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 uart0 anyways */
  42         while(!(UART0_LSR&(1<<6)))
  43                 continue;
  44 }
  45
  46 void uart0_send_buf16(u16 *buf,int len) {
  47
  48         int i;
  49
  50         i=0;
  51
  52         for(i=0;i<len/2;i++) {
  53                 if(!(i%8))
  54                         while(!(UART0_LSR&(1<<6)))
  55                                 continue;
  56                 UART0_THR=buf[i]&0xff;
  57                 UART0_THR=(buf[i]>>8)&0xff;
  58         }
  59 }
  60
  61 void uart0_send_buf32(u32 *buf,int len) {
  62
  63         int i;
  64
  65         i=0;
  66
  67         for(i=0;i<len/4;i++) {
  68                 if(!(i%4))
  69                         while(!(UART0_LSR&(1<<6)))
  70                                 continue;
  71                 UART0_THR=buf[i]&0xff;
  72                 UART0_THR=(buf[i]>>8)&0xff;
  73                 UART0_THR=(buf[i]>>16)&0xff;
  74                 UART0_THR=(buf[i]>>24)&0xff;
  75         }
  76 }
  77
  78 void uart0_send_byte(u8 send) {
  79
  80         while(!(UART0_LSR&(1<<5)))
  81                 continue;
  82
  83         UART0_THR=send;
  84 }
  85
  86 u8 uart0_get_byte(void) {
  87
  88         u8 rx;
  89
  90         while(!(UART0_LSR&(1<<0)))
  91                 continue;
  92
  93         rx=UART0_RBR;
  94
  95         return rx;
  96 }
  97