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hid-core.c
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hid-core.c
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/*
* HID support for Linux
*
* Copyright (c) 1999 Andreas Gal
* Copyright (c) 2000-2005 Vojtech Pavlik <[email protected]>
* Copyright (c) 2005 Michael Haboustak <[email protected]> for Concept2, Inc
* Copyright (c) 2006-2012 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/sched.h>
#include <linux/semaphore.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
#include <linux/hid-debug.h>
#include <linux/hidraw.h>
#include "hid-ids.h"
/*
* Version Information
*/
#define DRIVER_DESC "HID core driver"
#define DRIVER_LICENSE "GPL"
int hid_debug = 0;
module_param_named(debug, hid_debug, int, 0600);
MODULE_PARM_DESC(debug, "toggle HID debugging messages");
EXPORT_SYMBOL_GPL(hid_debug);
static int hid_ignore_special_drivers = 0;
module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
/*
* Register a new report for a device.
*/
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 (id >= HID_MAX_IDS)
return NULL;
if (report_enum->report_id_hash[id])
return report_enum->report_id_hash[id];
report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
if (!report)
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;
}
EXPORT_SYMBOL_GPL(hid_register_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) {
hid_err(report->device, "too many fields in report\n");
return NULL;
}
field = kzalloc((sizeof(struct hid_field) +
usages * sizeof(struct hid_usage) +
values * sizeof(unsigned)), GFP_KERNEL);
if (!field)
return NULL;
field->index = report->maxfield++;
report->field[field->index] = field;
field->usage = (struct hid_usage *)(field + 1);
field->value = (s32 *)(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) {
hid_err(parser->device, "collection stack overflow\n");
return -EINVAL;
}
if (parser->device->maxcollection == parser->device->collection_size) {
collection = kmalloc(sizeof(struct hid_collection) *
parser->device->collection_size * 2, GFP_KERNEL);
if (collection == NULL) {
hid_err(parser->device, "failed to reallocate collection array\n");
return -ENOMEM;
}
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) {
hid_err(parser->device, "collection stack underflow\n");
return -EINVAL;
}
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)
{
struct hid_collection *collection = parser->device->collection;
int n;
for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
unsigned index = parser->collection_stack[n];
if (collection[index].type == type)
return collection[index].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) {
hid_err(parser->device, "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;
unsigned usages;
unsigned offset;
unsigned i;
report = hid_register_report(parser->device, report_type, parser->global.report_id);
if (!report) {
hid_err(parser->device, "hid_register_report failed\n");
return -1;
}
/* Handle both signed and unsigned cases properly */
if ((parser->global.logical_minimum < 0 &&
parser->global.logical_maximum <
parser->global.logical_minimum) ||
(parser->global.logical_minimum >= 0 &&
(__u32)parser->global.logical_maximum <
(__u32)parser->global.logical_minimum)) {
dbg_hid("logical range invalid 0x%x 0x%x\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(unsigned, parser->local.usage_index,
parser->global.report_count);
field = hid_register_field(report, usages, parser->global.report_count);
if (!field)
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++) {
unsigned 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->usage[i].usage_index = i;
}
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)
{
__s32 raw_value;
switch (item->tag) {
case HID_GLOBAL_ITEM_TAG_PUSH:
if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
hid_err(parser->device, "global environment 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) {
