cpu/nios2/serial.c

   1 /*
   2  * (C) Copyright 2004, 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 <asm/io.h>
  28 #include <nios2-io.h>
  29
  30 DECLARE_GLOBAL_DATA_PTR;
  31
  32 /*------------------------------------------------------------------
  33  * JTAG acts as the serial port
  34  *-----------------------------------------------------------------*/
  35 #if defined(CONFIG_CONSOLE_JTAG)
  36
  37 static nios_jtag_t *jtag = (nios_jtag_t *)CFG_NIOS_CONSOLE;
  38
  39 void serial_setbrg( void ){ return; }
  40 int serial_init( void ) { return(0);}
  41
  42 void serial_putc (char c)
  43 {
  44         unsigned val;
  45
  46         while (NIOS_JTAG_WSPACE ( readl (&jtag->control)) == 0)
  47                 WATCHDOG_RESET ();
  48         writel (&jtag->data, (unsigned char)c);
  49 }
  50
  51 void serial_puts (const char *s)
  52 {
  53         while (*s != 0)
  54                 serial_putc (*s++);
  55 }
  56
  57 int serial_tstc (void)
  58 {
  59         return ( readl (&jtag->control) & NIOS_JTAG_RRDY);
  60 }
  61
  62 int serial_getc (void)
  63 {
  64         int c;
  65         unsigned val;
  66
  67         while (1) {
  68                 WATCHDOG_RESET ();
  69                 val = readl (&jtag->data);
  70                 if (val & NIOS_JTAG_RVALID)
  71                         break;
  72         }
  73         c = val & 0x0ff;
  74         return (c);
  75 }
  76
  77 /*------------------------------------------------------------------
  78  * UART the serial port
  79  *-----------------------------------------------------------------*/
  80 #else
  81
  82 static nios_uart_t *uart = (nios_uart_t *) CFG_NIOS_CONSOLE;
  83
  84 #if defined(CFG_NIOS_FIXEDBAUD)
  85
  86 /* Everything's already setup for fixed-baud PTF
  87  * assignment
  88  */
  89 void serial_setbrg (void){ return; }
  90 int serial_init (void) { return (0);}
  91
  92 #else
  93
  94 void serial_setbrg (void)
  95 {
  96         unsigned div;
  97
  98         div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
  99         writel (&uart->divisor,div);
 100         return;
 101 }
 102
 103 int serial_init (void)
 104 {
 105         serial_setbrg ();
 106         return (0);
 107 }
 108
 109 #endif /* CFG_NIOS_FIXEDBAUD */
 110
 111
 112 /*-----------------------------------------------------------------------
 113  * UART CONSOLE
 114  *---------------------------------------------------------------------*/
 115 void serial_putc (char c)
 116 {
 117         if (c == '\n')
 118                 serial_putc ('\r');
 119         while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
 120                 WATCHDOG_RESET ();
 121         writel (&uart->txdata,(unsigned char)c);
 122 }
 123
 124 void serial_puts (const char *s)
 125 {
 126         while (*s != 0) {
 127                 serial_putc (*s++);
 128         }
 129 }
 130
 131 int serial_tstc (void)
 132 {
 133         return (readl (&uart->status) & NIOS_UART_RRDY);
 134 }
 135
 136 int serial_getc (void)
 137 {
 138         while (serial_tstc () == 0)
 139                 WATCHDOG_RESET ();
 140         return (readl (&uart->rxdata) & 0x00ff );
 141 }
 142
 143 #endif /* CONFIG_JTAG_CONSOLE */