arch/mips/basler/excite/excite_iodev.c

   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 #include <linux/smp_lock.h>
  30
  31 #include "excite_iodev.h"
  32
  33
  34
  35 static const struct resource *iodev_get_resource(struct platform_device *, const char *, unsigned int);
  36 static int __init iodev_probe(struct platform_device *);
  37 static int __exit iodev_remove(struct platform_device *);
  38 static int iodev_open(struct inode *, struct file *);
  39 static int iodev_release(struct inode *, struct file *);
  40 static ssize_t iodev_read(struct file *, char __user *, size_t s, loff_t *);
  41 static unsigned int iodev_poll(struct file *, struct poll_table_struct *);
  42 static irqreturn_t iodev_irqhdl(int, void *);
  43
  44
  45
  46 static const char iodev_name[] = "iodev";
  47 static unsigned int iodev_irq;
  48 static DECLARE_WAIT_QUEUE_HEAD(wq);
  49
  50
  51
  52 static 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
  61 static struct miscdevice miscdev =
  62 {
  63         .minor          = MISC_DYNAMIC_MINOR,
  64         .name           = iodev_name,
  65         .fops           = &fops
  66 };
  67
  68 static struct platform_driver iodev_driver = {
  69         .driver = {
  70                 .name           = iodev_name,
  71                 .owner          = THIS_MODULE,
  72         },
  73         .probe          = iodev_probe,
  74         .remove         = __devexit_p(iodev_remove),
  75 };
  76
  77
  78
  79 static const struct resource *
  80 iodev_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 /* No hotplugging on the platform bus - use __init */
  92 static int __init iodev_probe(struct platform_device *dev)
  93 {
  94         const struct resource * const ri =
  95                 iodev_get_resource(dev, 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
 106 static int __exit iodev_remove(struct platform_device *dev)
 107 {
 108         return misc_deregister(&miscdev);
 109 }
 110
 111 static int iodev_open(struct inode *i, struct file *f)
 112 {
 113         int ret;
 114
 115         ret = request_irq(iodev_irq, iodev_irqhdl, IRQF_DISABLED,
 116                            iodev_name, &miscdev);
 117
 118         return ret;
 119 }
 120
 121 static int iodev_release(struct inode *i, struct file *f)
 122 {
 123         free_irq(iodev_irq, &miscdev);
 124         return 0;
 125 }
 126
 127
 128
 129
 130 static ssize_t
 131 iodev_read(struct file *f, char __user *d, size_t s, loff_t *o)
 132 {
 133         ssize_t ret;
 134         DEFINE_WAIT(w);
 135
 136         prepare_to_wait(&wq, &w, TASK_INTERRUPTIBLE);
 137         if (!signal_pending(current))
 138                 schedule();
 139         ret = signal_pending(current) ? -ERESTARTSYS : 0;
 140         finish_wait(&wq, &w);
 141         return ret;
 142 }
 143
 144
 145 static unsigned int iodev_poll(struct file *f, struct poll_table_struct *p)
 146 {
 147         poll_wait(f, &wq, p);
 148         return POLLOUT | POLLWRNORM;
 149 }
 150
 151 static irqreturn_t iodev_irqhdl(int irq, void *ctxt)
 152 {
 153         wake_up(&wq);
 154
 155         return IRQ_HANDLED;
 156 }
 157
 158 static int __init iodev_init_module(void)
 159 {
 160         return platform_driver_register(&iodev_driver);
 161 }
 162
 163
 164
 165 static void __exit iodev_cleanup_module(void)
 166 {
 167         platform_driver_unregister(&iodev_driver);
 168 }
 169
 170 module_init(iodev_init_module);
 171 module_exit(iodev_cleanup_module);
 172
 173
 174
 175 MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
 176 MODULE_DESCRIPTION("Basler eXcite i/o interrupt handler");
 177 MODULE_VERSION("0.0");
 178 MODULE_LICENSE("GPL");