drivers/serial/serial_ixp.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 /*
  35  *               14.7456 MHz
  36  * Baud Rate = --------------
  37  *              16 x Divisor
  38  */
  39 #define SERIAL_CLOCK 921600
  40
  41 DECLARE_GLOBAL_DATA_PTR;
  42
  43 void serial_setbrg (void)
  44 {
  45         unsigned int quot = 0;
  46         int uart = CONFIG_SYS_IXP425_CONSOLE;
  47
  48         if ((gd->baudrate <= SERIAL_CLOCK) && (SERIAL_CLOCK % gd->baudrate == 0))
  49                 quot = SERIAL_CLOCK / gd->baudrate;
  50         else
  51                 hang ();
  52
  53         IER(uart) = 0;                                  /* Disable for now */
  54         FCR(uart) = 0;                                  /* No fifos enabled */
  55
  56         /* set baud rate */
  57         LCR(uart) = LCR_WLS0 | LCR_WLS1 | LCR_DLAB;
  58         DLL(uart) = quot & 0xff;
  59         DLH(uart) = quot >> 8;
  60         LCR(uart) = LCR_WLS0 | LCR_WLS1;
  61 #ifdef CONFIG_SERIAL_RTS_ACTIVE
  62         MCR(uart) = MCR_RTS;                            /* set RTS active */
  63 #else
  64         MCR(uart) = 0;                                  /* set RTS inactive */
  65 #endif
  66         IER(uart) = IER_UUE;
  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(CONFIG_SYS_IXP425_CONSOLE) & LSR_TEMT) == 0);
  89
  90         THR(CONFIG_SYS_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(CONFIG_SYS_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(CONFIG_SYS_IXP425_CONSOLE) & LSR_DR));
 115
 116         return (char) RBR(CONFIG_SYS_IXP425_CONSOLE) & 0xff;
 117 }
 118
 119 void
 120 serial_puts (const char *s)
 121 {
 122         while (*s) {
 123                 serial_putc (*s++);
 124         }
 125 }