linux/arch/mips/basler/excite/excite_iodev.c

182 lines
4.1 KiB
C

/*
* 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 <linux/smp_lock.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)
{
int ret;
lock_kernel();
ret = request_irq(iodev_irq, iodev_irqhdl, IRQF_DISABLED,
iodev_name, &miscdev);
unlock_kernel();
return ret;
}
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");