LXR uboot/drivers/serial/serial

   1/*
   2 * (C) Copyright 2002
   3 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 *
  19 */
  20
  21#include <common.h>
  22#include <lh7a40x.h>
  23
  24DECLARE_GLOBAL_DATA_PTR;
  25
  26#if defined(CONFIG_CONSOLE_UART1)
  27# define UART_CONSOLE 1
  28#elif defined(CONFIG_CONSOLE_UART2)
  29# define UART_CONSOLE 2
  30#elif defined(CONFIG_CONSOLE_UART3)
  31# define UART_CONSOLE 3
  32#else
  33# error "No console configured ... "
  34#endif
  35
  36void serial_setbrg (void)
  37{
  38        lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
  39        int i;
  40        unsigned int reg = 0;
  41
  42        /*
  43         * userguide 15.1.2.4
  44         *
  45         * BAUDDIV is (UART_REF_FREQ/(16 X BAUD))-1
  46         *
  47         *   UART_REF_FREQ = external system clock input / 2 (Hz)
  48         *   BAUD is desired baudrate (bits/s)
  49         *
  50         *   NOTE: we add (divisor/2) to numerator to round for
  51         *         more precision
  52         */
  53        reg = (((get_PLLCLK()/2) + ((16*gd->baudrate)/2)) / (16 * gd->baudrate)) - 1;
  54        uart->brcon = reg;
  55
  56        for (i = 0; i < 100; i++);
  57}
  58
  59/*
  60 * Initialise the serial port with the given baudrate. The settings
  61 * are always 8 data bits, no parity, 1 stop bit, no start bits.
  62 *
  63 */
  64int serial_init (void)
  65{
  66        lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
  67
  68        /* UART must be enabled before writing to any config registers */
  69        uart->con |= (UART_EN);
  70
  71#ifdef CONFIG_CONSOLE_UART1
  72        /* infrared disabled */
  73        uart->con |= UART_SIRD;
  74#endif
  75        /* loopback disabled */
  76        uart->con &= ~(UART_LBE);
  77
  78        /* modem lines and tx/rx polarities */
  79        uart->con &= ~(UART_MXP | UART_TXP | UART_RXP);
  80
  81        /* FIFO enable, N81 */
  82        uart->fcon = (UART_WLEN_8 | UART_FEN | UART_STP2_1);
  83
  84        /* set baudrate */
  85        serial_setbrg ();
  86
  87        /* enable rx interrupt */
  88        uart->inten |= UART_RI;
  89
  90        return (0);
  91}
  92
  93/*
  94 * Read a single byte from the serial port. Returns 1 on success, 0
  95 * otherwise. When the function is succesfull, the character read is
  96 * written into its argument c.
  97 */
  98int serial_getc (void)
  99{
 100        lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 101
 102        /* wait for character to arrive */
 103        while (uart->status & UART_RXFE);
 104
 105        return(uart->data & 0xff);
 106}
 107
 108#ifdef CONFIG_HWFLOW
 109static int hwflow = 0; /* turned off by default */
 110int hwflow_onoff(int on)
 111{
 112        switch(on) {
 113        case 0:
 114        default:
 115                break; /* return current */
 116        case 1:
 117                hwflow = 1; /* turn on */
 118                break;
 119        case -1:
 120                hwflow = 0; /* turn off */
 121                break;
 122        }
 123        return hwflow;
 124}
 125#endif
 126
 127#ifdef CONFIG_MODEM_SUPPORT
 128static int be_quiet = 0;
 129void disable_putc(void)
 130{
 131        be_quiet = 1;
 132}
 133
 134void enable_putc(void)
 135{
 136        be_quiet = 0;
 137}
 138#endif
 139
 140
 141/*
 142 * Output a single byte to the serial port.
 143 */
 144void serial_putc (const char c)
 145{
 146        lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 147
 148#ifdef CONFIG_MODEM_SUPPORT
 149        if (be_quiet)
 150                return;
 151#endif
 152
 153        /* wait for room in the tx FIFO */
 154        while (!(uart->status & UART_TXFE));
 155
 156#ifdef CONFIG_HWFLOW
 157        /* Wait for CTS up */
 158        while(hwflow && !(uart->status & UART_CTS));
 159#endif
 160
 161        uart->data = c;
 162
 163        /* If \n, also do \r */
 164        if (c == '\n')
 165                serial_putc ('\r');
 166}
 167
 168/*
 169 * Test whether a character is in the RX buffer
 170 */
 171int serial_tstc (void)
 172{
 173        lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 174
 175        return(!(uart->status & UART_RXFE));
 176}
 177
 178void
 179serial_puts (const char *s)
 180{
 181        while (*s) {
 182                serial_putc (*s++);
 183        }
 184}
 185