1/*
2 *  Copyright (C) 2005 by Basler Vision Technologies AG
3 *  Author: Thomas Koeller <thomas.koeller@baslerweb.com>
4 *
5 *  This program is free software; you can redistribute it and/or modify
6 *  it under the terms of the GNU General Public License as published by
7 *  the Free Software Foundation; either version 2 of the License, or
8 *  (at your option) any later version.
9 *
10 *  This program is distributed in the hope that it will be useful,
11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *  GNU General Public License for more details.
14 *
15 *  You should have received a copy of the GNU General Public License
16 *  along with this program; if not, write to the Free Software
17 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18 */
19
20#include <linux/compiler.h>
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/sched.h>
24#include <linux/wait.h>
25#include <linux/poll.h>
26#include <linux/interrupt.h>
27#include <linux/platform_device.h>
28#include <linux/miscdevice.h>
29
30#include "excite_iodev.h"
31
32
33
34static const struct resource *iodev_get_resource(struct platform_device *, const char *, unsigned int);
35static int __init iodev_probe(struct device *);
36static int __exit iodev_remove(struct device *);
37static int iodev_open(struct inode *, struct file *);
38static int iodev_release(struct inode *, struct file *);
39static ssize_t iodev_read(struct file *, char __user *, size_t s, loff_t *);
40static unsigned int iodev_poll(struct file *, struct poll_table_struct *);
41static irqreturn_t iodev_irqhdl(int, void *);
42
43
44
45static const char iodev_name[] = "iodev";
46static unsigned int iodev_irq;
47static DECLARE_WAIT_QUEUE_HEAD(wq);
48
49
50
51static struct file_operations fops =
52{
53	.owner		= THIS_MODULE,
54	.open		= iodev_open,
55	.release	= iodev_release,
56	.read		= iodev_read,
57	.poll		= iodev_poll
58};
59
60static struct miscdevice miscdev =
61{
62	.minor		= MISC_DYNAMIC_MINOR,
63	.name		= iodev_name,
64	.fops		= &fops
65};
66
67static struct device_driver iodev_driver =
68{
69	.name		= (char *) iodev_name,
70	.bus		= &platform_bus_type,
71	.owner		= THIS_MODULE,
72	.probe		= iodev_probe,
73	.remove		= __exit_p(iodev_remove)
74};
75
76
77
78static const struct resource *
79iodev_get_resource(struct platform_device *pdv, const char *name,
80		     unsigned int type)
81{
82	char buf[80];
83	if (snprintf(buf, sizeof buf, "%s_0", name) >= sizeof buf)
84		return NULL;
85	return platform_get_resource_byname(pdv, type, buf);
86}
87
88
89
90/* No hotplugging on the platform bus - use __init */
91static int __init iodev_probe(struct device *dev)
92{
93	struct platform_device * const pdv = to_platform_device(dev);
94	const struct resource * const ri =
95		iodev_get_resource(pdv, IODEV_RESOURCE_IRQ, IORESOURCE_IRQ);
96
97	if (unlikely(!ri))
98		return -ENXIO;
99
100	iodev_irq = ri->start;
101	return misc_register(&miscdev);
102}
103
104
105
106static int __exit iodev_remove(struct device *dev)
107{
108	return misc_deregister(&miscdev);
109}
110
111static int iodev_open(struct inode *i, struct file *f)
112{
113	return request_irq(iodev_irq, iodev_irqhdl, IRQF_DISABLED,
114			   iodev_name, &miscdev);
115}
116
117static int iodev_release(struct inode *i, struct file *f)
118{
119	free_irq(iodev_irq, &miscdev);
120	return 0;
121}
122
123
124
125
126static ssize_t
127iodev_read(struct file *f, char __user *d, size_t s, loff_t *o)
128{
129	ssize_t ret;
130	DEFINE_WAIT(w);
131
132	prepare_to_wait(&wq, &w, TASK_INTERRUPTIBLE);
133	if (!signal_pending(current))
134		schedule();
135	ret = signal_pending(current) ? -ERESTARTSYS : 0;
136	finish_wait(&wq, &w);
137	return ret;
138}
139
140
141static unsigned int iodev_poll(struct file *f, struct poll_table_struct *p)
142{
143	poll_wait(f, &wq, p);
144	return POLLOUT | POLLWRNORM;
145}
146
147static irqreturn_t iodev_irqhdl(int irq, void *ctxt)
148{
149	wake_up(&wq);
150
151	return IRQ_HANDLED;
152}
153
154static int __init iodev_init_module(void)
155{
156	return driver_register(&iodev_driver);
157}
158
159
160
161static void __exit iodev_cleanup_module(void)
162{
163	driver_unregister(&iodev_driver);
164}
165
166module_init(iodev_init_module);
167module_exit(iodev_cleanup_module);
168
169
170
171MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
172MODULE_DESCRIPTION("Basler eXcite i/o interrupt handler");
173MODULE_VERSION("0.0");
174MODULE_LICENSE("GPL");
175