/***************************************************************************
 *   Copyright (C) 2007 by Pavel Chromy                                    *
 *   chromy@asix.cz                                                        *
 *                                                                         *
 *   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 "bitq.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>

bitq_interface_t *bitq_interface; /* low level bit queue interface */

bitq_state_t bitq_in_state; /* state of input queue */

u8 *bitq_in_buffer; /* buffer dynamically reallocated as needed */
unsigned long bitq_in_bufsize=32; /* min. buffer size */

/*
 * input queue processing does not use jtag_read_buffer() to avoid unnecessary overhead
 * also the buffer for incomming data is reallocated only if necessary
 * no parameters, makes use of stored state information
 */
void bitq_in_proc(void)
{
	/* static information preserved between calls to increase performance */
	static u8 *in_buff; /* pointer to buffer for scanned data */
	static int in_idx; /* index of byte being scanned */
	static u8 in_mask; /* mask of next bit to be scanned */

	scan_field_t *field;
	int tdo;

	/* loop through the queue */
	while (bitq_in_state.cmd) {
		/* only JTAG_SCAN command may return data */
		if (bitq_in_state.cmd->type==JTAG_SCAN) {
			/* loop through the fields */
			while (bitq_in_state.field_idx<bitq_in_state.cmd->cmd.scan->num_fields) {

				field=&bitq_in_state.cmd->cmd.scan->fields[bitq_in_state.field_idx];
				if ( field->in_value || field->in_handler) {

					if (bitq_in_state.bit_pos==0) {
						/* initialize field scanning */
						in_mask=0x01;
						in_idx=0;
						if (field->in_value) in_buff=field->in_value;
						else {
							/* buffer reallocation needed? */
							if (field->num_bits>bitq_in_bufsize*8) {
								/* buffer previously allocated? */
								if (bitq_in_buffer!=NULL) {
									/* free it */
									free(bitq_in_buffer);
									bitq_in_buffer=NULL;
								}
								/* double the buffer size until it fits */
								while (field->num_bits>bitq_in_bufsize*8) bitq_in_bufsize*=2;
							}
							/* if necessary, allocate buffer and check for malloc error */
							if (bitq_in_buffer==NULL && (bitq_in_buffer=malloc(bitq_in_bufsize))==NULL) {
								LOG_ERROR("malloc error");
								exit(-1);
							}
							in_buff=(void *)bitq_in_buffer;
						}
					}

					/* field scanning */
					while (bitq_in_state.bit_pos<field->num_bits) {
						if ((tdo=bitq_interface->in())<0) {
#ifdef _DEBUG_JTAG_IO_
							LOG_DEBUG("bitq in EOF");
#endif
							return;
						}
						if (in_mask==0x01) in_buff[in_idx]=0;
						if (tdo) in_buff[in_idx]|=in_mask;
						if (in_mask==0x80) {
							in_mask=0x01;
							in_idx++;
						}
						else in_mask<<=1;
						bitq_in_state.bit_pos++;
					}


					if (field->in_handler && bitq_in_state.status==ERROR_OK) {
						bitq_in_state.status=(*field->in_handler)(in_buff, field->in_handler_priv, field);
					}

				}

				bitq_in_state.field_idx++; /* advance to next field */
				bitq_in_state.bit_pos=0; /* start next field from the first bit */
			}

		}
		bitq_in_state.cmd=bitq_in_state.cmd->next; /* advance to next command */
		bitq_in_state.field_idx=0; /* preselect first field */
	}
}

void bitq_io(int tms, int tdi, int tdo_req)
{
	bitq_interface->out(tms, tdi, tdo_req);
	/* check and process the input queue */
	if (bitq_interface->in_rdy()) bitq_in_proc();
}

void bitq_end_state(enum tap_state state)
{
	if (state==-1) return;
	if (tap_move_map[state]==-1) {
		LOG_ERROR("BUG: %i is not a valid end state", state);
		exit(-1);
	}
	end_state = state;
}

void bitq_state_move(enum tap_state new_state)
{
	int i=0;
	u8 tms_scan;

	if (tap_move_map[cur_state]==-1 || tap_move_map[new_state]==-1) {
		LOG_ERROR("TAP move from or to unstable state");
		exit(-1);
	}

	tms_scan=TAP_MOVE(cur_state, new_state);

	for (i=0; i<7; i++) {
		bitq_io(tms_scan&1, 0, 0);
		tms_scan>>=1;
	}

	cur_state = new_state;
}

void bitq_path_move(pathmove_command_t *cmd)
{
	int i;

	for (i=0; i<=cmd->num_states; i++) {
		if (tap_transitions[cur_state].low == cmd->path[i]) bitq_io(0, 0, 0);
		else if (tap_transitions[cur_state].high == cmd->path[i]) bitq_io(1, 0, 0);
		else {
			LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", jtag_state_name(cur_state), jtag_state_name(cmd->path[i)]);
			exit(-1);
		}

		cur_state = cmd->path[i];
	}

	end_state = cur_state;
}

void bitq_runtest(int num_cycles)
{
	int i;

