Logo Search packages:      
Sourcecode: linux version File versions  Download package

excite_iodev.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 "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 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");

Generated by  Doxygen 1.6.0   Back to index