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

   1 /*
   2  * altera-lpt.c
   3  *
   4  * altera FPGA driver
   5  *
   6  * Copyright (C) Altera Corporation 1998-2001
   7  * Copyright (C) 2010 NetUP Inc.
   8  * Copyright (C) 2010 Abylay Ospan <aospan@netup.ru>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <linux/io.h>
  27 #include <linux/kernel.h>
  28 #include "altera-exprt.h"
  29
  30 static int lpt_hardware_initialized;
  31
  32 static void byteblaster_write(int port, int data)
  33 {
  34         outb((u8)data, (u16)(port + 0x378));
  35 };
  36
  37 static int byteblaster_read(int port)
  38 {
  39         int data = 0;
  40         data = inb((u16)(port + 0x378));
  41         return data & 0xff;
  42 };
  43
  44 int netup_jtag_io_lpt(void *device, int tms, int tdi, int read_tdo)
  45 {
  46         int data = 0;
  47         int tdo = 0;
  48         int initial_lpt_ctrl = 0;
  49
  50         if (!lpt_hardware_initialized) {
  51                 initial_lpt_ctrl = byteblaster_read(2);
  52                 byteblaster_write(2, (initial_lpt_ctrl | 0x02) & 0xdf);
  53                 lpt_hardware_initialized = 1;
  54         }
  55
  56         data = ((tdi ? 0x40 : 0) | (tms ? 0x02 : 0));
  57
  58         byteblaster_write(0, data);
  59
  60         if (read_tdo) {
  61                 tdo = byteblaster_read(1);
  62                 tdo = ((tdo & 0x80) ? 0 : 1);
  63         }
  64
  65         byteblaster_write(0, data | 0x01);
  66
  67         byteblaster_write(0, data);
  68
  69         return tdo;
  70 }