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
16static int lpt_hardware_initialized;
17
18static void byteblaster_write(int port, int data)
19{
20 outb(value: (u8)data, port: (u16)(port + 0x378));
21};
22
23static int byteblaster_read(int port)
24{
25 int data = 0;
26 data = inb(port: (u16)(port + 0x378));
27 return data & 0xff;
28};
29
30int 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(port: 2);
38 byteblaster_write(port: 2, data: (initial_lpt_ctrl | 0x02) & 0xdf);
39 lpt_hardware_initialized = 1;
40 }
41
42 data = ((tdi ? 0x40 : 0) | (tms ? 0x02 : 0));
43
44 byteblaster_write(port: 0, data);
45
46 if (read_tdo) {
47 tdo = byteblaster_read(port: 1);
48 tdo = ((tdo & 0x80) ? 0 : 1);
49 }
50
51 byteblaster_write(port: 0, data: data | 0x01);
52
53 byteblaster_write(port: 0, data);
54
55 return tdo;
56}
57

source code of linux/drivers/misc/altera-stapl/altera-lpt.c