src/jtag/bitbang.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.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                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include "bitbang.h"
  25
  26 /* project specific includes */
  27 #include "log.h"
  28 #include "types.h"
  29 #include "jtag.h"
  30 #include "configuration.h"
  31
  32 /* system includes */
  33 #include <string.h>
  34 #include <stdlib.h>
  35 #include <unistd.h>
  36
  37 #include <sys/time.h>
  38 #include <time.h>
  39
  40 bitbang_interface_t *bitbang_interface;
  41
  42 int bitbang_execute_queue(void);
  43
  44 void bitbang_end_state(enum tap_state state)
  45 {
  46         if (tap_move_map[state] != -1)
  47                 end_state = state;
  48         else
  49         {
  50                 ERROR("BUG: %i is not a valid end state", state);
  51                 exit(-1);
  52         }
  53 }
  54
  55 void bitbang_state_move(void) {
  56
  57         int i=0, tms=0;
  58         u8 tms_scan = TAP_MOVE(cur_state, end_state);
  59
  60         for (i = 0; i < 7; i++)
  61         {
  62                 tms = (tms_scan >> i) & 1;
  63                 bitbang_interface->write(0, tms, 0);
  64                 bitbang_interface->write(1, tms, 0);
  65         }
  66         bitbang_interface->write(0, tms, 0);
  67
  68         cur_state = end_state;
  69 }
  70
  71 void bitbang_path_move(pathmove_command_t *cmd)
  72 {
  73         int num_states = cmd->num_states;
  74         int state_count;
  75
  76         state_count = 0;
  77         while (num_states)
  78         {
  79                 if (tap_transitions[cur_state].low == cmd->path[state_count])
  80                 {
  81                         bitbang_interface->write(0, 0, 0);
  82                         bitbang_interface->write(1, 0, 0);
  83                 }
  84                 else if (tap_transitions[cur_state].high == cmd->path[state_count])
  85                 {
  86                         bitbang_interface->write(0, 1, 0);
  87                         bitbang_interface->write(1, 1, 0);
  88                 }
  89                 else
  90                 {
  91                         ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]);
  92                         exit(-1);
  93                 }
  94
  95                 cur_state = cmd->path[state_count];
  96                 state_count++;
  97                 num_states--;
  98         }
  99
 100         end_state = cur_state;
 101 }
 102
 103 void bitbang_runtest(int num_cycles)
 104 {
 105         int i;
 106
 107         enum tap_state saved_end_state = end_state;
 108
 109         /* only do a state_move when we're not already in RTI */
 110         if (cur_state != TAP_RTI)
 111         {
 112                 bitbang_end_state(TAP_RTI);
 113                 bitbang_state_move();
 114         }
 115
 116         /* execute num_cycles */
 117         bitbang_interface->write(0, 0, 0);
 118         for (i = 0; i < num_cycles; i++)
 119         {
 120                 bitbang_interface->write(1, 0, 0);
 121                 bitbang_interface->write(0, 0, 0);
 122         }
 123
 124         /* finish in end_state */
 125         bitbang_end_state(saved_end_state);
 126         if (cur_state != end_state)
 127                 bitbang_state_move();
 128 }
 129
 130 void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
 131 {
 132         enum tap_state saved_end_state = end_state;
 133         int bit_cnt;
 134
 135         if (ir_scan)
 136                 bitbang_end_state(TAP_SI);
 137         else
 138                 bitbang_end_state(TAP_SD);
 139
 140         bitbang_state_move();
 141         bitbang_end_state(saved_end_state);
 142
 143         for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
 144         {
 145                 /* if we're just reading the scan, but don't care about the output
 146                  * default to outputting 'low', this also makes valgrind traces more readable,
 147                  * as it removes the dependency on an uninitialised value
 148                  */
 149                 if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1)) {
 150                         bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 1);
 151                         bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 1);
 152                 } else {
 153                         bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 0);
 154                         bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 0);
 155                 }
 156
 157                 if (type != SCAN_OUT)
 158                 {
 159                         if (bitbang_interface->read())
 160                                 buffer[(bit_cnt)/8] |= 1 << ((bit_cnt) % 8);
 161                         else
