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 /* The bitbang driver leaves the TCK 0 when in idle */
  45
  46
  47 void bitbang_end_state(enum tap_state state)
  48 {
  49         if (tap_move_map[state] != -1)
  50                 end_state = state;
  51         else
  52         {
  53                 ERROR("BUG: %i is not a valid end state", state);
  54                 exit(-1);
  55         }
  56 }
  57
  58 void bitbang_state_move(void) {
  59
  60         int i=0, tms=0;
  61         u8 tms_scan = TAP_MOVE(cur_state, end_state);
  62
  63         for (i = 0; i < 7; i++)
  64         {
  65                 tms = (tms_scan >> i) & 1;
  66                 bitbang_interface->write(0, tms, 0);
  67                 bitbang_interface->write(1, tms, 0);
  68         }
  69         bitbang_interface->write(0, tms, 0);
  70
  71         cur_state = end_state;
  72 }
  73
  74 void bitbang_path_move(pathmove_command_t *cmd)
  75 {
  76         int num_states = cmd->num_states;
  77         int state_count;
  78         int tms = 0;
  79
  80         state_count = 0;
  81         while (num_states)
  82         {
  83                 if (tap_transitions[cur_state].low == cmd->path[state_count])
  84                 {
  85                         tms = 0;
  86                 }
  87                 else if (tap_transitions[cur_state].high == cmd->path[state_count])
  88                 {
  89                         tms = 1;
  90                 }
  91                 else
  92                 {
  93                         ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]);
  94                         exit(-1);
  95                 }
  96
  97                 bitbang_interface->write(0, tms, 0);
  98                 bitbang_interface->write(1, tms, 0);
  99
 100                 cur_state = cmd->path[state_count];
 101                 state_count++;
 102                 num_states--;
 103         }
 104
 105         bitbang_interface->write(0, tms, 0);
 106
 107         end_state = cur_state;
 108 }
 109
 110 void bitbang_runtest(int num_cycles)
 111 {
 112         int i;
 113
 114         enum tap_state saved_end_state = end_state;
 115
 116         /* only do a state_move when we're not already in RTI */
 117         if (cur_state != TAP_RTI)
 118         {
 119                 bitbang_end_state(TAP_RTI);
 120                 bitbang_state_move();
 121         }
 122
 123         /* execute num_cycles */
 124         bitbang_interface->write(0, 0, 0);
 125         for (i = 0; i < num_cycles; i++)
 126         {
 127                 bitbang_interface->write(1, 0, 0);
 128                 bitbang_interface->write(0, 0, 0);
 129         }
 130
 131         /* finish in end_state */
 132         bitbang_end_state(saved_end_state);
 133         if (cur_state != end_state)
 134                 bitbang_state_move();
 135 }
 136
 137 void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
 138 {
 139         enum tap_state saved_end_state = end_state;
 140         int bit_cnt;
 141
 142         if (!((!ir_scan && (cur_state == TAP_SD)) || (ir_scan && (cur_state == TAP_SI))))
 143         {
 144                 if (ir_scan)
 145                         bitbang_end_state(TAP_SI);
 146                 else
 147                         bitbang_end_state(TAP_SD);
 148
 149                 bitbang_state_move();
 150                 bitbang_end_state(saved_end_state);
 151         }
 152
 153         for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
 154         {
 155                 /* if we're just reading the scan, but don't care about the output
 156                  * default to outputting 'low', this also makes valgrind traces more readable,
 157                  * as it removes the dependency on an uninitialised value
 158                  */
 159                 if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1))
 160                 {
 161                         bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 1);
 162                         bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 1);
 163                 } else {
 164                         bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 0);
 165                         bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 0);
 166                 }
 167
 168                 if (type != SCAN_OUT)
 169                 {
 170                         if (bitbang_interface->read())
 171                                 buffer[(bit_cnt)/8] |= 1 << ((bit_cnt) % 8);
 172                         else
 173                                 buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8));
 174                 }
 175         }
 176
 177         /* Exit1 -> Pause */
 178         bitbang_interface->write(0, 0, 0);
 179         bitbang_interface->write(1, 0, 0);
