cpu/lh7a40x/serial.c

   1 /*
   2  * (C) Copyright 2002
   3  * Gary Jennejohn, DENX Software Engineering, <gj@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 #if defined(CONFIG_CONSOLE_UART1)
  25 # define UART_CONSOLE 1
  26 #elif defined(CONFIG_CONSOLE_UART2)
  27 # define UART_CONSOLE 2
  28 #elif defined(CONFIG_CONSOLE_UART3)
  29 # define UART_CONSOLE 3
  30 #else
  31 # error "No console configured ... "
  32 #endif
  33
  34 void serial_setbrg (void)
  35 {
  36         DECLARE_GLOBAL_DATA_PTR;
  37         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
  38         int i;
  39         unsigned int reg = 0;
  40
  41         /*
  42          * userguide 15.1.2.4
  43          *
  44          * BAUDDIV is (UART_REF_FREQ/(16 X BAUD))-1
  45          *
  46          *   UART_REF_FREQ = external system clock input / 2 (Hz)
  47          *   BAUD is desired baudrate (bits/s)
  48          *
  49          *   NOTE: we add (divisor/2) to numerator to round for
  50          *         more precision
  51          */
  52         reg = (((get_PLLCLK()/2) + ((16*gd->baudrate)/2)) / (16 * gd->baudrate)) - 1;
  53         uart->brcon = reg;
  54
  55         for (i = 0; i < 100; i++);
  56 }
  57
  58 /*
  59  * Initialise the serial port with the given baudrate. The settings
  60  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  61  *
  62  */
  63 int serial_init (void)
  64 {
  65         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
  66
  67         /* UART must be enabled before writing to any config registers */
  68         uart->con |= (UART_EN);
  69
  70 #ifdef CONFIG_CONSOLE_UART1
  71         /* infrared disabled */
  72         uart->con |= UART_SIRD;
  73 #endif
  74         /* loopback disabled */
  75         uart->con &= ~(UART_LBE);
  76
  77         /* modem lines and tx/rx polarities */
  78         uart->con &= ~(UART_MXP | UART_TXP | UART_RXP);
  79
  80         /* FIFO enable, N81 */
  81         uart->fcon = (UART_WLEN_8 | UART_FEN | UART_STP2_1);
  82
  83         /* set baudrate */
  84         serial_setbrg ();
  85
  86         /* enable rx interrupt */
  87         uart->inten |= UART_RI;
  88
  89         return (0);
  90 }
  91
  92 /*
  93  * Read a single byte from the serial port. Returns 1 on success, 0
  94  * otherwise. When the function is succesfull, the character read is
  95  * written into its argument c.
  96  */
  97 int serial_getc (void)
  98 {
  99         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 100
 101         /* wait for character to arrive */
 102         while (uart->status & UART_RXFE);
 103
 104         return(uart->data & 0xff);
 105 }
 106
 107 #ifdef CONFIG_HWFLOW
 108 static int hwflow = 0; /* turned off by default */
 109 int hwflow_onoff(int on)
 110 {
 111         switch(on) {
 112         case 0:
 113         default:
 114                 break; /* return current */
 115         case 1:
 116                 hwflow = 1; /* turn on */
 117                 break;
 118         case -1:
 119                 hwflow = 0; /* turn off */
 120                 break;
 121         }
 122         return hwflow;
 123 }
 124 #endif
 125
 126 #ifdef CONFIG_MODEM_SUPPORT
 127 static int be_quiet = 0;
 128 void disable_putc(void)
 129 {
 130         be_quiet = 1;
 131 }
 132
 133 void enable_putc(void)
 134 {
 135         be_quiet = 0;
 136 }
 137 #endif
 138
 139
 140 /*
 141  * Output a single byte to the serial port.
 142  */
 143 void serial_putc (const char c)
 144 {
 145         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 146
 147 #ifdef CONFIG_MODEM_SUPPORT
 148         if (be_quiet)
 149                 return;
 150 #endif
 151
 152         /* wait for room in the tx FIFO */
 153         while (!(uart->status & UART_TXFE));
 154
 155 #ifdef CONFIG_HWFLOW
 156         /* Wait for CTS up */
 157         while(hwflow && !(uart->status & UART_CTS));
 158 #endif
 159
 160         uart->data = c;
 161
 162         /* If \n, also do \r */
 163         if (c == '\n')
 164                 serial_putc ('\r');
 165 }
 166
 167 /*
 168  * Test whether a character is in the RX buffer
 169  */
 170 int serial_tstc (void)
 171 {
 172         lh7a40x_uart_t* uart = LH7A40X_UART_PTR(UART_CONSOLE);
 173
 174         return(!(uart->status & UART_RXFE));
 175 }
 176
 177 void
 178 serial_puts (const char *s)
 179 {
 180         while (*s) {
 181                 serial_putc (*s++);
 182         }
 183 }