hid-core.c

linux-2.6.15.6

/*
 *  USB HID support for Linux
 *
 *  Copyright (c) 1999 Andreas Gal
 *  Copyright (c) 2000-2005 Vojtech Pavlik <[e-mail]>
 *  Copyright (c) 2005 Michael Haboustak <[e-mail]> for Concept2, Inc
 */

/*
 * 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.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>
#include <linux/input.h>
#include <linux/wait.h>

#undef DEBUG
#undef DEBUG_DATA

#include <linux/usb.h>

#include "hid.h"
#include <linux/hiddev.h>

/*
 * Version Information
 */

#define DRIVER_VERSION "v2.6"
#define DRIVER_AUTHOR "Andreas Gal, Vojtech Pavlik"
#define DRIVER_DESC "USB HID core driver"
#define DRIVER_LICENSE "GPL"

static char *hid_types[] = {"Device", "Pointer", "Mouse", "Device", "Joystick",
				"Gamepad", "Keyboard", "Keypad", "Multi-Axis Controller"};
/*
 * Module parameters.
 */

static unsigned int hid_mousepoll_interval;
module_param_named(mousepoll, hid_mousepoll_interval, uint, 0644);
MODULE_PARM_DESC(mousepoll, "Polling interval of mice");

/*
 * Register a new report for a device.
 */

static struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id)
{
	struct hid_report_enum *report_enum = device->report_enum + type;
	struct hid_report *report;

	if (report_enum->report_id_hash[id])
		return report_enum->report_id_hash[id];

	if (!(report = kmalloc(sizeof(struct hid_report), GFP_KERNEL)))
		return NULL;
	memset(report, 0, sizeof(struct hid_report));

	if (id != 0)
		report_enum->numbered = 1;

	report->id = id;
	report->type = type;
	report->size = 0;
	report->device = device;
	report_enum->report_id_hash[id] = report;

	list_add_tail(&report->list, &report_enum->report_list);

	return report;
}

/*
 * Register a new field for this report.
 */

static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
{
	struct hid_field *field;

	if (report->maxfield == HID_MAX_FIELDS) {
		dbg("too many fields in report");
		return NULL;
	}

	if (!(field = kmalloc(sizeof(struct hid_field) + usages * sizeof(struct hid_usage)
		+ values * sizeof(unsigned), GFP_KERNEL))) return NULL;

	memset(field, 0, sizeof(struct hid_field) + usages * sizeof(struct hid_usage)
		+ values * sizeof(unsigned));

	field->index = report->maxfield++;
	report->field[field->index] = field;
	field->usage = (struct hid_usage *)(field + 1);
	field->value = (unsigned *)(field->usage + usages);
	field->report = report;

	return field;
}

/*
 * Open a collection. The type/usage is pushed on the stack.
 */

static int open_collection(struct hid_parser *parser, unsigned type)
{
	struct hid_collection *collection;
	unsigned usage;

	usage = parser->local.usage[0];

	if (parser->collection_stack_ptr == HID_COLLECTION_STACK_SIZE) {
		dbg("collection stack overflow");
		return -1;
	}

	if (parser->device->maxcollection == parser->device->collection_size) {
		collection = kmalloc(sizeof(struct hid_collection) *
				parser->device->collection_size * 2, GFP_KERNEL);
		if (collection == NULL) {
			dbg("failed to reallocate collection array");
			return -1;
		}
		memcpy(collection, parser->device->collection,
			sizeof(struct hid_collection) *
			parser->device->collection_size);
		memset(collection + parser->device->collection_size, 0,
			sizeof(struct hid_collection) *
			parser->device->collection_size);
		kfree(parser->device->collection);
		parser->device->collection = collection;
		parser->device->collection_size *= 2;
	}

	parser->collection_stack[parser->collection_stack_ptr++] =
		parser->device->maxcollection;

	collection = parser->device->collection +
		parser->device->maxcollection++;
	collection->type = type;
	collection->usage = usage;
	collection->level = parser->collection_stack_ptr - 1;

	if (type == HID_COLLECTION_APPLICATION)
		parser->device->maxapplication++;

	return 0;
}

/*
 * Close a collection.
 */

static int close_collection(struct hid_parser *parser)
{
	if (!parser->collection_stack_ptr) {
		dbg("collection stack underflow");
		return -1;
	}
	parser->collection_stack_ptr--;
	return 0;
}