hid_err(parser->device, "global environment 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:
/* Many devices provide unit exponent as a two's complement
* nibble due to the common misunderstanding of HID
* specification 1.11, 6.2.2.7 Global Items. Attempt to handle
* both this and the standard encoding. */
raw_value = item_sdata(item);
if (!(raw_value & 0xfffffff0))
parser->global.unit_exponent = hid_snto32(raw_value, 4);
else
parser->global.unit_exponent = raw_value;
return 0;
case HID_GLOBAL_ITEM_TAG_UNIT:
parser->global.unit = item_udata(item);
return 0;
case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
parser->global.report_size = item_udata(item);
if (parser->global.report_size > 128) {
hid_err(parser->device, "invalid report_size %d\n",
parser->global.report_size);
return -1;
}
return 0;
case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
parser->global.report_count = item_udata(item);
if (parser->global.report_count > HID_MAX_USAGES) {
hid_err(parser->device, "invalid report_count %d\n",
parser->global.report_count);
return -1;
}
return 0;
case HID_GLOBAL_ITEM_TAG_REPORT_ID:
parser->global.report_id = item_udata(item);
if (parser->global.report_id == 0 ||
parser->global.report_id >= HID_MAX_IDS) {
hid_err(parser->device, "report_id %u is invalid\n",
parser->global.report_id);
return -1;
}
return 0;
default:
hid_err(parser->device, "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;
__u32 count;
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) {
hid_err(parser->device, "nested delimiters\n");
return -1;
}
parser->local.delimiter_depth++;
parser->local.delimiter_branch++;
} else {
if (parser->local.delimiter_depth < 1) {
hid_err(parser->device, "bogus close delimiter\n");
return -1;
}
parser->local.delimiter_depth--;
}
return 0;
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;
count = data - parser->local.usage_minimum;
if (count + parser->local.usage_index >= HID_MAX_USAGES) {
/*
* We do not warn if the name is not set, we are
* actually pre-scanning the device.
*/
if (dev_name(&parser->device->dev))
hid_warn(parser->device,
"ignoring exceeding usage max\n");
data = HID_MAX_USAGES - parser->local.usage_index +
parser->local.usage_minimum - 1;
if (data <= 0) {
hid_err(parser->device,
"no more usage index available\n");
return -1;
}
}
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:
hid_err(parser->device, "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;
}
/*
* Process a reserved item.
*/
static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
{
dbg_hid("reserved item type, tag 0x%x\n", item->tag);
return 0;
}
/*
* Free a report and all registered fields. The field->usage and
* field->value table's are allocated behind the field, so we need
* only to free(field) itself.
*/
static void hid_free_report(struct hid_report *report)
{
unsigned n;
for (n = 0; n < report->maxfield; n++)
kfree(report->field[n]);
kfree(report);
}
/*
* Close report. This function returns the device
* state to the point prior to hid_open_report().
*/
static void hid_close_report(struct hid_device *device)
{
unsigned i, j;
for (i = 0; i < HID_REPORT_TYPES; i++) {
struct hid_report_enum *report_enum = device->report_enum + i;
for (j = 0; j < HID_MAX_IDS; j++) {
struct hid_report *report = report_enum->report_id_hash[j];
if (report)
hid_free_report(report);
}
memset(report_enum, 0, sizeof(*report_enum));
INIT_LIST_HEAD(&report_enum->report_list);
}
kfree(device->rdesc);
device->rdesc = NULL;
device->rsize = 0;
kfree(device->collection);
device->collection = NULL;
device->collection_size = 0;
device->maxcollection = 0;
device->maxapplication = 0;
device->status &= ~HID_STAT_PARSED;
}
/*
* Free a device structure, all reports, and all fields.
*/
static void hid_device_release(struct device *dev)
{
struct hid_device *hid = to_hid_device(dev);
hid_close_report(hid);
kfree(hid->dev_rdesc);
kfree(hid);
}
/*
* Fetch a report description item from the data stream. We support long
* items, though they are not used yet.
