betty/uart.c

   1 /*
   2  * uart.c - uart0/1 api
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  */
   7
   8 #include "uart.h"
   9
  10 /*
  11  * functions
  12  */
  13
  14 void uart0_init(void) {
  15
  16         /* configure uart 0 */
  17         UART0_FCR=0x07;                 // enable fifo
  18         UART0_LCR=0x83;                 // set dlab + word length
  19         UART0_DLL=0x04;                 // br: 115200
  20         UART0_DLM=0x00;
  21         UART0_LCR=0x03;                 // unset dlab
  22 }
  23
  24 void uart0_send_string(char *txbuf) {
  25
  26         int i;
  27
  28         i=0;
  29
  30         while(txbuf[i]) {
  31                 UART0_THR=txbuf[i++];
  32                 /* flush if tx buffer maximum reached */
  33                 if(!(i%16))
  34                         while(!(UART0_LSR&(1<<6)))
  35                                 continue;
  36         }
  37
  38         /* flush uart0 anyways */
  39         while(!(UART0_LSR&(1<<6)))
  40                 continue;
  41 }
  42
  43 void uart0_send_buf16(u16 *buf,int len) {
  44
  45         int i;
  46
  47         i=0;
  48
  49         for(i=0;i<len/2;i++) {
  50                 if(!(i%8))
  51                         while(!(UART0_LSR&(1<<6)))
  52                                 continue;
  53                 UART0_THR=buf[i]&0xff;
  54                 UART0_THR=(buf[i]>>8)&0xff;
  55         }
  56 }
  57
  58 void uart0_send_buf32(u32 *buf,int len) {
  59
  60         int i;
  61
  62         i=0;
  63
  64         for(i=0;i<len/4;i++) {
  65                 if(!(i%4))
  66                         while(!(UART0_LSR&(1<<6)))
  67                                 continue;
  68                 UART0_THR=buf[i]&0xff;
  69                 UART0_THR=(buf[i]>>8)&0xff;
  70                 UART0_THR=(buf[i]>>16)&0xff;
  71                 UART0_THR=(buf[i]>>24)&0xff;
  72         }
  73 }
  74
  75 void uart0_send_byte(u8 send) {
  76
  77         while(!(UART0_LSR&(1<<5)))
  78                 continue;
  79
  80         UART0_THR=send;
  81 }
  82
  83 u8 uart0_get_byte(void) {
  84
  85         u8 rx;
  86
  87         while(!(UART0_LSR&(1<<0)))
  88                 continue;
  89
  90         rx=UART0_RBR;
  91
  92         return rx;
  93 }
  94