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         /* select pins 0.0 and 0.1 as tx and rx */
  17         PINSEL0=(PINSEL0&~(0xf))|0x05;
  18
  19         /* configure uart 0 */
  20         UART0_FCR=0x07;                 // enable fifo
  21         UART0_LCR=0x83;                 // set dlab + word length
  22         UART0_DLL=0x04;                 // br: 115200
  23         UART0_DLM=0x00;
  24         UART0_LCR=0x03;                 // unset dlab
  25 }
  26
  27 void uart0_send_string(char *txbuf) {
  28
  29         int i;
  30
  31         i=0;
  32
  33         while(txbuf[i]) {
  34                 UART0_THR=txbuf[i++];
  35                 /* flush if tx buffer maximum reached */
  36                 if(!(i%16))
  37                         while(!(UART0_LSR&(1<<6)))
  38                                 continue;
  39         }
  40
  41         /* flush if \n and \r do not fit in the tx buffer */
  42         if(i>14)
  43                 while(!(UART0_LSR&(1<<6)))
  44                         continue;
  45
  46         UART0_THR='\n';
  47         UART0_THR='\r';
  48
  49         /* flush uart0 anyways */
  50         while(!(UART0_LSR&(1<<6)))
  51                 continue;
  52 }
  53
  54 void uart0_send_buf16(u16 *buf,int len) {
  55
  56         int i;
  57
  58         i=0;
  59
  60         for(i=0;i<len/2;i++) {
  61                 if(!(i%8))
  62                         while(!(UART0_LSR&(1<<6)))
  63                                 continue;
  64                 UART0_THR=buf[i]&0xff;
  65                 UART0_THR=(buf[i]>>8)&0xff;
  66         }
  67 }
  68
  69 void uart0_send_buf32(u32 *buf,int len) {
  70
  71         int i;
  72
  73         i=0;
  74
  75         for(i=0;i<len/4;i++) {
  76                 if(!(i%4))
  77                         while(!(UART0_LSR&(1<<6)))
  78                                 continue;
  79                 UART0_THR=buf[i]&0xff;
  80                 UART0_THR=(buf[i]>>8)&0xff;
  81                 UART0_THR=(buf[i]>>16)&0xff;
  82                 UART0_THR=(buf[i]>>24)&0xff;
  83         }
  84 }
  85
  86 void uart0_send_byte(u8 send) {
  87
  88         while(!(UART0_LSR&(1<<5)))
  89                 continue;
  90
  91         UART0_THR=send;
  92 }
  93
  94 u8 uart0_get_byte(void) {
  95
  96         u8 rx;
  97
  98         while(!(UART0_LSR&(1<<0)))
  99                 continue;
 100
 101         rx=UART0_RBR;
 102
 103         return rx;
 104 }
 105