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/***************************************************************************
* Copyright (C) 2008 by �yvind 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 "replacements.h"
#include "jtag.h"
#include "bitbang.h"
/* my private tap controller state, which tracks state for calling code */
static tap_state_t dummy_state = TAP_RESET;
static int dummy_clock; /* edge detector */
static tap_state_t tap_state_transition(tap_state_t cur_state, int tms);
int dummy_speed(int speed);
int dummy_register_commands(struct command_context_s *cmd_ctx);
int dummy_init(void);
int dummy_quit(void);
static int dummy_khz(int khz, int *jtag_speed);
static int dummy_speed_div(int speed, int *khz);
/* The dummy driver is used to easily check the code path
* where the target is unresponsive.
*/
jtag_interface_t dummy_interface =
{
.name = "dummy",
.execute_queue = bitbang_execute_queue,
.speed = dummy_speed,
.register_commands = dummy_register_commands,
.khz = dummy_khz,
.speed_div = dummy_speed_div,
.init = dummy_init,
.quit = dummy_quit,
};
int dummy_read(void);
void dummy_write(int tck, int tms, int tdi);
void dummy_reset(int trst, int srst);
void dummy_led(int on);
bitbang_interface_t dummy_bitbang =
{
.read = dummy_read,
.write = dummy_write,
.reset = dummy_reset,
.blink = dummy_led
};
int dummy_read(void)
{
return 1;
}
void dummy_write(int tck, int tms, int tdi)
{
/* TAP standard: "state transitions occur on rising edge of clock" */
if( tck != dummy_clock )
{
if( tck )
{
int old_state = dummy_state;
dummy_state = tap_state_transition( dummy_state, tms );
if( old_state != dummy_state )
LOG_INFO( "dummy_tap=%s", jtag_state_name(dummy_state) );
}
dummy_clock = tck;
}
}
void dummy_reset(int trst, int srst)
{
dummy_clock = 0;
dummy_state = TAP_RESET;
LOG_DEBUG( "reset to %s", jtag_state_name(dummy_state) );
}
static int dummy_khz(int khz, int *jtag_speed)
{
if (khz==0)
{
*jtag_speed=0;
}
else
{
*jtag_speed=64000/khz;
}
return ERROR_OK;
}
static int dummy_speed_div(int speed, int *khz)
{
if (speed==0)
{
*khz = 0;
}
else
{
*khz=64000/speed;
}
return ERROR_OK;
}
int dummy_speed(int speed)
{
return ERROR_OK;
}
int dummy_register_commands(struct command_context_s *cmd_ctx)
{
return ERROR_OK;
}
int dummy_init(void)
{
bitbang_interface = &dummy_bitbang;
return ERROR_OK;
}
int dummy_quit(void)
{
return ERROR_OK;
}
void dummy_led(int on)
{
}
/**
* Function tap_state_transition
* takes a current TAP state and returns the next state according to the tms value.
*
* Even though there is code to duplicate this elsewhere, we do it here a little
* differently just to get a second opinion, i.e. a verification, on state tracking
* in that other logic. Plus array lookups without index checking are no favorite thing.
* This is educational for developers new to TAP controllers.
*/
static tap_state_t tap_state_transition(tap_state_t cur_state, int tms)
{
tap_state_t new_state;
if (tms)
{
switch (cur_state)
{
case TAP_RESET:
new_state = cur_state;
break;
case TAP_IDLE:
case TAP_DRUPDATE:
case TAP_IRUPDATE:
new_state = TAP_DRSELECT;
break;
case TAP_DRSELECT:
new_state = TAP_IRSELECT;
break;
case TAP_DRCAPTURE:
case TAP_DRSHIFT:
new_state = TAP_DREXIT1;
break;
case TAP_DREXIT1:
case TAP_DREXIT2:
new_state = TAP_DRUPDATE;
break;
case TAP_DRPAUSE:
new_state = TAP_DREXIT2;
break;
case TAP_IRSELECT:
new_state = TAP_RESET;
break;
case TAP_IRCAPTURE:
case TAP_IRSHIFT:
new_state = TAP_IREXIT1;
break;
case TAP_IREXIT1:
case TAP_IREXIT2:
new_state = TAP_IRUPDATE;
break;
case TAP_IRPAUSE:
new_state = TAP_IREXIT2;
break;
default:
LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
exit(1);
break;
}
}
else
{
switch (cur_state)
{
case TAP_RESET:
case TAP_IDLE:
case TAP_DRUPDATE:
case TAP_IRUPDATE:
new_state = TAP_IDLE;
break;
case TAP_DRSELECT:
new_state = TAP_DRCAPTURE;
break;
case TAP_DRCAPTURE:
case TAP_DRSHIFT:
case TAP_DREXIT2:
new_state = TAP_DRSHIFT;
break;
case TAP_DREXIT1:
case TAP_DRPAUSE:
new_state = TAP_DRPAUSE;
break;
case TAP_IRSELECT:
new_state = TAP_IRCAPTURE;
break;
case TAP_IRCAPTURE:
case TAP_IRSHIFT:
case TAP_IREXIT2:
new_state = TAP_IRSHIFT;
break;
case TAP_IREXIT1:
case TAP_IRPAUSE:
new_state = TAP_IRPAUSE;
break;
default:
LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
exit(1);
break;
}
}
return new_state;
}
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