kernel/drivers/char/rs232/rs232.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2007  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   5  *  Copyright (C) 2009  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   6  *
   7  *  This program is free software: you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation, either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21
  22 #include <build.h>
  23 #include <config.h>
  24 #include <system.h>
  25 #include <arch/io.h>
  26 #include <rs232.h>
  27
  28 unsigned int init_rs232 ()
  29 {
  30 #ifdef ARCH_i386
  31         int baud = CONFIG_DRV_RS232BAUDS;       // Set to 9600 baud
  32
  33         unsigned divisor = (unsigned) (115200L / baud);
  34
  35         outb (PORT + 1, 0x00);    // Disable all interrupts
  36         outb (PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
  37         outb (PORT + 0, divisor);    // Set divisor to 3 (lo byte) 38400 baud
  38         divisor >>= 8;
  39         outb (PORT + 1, divisor);    //                  (hi byte)
  40         outb (PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
  41         outb (PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
  42         outb (PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
  43 #endif
  44 #ifdef ARCH_arm
  45
  46 #endif
  47         return 1;
  48 }
  49
  50 int serial_recieved()
  51 {
  52 #ifdef ARCH_i386
  53         return inb (PORT + 5) & 1;
  54 #endif
  55 }
  56
  57 char rs232_read_nonblock ()
  58 {
  59 #ifdef ARCH_i386
  60         int r = serial_recieved ();
  61
  62         if (r == 0)
  63                 return 0;
  64
  65         return inb (PORT);
  66 #endif
  67 #ifdef ARCH_arm
  68         return (char) armbd_uart_read (0);
  69 #endif
  70 }
  71
  72
  73 char rs232_read ()
  74 {
  75 #ifdef ARCH_i386
  76         while (serial_recieved () == 0)
  77                 schedule ();
  78
  79         return inb (PORT);
  80 #endif
  81 #ifdef ARCH_arm
  82         if (armbd_uart_received (0))
  83                 return (char) armbd_uart_read (0);
  84         else
  85                 return 0;
  86
  87 #endif
  88 }
  89
  90 #ifdef ARCH_i386
  91 int is_transmit_empty ()
  92 {
  93         return inb (PORT + 5) & 0x20;
  94 }
  95 #endif
  96
  97 void rs232_write (char a)
  98 {
  99 #ifdef ARCH_i386
 100         while (is_transmit_empty() == 0) {
 101                 schedule ();
 102                 continue;
 103         }
 104
 105         outb (PORT, a);
 106 #endif
 107
 108 #ifdef ARCH_arm
 109         armbd_uart_write (0, (unsigned char) a);
 110 #endif
 111 }
 112
 113 bool rs232_acthandler (unsigned act, char *block, unsigned block_len)
 114 {
 115         switch (act) {
 116                 case DEV_ACT_INIT:
 117                 {
 118                         init_rs232 ();
 119
 120                         return 1;
 121                 }
 122                 break;
 123                 case DEV_ACT_READ:
 124                 {
 125                         unsigned len = 0;
 126
 127                         while (len != block_len) {
 128                                 block[len] = rs232_read ();
 129                                 len ++;
 130                         }
 131
 132                         return 1;
 133                 }
 134                 break;
 135                 case DEV_ACT_WRITE:
 136                 {
 137                         unsigned len = 0;
 138
 139                         while (len != block_len) {
 140                                 rs232_write (block[len]);
 141                                 len ++;
 142                         }
 143
 144                         return 1;
 145                 }
 146                 break;
 147         }
 148
 149         return 0;
 150 }