path: root/drivers/staging/comedi/drivers.c

/*
    module/drivers.c
    functions for manipulating drivers

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#define _GNU_SOURCE

#define __NO_VERSION__
#include "comedi_fops.h"
#include <linux/device.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/highmem.h>	/* for SuSE brokenness */
#include <linux/vmalloc.h>
#include <linux/cdev.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <asm/system.h>

#include "comedidev.h"
#include "internal.h"

static int postconfig(struct comedi_device *dev);
static int insn_rw_emulate_bits(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_insn *insn, unsigned int *data);
static void *comedi_recognize(struct comedi_driver *driv, const char *name);
static void comedi_report_boards(struct comedi_driver *driv);
static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s);

struct comedi_driver *comedi_drivers;

static void cleanup_device(struct comedi_device *dev)
{
	int i;
	struct comedi_subdevice *s;

	if (dev->subdevices) {
		for (i = 0; i < dev->n_subdevices; i++) {
			s = dev->subdevices + i;
			comedi_free_subdevice_minor(s);
			if (s->async) {
				comedi_buf_alloc(dev, s, 0);
				kfree(s->async);
			}
		}
		kfree(dev->subdevices);
		dev->subdevices = NULL;
		dev->n_subdevices = 0;
	}
	kfree(dev->private);
	dev->private = NULL;
	dev->driver = NULL;
	dev->board_name = NULL;
	dev->board_ptr = NULL;
	dev->iobase = 0;
	dev->irq = 0;
	dev->read_subdev = NULL;
	dev->write_subdev = NULL;
	dev->open = NULL;
	dev->close = NULL;
	comedi_set_hw_dev(dev, NULL);
}

static void __comedi_device_detach(struct comedi_device *dev)
{
	dev->attached = 0;
	if (dev->driver)
		dev->driver->detach(dev);
	else
		printk(KERN_WARNING
		       "BUG: dev->driver=NULL in comedi_device_detach()\n");
	cleanup_device(dev);
}

void comedi_device_detach(struct comedi_device *dev)
{
	if (!dev->attached)
		return;
	__comedi_device_detach(dev);
}

int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
	struct comedi_driver *driv;
	int ret;

	if (dev->attached)
		return -EBUSY;

	for (driv = comedi_drivers; driv; driv = driv->next) {
		if (!try_module_get(driv->module)) {
			printk(KERN_INFO "comedi: failed to increment module count, skipping\n");
			continue;
		}
		if (driv->num_names) {
			dev->board_ptr = comedi_recognize(driv, it->board_name);
			if (dev->board_ptr == NULL) {
				module_put(driv->module);
				continue;
			}
		} else {
			if (strcmp(driv->driver_name, it->board_name)) {
				module_put(driv->module);
				continue;
			}
		}
		/* initialize dev->driver here so
		 * comedi_error() can be called from attach */
		dev->driver = driv;
		ret = driv->attach(dev, it);
		if (ret < 0) {
			module_put(dev->driver->module);
			__comedi_device_detach(dev);
			return ret;
		}
		goto attached;
	}

	/*  recognize has failed if we get here */
	/*  report valid board names before returning error */
	for (driv = comedi_drivers; driv; driv = driv->next) {
		if (!try_module_get(driv->module)) {
			printk(KERN_INFO
			       "comedi: failed to increment module count\n");
			continue;
		}
		comedi_report_boards(driv);
		module_put(driv->module);
	}
	return -EIO;

attached:
	/* do a little post-config cleanup */
	ret = postconfig(dev);
	module_put(dev->driver->module);
	if (ret < 0) {
		__comedi_device_detach(dev);
		return ret;
	}

	if (!dev->board_name) {
		printk(KERN_WARNING "BUG: dev->board_name=<%p>\n",
		       dev->board_name);
		dev->board_n