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/***************************************************************************
* Copyright (C) 2005 by Dominic Rath *
* Dominic.Rath@gmx.de *
* *
* Copyright (C) 2007,2008 Øyvind Harboe *
* oyvind.harboe@zylin.com *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "bitbang.h"
/* project specific includes */
#include "log.h"
#include "types.h"
#include "jtag.h"
#include "configuration.h"
/* system includes */
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
bitbang_interface_t *bitbang_interface;
/* DANGER!!!! clock absolutely *MUST* be 0 in idle or reset won't work!
*
* Set this to 1 and str912 reset halt will fail.
*
* If someone can submit a patch with an explanation it will be greatly
* appreciated, but as far as I can tell (ØH) DCLK is generated upon
* clk=0 in TAP_RTI. Good luck deducing that from the ARM documentation!
* The ARM documentation uses the term "DCLK is asserted while in the TAP_RTI
* state". With hardware there is no such thing as *while* in a state. There
* are only edges. So clk => 0 is in fact a very subtle state transition that
* happens *while* in the TAP_RTI state. "#&€"#€&"#&"#&
*
* For "reset halt" the last thing that happens before srst is asserted
* is that the breakpoint is set up. If DCLK is not wiggled one last
* time before the reset, then the breakpoint is not set up and
* "reset halt" will fail to halt.
*
*/
#define CLOCK_IDLE() 0
int bitbang_execute_queue(void);
/* The bitbang driver leaves the TCK 0 when in idle */
void bitbang_end_state(enum tap_state state)
{
if (tap_move_map[state] != -1)
end_state = state;
else
{
LOG_ERROR("BUG: %i is not a valid end state", state);
exit(-1);
}
}
void bitbang_state_move(void) {
int i=0, tms=0;
u8 tms_scan = TAP_MOVE(cur_state, end_state);
for (i = 0; i < 7; i++)
{
tms = (tms_scan >> i) & 1;
bitbang_interface->write(0, tms, 0);
bitbang_interface->write(1, tms, 0);
}
bitbang_interface->write(CLOCK_IDLE(), tms, 0);
cur_state = end_state;
}
void bitbang_path_move(pathmove_command_t *cmd)
{
int num_states = cmd->num_states;
int state_count;
int tms = 0;
state_count = 0;
while (num_states)
{
if (tap_transitions[cur_state].low == cmd->path[state_count])
{
tms = 0;
}
else if (tap_transitions[cur_state].high == cmd->path[state_count])
{
tms = 1;
}
else
{
LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]);
exit(-1);
}
bitbang_interface->write(0, tms, 0);
bitbang_interface->write(1, tms, 0);
cur_state = cmd->path[state_count];
state_count++;
num_states--;
}
bitbang_interface->write(CLOCK_IDLE(), tms, 0);
end_state = cur_state;
}
void bitbang_runtest(int num_cycles)
{
int i;
enum tap_state saved_end_state = end_state;
/* only do a state_move when we're not already in RTI */
if (cur_state != TAP_RTI)
{
bitbang_end_state(TAP_RTI);
bitbang_state_move();
}
/* execute num_cycles */
for (i = 0; i < num_cycles; i++)
{
bitbang_interface->write(0, 0, 0);
bitbang_interface->write(1, 0, 0);
}
bitbang_interface->write(CLOCK_IDLE(), 0, 0);
/* finish in end_state */
bitbang_end_state(saved_end_state);
if (cur_state != end_state)
bitbang_state_move();
}
void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
{
enum tap_state saved_end_state = end_state;
int bit_cnt;
if (!((!ir_scan && (cur_state == TAP_SD)) || (ir_scan && (cur_state == TAP_SI))))
{
if (ir_scan)
bitbang_end_state(TAP_SI);
else
bitbang_end_state(TAP_SD);
bitbang_state_move();
bitbang_end_state(saved_end_state);
}
for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
{
int val=0;
int tms=(bit_cnt==scan_size-1) ? 1 : 0;
int tdi;
int bytec=bit_cnt/8;
int bcval=1<<(bit_cnt % 8);
/* if we're just reading the scan, but don't care about the output
* default to outputting 'low', this also makes valgrind traces more readable,
* as it removes the dependency on an uninitialised value
*/
tdi=0;
if ((type != SCAN_IN) && (buffer[bytec] & bcval))
tdi=1;
bitbang_interface->write(0, tms, tdi);
if (type!=SCAN_OUT)
val=bitbang_interface->read();
bitbang_interface->write(1, tms, tdi);
if (type != SCAN_OUT)
{
if (val)
buffer[bytec] |= bcval;
else
buffer[bytec] &= ~bcval;
}
}
/* TAP_SD & TAP_SI are illegal end states, so we always transition to the pause
* state which is a legal stable state from which statemove will work.
