freeldr/freeldr/comm/rs232.c

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 2001  Brian Palmer  <brianp@sginet.com>
   4  *  Copyright (C) 2001  Eric Kohl
   5  *  Copyright (C) 2001  Emanuele Aliberti
   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 2 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, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <freeldr.h>
  23 #include <comm.h>
  24 #include <portio.h>
  25
  26
  27 /* MACROS *******************************************************************/
  28
  29 #define DEFAULT_BAUD_RATE    19200
  30
  31 #define   SER_RBR(x)   ((x)+0)
  32 #define   SER_THR(x)   ((x)+0)
  33 #define   SER_DLL(x)   ((x)+0)
  34 #define   SER_IER(x)   ((x)+1)
  35 #define   SER_DLM(x)   ((x)+1)
  36 #define   SER_IIR(x)   ((x)+2)
  37 #define   SER_LCR(x)   ((x)+3)
  38 #define     SR_LCR_CS5 0x00
  39 #define     SR_LCR_CS6 0x01
  40 #define     SR_LCR_CS7 0x02
  41 #define     SR_LCR_CS8 0x03
  42 #define     SR_LCR_ST1 0x00
  43 #define     SR_LCR_ST2 0x04
  44 #define     SR_LCR_PNO 0x00
  45 #define     SR_LCR_POD 0x08
  46 #define     SR_LCR_PEV 0x18
  47 #define     SR_LCR_PMK 0x28
  48 #define     SR_LCR_PSP 0x38
  49 #define     SR_LCR_BRK 0x40
  50 #define     SR_LCR_DLAB 0x80
  51 #define   SER_MCR(x)   ((x)+4)
  52 #define     SR_MCR_DTR 0x01
  53 #define     SR_MCR_RTS 0x02
  54 #define   SER_LSR(x)   ((x)+5)
  55 #define     SR_LSR_DR  0x01
  56 #define     SR_LSR_TBE 0x20
  57 #define   SER_MSR(x)   ((x)+6)
  58 #define     SR_MSR_CTS 0x10
  59 #define     SR_MSR_DSR 0x20
  60 #define   SER_SCR(x)   ((x)+7)
  61
  62 /* STATIC VARIABLES *********************************************************/
  63
  64 static U32 Rs232ComPort = 0;
  65 static U32 Rs232BaudRate = 0;
  66 static PUCHAR Rs232PortBase = (PUCHAR)0;
  67
  68 /* The com port must only be initialized once! */
  69 static BOOLEAN PortInitialized = FALSE;
  70
  71 /* STATIC FUNCTIONS *********************************************************/
  72
  73 static BOOL Rs232DoesComPortExist(PUCHAR BaseAddress)
  74 {
  75         BOOLEAN found;
  76         U8 mcr;
  77         U8 msr;
  78
  79         found = FALSE;
  80
  81         /* save Modem Control Register (MCR) */
  82         mcr = READ_PORT_UCHAR (SER_MCR(BaseAddress));
  83
  84         /* enable loop mode (set Bit 4 of the MCR) */
  85         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  86
  87         /* clear all modem output bits */
  88         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  89
  90         /* read the Modem Status Register */
  91         msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
  92
  93         /*
  94          * the upper nibble of the MSR (modem output bits) must be
  95          * equal to the lower nibble of the MCR (modem input bits)
  96          */
  97         if ((msr & 0xF0) == 0x00)
  98         {
  99                 /* set all modem output bits */
 100                 WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x1F);
 101
 102                 /* read the Modem Status Register */
 103                 msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
 104
 105                 /*
 106                  * the upper nibble of the MSR (modem output bits) must be
 107                  * equal to the lower nibble of the MCR (modem input bits)
 108                  */
 109                 if ((msr & 0xF0) == 0xF0)
 110                         found = TRUE;
 111         }
 112
 113         /* restore MCR */
 114         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), mcr);
 115
 116         return (found);
 117 }
 118
 119 /* FUNCTIONS *********************************************************/
 120
 121 BOOL Rs232PortInitialize(U32 ComPort, U32 BaudRate)
 122 {
 123         U32 BaseArray[5] = {0, 0x3F8, 0x2F8, 0x3E8, 0x2E8};
 124         //char buffer[80];
 125         U32 divisor;
 126         U8 lcr;
 127
 128         if (PortInitialized == FALSE)
 129         {
 130                 if (BaudRate != 0)
 131                 {
 132                         Rs232BaudRate = BaudRate;
 133                 }
 134                 else
 135                 {
 136                         Rs232BaudRate = DEFAULT_BAUD_RATE;
 137                 }
 138
 139                 if (ComPort == 0)
 140                 {
 141                         if (Rs232DoesComPortExist ((PUCHAR)BaseArray[2]))
 142                         {
 143                                 Rs232PortBase = (PUCHAR)BaseArray[2];
 144                                 Rs232ComPort = 2;
 145 /*#ifndef NDEBUG
 146                                 sprintf (buffer,
 147                                          "\nSerial port COM%ld found at 0x%lx\n",
 148                                          ComPort,
 149                                          (U32)PortBase);
