summaryrefslogtreecommitdiffstats
path: root/arch/mips/basler/excite/excite_iodev.c
blob: 476d20e08d0e4ceb2251b745ad3e81620f77589e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 *  Copyright (C) 2005 by Basler Vision Technologies AG
 *  Author: Thomas Koeller <thomas.koeller@baslerweb.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>

#include "excite_iodev.h"



static const struct resource *iodev_get_resource(struct platform_device *, const char *, unsigned int);
static int __init iodev_probe(struct device *);
static int __exit iodev_remove(struct device *);
static int iodev_open(struct inode *, struct file *);
static int iodev_release(struct inode *, struct file *);
static ssize_t iodev_read(struct file *, char __user *, size_t s, loff_t *);
static unsigned int iodev_poll(struct file *, struct poll_table_struct *);
static irqreturn_t iodev_irqhdl(int, void *);



static const char iodev_name[] = "iodev";
static unsigned int iodev_irq;
static DECLARE_WAIT_QUEUE_HEAD(wq);



static const struct file_operations fops =
{
	.owner		= THIS_MODULE,
	.open		= iodev_open,
	.release	= iodev_release,
	.read		= iodev_read,
	.poll		= iodev_poll
};

static struct miscdevice miscdev =
{
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= iodev_name,
	.fops		= &fops
};

static struct device_driver iodev_driver =
{
	.name		= (char *) iodev_name,
	.bus		= &platform_bus_type,
	.owner		= THIS_MODULE,
	.probe		= iodev_probe,
	.remove		= __exit_p(iodev_remove)
};



static const struct resource *
iodev_get_resource(struct platform_device *pdv, const char *name,
		     unsigned int type)
{
	char buf[80];
	if (snprintf(buf, sizeof buf, "%s_0", name) >= sizeof buf)
		return NULL;
	return platform_get_resource_byname(pdv, type, buf);
}



/* No hotplugging on the platform bus - use __init */
static int __init iodev_probe(struct device *dev)
{
	struct platform_device * const pdv = to_platform_device(dev);
	const struct resource * const ri =
		iodev_get_resource(pdv, IODEV_RESOURCE_IRQ, IORESOURCE_IRQ);

	if (unlikely(!ri))
		return -ENXIO;

	iodev_irq = ri->start;
	return misc_register(&miscdev);
}



static int __exit iodev_remove(struct device *dev)
{
	return misc_deregister(&miscdev);
}

static int iodev_open(struct inode *i, struct file *f)
{
	return request_irq(iodev_irq, iodev_irqhdl, IRQF_DISABLED,
			   iodev_name, &miscdev);
}

static int iodev_release(struct inode *i, struct file *f)
{
	free_irq(iodev_irq, &miscdev);
	return 0;
}




static ssize_t
iodev_read(struct file *f, char __user *d, size_t s, loff_t *o)
{
	ssize_t ret;
	DEFINE_WAIT(w);

	prepare_to_wait(&wq, &w, TASK_INTERRUPTIBLE);
	if (!signal_pending(current))
		schedule();
	ret = signal_pending(current) ? -ERESTARTSYS : 0;
	finish_wait(&wq, &w);
	return ret;
}


static unsigned int iodev_poll(struct file *f, struct poll_table_struct *p)
{
	poll_wait(f, &wq, p);
	return POLLOUT | POLLWRNORM;
}

static irqreturn_t iodev_irqhdl(int irq, void *ctxt)
{
	wake_up(&wq);

	return IRQ_HANDLED;
}

static int __init iodev_init_module(void)
{
	return driver_register(&iodev_driver);
}



static void __exit iodev_cleanup_module(void)
{
	driver_unregister(&iodev_driver);
}

module_init(iodev_init_module);
module_exit(iodev_cleanup_module);



MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
MODULE_DESCRIPTION("Basler eXcite i/o interrupt handler");
MODULE_VERSION("0.0");
MODULE_LICENSE("GPL");