path: root/drivers/hid/usbhid/hiddev.c

/*
 *  Copyright (c) 2001 Paul Stewart
 *  Copyright (c) 2001 Vojtech Pavlik
 *
 *  HID char devices, giving access to raw HID device events.
 *
 */

/*
 * 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
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
 */

#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
#include <linux/compat.h>
#include "usbhid.h"

#ifdef CONFIG_USB_DYNAMIC_MINORS
#define HIDDEV_MINOR_BASE	0
#define HIDDEV_MINORS		256
#else
#define HIDDEV_MINOR_BASE	96
#define HIDDEV_MINORS		16
#endif
#define HIDDEV_BUFFER_SIZE	2048

struct hiddev {
	int exist;
	int open;
	struct mutex existancelock;
	wait_queue_head_t wait;
	struct hid_device *hid;
	struct list_head list;
	spinlock_t list_lock;
};

struct hiddev_list {
	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
	int head;
	int tail;
	unsigned flags;
	struct fasync_struct *fasync;
	struct hiddev *hiddev;
	struct list_head node;
	struct mutex thread_lock;
};

static struct usb_driver hiddev_driver;

/*
 * Find a report, given the report's type and ID.  The ID can be specified
 * indirectly by REPORT_ID_FIRST (which returns the first report of the given
 * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
 * given type which follows old_id.
 */
static struct hid_report *
hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
{
	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
	struct hid_report_enum *report_enum;
	struct hid_report *report;
	struct list_head *list;

	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
	    rinfo->report_type > HID_REPORT_TYPE_MAX)
		return NULL;

	report_enum = hid->report_enum +
		(rinfo->report_type - HID_REPORT_TYPE_MIN);

	switch (flags) {
	case 0: /* Nothing to do -- report_id is already set correctly */
		break;

	case HID_REPORT_ID_FIRST:
		if (list_empty(&report_enum->report_list))
			return NULL;

		list = report_enum->report_list.next;
		report = list_entry(list, struct hid_report, list);
		rinfo->report_id = report->id;
		break;

	case HID_REPORT_ID_NEXT:
		report = report_enum->report_id_hash[rid];
		if (!report)
			return NULL;

		list = report->list.next;
		if (list == &report_enum->report_list)
			return NULL;

		report = list_entry(list, struct hid_report, list);
		rinfo->report_id = report->id;
		break;

	default:
		return NULL;
	}

	return report_enum->report_id_hash[rinfo->report_id];
}

/*
 * Perform an exhaustive search of the report table for a usage, given its
 * type and usage id.
 */
static struct hid_field *
hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
{
	int i, j;
	struct hid_report *report;
	struct hid_report_enum *report_enum;
	struct hid_field *field;

	if (uref->report_type < HID_REPORT_TYPE_MIN ||
	    uref->report_type > HID_REPORT_TYPE_MAX)
		return NULL;

	report_enum = hid->report_enum +
		(uref->report_type - HID_REPORT_TYPE_MIN);

	list_for_each_entry(report, &report_enum->report_list, list) {
		for (i = 0; i < report->maxfield; i++) {
			field = report->field[i];
			for (j = 0; j < field->maxusage; j++) {
				if (field->usage[j].hid == uref->usage_code) {
					uref->report_id = report->id;
					uref->field_index = i;
					uref->usage_index = j;
					return field;
				}
			}
		}
	}

	return NULL;
}

static void hiddev_send_event(struct hid_device *hid,
			      struct hiddev_usage_ref *uref)
{
	struct hiddev *hiddev = hid->hiddev;
	struct hiddev_list *list;
	unsigned long flags;

	spin_lock_irqsave(&hiddev->list_lock, flags);
	list_for_each_entry(list, &hiddev->list, node) {