*
* Exit1 -> Pause
*/
bitbang_interface->write(0, 0, 0);
bitbang_interface->write(1, 0, 0);
bitbang_interface->write(CLOCK_IDLE(), 0, 0);
if (ir_scan)
cur_state = TAP_PI;
else
cur_state = TAP_PD;
if (cur_state != end_state)
bitbang_state_move();
}
int bitbang_execute_queue(void)
{
jtag_command_t *cmd = jtag_command_queue; /* currently processed command */
int scan_size;
enum scan_type type;
u8 *buffer;
int retval;
if (!bitbang_interface)
{
LOG_ERROR("BUG: Bitbang interface called, but not yet initialized");
exit(-1);
}
/* return ERROR_OK, unless a jtag_read_buffer returns a failed check
* that wasn't handled by a caller-provided error handler
*/
retval = ERROR_OK;
if(bitbang_interface->blink)
bitbang_interface->blink(1);
while (cmd)
{
switch (cmd->type)
{
case JTAG_END_STATE:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("end_state: %i", cmd->cmd.end_state->end_state);
#endif
if (cmd->cmd.end_state->end_state != -1)
bitbang_end_state(cmd->cmd.end_state->end_state);
break;
case JTAG_RESET:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
#endif
if ((cmd->cmd.reset->trst == 1) || (cmd->cmd.reset->srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))
{
cur_state = TAP_TLR;
}
bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
break;
case JTAG_RUNTEST:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state);
#endif
if (cmd->cmd.runtest->end_state != -1)
bitbang_end_state(cmd->cmd.runtest->end_state);
bitbang_runtest(cmd->cmd.runtest->num_cycles);
break;
case JTAG_STATEMOVE:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("statemove end in %i", cmd->cmd.statemove->end_state);
#endif
if (cmd->cmd.statemove->end_state != -1)
bitbang_end_state(cmd->cmd.statemove->end_state);
bitbang_state_move();
break;
case JTAG_PATHMOVE:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
#endif
bitbang_path_move(cmd->cmd.pathmove);
break;
case JTAG_SCAN:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("%s scan end in %i", (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state);
#endif
if (cmd->cmd.scan->end_state != -1)
bitbang_end_state(cmd->cmd.scan->end_state);
scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
type = jtag_scan_type(cmd->cmd.scan);
bitbang_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size);
if (jtag_read_buffer(buffer, cmd->cmd.scan) != ERROR_OK)
retval = ERROR_JTAG_QUEUE_FAILED;
if (buffer)
free(buffer);
break;
case JTAG_SLEEP:
#ifdef _DEBUG_JTAG_IO_
LOG_DEBUG("sleep %i", cmd->cmd.sleep->us);
#endif
jtag_sleep(cmd->cmd.sleep->us);
break;
default:
LOG_ERROR("BUG: unknown JTAG command type encountered");
exit(-1);
}
cmd = cmd->next;
}
if(bitbang_interface->blink)
bitbang_interface->blink(0);
return retval;
}
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