[PATCH] Generic HID layer - code split
The "big main" split of USB HID code into generic HID code and
USB-transport specific HID handling.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
new file mode 100644
index 0000000..689ae16
--- /dev/null
+++ b/drivers/hid/hid-core.c
@@ -0,0 +1,940 @@
+/*
+ * USB 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 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/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 <linux/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"
+
+/*
+ * 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 = 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("too many fields in report");
+ 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("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 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("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);
+ 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("unknown main item tag 0x%x", 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("reserved item type, tag 0x%x", 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);
+}
+
+/*
+ * Free a device structure, all reports, and all fields.
+ */
+
+static void hid_free_device(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 < 256; j++) {
+ struct hid_report *report = report_enum->report_id_hash[j];
+ if (report)
+ hid_free_report(report);
+ }
+ }
+
+ kfree(device->rdesc);
+ kfree(device);
+}
+
+/*
+ * 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 = le16_to_cpu(get_unaligned((__le16*)start));
+ start = (__u8 *)((__le16 *)start + 1);
+ return start;
+
+ case 3:
+ item->size++;
+ if ((end - start) < 4)
+ return NULL;
+ item->data.u32 = le32_to_cpu(get_unaligned((__le32*)start));
+ start = (__u8 *)((__le32 *)start + 1);
+ return start;
+ }
+
+ return NULL;
+}
+
+/*
+ * Parse a report description into a hid_device structure. Reports are
+ * enumerated, fields are attached to these reports.
+ */
+
+static struct hid_device *hid_parse_report(__u8 *start, unsigned size)
+{
+ struct hid_device *device;
+ struct hid_parser *parser;
+ struct hid_item item;
+ __u8 *end;
+ unsigned i;
+ 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 (!(device = kzalloc(sizeof(struct hid_device), GFP_KERNEL)))
+ return NULL;
+
+ if (!(device->collection = kzalloc(sizeof(struct hid_collection) *
+ HID_DEFAULT_NUM_COLLECTIONS, GFP_KERNEL))) {
+ kfree(device);
+ return NULL;
+ }
+ device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
+
+ for (i = 0; i < HID_REPORT_TYPES; i++)
+ INIT_LIST_HEAD(&device->report_enum[i].report_list);
+
+ if (!(device->rdesc = (__u8 *)kmalloc(size, GFP_KERNEL))) {
+ kfree(device->collection);
+ kfree(device);
+ return NULL;
+ }
+ memcpy(device->rdesc, start, size);
+ device->rsize = size;
+
+ if (!(parser = kzalloc(sizeof(struct hid_parser), GFP_KERNEL))) {
+ kfree(device->rdesc);
+ kfree(device->collection);
+ kfree(device);
+ return NULL;
+ }
+ parser->device = device;
+
+ end = start + size;
+ while ((start = fetch_item(start, end, &item)) != NULL) {
+
+ if (item.format != HID_ITEM_FORMAT_SHORT) {
+ dbg("unexpected long global item");
+ kfree(device->collection);
+ hid_free_device(device);
+ kfree(parser);
+ return NULL;
+ }
+
+ if (dispatch_type[item.type](parser, &item)) {
+ dbg("item %u %u %u %u parsing failed\n",
+ item.format, (unsigned)item.size, (unsigned)item.type, (unsigned)item.tag);
+ kfree(device->collection);
+ hid_free_device(device);
+ kfree(parser);
+ return NULL;
+ }
+
+ if (start == end) {
+ if (parser->collection_stack_ptr) {
+ dbg("unbalanced collection at end of report description");
+ kfree(device->collection);
+ hid_free_device(device);
+ kfree(parser);
+ return NULL;
+ }
+ if (parser->local.delimiter_depth) {
+ dbg("unbalanced delimiter at end of report description");
+ kfree(device->collection);
+ hid_free_device(device);
+ kfree(parser);
+ return NULL;
+ }
+ kfree(parser);
+ return device;
+ }
+ }
+
+ dbg("item fetching failed at offset %d\n", (int)(end - start));
+ kfree(device->collection);
+ hid_free_device(device);
+ kfree(parser);
+ return NULL;
+}
+
+/*
+ * Convert a signed n-bit integer to signed 32-bit integer. Common
+ * cases are done through the compiler, the screwed things has to be
+ * done by hand.
+ */
+
+static s32 snto32(__u32 value, unsigned n)
+{
+ switch (n) {
+ case 8: return ((__s8)value);
+ case 16: return ((__s16)value);
+ case 32: return ((__s32)value);
+ }
+ return value & (1 << (n - 1)) ? value | (-1 << n) : value;
+}
+
+/*
+ * Convert a signed 32-bit integer to a signed n-bit integer.
+ */
+
+static u32 s32ton(__s32 value, unsigned n)
+{
+ s32 a = value >> (n - 1);
+ if (a && a != -1)
+ return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
+ return value & ((1 << n) - 1);
+}
+
+/*
+ * Extract/implement a data field from/to a little endian report (bit array).
+ *
+ * Code sort-of follows HID spec:
+ * http://www.usb.org/developers/devclass_docs/HID1_11.pdf
+ *
+ * While the USB HID spec allows unlimited length bit fields in "report
+ * descriptors", most devices never use more than 16 bits.