	/* only do a state_move when we're not already in IDLE */
	if (cur_state != TAP_IDLE) bitq_state_move(TAP_IDLE);

	/* execute num_cycles */
	for (i = 0; i < num_cycles; i++)
		bitq_io(0, 0, 0);

	/* finish in end_state */
	if (cur_state != end_state) bitq_state_move(end_state);
}

void bitq_scan_field(scan_field_t *field, int pause)
{
	int bit_cnt;
	int tdo_req;

	u8 *out_ptr;
	u8 out_mask;

	if ( field->in_value || field->in_handler) tdo_req=1;
	else tdo_req=0;

	if (field->out_value==NULL) {
		/* just send zeros and request data from TDO */
		for (bit_cnt=field->num_bits; bit_cnt>1; bit_cnt--)
			bitq_io(0, 0, tdo_req);
		bitq_io(pause, 0, tdo_req);
	}
	else {
		/* send data, and optionally request TDO */
		out_mask=0x01;
		out_ptr=field->out_value;
		for (bit_cnt=field->num_bits; bit_cnt>1; bit_cnt--) {
			bitq_io(0, ((*out_ptr)&out_mask)!=0, tdo_req);
			if (out_mask==0x80) {
				out_mask=0x01;
				out_ptr++;
			}
			else out_mask<<=1;
		}
		bitq_io(pause, ((*out_ptr)&out_mask)!=0, tdo_req);
	}

	if (pause) {
		bitq_io(0,0,0);
		if (cur_state==TAP_IRSHIFT) cur_state=TAP_IRPAUSE;
		else if (cur_state==TAP_DRSHIFT) cur_state=TAP_DRPAUSE;
	}
}

void bitq_scan(scan_command_t *cmd)
{
	int i;

	if (cmd->ir_scan) bitq_state_move(TAP_IRSHIFT);
	else bitq_state_move(TAP_DRSHIFT);

	for (i=0; i < cmd->num_fields-1; i++)
		bitq_scan_field(&cmd->fields[i], 0);
	bitq_scan_field(&cmd->fields[i], 1);
}

int bitq_execute_queue(void)
{
	jtag_command_t *cmd = jtag_command_queue; /* currently processed command */

	bitq_in_state.cmd = jtag_command_queue;
	bitq_in_state.field_idx = 0;
	bitq_in_state.bit_pos = 0;
	bitq_in_state.status = ERROR_OK;

	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
				bitq_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_RESET;
				}
				bitq_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
				if (bitq_interface->in_rdy()) bitq_in_proc();
				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
				bitq_end_state(cmd->cmd.runtest->end_state);
				bitq_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
				bitq_end_state(cmd->cmd.statemove->end_state);
				bitq_state_move(end_state); /* uncoditional TAP 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
				bitq_path_move(cmd->cmd.pathmove);
				break;

			case JTAG_SCAN:
#ifdef _DEBUG_JTAG_IO_
				LOG_DEBUG("scan end in %i", cmd->cmd.scan->end_state);
				if (cmd->cmd.scan->ir_scan) LOG_DEBUG("scan ir");
				else LOG_DEBUG("scan dr");
#endif
				bitq_end_state(cmd->cmd.scan->end_state);
				bitq_scan(cmd->cmd.scan);
				if (cur_state != end_state) bitq_state_move(end_state);
				break;

			case JTAG_SLEEP:
#ifdef _DEBUG_JTAG_IO_
				LOG_DEBUG("sleep %i", cmd->cmd.sleep->us);
#endif
				bitq_interface->sleep(cmd->cmd.sleep->us);
				if (bitq_interface->in_rdy()) bitq_in_proc();
				break;

			default:
				LOG_ERROR("BUG: unknown JTAG command type encountered");
				exit(-1);
		}

		cmd = cmd->next;
	}

	bitq_interface->flush();
	bitq_in_proc();

	if (bitq_in_state.cmd) {
		LOG_ERROR("missing data from bitq interface");
		return ERROR_JTAG_QUEUE_FAILED;
	}
	if (bitq_interface->in()>=0) {
		LOG_ERROR("extra data from bitq interface");
		return ERROR_JTAG_QUEUE_FAILED;
	}

	return bitq_in_state.status;
}

void bitq_cleanup(void)
{
	if (bitq_in_buffer!=NULL)
	{
		free(bitq_in_buffer);
		bitq_in_buffer=NULL;
	}
}