LXR uboot/drivers/serial/serial

   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#include <watchdog.h>
  34
  35/*
  36 *               14.7456 MHz
  37 * Baud Rate = --------------
  38 *              16 x Divisor
  39 */
  40#define SERIAL_CLOCK 921600
  41
  42DECLARE_GLOBAL_DATA_PTR;
  43
  44void serial_setbrg (void)
  45{
  46        unsigned int quot = 0;
  47        int uart = CONFIG_SYS_IXP425_CONSOLE;
  48
  49        if ((gd->baudrate <= SERIAL_CLOCK) && (SERIAL_CLOCK % gd->baudrate == 0))
  50                quot = SERIAL_CLOCK / gd->baudrate;
  51        else
  52                hang ();
  53
  54        IER(uart) = 0;                                  /* Disable for now */
  55        FCR(uart) = 0;                                  /* No fifos enabled */
  56
  57        /* set baud rate */
  58        LCR(uart) = LCR_WLS0 | LCR_WLS1 | LCR_DLAB;
  59        DLL(uart) = quot & 0xff;
  60        DLH(uart) = quot >> 8;
  61        LCR(uart) = LCR_WLS0 | LCR_WLS1;
  62#ifdef CONFIG_SERIAL_RTS_ACTIVE
  63        MCR(uart) = MCR_RTS;                            /* set RTS active */
  64#else
  65        MCR(uart) = 0;                                  /* set RTS inactive */
  66#endif
  67        IER(uart) = IER_UUE;
  68}
  69
  70/*
  71 * Initialise the serial port with the given baudrate. The settings
  72 * are always 8 data bits, no parity, 1 stop bit, no start bits.
  73 *
  74 */
  75int serial_init (void)
  76{
  77        serial_setbrg ();
  78
  79        return (0);
  80}
  81
  82
  83/*
  84 * Output a single byte to the serial port.
  85 */
  86void serial_putc (const char c)
  87{
  88        /* wait for room in the tx FIFO on UART */
  89        while ((LSR(CONFIG_SYS_IXP425_CONSOLE) & LSR_TEMT) == 0)
  90                WATCHDOG_RESET();       /* Reset HW Watchdog, if needed */
  91
  92        THR(CONFIG_SYS_IXP425_CONSOLE) = c;
  93
  94        /* If \n, also do \r */
  95        if (c == '\n')
  96                serial_putc ('\r');
  97}
  98
  99/*
 100 * Read a single byte from the serial port. Returns 1 on success, 0
 101 * otherwise. When the function is succesfull, the character read is
 102 * written into its argument c.
 103 */
 104int serial_tstc (void)
 105{
 106        return LSR(CONFIG_SYS_IXP425_CONSOLE) & LSR_DR;
 107}
 108
 109/*
 110 * Read a single byte from the serial port. Returns 1 on success, 0
 111 * otherwise. When the function is succesfull, the character read is
 112 * written into its argument c.
 113 */
 114int serial_getc (void)
 115{
 116        while (!(LSR(CONFIG_SYS_IXP425_CONSOLE) & LSR_DR))
 117                WATCHDOG_RESET();       /* Reset HW Watchdog, if needed */
 118
 119        return (char) RBR(CONFIG_SYS_IXP425_CONSOLE) & 0xff;
 120}
 121
 122void
 123serial_puts (const char *s)
 124{
 125        while (*s) {
 126                serial_putc (*s++);
 127        }
 128}
 129