 162                                 buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8));
 163                 }
 164         }
 165
 166         /* Exit1 -> Pause */
 167         bitbang_interface->write(0, 0, 0);
 168         bitbang_interface->write(1, 0, 0);
 169
 170         if (ir_scan)
 171                 cur_state = TAP_PI;
 172         else
 173                 cur_state = TAP_PD;
 174
 175         if (cur_state != end_state)
 176                 bitbang_state_move();
 177 }
 178
 179 int bitbang_execute_queue(void)
 180 {
 181         jtag_command_t *cmd = jtag_command_queue; /* currently processed command */
 182         int scan_size;
 183         enum scan_type type;
 184         u8 *buffer;
 185         int retval;
 186
 187         if (!bitbang_interface)
 188         {
 189                 ERROR("BUG: Bitbang interface called, but not yet initialized");
 190                 exit(-1);
 191         }
 192
 193         /* return ERROR_OK, unless a jtag_read_buffer returns a failed check
 194          * that wasn't handled by a caller-provided error handler
 195          */
 196         retval = ERROR_OK;
 197
 198         while (cmd)
 199         {
 200                 switch (cmd->type)
 201                 {
 202                         case JTAG_END_STATE:
 203 #ifdef _DEBUG_JTAG_IO_
 204                                 DEBUG("end_state: %i", cmd->cmd.end_state->end_state);
 205 #endif
 206                                 if (cmd->cmd.end_state->end_state != -1)
 207                                         bitbang_end_state(cmd->cmd.end_state->end_state);
 208                                 break;
 209                         case JTAG_RESET:
 210 #ifdef _DEBUG_JTAG_IO_
 211                                 DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 212 #endif
 213                                 if (cmd->cmd.reset->trst == 1)
 214                                 {
 215                                         cur_state = TAP_TLR;
 216                                 }
 217                                 bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 218                                 break;
 219                         case JTAG_RUNTEST:
 220 #ifdef _DEBUG_JTAG_IO_
 221                                 DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state);
 222 #endif
 223                                 if (cmd->cmd.runtest->end_state != -1)
 224                                         bitbang_end_state(cmd->cmd.runtest->end_state);
 225                                 bitbang_runtest(cmd->cmd.runtest->num_cycles);
 226                                 break;
 227                         case JTAG_STATEMOVE:
 228 #ifdef _DEBUG_JTAG_IO_
 229                                 DEBUG("statemove end in %i", cmd->cmd.statemove->end_state);
 230 #endif
 231                                 if (cmd->cmd.statemove->end_state != -1)
 232                                         bitbang_end_state(cmd->cmd.statemove->end_state);
 233                                 bitbang_state_move();
 234                                 break;
 235                         case JTAG_PATHMOVE:
 236 #ifdef _DEBUG_JTAG_IO_
 237                                 DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 238 #endif
 239                                 bitbang_path_move(cmd->cmd.pathmove);
 240                                 break;
 241                         case JTAG_SCAN:
 242 #ifdef _DEBUG_JTAG_IO_
 243                                 DEBUG("%s scan end in %i",  (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state);
 244 #endif
 245                                 if (cmd->cmd.scan->end_state != -1)
 246                                         bitbang_end_state(cmd->cmd.scan->end_state);
 247                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 248                                 type = jtag_scan_type(cmd->cmd.scan);
 249                                 bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
 250                                 if (jtag_read_buffer(buffer, cmd->cmd.scan) != ERROR_OK)
 251                                         retval = ERROR_JTAG_QUEUE_FAILED;
 252                                 if (buffer)
 253                                         free(buffer);
 254                                 break;
 255                         case JTAG_SLEEP:
 256 #ifdef _DEBUG_JTAG_IO_
 257                                 DEBUG("sleep %i", cmd->cmd.sleep->us);
 258 #endif
 259                                 jtag_sleep(cmd->cmd.sleep->us);
 260                                 break;
 261                         default:
 262                                 ERROR("BUG: unknown JTAG command type encountered");
 263                                 exit(-1);
 264                 }
 265                 cmd = cmd->next;
 266         }
 267
 268         return retval;
 269 }
 270