Rx */
	GPIO_PinAFConfig(UART2_GPIO, UART2_GPIO_RX_SOURCE, UART2_GPIO_AF);

	/* Configure USART Tx, Rx as alternate function push-pull */
	GPIO_InitStructure.GPIO_Pin = UART2_GPIO_TX | UART2_GPIO_RX;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
	GPIO_Init(UART2_GPIO, &GPIO_InitStructure);
#endif /* RT_USING_UART2 */
}

static void NVIC_Configuration(struct stm32_uart* uart)
{
    NVIC_InitTypeDef NVIC_InitStructure;

    /* Enable the USART Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel = uart->irq;
    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

void rt_hw_usart_init(void)
{
    struct stm32_uart* uart;
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;

    RCC_Configuration();
    GPIO_Configuration();

#ifdef RT_USING_UART1
    uart = &uart1;
    config.baud_rate = BAUD_RATE_115200;

    serial1.ops    = &stm32_uart_ops;
    serial1.config = config;

    NVIC_Configuration(&uart1);

    /* register UART1 device */
    rt_hw_serial_register(&serial1, "uart1",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          uart);
#endif /* RT_USING_UART1 */

#ifdef RT_USING_UART2
    uart = &uart2;

    config.baud_rate = BAUD_RATE_115200;
    serial2.ops    = &stm32_uart_ops;
    serial2.config = config;

    NVIC_Configuration(&uart2);

    /* register UART1 device */
    rt_hw_serial_register(&serial2, "uart2",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          uart);
#endif /* RT_USING_UART2 */
}