 150                                 HalDisplayString (buffer);
 151 #endif*/ /* NDEBUG */
 152                         }
 153                         else if (Rs232DoesComPortExist ((PUCHAR)BaseArray[1]))
 154                         {
 155                                 Rs232PortBase = (PUCHAR)BaseArray[1];
 156                                 Rs232ComPort = 1;
 157 /*#ifndef NDEBUG
 158                                 sprintf (buffer,
 159                                          "\nSerial port COM%ld found at 0x%lx\n",
 160                                          ComPort,
 161                                          (U32)PortBase);
 162                                 HalDisplayString (buffer);
 163 #endif*/ /* NDEBUG */
 164                         }
 165                         else
 166                         {
 167                                 /*sprintf (buffer,
 168                                          "\nKernel Debugger: No COM port found!!!\n\n");
 169                                 HalDisplayString (buffer);*/
 170                                 return FALSE;
 171                         }
 172                 }
 173                 else
 174                 {
 175                         if (Rs232DoesComPortExist ((PUCHAR)BaseArray[ComPort]))
 176                         {
 177                                 Rs232PortBase = (PUCHAR)BaseArray[ComPort];
 178                                 Rs232ComPort = ComPort;
 179 /*#ifndef NDEBUG
 180                                 sprintf (buffer,
 181                                          "\nSerial port COM%ld found at 0x%lx\n",
 182                                          ComPort,
 183                                          (U32)PortBase);
 184                                 HalDisplayString (buffer);
 185 #endif*/ /* NDEBUG */
 186                         }
 187                         else
 188                         {
 189                                 /*sprintf (buffer,
 190                                          "\nKernel Debugger: No serial port found!!!\n\n");
 191                                 HalDisplayString (buffer);*/
 192                                 return FALSE;
 193                         }
 194                 }
 195
 196                 PortInitialized = TRUE;
 197         }
 198
 199         /*
 200          * set baud rate and data format (8N1)
 201          */
 202
 203         /*  turn on DTR and RTS  */
 204         WRITE_PORT_UCHAR (SER_MCR(Rs232PortBase), SR_MCR_DTR | SR_MCR_RTS);
 205
 206         /* set DLAB */
 207         lcr = READ_PORT_UCHAR (SER_LCR(Rs232PortBase)) | SR_LCR_DLAB;
 208         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase), lcr);
 209
 210         /* set baud rate */
 211         divisor = 115200 / BaudRate;
 212         WRITE_PORT_UCHAR (SER_DLL(Rs232PortBase), divisor & 0xff);
 213         WRITE_PORT_UCHAR (SER_DLM(Rs232PortBase), (divisor >> 8) & 0xff);
 214
 215         /* reset DLAB and set 8N1 format */
 216         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase),
 217                           SR_LCR_CS8 | SR_LCR_ST1 | SR_LCR_PNO);
 218
 219         /* read junk out of the RBR */
 220         lcr = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 221
 222         /*
 223          * set global info
 224          */
 225         //KdComPortInUse = (U32)PortBase;
 226
 227         /*
 228          * print message to blue screen
 229          */
 230         /*sprintf (buffer,
 231                  "\nKernel Debugger: COM%ld (Port 0x%lx) BaudRate %ld\n\n",
 232                  ComPort,
 233                  (U32)PortBase,
 234                  BaudRate);
 235
 236         HalDisplayString (buffer);*/
 237
 238         return TRUE;
 239 }
 240
 241 BOOL Rs232PortGetByte(PUCHAR ByteRecieved)
 242 {
 243         if (PortInitialized == FALSE)
 244                 return FALSE;
 245
 246         if ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR))
 247         {
 248                 *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 249                 return TRUE;
 250         }
 251
 252         return FALSE;
 253 }
 254
 255 BOOL Rs232PortPollByte(PUCHAR ByteRecieved)
 256 {
 257         if (PortInitialized == FALSE)
 258                 return FALSE;
 259
 260         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR) == 0)
 261                 ;
 262
 263         *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 264
 265         return TRUE;
 266 }
 267
 268 VOID Rs232PortPutByte(UCHAR ByteToSend)
 269 {
 270         if (PortInitialized == FALSE)
 271                 return;
 272
 273         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_TBE) == 0)
 274                 ;
 275
 276         WRITE_PORT_UCHAR (SER_THR(Rs232PortBase), ByteToSend);
 277 }