cpu/lh7a40x/serial.c

   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
  24 DECLARE_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
  36 void 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  */
  64 int 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  */
  98 int 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
 109 static int hwflow = 0; /* turned off by default */
 110 int 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
 128 static int be_quiet = 0;
 129 void disable_putc(void)
 130 {
 131         be_quiet = 1;
 132 }
 133
 134 void enable_putc(void)
 135 {
 136         be_quiet = 0;
 137 }
 138 #endif
 139
 140
 141 /*
 142  * Output a single byte to the serial port.
 143  */
 144 void 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  */
 171 int serial_tstc (void)
 172 {
 173         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 174
 175         return(!(uart->status & UART_RXFE));
 176 }
 177
 178 void
 179 serial_puts (const char *s)
 180 {
 181         while (*s) {
 182                 serial_putc (*s++);
 183         }
 184 }