 180         bitbang_interface->write(0, 0, 0);
 181
 182         if (ir_scan)
 183                 cur_state = TAP_PI;
 184         else
 185                 cur_state = TAP_PD;
 186
 187         if (cur_state != end_state)
 188                 bitbang_state_move();
 189 }
 190
 191 int bitbang_execute_queue(void)
 192 {
 193         jtag_command_t *cmd = jtag_command_queue; /* currently processed command */
 194         int scan_size;
 195         enum scan_type type;
 196         u8 *buffer;
 197         int retval;
 198
 199         if (!bitbang_interface)
 200         {
 201                 ERROR("BUG: Bitbang interface called, but not yet initialized");
 202                 exit(-1);
 203         }
 204
 205         /* return ERROR_OK, unless a jtag_read_buffer returns a failed check
 206          * that wasn't handled by a caller-provided error handler
 207          */
 208         retval = ERROR_OK;
 209
 210         if(bitbang_interface->blink)
 211                 bitbang_interface->blink(1);
 212
 213         while (cmd)
 214         {
 215                 switch (cmd->type)
 216                 {
 217                         case JTAG_END_STATE:
 218 #ifdef _DEBUG_JTAG_IO_
 219                                 DEBUG("end_state: %i", cmd->cmd.end_state->end_state);
 220 #endif
 221                                 if (cmd->cmd.end_state->end_state != -1)
 222                                         bitbang_end_state(cmd->cmd.end_state->end_state);
 223                                 break;
 224                         case JTAG_RESET:
 225 #ifdef _DEBUG_JTAG_IO_
 226                                 DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 227 #endif
 228                                 if (cmd->cmd.reset->trst == 1)
 229                                 {
 230                                         cur_state = TAP_TLR;
 231                                 }
 232                                 bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 233                                 break;
 234                         case JTAG_RUNTEST:
 235 #ifdef _DEBUG_JTAG_IO_
 236                                 DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state);
 237 #endif
 238                                 if (cmd->cmd.runtest->end_state != -1)
 239                                         bitbang_end_state(cmd->cmd.runtest->end_state);
 240                                 bitbang_runtest(cmd->cmd.runtest->num_cycles);
 241                                 break;
 242                         case JTAG_STATEMOVE:
 243 #ifdef _DEBUG_JTAG_IO_
 244                                 DEBUG("statemove end in %i", cmd->cmd.statemove->end_state);
 245 #endif
 246                                 if (cmd->cmd.statemove->end_state != -1)
 247                                         bitbang_end_state(cmd->cmd.statemove->end_state);
 248                                 bitbang_state_move();
 249                                 break;
 250                         case JTAG_PATHMOVE:
 251 #ifdef _DEBUG_JTAG_IO_
 252                                 DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 253 #endif
 254                                 bitbang_path_move(cmd->cmd.pathmove);
 255                                 break;
 256                         case JTAG_SCAN:
 257 #ifdef _DEBUG_JTAG_IO_
 258                                 DEBUG("%s scan end in %i",  (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state);
 259 #endif
 260                                 if (cmd->cmd.scan->end_state != -1)
 261                                         bitbang_end_state(cmd->cmd.scan->end_state);
 262                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 263                                 type = jtag_scan_type(cmd->cmd.scan);
 264                                 bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
 265                                 if (jtag_read_buffer(buffer, cmd->cmd.scan) != ERROR_OK)
 266                                         retval = ERROR_JTAG_QUEUE_FAILED;
 267                                 if (buffer)
 268                                         free(buffer);
 269                                 break;
 270                         case JTAG_SLEEP:
 271 #ifdef _DEBUG_JTAG_IO_
 272                                 DEBUG("sleep %i", cmd->cmd.sleep->us);
 273 #endif
 274                                 jtag_sleep(cmd->cmd.sleep->us);
 275                                 break;
 276                         default:
 277                                 ERROR("BUG: unknown JTAG command type encountered");
 278                                 exit(-1);
 279                 }
 280                 cmd = cmd->next;
 281         }
 282         if(bitbang_interface->blink)
 283                 bitbang_interface->blink(0);
 284
 285         return retval;
 286 }
 287