Fuart在uboot下使用方法

1. 将cmd_fuart.c放到uboot/common下，在Makefile里增加：obj-y += cmd_fuart.o

2. 之后make即可在boot菜单下使用fuart命令测试。

   cmd_fuart.c代码如下：

   #include < common.h >  
   #include "linux/string.h"  
   #include "asm/arch/mach/ms_types.h"  
   #include "asm/arch/mach/platform.h"  
   #include "../arch/arm/cpu/armv7/infinity3/ms_serial.h"  
   //#include < stdlib.h >
   
   #define FUART_BASE 0x1F220400  //UART0_BASE 0x1F221000  
   #define FUART_REG8(_x_)  ((U8 volatile *)(FUART_BASE))[((_x_) * 4) - ((_x_) & 1)]  
   #define FUART_CHIPTOP_BASE 0x1F203C00  
   #define FUART_CHIPTOP_REG16(_x_) ((U16 volatile *)(FUART_CHIPTOP_BASE))[((_x_) * 2) ]  
   #define FUART_BAUDRATE_DEFAULT  115200  
   #define FUART_CLK CONFIG_UART_CLOCK  
   #define FUART_REGCLK_BASE 0x1F207000  
   #define FUART_REGCLK_REG16(_x_) ((U16 volatile *)(FUART_REGCLK_BASE))[((_x_) * 2) ]
   
   static void ms_fuart_setbrg (void)  
   {  
   //    // set baud_rate  
   //
   
       U16 DLR = ((FUART_CLK+8*FUART_BAUDRATE_DEFAULT)/ (16 * FUART_BAUDRATE_DEFAULT));
   
       //i.   Set "reg_mcr_loopback";  
       FUART_REG8(UART_MCR) |= 0x10;
   
       //  Clear FIFO Buffer  
       FUART_REG8(UART_FCR) |= 0x07;
   
       //ii.   Poll "reg_usr_busy" till 0;  
       while(FUART_REG8(UART_USR) & 0x01)  
       {  
           FUART_REG8(UART_IIR)=(FUART_REG8(UART_IIR)|(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT));  
       }  
   //  
       FUART_REG8(UART_LCR) |= UART_LCR_DLAB;  
       FUART_REG8(UART_DLL) = (DLR & 0xFF);  
       FUART_REG8(UART_DLM) = ((DLR >> 8) & 0xFF);  
       FUART_REG8(UART_LCR) &= ~(UART_LCR_DLAB);  
   //  
       FUART_REG8(UART_MCR) &= ~0x10;  
   }
   
   static void ms_fuart_clk_enable(void)  
   {
   
       //printf("0x34 = 0x%04x\n",FUART_REGCLK_REG16(0x34));  
       FUART_REGCLK_REG16(0x34) &= (~0x01);  
   }  
   static void ms_faurt_select_pad(void)  
   {  
       if( FUART_BASE == 0x1F220400 ) //fuart  
       {  
           FUART_CHIPTOP_REG16(0x03) &= ~(0x3 << 4);  
           FUART_CHIPTOP_REG16(0x03) |= (0x2 << 4);   //pad_mode
   
           FUART_CHIPTOP_REG16(0x53) &= ~(0xf00);  
           FUART_CHIPTOP_REG16(0x53) |= 0x100;
   
           FUART_CHIPTOP_REG16(0x57) &= ~(0x1 << 1);  
           //printf("03=0x%04x ,53=0x%04x, 57=0x%04x",FUART_CHIPTOP_REG16(0x03),FUART_CHIPTOP_REG16(0x53),FUART_CHIPTOP_REG16(0x57));  
       }  
       else if( FUART_BASE == 0x1F221000 ){ //uart0  
           //FUART_CHIPTOP_REG8(0x06) &= (~0x30);  
           //FUART_CHIPTOP_REG8(0x06) |= 0x0;  
       }  
   }  
   static int ms_fuart_init(void)  
   {  
       ms_fuart_clk_enable();  //must first  
       //i.   Set "reg_mcr_loopback";  
       FUART_REG8(UART_MCR) |= 0x10;
   
       //ii.   Poll "reg_usr_busy" till 0;  
       while(FUART_REG8(UART_USR) & 0x01)  
       {  
           FUART_REG8(UART_IIR)=(FUART_REG8(UART_IIR)|(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT));  
       }  
       printf("2");  
       FUART_REG8(UART_IER) = 0x00;
   
       // Reset receiver and transmiter  
       FUART_REG8(UART_FCR) = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_1;
   
       // Set 8 bit char, 1 stop bit, no parity  
       FUART_REG8(UART_LCR) = UART_LCR_WLEN8 & ~(UART_LCR_STOP2 | UART_LCR_PARITY);
   
       //i.   Set "reg_mcr_loopback back;  
       FUART_REG8(UART_MCR) &= ~0x10;
   
       ms_fuart_setbrg();  
       ms_faurt_select_pad();
   
       return (0);  
   }
   
   static void ms_fuart_serial_putc(const char c)  
   {  
       while (!(FUART_REG8(UART_LSR) & UART_LSR_THRE));
   
       FUART_REG8(UART_TX) = c;
   
   }
   
   static void ms_fuart_putc (const char c)  
   {  
       if (c == '\n')  
           ms_fuart_serial_putc('\r');
   
       ms_fuart_serial_putc(c);  
   }
   
   static char ms_fuart_getc (void)  
   {  
       char c;  
   //  
       while(!(FUART_REG8(UART_LSR) & UART_LSR_DR));
   
       c=(char) ( FUART_REG8(UART_TX) & 0xff);
   
       return c;  
   }
   
   /*
   static int ms_fuart_tstc (void)  
   {  
       return  ((FUART_REG8(UART_LSR) & UART_LSR_DR));  
   }  
   */
   
   static void ms_fuart_help(void)  
   {  
       printf("do_fuart tx strins\n");  
       printf("do_fuart rx number\n");  
   }
   
   static int do_fuart(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])  
   {  
       int i=0,len = 0;
   
       printf("doing fuart service for you:\n");  
       if(argc!=3){ms_fuart_help();return 0;}
   
       ms_fuart_init();  
       if(0 == strcmp(argv[1],"tx"))  
       {  
           len = strlen(argv[2]);  
           for(i=0;i<len;i++){
   
               ms_fuart_putc(*(argv[2]+i));  
           }  
           return 0;  
       }  
       else if(0 == strcmp(argv[1],"rx"))  
       {  
           //len = atoi(argv[2]);  
           len=10;  
           for(i=0;i<len;i++){  
               printf(" %c",ms_fuart_getc());  
           }  
           printf("\n");  
           return 0;  
       }  
       else {  
           ms_fuart_help();  
       }  
       return 0;  
   }  
   U_BOOT_CMD(  
       fuart, CONFIG_SYS_MAXARGS , 1 ,do_fuart,  
       "use fuart_tx & fuart_rx as transmission",  
       "20180713"  
   );