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 along
  18  *  with this program; if not, write to the Free Software Foundation, Inc.,
  19  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #ifndef _M_ARM
  23
  24 #include <freeldr.h>
  25
  26 /* MACROS *******************************************************************/
  27
  28 #if DBG
  29
  30 #define DEFAULT_BAUD_RATE    19200
  31
  32 #define   SER_RBR(x)   ((x)+0)
  33 #define   SER_THR(x)   ((x)+0)
  34 #define   SER_DLL(x)   ((x)+0)
  35 #define   SER_IER(x)   ((x)+1)
  36 #define   SER_DLM(x)   ((x)+1)
  37 #define   SER_IIR(x)   ((x)+2)
  38 #define   SER_LCR(x)   ((x)+3)
  39 #define     SR_LCR_CS5 0x00
  40 #define     SR_LCR_CS6 0x01
  41 #define     SR_LCR_CS7 0x02
  42 #define     SR_LCR_CS8 0x03
  43 #define     SR_LCR_ST1 0x00
  44 #define     SR_LCR_ST2 0x04
  45 #define     SR_LCR_PNO 0x00
  46 #define     SR_LCR_POD 0x08
  47 #define     SR_LCR_PEV 0x18
  48 #define     SR_LCR_PMK 0x28
  49 #define     SR_LCR_PSP 0x38
  50 #define     SR_LCR_BRK 0x40
  51 #define     SR_LCR_DLAB 0x80
  52 #define   SER_MCR(x)   ((x)+4)
  53 #define     SR_MCR_DTR 0x01
  54 #define     SR_MCR_RTS 0x02
  55 #define   SER_LSR(x)   ((x)+5)
  56 #define     SR_LSR_DR  0x01
  57 #define     SR_LSR_TBE 0x20
  58 #define   SER_MSR(x)   ((x)+6)
  59 #define     SR_MSR_CTS 0x10
  60 #define     SR_MSR_DSR 0x20
  61 #define   SER_SCR(x)   ((x)+7)
  62
  63 /* STATIC VARIABLES *********************************************************/
  64
  65 static ULONG Rs232ComPort = 0;
  66 static ULONG Rs232BaudRate = 0;
  67 static PUCHAR Rs232PortBase = (PUCHAR)0;
  68
  69 /* The com port must only be initialized once! */
  70 static BOOLEAN PortInitialized = FALSE;
  71
  72 /* STATIC FUNCTIONS *********************************************************/
  73
  74 static BOOLEAN Rs232DoesComPortExist(PUCHAR BaseAddress)
  75 {
  76         BOOLEAN found;
  77         UCHAR mcr;
  78         UCHAR msr;
  79
  80         found = FALSE;
  81
  82         /* save Modem Control Register (MCR) */
  83         mcr = READ_PORT_UCHAR (SER_MCR(BaseAddress));
  84
  85         /* enable loop mode (set Bit 4 of the MCR) */
  86         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  87
  88         /* clear all modem output bits */
  89         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x10);
  90
  91         /* read the Modem Status Register */
  92         msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
  93
  94         /*
  95          * the upper nibble of the MSR (modem output bits) must be
  96          * equal to the lower nibble of the MCR (modem input bits)
  97          */
  98         if ((msr & 0xF0) == 0x00)
  99         {
 100                 /* set all modem output bits */
 101                 WRITE_PORT_UCHAR (SER_MCR(BaseAddress), 0x1F);
 102
 103                 /* read the Modem Status Register */
 104                 msr = READ_PORT_UCHAR (SER_MSR(BaseAddress));
 105
 106                 /*
 107                  * the upper nibble of the MSR (modem output bits) must be
 108                  * equal to the lower nibble of the MCR (modem input bits)
 109                  */
 110                 if ((msr & 0xF0) == 0xF0)
 111                         found = TRUE;
 112         }
 113
 114         /* restore MCR */
 115         WRITE_PORT_UCHAR (SER_MCR(BaseAddress), mcr);
 116
 117         return (found);
 118 }
 119
 120 /* FUNCTIONS *********************************************************/
 121
 122 BOOLEAN Rs232PortInitialize(ULONG ComPort, ULONG BaudRate)
 123 {
 124         ULONG BaseArray[5] = {0, 0x3F8, 0x2F8, 0x3E8, 0x2E8};
 125         //char buffer[80];
 126         ULONG divisor;
 127         UCHAR lcr;
 128
 129         if (PortInitialized == FALSE)
 130         {
 131                 if (BaudRate != 0)
 132                 {
 133                         Rs232BaudRate = BaudRate;
 134                 }
 135                 else
 136                 {
 137                         Rs232BaudRate = DEFAULT_BAUD_RATE;
 138                 }
 139
 140                 if (ComPort == 0)
 141                 {
 142                         if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[2]))
 143                         {
 144                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[2];
 145                                 Rs232ComPort = 2;
 146 /*#ifndef NDEBUG
 147                                 sprintf (buffer,
 148                                          "\nSerial port COM%ld found at 0x%lx\n",
 149                                          ComPort,
 150                                          (ULONG)PortBase);
 151                                 HalDisplayString (buffer);
 152 #endif*/ /* NDEBUG */
 153                         }
 154                         else if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[1]))
