linux/drivers/misc/altera-stapl/altera-lpt.c

/*
 * altera-lpt.c
 *
 * altera FPGA driver
 *
 * Copyright (C) Altera Corporation 1998-2001
 * Copyright (C) 2010 NetUP Inc.
 * Copyright (C) 2010 Abylay Ospan <aospan@netup.ru>
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/io.h>
#include <linux/kernel.h>
#include "altera-exprt.h"

static int lpt_hardware_initialized;

static void byteblaster_write(int port, int data)
{
	outb((u8)data, (u16)(port + 0x378));
};

static int byteblaster_read(int port)
{
	int data = 0;
	data = inb((u16)(port + 0x378));
	return data & 0xff;
};

int netup_jtag_io_lpt(void *device, int tms, int tdi, int read_tdo)
{
	int data = 0;
	int tdo = 0;
	int initial_lpt_ctrl = 0;

	if (!lpt_hardware_initialized) {
		initial_lpt_ctrl = byteblaster_read(2);
		byteblaster_write(2, (initial_lpt_ctrl | 0x02) & 0xdf);
		lpt_hardware_initialized = 1;
	}

	data = ((tdi ? 0x40 : 0) | (tms ? 0x02 : 0));

	byteblaster_write(0, data);

	if (read_tdo) {
		tdo = byteblaster_read(1);
		tdo = ((tdo & 0x80) ? 0 : 1);
	}

	byteblaster_write(0, data | 0x01);

	byteblaster_write(0, data);

	return tdo;
}