reactos/boot/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
  24 /* MACROS *******************************************************************/
  25
  26 #ifdef DBG
  27
  28 #define DEFAULT_BAUD_RATE    19200
  29
  30 #define   SER_RBR(x)   ((x)+0)
  31 #define   SER_THR(x)   ((x)+0)
  32 #define   SER_DLL(x)   ((x)+0)
  33 #define   SER_IER(x)   ((x)+1)
  34 #define   SER_DLM(x)   ((x)+1)
  35 #define   SER_IIR(x)   ((x)+2)
  36 #define   SER_LCR(x)   ((x)+3)
  37 #define     SR_LCR_CS5 0x00
  38 #define     SR_LCR_CS6 0x01
  39 #define     SR_LCR_CS7 0x02
  40 #define     SR_LCR_CS8 0x03
  41 #define     SR_LCR_ST1 0x00
  42 #define     SR_LCR_ST2 0x04
  43 #define     SR_LCR_PNO 0x00
  44 #define     SR_LCR_POD 0x08
  45 #define     SR_LCR_PEV 0x18
  46 #define     SR_LCR_PMK 0x28
  47 #define     SR_LCR_PSP 0x38
  48 #define     SR_LCR_BRK 0x40
  49 #define     SR_LCR_DLAB 0x80
  50 #define   SER_MCR(x)   ((x)+4)
  51 #define     SR_MCR_DTR 0x01
  52 #define     SR_MCR_RTS 0x02
  53 #define   SER_LSR(x)   ((x)+5)
  54 #define     SR_LSR_DR  0x01
  55 #define     SR_LSR_TBE 0x20
  56 #define   SER_MSR(x)   ((x)+6)
  57 #define     SR_MSR_CTS 0x10
  58 #define     SR_MSR_DSR 0x20
  59 #define   SER_SCR(x)   ((x)+7)
  60
  61 /* STATIC VARIABLES *********************************************************/
  62
  63 static ULONG Rs232ComPort = 0;
  64 static ULONG Rs232BaudRate = 0;
  65 static PUCHAR Rs232PortBase = (PUCHAR)0;
  66
  67 /* The com port must only be initialized once! */
  68 static BOOLEAN PortInitialized = FALSE;
  69
  70 /* STATIC FUNCTIONS *********************************************************/
  71
  72 static BOOLEAN Rs232DoesComPortExist(PUCHAR BaseAddress)
  73 {
  74         BOOLEAN found;
  75         UCHAR mcr;
  76         UCHAR msr;
  77
  78         found = FALSE;
  79
  80         /* save Modem Control Register (MCR) */
  81         mcr = READ_PORT_UCHAR (SER_MCR(BaseAddress));
  82
  83         /* enable loop mode (set Bit 4 of the MCR) */
  84         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  85
  86         /* clear all modem output bits */
  87         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  88
  89         /* read the Modem Status Register */
  90         msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
  91
  92         /*
  93          * the upper nibble of the MSR (modem output bits) must be
  94          * equal to the lower nibble of the MCR (modem input bits)
  95          */
  96         if ((msr & 0xF0) == 0x00)
  97         {
  98                 /* set all modem output bits */
  99                 WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x1F);
 100
 101                 /* read the Modem Status Register */
 102                 msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
 103
 104                 /*
 105                  * the upper nibble of the MSR (modem output bits) must be
 106                  * equal to the lower nibble of the MCR (modem input bits)
 107                  */
 108                 if ((msr & 0xF0) == 0xF0)
 109                         found = TRUE;
 110         }
 111
 112         /* restore MCR */
 113         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), mcr);
 114
 115         return (found);
 116 }
 117
 118 /* FUNCTIONS *********************************************************/
 119
 120 BOOLEAN Rs232PortInitialize(ULONG ComPort, ULONG BaudRate)
 121 {
 122         ULONG BaseArray[5] = {0, 0x3F8, 0x2F8, 0x3E8, 0x2E8};
 123         //char buffer[80];
 124         ULONG divisor;
 125         UCHAR lcr;
 126
 127         if (PortInitialized == FALSE)
 128         {
 129                 if (BaudRate != 0)
 130                 {
 131                         Rs232BaudRate = BaudRate;
 132                 }
 133                 else
 134                 {
 135                         Rs232BaudRate = DEFAULT_BAUD_RATE;
 136                 }
 137
 138                 if (ComPort == 0)
 139                 {
 140                         if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[2]))
 141                         {
 142                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[2];
 143                                 Rs232ComPort = 2;
 144 /*#ifndef NDEBUG
 145                                 sprintf (buffer,
 146                                          "\nSerial port COM%ld found at 0x%lx\n",
 147                                          ComPort,
 148                                          (ULONG)PortBase);
 149                                 HalDisplayString (buffer);
 150 #endif*/ /* NDEBUG */
 151                         }
 152                         else if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[1]))
 153                         {