 155                         {
 156                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[1];
 157                                 Rs232ComPort = 1;
 158 /*#ifndef NDEBUG
 159                                 sprintf (buffer,
 160                                          "\nSerial port COM%ld found at 0x%lx\n",
 161                                          ComPort,
 162                                          (ULONG)PortBase);
 163                                 HalDisplayString (buffer);
 164 #endif*/ /* NDEBUG */
 165                         }
 166                         else
 167                         {
 168                                 /*sprintf (buffer,
 169                                          "\nKernel Debugger: No COM port found!!!\n\n");
 170                                 HalDisplayString (buffer);*/
 171                                 return FALSE;
 172                         }
 173                 }
 174                 else
 175                 {
 176                         if (Rs232DoesComPortExist ((PUCHAR)(ULONG_PTR)BaseArray[ComPort]))
 177                         {
 178                                 Rs232PortBase = (PUCHAR)(ULONG_PTR)BaseArray[ComPort];
 179                                 Rs232ComPort = ComPort;
 180 /*#ifndef NDEBUG
 181                                 sprintf (buffer,
 182                                          "\nSerial port COM%ld found at 0x%lx\n",
 183                                          ComPort,
 184                                          (ULONG)PortBase);
 185                                 HalDisplayString (buffer);
 186 #endif*/ /* NDEBUG */
 187                         }
 188                         else
 189                         {
 190                                 /*sprintf (buffer,
 191                                          "\nKernel Debugger: No serial port found!!!\n\n");
 192                                 HalDisplayString (buffer);*/
 193                                 return FALSE;
 194                         }
 195                 }
 196
 197                 PortInitialized = TRUE;
 198         }
 199
 200         /*
 201          * set baud rate and data format (8N1)
 202          */
 203
 204         /*  turn on DTR and RTS  */
 205         WRITE_PORT_UCHAR (SER_MCR(Rs232PortBase), SR_MCR_DTR | SR_MCR_RTS);
 206
 207         /* set DLAB */
 208         lcr = READ_PORT_UCHAR (SER_LCR(Rs232PortBase)) | SR_LCR_DLAB;
 209         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase), lcr);
 210
 211         /* set baud rate */
 212         divisor = 115200 / BaudRate;
 213         WRITE_PORT_UCHAR (SER_DLL(Rs232PortBase), divisor & 0xff);
 214         WRITE_PORT_UCHAR (SER_DLM(Rs232PortBase), (divisor >> 8) & 0xff);
 215
 216         /* reset DLAB and set 8N1 format */
 217         WRITE_PORT_UCHAR (SER_LCR(Rs232PortBase),
 218                           SR_LCR_CS8 | SR_LCR_ST1 | SR_LCR_PNO);
 219
 220         /* read junk out of the RBR */
 221         lcr = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 222
 223         /*
 224          * set global info
 225          */
 226         //KdComPortInUse = (ULONG)PortBase;
 227
 228         /*
 229          * print message to blue screen
 230          */
 231         /*sprintf (buffer,
 232                  "\nKernel Debugger: COM%ld (Port 0x%lx) BaudRate %ld\n\n",
 233                  ComPort,
 234                  (ULONG)PortBase,
 235                  BaudRate);
 236
 237         HalDisplayString (buffer);*/
 238
 239         return TRUE;
 240 }
 241
 242 BOOLEAN Rs232PortGetByte(PUCHAR ByteRecieved)
 243 {
 244         if (PortInitialized == FALSE)
 245                 return FALSE;
 246
 247         if ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR))
 248         {
 249                 *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 250                 return TRUE;
 251         }
 252
 253         return FALSE;
 254 }
 255
 256 BOOLEAN Rs232PortPollByte(PUCHAR ByteRecieved)
 257 {
 258         if (PortInitialized == FALSE)
 259                 return FALSE;
 260
 261         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_DR) == 0)
 262                 ;
 263
 264         *ByteRecieved = READ_PORT_UCHAR (SER_RBR(Rs232PortBase));
 265
 266         return TRUE;
 267 }
 268
 269 VOID Rs232PortPutByte(UCHAR ByteToSend)
 270 {
 271         if (PortInitialized == FALSE)
 272                 return;
 273
 274         while ((READ_PORT_UCHAR (SER_LSR(Rs232PortBase)) & SR_LSR_TBE) == 0)
 275                 ;
 276
 277         WRITE_PORT_UCHAR (SER_THR(Rs232PortBase), ByteToSend);
 278 }
 279
 280 #endif /* DBG */
 281
 282 BOOLEAN Rs232PortInUse(ULONG Base)
 283 {
 284 #if DBG
 285     return PortInitialized && Rs232PortBase == (PUCHAR)(ULONG_PTR)Base ? TRUE : FALSE;
 286 #else
 287     return FALSE;
 288 #endif
 289 }
 290
 291 #endif /* not _M_ARM */