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

http://github.com/mirrors/linux
C | 56 lines | 34 code | 12 blank | 10 comment | 2 complexity | 122acf2801aa10616e64b1e5968610a1 MD5 | raw file
 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((u8)data, (u16)(port + 0x378));
21};
22
23static int byteblaster_read(int port)
24{
25	int data = 0;
26	data = inb((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(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}