 154                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[1];
 155                                 Rs232ComPort = 1;
 156 /*#ifndef NDEBUG
 157                                 sprintf (buffer,
 158                                          "\nSerial port COM%ld found at 0x%lx\n",
 159                                          ComPort,
 160                                          (ULONG)PortBase);
 161                                 HalDisplayString (buffer);
 162 #endif*/ /* NDEBUG */
 163                         }
 164                         else
 165                         {
 166                                 /*sprintf (buffer,
 167                                          "\nKernel Debugger: No COM port found!!!\n\n");
 168                                 HalDisplayString (buffer);*/
 169                                 return FALSE;
 170                         }
 171                 }
 172                 else
 173                 {
 174                         if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[ComPort]))
 175                         {
 176                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[ComPort];
 177                                 Rs232ComPort = ComPort;
 178 /*#ifndef NDEBUG
 179                                 sprintf (buffer,
 180                                          "\nSerial port COM%ld found at 0x%lx\n",
 181                                          ComPort,
 182                                          (ULONG)PortBase);
 183                                 HalDisplayString (buffer);
 184 #endif*/ /* NDEBUG */
 185                         }
 186                         else
 187                         {
 188                                 /*sprintf (buffer,
 189                                          "\nKernel Debugger: No serial port found!!!\n\n");
 190                                 HalDisplayString (buffer);*/
 191                                 return FALSE;
 192                         }
 193                 }
 194
 195                 PortInitialized = TRUE;
 196         }
 197
 198         /*
 199          * set baud rate and data format (8N1)
 200          */
 201
 202         /*  turn on DTR and RTS  */
 203         WRITE_PORT_UCHAR (SER_MCR(Rs232PortBase), SR_MCR_DTR | SR_MCR_RTS);
 204
 205         /* set DLAB */
 206         lcr = READ_PORT_UCHAR (SER_LCR(Rs232PortBase)) | SR_LCR_DLAB;
 207         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase), lcr);
 208
 209         /* set baud rate */
 210         divisor = 115200 / BaudRate;
 211         WRITE_PORT_UCHAR (SER_DLL(Rs232PortBase), divisor & 0xff);
 212         WRITE_PORT_UCHAR (SER_DLM(Rs232PortBase), (divisor >> 8) & 0xff);
 213
 214         /* reset DLAB and set 8N1 format */
 215         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase),
 216                           SR_LCR_CS8 | SR_LCR_ST1 | SR_LCR_PNO);
 217
 218         /* read junk out of the RBR */
 219         lcr = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 220
 221         /*
 222          * set global info
 223          */
 224         //KdComPortInUse = (ULONG)PortBase;
 225
 226         /*
 227          * print message to blue screen
 228          */
 229         /*sprintf (buffer,
 230                  "\nKernel Debugger: COM%ld (Port 0x%lx) BaudRate %ld\n\n",
 231                  ComPort,
 232                  (ULONG)PortBase,
 233                  BaudRate);
 234
 235         HalDisplayString (buffer);*/
 236
 237         return TRUE;
 238 }
 239
 240 BOOLEAN Rs232PortGetByte(PUCHAR ByteRecieved)
 241 {
 242         if (PortInitialized == FALSE)
 243                 return FALSE;
 244
 245         if ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR))
 246         {
 247                 *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 248                 return TRUE;
 249         }
 250
 251         return FALSE;
 252 }
 253
 254 BOOLEAN Rs232PortPollByte(PUCHAR ByteRecieved)
 255 {
 256         if (PortInitialized == FALSE)
 257                 return FALSE;
 258
 259         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR) == 0)
 260                 ;
 261
 262         *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 263
 264         return TRUE;
 265 }
 266
 267 VOID Rs232PortPutByte(UCHAR ByteToSend)
 268 {
 269         if (PortInitialized == FALSE)
 270                 return;
 271
 272         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_TBE) == 0)
 273                 ;
 274
 275         WRITE_PORT_UCHAR (SER_THR(Rs232PortBase), ByteToSend);
 276 }
 277
 278 #endif /* defined DBG */
 279
 280 BOOLEAN Rs232PortInUse(ULONG Base)
 281 {
 282 #ifdef DBG
 283     return PortInitialized && Rs232PortBase == (PUCHAR)(ULONG_PTR)Base ? TRUE : FALSE;
 284 #else
 285     return FALSE;
 286 #endif
 287 }