cpu/ixp/serial.c

   1 /*
   2  * (C) Copyright 2002
   3  * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
   4  *
   5  * (C) Copyright 2002
   6  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Marius Groeger <mgroeger@sysgo.de>
   8  *
   9  * (C) Copyright 2002
  10  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  11  * Alex Zuepke <azu@sysgo.de>
  12  *
  13  * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  28  *
  29  */
  30
  31 #include <common.h>
  32 #include <asm/arch/ixp425.h>
  33
  34 void serial_setbrg (void)
  35 {
  36         DECLARE_GLOBAL_DATA_PTR;
  37
  38         unsigned int quot = 0;
  39         int uart = CFG_IXP425_CONSOLE;
  40
  41         if (gd->baudrate == 1200)
  42                 quot = 192;
  43         else if (gd->baudrate == 9600)
  44                 quot = 96;
  45         else if (gd->baudrate == 19200)
  46                 quot = 48;
  47         else if (gd->baudrate == 38400)
  48                 quot = 24;
  49         else if (gd->baudrate == 57600)
  50                 quot = 16;
  51         else if (gd->baudrate == 115200)
  52                 quot = 8;
  53         else
  54                 hang ();
  55
  56         IER(uart) = 0;                                  /* Disable for now */
  57         FCR(uart) = 0;                                  /* No fifos enabled */
  58
  59         /* set baud rate */
  60         LCR(uart) = LCR_WLS0 | LCR_WLS1 | LCR_DLAB;
  61         DLL(uart) = quot & 0xff;
  62         DLH(uart) = quot >> 8;
  63         LCR(uart) = LCR_WLS0 | LCR_WLS1;
  64
  65         IER(uart) = IER_UUE;
  66 }
  67
  68
  69 /*
  70  * Initialise the serial port with the given baudrate. The settings
  71  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  72  *
  73  */
  74 int serial_init (void)
  75 {
  76         serial_setbrg ();
  77
  78         return (0);
  79 }
  80
  81
  82 /*
  83  * Output a single byte to the serial port.
  84  */
  85 void serial_putc (const char c)
  86 {
  87         /* wait for room in the tx FIFO on UART */
  88         while ((LSR(CFG_IXP425_CONSOLE) & LSR_TEMT) == 0);
  89
  90         THR(CFG_IXP425_CONSOLE) = c;
  91
  92         /* If \n, also do \r */
  93         if (c == '\n')
  94                 serial_putc ('\r');
  95 }
  96
  97 /*
  98  * Read a single byte from the serial port. Returns 1 on success, 0
  99  * otherwise. When the function is succesfull, the character read is
 100  * written into its argument c.
 101  */
 102 int serial_tstc (void)
 103 {
 104         return LSR(CFG_IXP425_CONSOLE) & LSR_DR;
 105 }
 106
 107 /*
 108  * Read a single byte from the serial port. Returns 1 on success, 0
 109  * otherwise. When the function is succesfull, the character read is
 110  * written into its argument c.
 111  */
 112 int serial_getc (void)
 113 {
 114         while (!(LSR(CFG_IXP425_CONSOLE) & LSR_DR));
 115
 116         return (char) RBR(CFG_IXP425_CONSOLE) & 0xff;
 117 }
 118
 119 void
 120 serial_puts (const char *s)
 121 {
 122         while (*s) {
 123                 serial_putc (*s++);
 124         }
 125 }