diff options
author | Jiri Kosina <jkosina@suse.cz> | 2006-12-08 18:40:44 +0100 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-12-08 10:43:01 -0800 |
commit | dde5845a529ff753364a6d1aea61180946270bfa (patch) | |
tree | e0160fe45c047024b281a2805196a8c64242b59e /drivers/hid/hid-core.c | |
parent | 64bb67b1702958759f650adb64ab33496641e526 (diff) | |
download | op-kernel-dev-dde5845a529ff753364a6d1aea61180946270bfa.zip op-kernel-dev-dde5845a529ff753364a6d1aea61180946270bfa.tar.gz |
[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>
Diffstat (limited to 'drivers/hid/hid-core.c')
-rw-r--r-- | drivers/hid/hid-core.c | 940 |
1 files changed, 940 insertions, 0 deletions
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; +} + |