+ * One model of UPS is claimed to report "LINEV" as a 32-bit field.
+ * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
+ */
+
+static __inline__ __u32 extract(__u8 *report, unsigned offset, unsigned n)
+{
+ u64 x;
+
+ WARN_ON(n > 32);
+
+ report += offset >> 3; /* adjust byte index */
+ offset &= 7; /* now only need bit offset into one byte */
+ x = get_unaligned((u64 *) report);
+ x = le64_to_cpu(x);
+ x = (x >> offset) & ((1ULL << n) - 1); /* extract bit field */
+ return (u32) x;
+}
+
+/*
+ * "implement" : set bits in a little endian bit stream.
+ * Same concepts as "extract" (see comments above).
+ * The data mangled in the bit stream remains in little endian
+ * order the whole time. It make more sense to talk about
+ * endianness of register values by considering a register
+ * a "cached" copy of the little endiad bit stream.
+ */
+static __inline__ void implement(__u8 *report, unsigned offset, unsigned n, __u32 value)
+{
+ u64 x;
+ u64 m = (1ULL << n) - 1;
+
+ WARN_ON(n > 32);
+
+ WARN_ON(value > m);
+ value &= m;
+
+ report += offset >> 3;
+ offset &= 7;
+
+ x = get_unaligned((u64 *)report);
+ x &= cpu_to_le64(~(m << offset));
+ x |= cpu_to_le64(((u64) value) << offset);
+ put_unaligned(x, (u64 *) report);
+}
+
+/*
+ * Search an array for a value.
+ */
+
+static __inline__ int search(__s32 *array, __s32 value, unsigned n)
+{
+ while (n--) {
+ if (*array++ == value)
+ return 0;
+ }
+ return -1;
+}
+
+static void hid_process_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value, int interrupt)
+{
+ hid_dump_input(usage, value);
+ if (hid->claimed & HID_CLAIMED_INPUT)
+ hidinput_hid_event(hid, field, usage, value);
+ if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt)
+ hiddev_hid_event(hid, field, usage, value);
+}
+
+/*
+ * Analyse a received field, and fetch the data from it. The field
+ * content is stored for next report processing (we do differential
+ * reporting to the layer).
+ */
+
+static void hid_input_field(struct hid_device *hid, struct hid_field *field, __u8 *data, int interrupt)
+{
+ unsigned n;
+ unsigned count = field->report_count;
+ unsigned offset = field->report_offset;
+ unsigned size = field->report_size;
+ __s32 min = field->logical_minimum;
+ __s32 max = field->logical_maximum;
+ __s32 *value;
+
+ if (!(value = kmalloc(sizeof(__s32) * count, GFP_ATOMIC)))
+ return;
+
+ for (n = 0; n < count; n++) {
+
+ value[n] = min < 0 ? snto32(extract(data, offset + n * size, size), size) :
+ extract(data, offset + n * size, size);
+
+ if (!(field->flags & HID_MAIN_ITEM_VARIABLE) /* Ignore report if ErrorRollOver */
+ && value[n] >= min && value[n] <= max
+ && field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
+ goto exit;
+ }
+
+ for (n = 0; n < count; n++) {
+
+ if (HID_MAIN_ITEM_VARIABLE & field->flags) {
+ hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
+ continue;
+ }
+
+ if (field->value[n] >= min && field->value[n] <= max
+ && field->usage[field->value[n] - min].hid
+ && search(value, field->value[n], count))
+ hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
+
+ if (value[n] >= min && value[n] <= max
+ && field->usage[value[n] - min].hid
+ && search(field->value, value[n], count))
+ hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
+ }
+
+ memcpy(field->value, value, count * sizeof(__s32));
+exit:
+ kfree(value);
+}
+
+
+/*
+ * Output the field into the report.
+ */
+
+static void hid_output_field(struct hid_field *field, __u8 *data)
+{
+ unsigned count = field->report_count;
+ unsigned offset = field->report_offset;
+ unsigned size = field->report_size;
+ unsigned n;
+
+ for (n = 0; n < count; n++) {
+ if (field->logical_minimum < 0) /* signed values */
+ implement(data, offset + n * size, size, s32ton(field->value[n], size));
+ else /* unsigned values */
+ implement(data, offset + n * size, size, field->value[n]);
+ }
+}
+
+/*
+ * Create a report.
+ */
+
+static void hid_output_report(struct hid_report *report, __u8 *data)
+{
+ unsigned n;
+
+ if (report->id > 0)
+ *data++ = report->id;
+
+ for (n = 0; n < report->maxfield; n++)
+ hid_output_field(report->field[n], data);
+}
+
+/*
+ * Set a field value. The report this field belongs to has to be
+ * created and transferred to the device, to set this value in the
+ * device.
+ */
+
+int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
+{
+ unsigned size = field->report_size;
+
+ hid_dump_input(field->usage + offset, value);
+
+ if (offset >= field->report_count) {
+ dbg("offset (%d) exceeds report_count (%d)", offset, field->report_count);
+ hid_dump_field(field, 8);
+ return -1;
+ }
+ if (field->logical_minimum < 0) {
+ if (value != snto32(s32ton(value, size), size)) {
+ dbg("value %d is out of range", value);
+ return -1;
+ }
+ }
+ field->value[offset] = value;
+ return 0;
+}
+