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>
    Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>

    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.
*/

#include <linux/device.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fcntl.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 <linux/interrupt.h>
#include <linux/firmware.h>

#include "comedidev.h"
#include "comedi_internal.h"

struct comedi_driver *comedi_drivers;
/* protects access to comedi_drivers */
DEFINE_MUTEX(comedi_drivers_list_lock);

int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
{
	if (hw_dev == dev->hw_dev)
		return 0;
	if (dev->hw_dev)
		return -EEXIST;
	dev->hw_dev = get_device(hw_dev);
	return 0;
}
EXPORT_SYMBOL_GPL(comedi_set_hw_dev);

static void comedi_clear_hw_dev(struct comedi_device *dev)
{
	put_device(dev->hw_dev);
	dev->hw_dev = NULL;
}

/**
 * comedi_alloc_devpriv() - Allocate memory for the device private data.
 * @dev: comedi_device struct
 * @size: size of the memory to allocate
 */
void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
{
	dev->private = kzalloc(size, GFP_KERNEL);
	return dev->private;
}
EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);

int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
{
	struct comedi_subdevice *s;
	int i;

	if (num_subdevices < 1)
		return -EINVAL;

	s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
	if (!s)
		return -ENOMEM;
	dev->subdevices = s;
	dev->n_subdevices = num_subdevices;

	for (i = 0; i < num_subdevices; ++i) {
		s = &dev->subdevices[i];
		s->device = dev;
		s->index = i;
		s->async_dma_dir = DMA_NONE;
		spin_lock_init(&s->spin_lock);
		s->minor = -1;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);

/**
 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback.
 * @s: comedi_subdevice struct
 */
int comedi_alloc_subdev_readback(struct comedi_subdevice *s)
{
	if (!s->n_chan)
		return -EINVAL;

	s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL);
	if (!s->readback)
		return -ENOMEM;

	if (!s->insn_read)
		s->insn_read = comedi_readback_insn_read;

	return 0;
}
EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback);

static void comedi_device_detach_cleanup(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];
			if (comedi_can_auto_free_spriv(s))
				kfree(s->private);
			comedi_free_subdevice_minor(s);
			if (s->async) {
				comedi_buf_alloc(dev, s, 0);
				kfree(s->async);
			}
			kfree(s->readback);
		}
		kfree(dev->subdevices);
		dev->subdevices = NULL;
		dev->n_subdevices = 0;
	}
	kfree(dev->private);
	kfree(dev->pacer);
	dev->private = NULL;
	dev->pacer = NULL;
	dev->driver = NULL;
	dev->board_name = NULL;
	dev->board_ptr = NULL;
	dev->mmio = NULL;
	dev->iobase = 0;
	dev->iolen = 0;
	dev->ioenabled = false;
	dev->irq = 0;
	dev->read_subdev = NULL;
	dev->write_subdev = NULL;
	dev->open = NULL;
	dev->close = NULL;
	comedi_clear_hw_dev(dev);
}

void comedi_device_detach(struct comedi_device *dev)
{
	comedi_device_cancel_all