cpu/nios/serial.c

   1 /*
   2  * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
   3  * Scott McNutt <smcnutt@psyent.com>
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24
  25 #include <common.h>
  26 #include <watchdog.h>
  27 #include <nios-io.h>
  28
  29 DECLARE_GLOBAL_DATA_PTR;
  30
  31 /*------------------------------------------------------------------
  32  * JTAG acts as the serial port
  33  *-----------------------------------------------------------------*/
  34 #if defined(CONFIG_CONSOLE_JTAG)
  35
  36 static nios_jtag_t *jtag = (nios_jtag_t *)CFG_NIOS_CONSOLE;
  37
  38 void serial_setbrg( void ){ return; }
  39 int serial_init( void ) { return(0);}
  40
  41 void serial_putc (char c)
  42 {
  43         while ((jtag->txcntl & NIOS_JTAG_TRDY) != 0)
  44                 WATCHDOG_RESET ();
  45         jtag->txcntl = NIOS_JTAG_TRDY | (unsigned char)c;
  46 }
  47
  48 void serial_puts (const char *s)
  49 {
  50         while (*s != 0)
  51                 serial_putc (*s++);
  52 }
  53
  54 int serial_tstc (void)
  55 {
  56         return (jtag->rxcntl & NIOS_JTAG_RRDY);
  57 }
  58
  59 int serial_getc (void)
  60 {
  61         int c;
  62         while (serial_tstc() == 0)
  63                 WATCHDOG_RESET ();
  64         c = jtag->rxcntl & 0x0ff;
  65         jtag->rxcntl = 0;
  66         return (c);
  67 }
  68
  69 /*------------------------------------------------------------------
  70  * UART the serial port
  71  *-----------------------------------------------------------------*/
  72 #else
  73
  74 static nios_uart_t *uart = (nios_uart_t *)CFG_NIOS_CONSOLE;
  75
  76 #if defined(CFG_NIOS_FIXEDBAUD)
  77
  78 /* Everything's already setup for fixed-baud PTF
  79  * assignment
  80  */
  81 void serial_setbrg (void){ return; }
  82 int serial_init (void) { return (0);}
  83
  84 #else
  85
  86 void serial_setbrg (void)
  87 {
  88         unsigned div;
  89
  90         div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
  91         uart->divisor = div;
  92         return;
  93 }
  94
  95 int serial_init (void)
  96 {
  97         serial_setbrg ();
  98         return (0);
  99 }
 100
 101 #endif /* CFG_NIOS_FIXEDBAUD */
 102
 103
 104 /*-----------------------------------------------------------------------
 105  * UART CONSOLE
 106  *---------------------------------------------------------------------*/
 107 void serial_putc (char c)
 108 {
 109         if (c == '\n')
 110                 serial_putc ('\r');
 111         while ((uart->status & NIOS_UART_TRDY) == 0)
 112                 WATCHDOG_RESET ();
 113         uart->txdata = (unsigned char)c;
 114 }
 115
 116 void serial_puts (const char *s)
 117 {
 118         while (*s != 0) {
 119                 serial_putc (*s++);
 120         }
 121 }
 122
 123 int serial_tstc (void)
 124 {
 125         return (uart->status & NIOS_UART_RRDY);
 126 }
 127
 128 int serial_getc (void)
 129 {
 130         while (serial_tstc () == 0)
 131                 WATCHDOG_RESET ();
 132         return( uart->rxdata & 0x00ff );
 133 }
 134
 135 #endif /* CONFIG_JTAG_CONSOLE */