1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * altera-lpt.c
4  *
5  * altera FPGA driver
6  *
7  * Copyright (C) Altera Corporation 1998-2001
8  * Copyright (C) 2010 NetUP Inc.
9  * Copyright (C) 2010 Abylay Ospan <aospan@netup.ru>
10  */
11 
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include "altera-exprt.h"
15 
16 static int lpt_hardware_initialized;
17 
byteblaster_write(int port,int data)18 static void byteblaster_write(int port, int data)
19 {
20 	outb((u8)data, (u16)(port + 0x378));
21 };
22 
byteblaster_read(int port)23 static int byteblaster_read(int port)
24 {
25 	int data = 0;
26 	data = inb((u16)(port + 0x378));
27 	return data & 0xff;
28 };
29 
netup_jtag_io_lpt(void * device,int tms,int tdi,int read_tdo)30 int netup_jtag_io_lpt(void *device, int tms, int tdi, int read_tdo)
31 {
32 	int data = 0;
33 	int tdo = 0;
34 	int initial_lpt_ctrl = 0;
35 
36 	if (!lpt_hardware_initialized) {
37 		initial_lpt_ctrl = byteblaster_read(2);
38 		byteblaster_write(2, (initial_lpt_ctrl | 0x02) & 0xdf);
39 		lpt_hardware_initialized = 1;
40 	}
41 
42 	data = ((tdi ? 0x40 : 0) | (tms ? 0x02 : 0));
43 
44 	byteblaster_write(0, data);
45 
46 	if (read_tdo) {
47 		tdo = byteblaster_read(1);
48 		tdo = ((tdo & 0x80) ? 0 : 1);
49 	}
50 
51 	byteblaster_write(0, data | 0x01);
52 
53 	byteblaster_write(0, data);
54 
55 	return tdo;
56 }
57