/*
 * Climb up the stack, search for the specified collection type
 * and return the usage.
 */

static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
{
	int n;
	for (n = parser->collection_stack_ptr - 1; n >= 0; n--)
		if (parser->device->collection[parser->collection_stack[n]].type == type)
			return parser->device->collection[parser->collection_stack[n]].usage;
	return 0; /* we know nothing about this usage type */
}

/*
 * Add a usage to the temporary parser table.
 */

static int hid_add_usage(struct hid_parser *parser, unsigned usage)
{
	if (parser->local.usage_index >= HID_MAX_USAGES) {
		dbg("usage index exceeded");
		return -1;
	}
	parser->local.usage[parser->local.usage_index] = usage;
	parser->local.collection_index[parser->local.usage_index] =
		parser->collection_stack_ptr ?
		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
	parser->local.usage_index++;
	return 0;
}

/*
 * Register a new field for this report.
 */

static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
{
	struct hid_report *report;
	struct hid_field *field;
	int usages;
	unsigned offset;
	int i;

	if (!(report = hid_register_report(parser->device, report_type, parser->global.report_id))) {
		dbg("hid_register_report failed");
		return -1;
	}

	if (parser->global.logical_maximum < parser->global.logical_minimum) {
		dbg("logical range invalid %d %d", parser->global.logical_minimum, parser->global.logical_maximum);
		return -1;
	}

	offset = report->size;
	report->size += parser->global.report_size * parser->global.report_count;

	if (!parser->local.usage_index) /* Ignore padding fields */
		return 0;

	usages = max_t(int, parser->local.usage_index, parser->global.report_count);

	if ((field = hid_register_field(report, usages, parser->global.report_count)) == NULL)
		return 0;

	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
	field->application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);

	for (i = 0; i < usages; i++) {
		int j = i;
		/* Duplicate the last usage we parsed if we have excess values */
		if (i >= parser->local.usage_index)
			j = parser->local.usage_index - 1;
		field->usage[i].hid = parser->local.usage[j];
		field->usage[i].collection_index =
			parser->local.collection_index[j];
	}

	field->maxusage = usages;
	field->flags = flags;
	field->report_offset = offset;
	field->report_type = report_type;
	field->report_size = parser->global.report_size;
	field->report_count = parser->global.report_count;
	field->logical_minimum = parser->global.logical_minimum;
	field->logical_maximum = parser->global.logical_maximum;
	field->physical_minimum = parser->global.physical_minimum;
	field->physical_maximum = parser->global.physical_maximum;
	field->unit_exponent = parser->global.unit_exponent;
	field->unit = parser->global.unit;

	return 0;
}

/*
 * Read data value from item.
 */

static __inline__ __u32 item_udata(struct hid_item *item)
{
	switch (item->size) {
		case 1: return item->data.u8;
		case 2: return item->data.u16;
		case 4: return item->data.u32;
	}
	return 0;
}

static __inline__ __s32 item_sdata(struct hid_item *item)
{
	switch (item->size) {
		case 1: return item->data.s8;
		case 2: return item->data.s16;
		case 4: return item->data.s32;
	}
	return 0;
}

