1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * comedi/drivers/amplc_pc236.c
4 * Driver for Amplicon PC36AT DIO boards.
5 *
6 * Copyright (C) 2002 MEV Ltd. <https://www.mev.co.uk/>
7 *
8 * COMEDI - Linux Control and Measurement Device Interface
9 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
10 */
11/*
12 * Driver: amplc_pc236
13 * Description: Amplicon PC36AT
14 * Author: Ian Abbott <abbotti@mev.co.uk>
15 * Devices: [Amplicon] PC36AT (pc36at)
16 * Updated: Fri, 25 Jul 2014 15:32:40 +0000
17 * Status: works
18 *
19 * Configuration options - PC36AT:
20 *   [0] - I/O port base address
21 *   [1] - IRQ (optional)
22 *
23 * The PC36AT board has a single 8255 appearing as subdevice 0.
24 *
25 * Subdevice 1 pretends to be a digital input device, but it always returns
26 * 0 when read. However, if you run a command with scan_begin_src=TRIG_EXT,
27 * a rising edge on port C bit 3 acts as an external trigger, which can be
28 * used to wake up tasks.  This is like the comedi_parport device, but the
29 * only way to physically disable the interrupt on the PC36AT is to remove
30 * the IRQ jumper.  If no interrupt is connected, then subdevice 1 is
31 * unused.
32 */
33
34#include <linux/module.h>
35#include <linux/comedi/comedidev.h>
36
37#include "amplc_pc236.h"
38
39static int pc236_attach(struct comedi_device *dev, struct comedi_devconfig *it)
40{
41	struct pc236_private *devpriv;
42	int ret;
43
44	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
45	if (!devpriv)
46		return -ENOMEM;
47
48	ret = comedi_request_region(dev, it->options[0], 0x4);
49	if (ret)
50		return ret;
51
52	return amplc_pc236_common_attach(dev, dev->iobase, it->options[1], 0);
53}
54
55static const struct pc236_board pc236_boards[] = {
56	{
57		.name = "pc36at",
58	},
59};
60
61static struct comedi_driver amplc_pc236_driver = {
62	.driver_name = "amplc_pc236",
63	.module = THIS_MODULE,
64	.attach = pc236_attach,
65	.detach = comedi_legacy_detach,
66	.board_name = &pc236_boards[0].name,
67	.offset = sizeof(struct pc236_board),
68	.num_names = ARRAY_SIZE(pc236_boards),
69};
70
71module_comedi_driver(amplc_pc236_driver);
72
73MODULE_AUTHOR("Comedi https://www.comedi.org");
74MODULE_DESCRIPTION("Comedi driver for Amplicon PC36AT DIO boards");
75MODULE_LICENSE("GPL");
76