rtems bbb板uart驱动编写

进行串口驱动编写，主要参考源码中的console-config.c文件

以下是代码：

void beagle_console_init(void)
{
if(init_needed)
{
const uint32_t div = UART_CLOCK / 16 / CONSOLE_BAUD;
CONSOLE_SYSC = 2;
while ((CONSOLE_SYSS & 1) == 0)
;
if ((CONSOLE_LSR & (CONSOLE_LSR_THRE | CONSOLE_LSR_TEMT)) == CONSOLE_LSR_THRE)
{
CONSOLE_LCR = 0x83;
CONSOLE_DLL = div;
CONSOLE_DLM = (div >> 8) & 0xff;
CONSOLE_LCR = 0x03;
CONSOLE_ACR = 0x00;
}
while ((CONSOLE_LSR & CONSOLE_LSR_TEMT) == 0)
;
CONSOLE_LCR = 0x80 | 0x03;
CONSOLE_DLL = 0x00;
CONSOLE_DLM = 0x00;
CONSOLE_LCR = 0x03;
CONSOLE_MCR = 0x03;
CONSOLE_FCR = 0x07;
CONSOLE_LCR = 0x83;
CONSOLE_DLL = div;
CONSOLE_DLM = (div >> 8) & 0xff;
CONSOLE_LCR = 0x03;
CONSOLE_ACR = 0x00;
init_needed = 0;
}
}

以下是发送部分程序：

#include <stdio.h>
#include <stdlib.h>

#include <bsp.h>
#define Control_Module_Registers1 (*(volatile uint32_t *)(0x44E10000+0x984))
#define UART1_THR    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x00))
#define UART1_RHR    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x00))
#define UART1_IER    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x04))
#define UART1_DLL    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x00))
#define UART1_DLM    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x04))
#define UART1_LCR    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x0c))
#define UART1_LSR    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x14))
#define UART1_MDR1    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x20))
#define UART1_SYSC    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x54))
#define UART1_SYSS    (*(volatile uint32_t *)(BEAGLE_BASE_UART_2+0x58))

#define TX_FIFO_E (1<<5)
#define RX_FIFO_E (1<<0)

发送函数：

int uart_send_command(rtems_task_argument ignored)
{
    uint32_t div;
    Control_Module_Registers1 = 0x00;
    UART1_SYSC = 2;        // software reset
    while((UART1_SYSS & 1) == 0)    ;
    
    UART1_LCR = 0x83;
    div = UART_CLOCK / 16 / 115200;
    UART1_DLL = div;
    UART1_DLM = (div >> 8) & 0xff;
    UART1_LCR = 0x03;
    UART1_MDR1 = 0x00;
    char              c;
    while(1) {
        for(c = 'A'; c <= 'Z'; c++) {
            UART1_THR = c;
            rtems_task_wake_after(rtems_clock_get_ticks_per_second());
        }
    }
    

    return 0;
}

接收部分下次再聊。