*/
static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
{
u8 b;
if ((end - start) <= 0)
return NULL;
b = *start++;
item->type = (b >> 2) & 3;
item->tag = (b >> 4) & 15;
if (item->tag == HID_ITEM_TAG_LONG) {
item->format = HID_ITEM_FORMAT_LONG;
if ((end - start) < 2)
return NULL;
item->size = *start++;
item->tag = *start++;
if ((end - start) < item->size)
return NULL;
item->data.longdata = start;
start += item->size;
return start;
}
item->format = HID_ITEM_FORMAT_SHORT;
item->size = b & 3;
switch (item->size) {
case 0:
return start;
case 1:
if ((end - start) < 1)
return NULL;
item->data.u8 = *start++;
return start;
case 2:
if ((end - start) < 2)
return NULL;
item->data.u16 = get_unaligned_le16(start);
start = (__u8 *)((__le16 *)start + 1);
return start;
case 3:
item->size++;
if ((end - start) < 4)
return NULL;
item->data.u32 = get_unaligned_le32(start);
start = (__u8 *)((__le32 *)start + 1);
return start;
}
return NULL;
}
static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
{
struct hid_device *hid = parser->device;
if (usage == HID_DG_CONTACTID)
hid->group = HID_GROUP_MULTITOUCH;
}
static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
{
if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
parser->global.report_size == 8)
parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
}
static void hid_scan_collection(struct hid_parser *parser, unsigned type)
{
struct hid_device *hid = parser->device;
int i;
if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
type == HID_COLLECTION_PHYSICAL)
hid->group = HID_GROUP_SENSOR_HUB;
if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
(hid->product == USB_DEVICE_ID_MS_TYPE_COVER_PRO_3 ||
hid->product == USB_DEVICE_ID_MS_TYPE_COVER_PRO_3_2 ||
hid->product == USB_DEVICE_ID_MS_TYPE_COVER_PRO_3_JP ||
hid->product == USB_DEVICE_ID_MS_TYPE_COVER_PRO_4_JP ||
hid->product == USB_DEVICE_ID_MS_TYPE_COVER_3 ||
hid->product == USB_DEVICE_ID_MS_POWER_COVER) &&
hid->group == HID_GROUP_MULTITOUCH)
hid->group = HID_GROUP_GENERIC;
if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
for (i = 0; i < parser->local.usage_index; i++)
if (parser->local.usage[i] == HID_GD_POINTER)
parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
}
static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
{
__u32 data;
int i;
data = item_udata(item);
switch (item->tag) {
case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
hid_scan_collection(parser, data & 0xff);
break;
case HID_MAIN_ITEM_TAG_END_COLLECTION:
break;
case HID_MAIN_ITEM_TAG_INPUT:
/* ignore constant inputs, they will be ignored by hid-input */
if (data & HID_MAIN_ITEM_CONSTANT)
break;
for (i = 0; i < parser->local.usage_index; i++)
hid_scan_input_usage(parser, parser->local.usage[i]);
break;
case HID_MAIN_ITEM_TAG_OUTPUT:
break;
case HID_MAIN_ITEM_TAG_FEATURE:
for (i = 0; i < parser->local.usage_index; i++)
hid_scan_feature_usage(parser, parser->local.usage[i]);
break;
}
/* Reset the local parser environment */
memset(&parser->local, 0, sizeof(parser->local));
return 0;
}
/*
* Scan a report descriptor before the device is added to the bus.
* Sets device groups and other properties that determine what driver
* to load.
*/
static int hid_scan_report(struct hid_device *hid)
{
struct hid_parser *parser;
struct hid_item item;
__u8 *start = hid->dev_rdesc;
__u8 *end = start + hid->dev_rsize;
static int (*dispatch_type[])(struct hid_parser *parser,
struct hid_item *item) = {
hid_scan_main,
hid_parser_global,
hid_parser_local,
hid_parser_reserved
};
parser = vzalloc(sizeof(struct hid_parser));
if (!parser)
return -ENOMEM;
parser->device = hid;
hid->group = HID_GROUP_GENERIC;
/*
* The parsing is simpler than the one in hid_open_report() as we should
* be robust against hid errors. Those errors will be raised by
* hid_open_report() anyway.
*/
while ((start = fetch_item(start, end, &item)) != NULL)
dispatch_type[item.type](parser, &item);
/*
* Handle special flags set during scanning.
