cpu/arm920t/s3c24x0/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 #if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB)
  23
  24 #if defined(CONFIG_S3C2400) || defined(CONFIG_TRAB)
  25 #include <s3c2400.h>
  26 #elif defined(CONFIG_S3C2410)
  27 #include <s3c2410.h>
  28 #endif
  29
  30 #ifdef CONFIG_SERIAL1
  31 #define UART_NR S3C24X0_UART0
  32
  33 #elif defined(CONFIG_SERIAL2)
  34 # if defined(CONFIG_TRAB)
  35 #  error "TRAB supports only CONFIG_SERIAL1"
  36 # endif
  37 #define UART_NR S3C24X0_UART1
  38
  39 #elif defined(CONFIG_SERIAL3)
  40 # if defined(CONFIG_TRAB)
  41 #  #error "TRAB supports only CONFIG_SERIAL1"
  42 # endif
  43 #define UART_NR S3C24X0_UART2
  44
  45 #else
  46 #error "Bad: you didn't configure serial ..."
  47 #endif
  48
  49 void serial_setbrg (void)
  50 {
  51         DECLARE_GLOBAL_DATA_PTR;
  52         S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
  53         int i;
  54         unsigned int reg = 0;
  55
  56         /* value is calculated so : (int)(PCLK/16./baudrate) -1 */
  57         reg = get_PCLK() / (16 * gd->baudrate) - 1;
  58
  59         /* FIFO enable, Tx/Rx FIFO clear */
  60         uart->UFCON = 0x07;
  61         uart->UMCON = 0x0;
  62         /* Normal,No parity,1 stop,8 bit */
  63         uart->ULCON = 0x3;
  64         /*
  65          * tx=level,rx=edge,disable timeout int.,enable rx error int.,
  66          * normal,interrupt or polling
  67          */
  68         uart->UCON = 0x245;
  69         uart->UBRDIV = reg;
  70
  71 #ifdef CONFIG_HWFLOW
  72         uart->UMCON = 0x1; /* RTS up */
  73 #endif
  74         for (i = 0; i < 100; i++);
  75 }
  76
  77 /*
  78  * Initialise the serial port with the given baudrate. The settings
  79  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  80  *
  81  */
  82 int serial_init (void)
  83 {
  84         serial_setbrg ();
  85
  86         return (0);
  87 }
  88
  89 /*
  90  * Read a single byte from the serial port. Returns 1 on success, 0
  91  * otherwise. When the function is succesfull, the character read is
  92  * written into its argument c.
  93  */
  94 int serial_getc (void)
  95 {
  96         S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
  97
  98         /* wait for character to arrive */
  99         while (!(uart->UTRSTAT & 0x1));
 100
 101         return uart->URXH & 0xff;
 102 }
 103
 104 #ifdef CONFIG_HWFLOW
 105 static int hwflow = 0; /* turned off by default */
 106 int hwflow_onoff(int on)
 107 {
 108         switch(on) {
 109         case 0:
 110         default:
 111                 break; /* return current */
 112         case 1:
 113                 hwflow = 1; /* turn on */
 114                 break;
 115         case -1:
 116                 hwflow = 0; /* turn off */
 117                 break;
 118         }
 119         return hwflow;
 120 }
 121 #endif
 122
 123 #ifdef CONFIG_MODEM_SUPPORT
 124 static int be_quiet = 0;
 125 void disable_putc(void)
 126 {
 127         be_quiet = 1;
 128 }
 129
 130 void enable_putc(void)
 131 {
 132         be_quiet = 0;
 133 }
 134 #endif
 135
 136
 137 /*
 138  * Output a single byte to the serial port.
 139  */
 140 void serial_putc (const char c)
 141 {
 142         S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
 143 #ifdef CONFIG_MODEM_SUPPORT
 144         if (be_quiet)
 145                 return;
 146 #endif
 147
 148         /* wait for room in the tx FIFO */
 149         while (!(uart->UTRSTAT & 0x2));
 150
 151 #ifdef CONFIG_HWFLOW
 152         /* Wait for CTS up */
 153         while(hwflow && !(uart->UMSTAT & 0x1))
 154                 ;
 155 #endif
 156
 157         uart->UTXH = c;
 158
 159         /* If \n, also do \r */
 160         if (c == '\n')
 161                 serial_putc ('\r');
 162 }
 163
 164 /*
 165  * Test whether a character is in the RX buffer
 166  */
 167 int serial_tstc (void)
 168 {
 169         S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
 170
 171         return uart->UTRSTAT & 0x1;
 172 }
 173
 174 void
 175 serial_puts (const char *s)
 176 {
 177         while (*s) {
 178                 serial_putc (*s++);
 179         }
 180 }
 181
 182 #endif /* defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) */