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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#include <linux/smp_lock.h>
30
31#include "excite_iodev.h"
32
33
34
35static const struct resource *iodev_get_resource(struct platform_device *, const char *, unsigned int);
36static int __init iodev_probe(struct device *);
37static int __exit iodev_remove(struct device *);
38static int iodev_open(struct inode *, struct file *);
39static int iodev_release(struct inode *, struct file *);
40static ssize_t iodev_read(struct file *, char __user *, size_t s, loff_t *);
41static unsigned int iodev_poll(struct file *, struct poll_table_struct *);
42static irqreturn_t iodev_irqhdl(int, void *);
43
44
45
46static const char iodev_name[] = "iodev";
47static unsigned int iodev_irq;
48static DECLARE_WAIT_QUEUE_HEAD(wq);
49
50
51
52static const struct file_operations fops =
53{
54 .owner = THIS_MODULE,
55 .open = iodev_open,
56 .release = iodev_release,
57 .read = iodev_read,
58 .poll = iodev_poll
59};
60
61static struct miscdevice miscdev =
62{
63 .minor = MISC_DYNAMIC_MINOR,
64 .name = iodev_name,
65 .fops = &fops
66};
67
68static struct device_driver iodev_driver =
69{
70 .name = (char *) iodev_name,
71 .bus = &platform_bus_type,
72 .owner = THIS_MODULE,
73 .probe = iodev_probe,
74 .remove = __exit_p(iodev_remove)
75};
76
77
78
79static const struct resource *
80iodev_get_resource(struct platform_device *pdv, const char *name,
81 unsigned int type)
82{
83 char buf[80];
84 if (snprintf(buf, sizeof buf, "%s_0", name) >= sizeof buf)
85 return NULL;
86 return platform_get_resource_byname(pdv, type, buf);
87}
88
89
90
91
92static int __init iodev_probe(struct device *dev)
93{
94 struct platform_device * const pdv = to_platform_device(dev);
95 const struct resource * const ri =
96 iodev_get_resource(pdv, IODEV_RESOURCE_IRQ, IORESOURCE_IRQ);
97
98 if (unlikely(!ri))
99 return -ENXIO;
100
101 iodev_irq = ri->start;
102 return misc_register(&miscdev);
103}
104
105
106
107static int __exit iodev_remove(struct device *dev)
108{
109 return misc_deregister(&miscdev);
110}
111
112static int iodev_open(struct inode *i, struct file *f)
113{
114 int ret;
115
116 lock_kernel();
117 ret = request_irq(iodev_irq, iodev_irqhdl, IRQF_DISABLED,
118 iodev_name, &miscdev);
119 unlock_kernel();
120
121 return ret;
122}
123
124static int iodev_release(struct inode *i, struct file *f)
125{
126 free_irq(iodev_irq, &miscdev);
127 return 0;
128}
129
130
131
132
133static ssize_t
134iodev_read(struct file *f, char __user *d, size_t s, loff_t *o)
135{
136 ssize_t ret;
137 DEFINE_WAIT(w);
138
139 prepare_to_wait(&wq, &w, TASK_INTERRUPTIBLE);
140 if (!signal_pending(current))
141 schedule();
142 ret = signal_pending(current) ? -ERESTARTSYS : 0;
143 finish_wait(&wq, &w);
144 return ret;
145}
146
147
148static unsigned int iodev_poll(struct file *f, struct poll_table_struct *p)
149{
150 poll_wait(f, &wq, p);
151 return POLLOUT | POLLWRNORM;
152}
153
154static irqreturn_t iodev_irqhdl(int irq, void *ctxt)
155{
156 wake_up(&wq);
157
158 return IRQ_HANDLED;
159}
160
161static int __init iodev_init_module(void)
162{
163 return driver_register(&iodev_driver);
164}
165
166
167
168static void __exit iodev_cleanup_module(void)
169{
170 driver_unregister(&iodev_driver);
171}
172
173module_init(iodev_init_module);
174module_exit(iodev_cleanup_module);
175
176
177
178MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
179MODULE_DESCRIPTION("Basler eXcite i/o interrupt handler");
180MODULE_VERSION("0.0");
181MODULE_LICENSE("GPL");
182