*/
if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
(hid->group == HID_GROUP_MULTITOUCH))
hid->group = HID_GROUP_MULTITOUCH_WIN_8;
/*
* Vendor specific handlings
*/
switch (hid->vendor) {
case USB_VENDOR_ID_WACOM:
hid->group = HID_GROUP_WACOM;
break;
case USB_VENDOR_ID_SYNAPTICS:
if (hid->group == HID_GROUP_GENERIC)
if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
&& (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
/*
* hid-rmi should take care of them,
* not hid-generic
*/
hid->group = HID_GROUP_RMI;
break;
}
vfree(parser);
return 0;
}
/**
* hid_parse_report - parse device report
*
* @device: hid device
* @start: report start
* @size: report size
*
* Allocate the device report as read by the bus driver. This function should
* only be called from parse() in ll drivers.
*/
int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
{
hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
if (!hid->dev_rdesc)
return -ENOMEM;
hid->dev_rsize = size;
return 0;
}
EXPORT_SYMBOL_GPL(hid_parse_report);
static const char * const hid_report_names[] = {
"HID_INPUT_REPORT",
"HID_OUTPUT_REPORT",
"HID_FEATURE_REPORT",
};
/**
* hid_validate_values - validate existing device report's value indexes
*
* @device: hid device
* @type: which report type to examine
* @id: which report ID to examine (0 for first)
* @field_index: which report field to examine
* @report_counts: expected number of values
*
* Validate the number of values in a given field of a given report, after
* parsing.
*/
struct hid_report *hid_validate_values(struct hid_device *hid,
unsigned int type, unsigned int id,
unsigned int field_index,
unsigned int report_counts)
{
struct hid_report *report;
if (type > HID_FEATURE_REPORT) {
hid_err(hid, "invalid HID report type %u\n", type);
return NULL;
}
if (id >= HID_MAX_IDS) {
hid_err(hid, "invalid HID report id %u\n", id);
return NULL;
}
/*
* Explicitly not using hid_get_report() here since it depends on
* ->numbered being checked, which may not always be the case when
* drivers go to access report values.
*/
if (id == 0) {
/*
* Validating on id 0 means we should examine the first
* report in the list.
*/
report = list_entry(
hid->report_enum[type].report_list.next,
struct hid_report, list);
} else {
report = hid->report_enum[type].report_id_hash[id];
}
if (!report) {
hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
return NULL;
}
if (report->maxfield <= field_index) {
hid_err(hid, "not enough fields in %s %u\n",
hid_report_names[type], id);
return NULL;
}
if (report->field[field_index]->report_count < report_counts) {
hid_err(hid, "not enough values in %s %u field %u\n",
hid_report_names[type], id, field_index);
return NULL;
}
return report;
}
EXPORT_SYMBOL_GPL(hid_validate_values);
/**
* hid_open_report - open a driver-specific device report
*
* @device: hid device
*
* Parse a report description into a hid_device structure. Reports are
* enumerated, fields are attached to these reports.
* 0 returned on success, otherwise nonzero error value.
*
* This function (or the equivalent hid_parse() macro) should only be
* called from probe() in drivers, before starting the device.
*/
int hid_open_report(struct hid_device *device)
{
struct hid_parser *parser;
struct hid_item item;
unsigned int size;
__u8 *start;
__u8 *buf;
__u8 *end;
int ret;
static int (*dispatch_type[])(struct hid_parser *parser,
struct hid_item *item) = {
hid_parser_main,
hid_parser_global,
hid_parser_local,
hid_parser_reserved
};
if (WARN_ON(device->status & HID_STAT_PARSED))
return -EBUSY;
start = device->dev_rdesc;
if (WARN_ON(!start))
return -ENODEV;
size = device->dev_rsize;
buf = kmemdup(start, size, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
if (device->driver->report_fixup)
start = device->driver->report_fixup(device, buf, &size);
else
start = buf;
start = kmemdup(start, size, GFP_KERNEL);
kfree(buf);
if (start == NULL)
return -ENOMEM;
device->rdesc = start;
device->rsize = size;
parser = vzalloc(sizeof(struct hid_parser));
if (!parser) {
ret = -ENOMEM;
goto err;
}
parser->device = device;
end = start + size;
device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
sizeof(struct hid_collection), GFP_KERNEL);
if (!device->collection) {
ret = -ENOMEM;
goto err;
}