drivers/serial/altera_uart.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  * UART the serial port
  34  *-----------------------------------------------------------------*/
  35
  36 static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
  37
  38 #if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
  39
  40 /* Everything's already setup for fixed-baud PTF
  41  * assignment
  42  */
  43 void serial_setbrg (void){ return; }
  44 int serial_init (void) { return (0);}
  45
  46 #else
  47
  48 void serial_setbrg (void)
  49 {
  50         unsigned div;
  51
  52         div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
  53         writel (div, &uart->divisor);
  54         return;
  55 }
  56
  57 int serial_init (void)
  58 {
  59         serial_setbrg ();
  60         return (0);
  61 }
  62
  63 #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
  64
  65 /*-----------------------------------------------------------------------
  66  * UART CONSOLE
  67  *---------------------------------------------------------------------*/
  68 void serial_putc (char c)
  69 {
  70         if (c == '\n')
  71                 serial_putc ('\r');
  72         while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
  73                 WATCHDOG_RESET ();
  74         writel ((unsigned char)c, &uart->txdata);
  75 }
  76
  77 void serial_puts (const char *s)
  78 {
  79         while (*s != 0) {
  80                 serial_putc (*s++);
  81         }
  82 }
  83
  84 int serial_tstc (void)
  85 {
  86         return (readl (&uart->status) & NIOS_UART_RRDY);
  87 }
  88
  89 int serial_getc (void)
  90 {
  91         while (serial_tstc () == 0)
  92                 WATCHDOG_RESET ();
  93         return (readl (&uart->rxdata) & 0x00ff );
  94 }