/* *  HID support for Linux * *  Copyright (c) 1999 Andreas Gal *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz> *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc *  Copyright (c) 2006-2007 Jiri Kosina *//* * 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/list.h>#include <linux/mm.h>#include <linux/spinlock.h>#include <asm/unaligned.h>#include <asm/byteorder.h>#include <linux/input.h>#include <linux/wait.h>#include <linux/vmalloc.h>#include <linux/hid.h>#include <linux/hiddev.h>#include <linux/hid-debug.h>#include <linux/hidraw.h>/* * Version Information */#define DRIVER_VERSION "v2.6"#define DRIVER_AUTHOR "Andreas Gal, Vojtech Pavlik, Jiri Kosina"#define DRIVER_DESC "HID core driver"#define DRIVER_LICENSE "GPL"#ifdef CONFIG_HID_DEBUGint hid_debug = 0;module_param_named(debug, hid_debug, bool, 0600);MODULE_PARM_DESC(debug, "Turn HID debugging mode on and off");EXPORT_SYMBOL_GPL(hid_debug);#endif/* * 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 = kzalloc(sizeof(struct hid_report), GFP_KERNEL)))		return NULL;	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_hid("too many fields in report\n");		return NULL;	}	if (!(field = kzalloc(sizeof(struct hid_field) + usages * sizeof(struct hid_usage)		+ values * sizeof(unsigned), GFP_KERNEL))) return NULL;	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_hid("collection stack overflow\n");		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_hid("failed to reallocate collection array\n");			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_hid("collection stack underflow\n");		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_hid("usage index exceeded\n");		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("hid_register_report failed\n");		return -1;	}	if (parser->global.logical_maximum < parser->global.logical_minimum) {		dbg_hid("logical range invalid %d %d\n", 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 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 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_hid("global enviroment stack overflow\n");				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_hid("global enviroment stack underflow\n");				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_hid("invalid report_size %d\n", 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_hid("invalid report_count %d\n", 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_hid("report_id 0 is invalid\n");				return -1;			}			return 0;		default:			dbg_hid("unknown global tag 0x%x\n", 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_hid("item data expected for local item\n");		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_hid("nested delimiters\n");					return -1;				}				parser->local.delimiter_depth++;				parser->local.delimiter_branch++;			} else {				if (parser->local.delimiter_depth < 1) {					dbg_hid("bogus close delimiter\n");					return -1;				}				parser->local.delimiter_depth--;			}			return 1;		case HID_LOCAL_ITEM_TAG_USAGE:			if (parser->local.delimiter_branch > 1) {				dbg_hid("alternative usage ignored\n");				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_hid("alternative usage ignored\n");				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_hid("alternative usage ignored\n");				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("hid_add_usage failed\n");					return -1;				}			return 0;		default:			dbg_hid("unknown local item tag 0x%x\n", 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);			break;		case HID_MAIN_ITEM_TAG_END_COLLECTION:			ret = close_collection(parser);			break;		case HID_MAIN_ITEM_TAG_INPUT:			ret = hid_add_field(parser, HID_INPUT_REPORT, data);			break;		case HID_MAIN_ITEM_TAG_OUTPUT:			ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);			break;		case HID_MAIN_ITEM_TAG_FEATURE:			ret = hid_add_field(parser, HID_FEATURE_REPORT, data);			break;		default:			dbg_hid("unknown main item tag 0x%x\n", item->tag);			ret = 0;	}	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */	return ret;}