/*
 * Process a global item.
 */

static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
{
	switch (item->tag) {

		case HID_GLOBAL_ITEM_TAG_PUSH:

			if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
				dbg("global enviroment stack overflow");
				return -1;
			}

			memcpy(parser->global_stack + parser->global_stack_ptr++,
				&parser->global, sizeof(struct hid_global));
			return 0;

		case HID_GLOBAL_ITEM_TAG_POP:

			if (!parser->global_stack_ptr) {
				dbg("global enviroment stack underflow");
				return -1;
			}

			memcpy(&parser->global, parser->global_stack + --parser->global_stack_ptr,
				sizeof(struct hid_global));
			return 0;

		case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
			parser->global.usage_page = item_udata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
			parser->global.logical_minimum = item_sdata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
			if (parser->global.logical_minimum < 0)
				parser->global.logical_maximum = item_sdata(item);
			else
				parser->global.logical_maximum = item_udata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
			parser->global.physical_minimum = item_sdata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
			if (parser->global.physical_minimum < 0)
				parser->global.physical_maximum = item_sdata(item);
			else
				parser->global.physical_maximum = item_udata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
			parser->global.unit_exponent = item_sdata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_UNIT:
			parser->global.unit = item_udata(item);
			return 0;

		case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
			if ((parser->global.report_size = item_udata(item)) > 32) {
				dbg("invalid report_size %d", parser->global.report_size);
				return -1;
			}
			return 0;

		case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
			if ((parser->global.report_count = item_udata(item)) > HID_MAX_USAGES) {
				dbg("invalid report_count %d", parser->global.report_count);
				return -1;
			}
			return 0;

		case HID_GLOBAL_ITEM_TAG_REPORT_ID:
			if ((parser->global.report_id = item_udata(item)) == 0) {
				dbg("report_id 0 is invalid");
				return -1;
			}
			return 0;

		default:
			dbg("unknown global tag 0x%x", item->tag);
			return -1;
	}
}

/*
 * Process a local item.
 */

static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
{
	__u32 data;
	unsigned n;

	if (item->size == 0) {
		dbg("item data expected for local item");
		return -1;
	}

	data = item_udata(item);

	switch (item->tag) {

		case HID_LOCAL_ITEM_TAG_DELIMITER:

			if (data) {
				/*
				 * We treat items before the first delimiter
				 * as global to all usage sets (branch 0).
				 * In the moment we process only these global
				 * items and the first delimiter set.
				 */
				if (parser->local.delimiter_depth != 0) {
					dbg("nested delimiters");
					return -1;
				}
				parser->local.delimiter_depth++;
				parser->local.delimiter_branch++;
			} else {
				if (parser->local.delimiter_depth < 1) {
					dbg("bogus close delimiter");
					return -1;
				}
				parser->local.delimiter_depth--;
			}
			return 1;

		case HID_LOCAL_ITEM_TAG_USAGE:

			if (parser->local.delimiter_branch > 1) {
				dbg("alternative usage ignored");
				return 0;
			}

			if (item->size <= 2)
				data = (parser->global.usage_page << 16) + data;

			return hid_add_usage(parser, data);

		case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:

			if (parser->local.delimiter_branch > 1) {
				dbg("alternative usage ignored");
				return 0;
			}

			if (item->size <= 2)
				data = (parser->global.usage_page << 16) + data;

			parser->local.usage_minimum = data;
			return 0;

		case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:

			if (parser->local.delimiter_branch > 1) {
				dbg("alternative usage ignored");
				return 0;
			}

			if (item->size <= 2)
				data = (parser->global.usage_page << 16) + data;

			for (n = parser->local.usage_minimum; n <= data; n++)
				if (hid_add_usage(parser, n)) {
					dbg("hid_add_usage failed\n");
					return -1;
				}
			return 0;

		default:

			dbg("unknown local item tag 0x%x", item->tag);
			return 0;
	}
	return 0;
}

/*
 * Process a main item.
 */

static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
{
	__u32 data;
	int ret;

	data = item_udata(item);

	switch (item->tag) {
		case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
			ret = open_collection(parser, data & 0xff);