source: mainline/uspace/lib/usbhid/src/hidparser.c@ f3b39b4

/*
 * Copyright (c) 2011 Matej Klonfar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libusbhid
 * @{
 */
/** @file
 * USB HID report data parser implementation.
 */
#include <usb/hid/hidparser.h>
#include <errno.h>
#include <stdio.h>
#include <malloc.h>
#include <mem.h>
#include <usb/debug.h>
#include <assert.h>

/*---------------------------------------------------------------------------*/
/*
 * Data translation private functions
 */
uint32_t usb_hid_report_tag_data_uint32(const uint8_t *data, size_t size);

int usb_hid_translate_data(usb_hid_report_field_t *item, const uint8_t *data);

uint32_t usb_hid_translate_data_reverse(usb_hid_report_field_t *item, 
        int32_t value);

int usb_pow(int a, int b);

/*---------------------------------------------------------------------------*/

// TODO: tohle ma bejt asi jinde
int usb_pow(int a, int b)
{
        switch(b) {
        case 0:
                return 1;
                break;
        case 1:
                return a;
                break;
        default:
                return a * usb_pow(a, b-1);
                break;
        }
}
/*---------------------------------------------------------------------------*/

/** Returns size of report of specified report id and type in items
 *
 * @param parser Opaque report parser structure
 * @param report_id 
 * @param type
 * @return Number of items in specified report
 */
size_t usb_hid_report_size(usb_hid_report_t *report, uint8_t report_id, 
                           usb_hid_report_type_t type)
{
        usb_hid_report_description_t *report_des;

        if(report == NULL) {
                return 0;
        }

        report_des = usb_hid_report_find_description (report, report_id, type);
        if(report_des == NULL){
                return 0;
        }
        else {
                return report_des->item_length;
        }
}

/** Returns size of report of specified report id and type in bytes
 *
 * @param parser Opaque report parser structure
 * @param report_id 
 * @param type
 * @return Number of items in specified report
 */
size_t usb_hid_report_byte_size(usb_hid_report_t *report, uint8_t report_id, 
                           usb_hid_report_type_t type)
{
        usb_hid_report_description_t *report_des;

        if(report == NULL) {
                return 0;
        }

        report_des = usb_hid_report_find_description (report, report_id, type);
        if(report_des == NULL){
                return 0;
        }
        else {
                if(report_id == 0) {                    
                        return ((report_des->bit_length + 7) / 8) ;
                }
                else {
                        return 1 + ((report_des->bit_length + 7) / 8);
                }
        }
}
/*---------------------------------------------------------------------------*/

/** Parse and act upon a HID report.
 *
 * @see usb_hid_parse_report_descriptor
 *
 * @param parser Opaque HID report parser structure.
 * @param data Data for the report.
 * @return Error code.
 */ 
int usb_hid_parse_report(const usb_hid_report_t *report, const uint8_t *data, 
        size_t size, uint8_t *report_id)
{
        link_t *list_item;
        usb_hid_report_field_t *item;

        usb_hid_report_description_t *report_des;
        usb_hid_report_type_t type = USB_HID_REPORT_TYPE_INPUT;
        
        if(report == NULL) {
                return EINVAL;
        }

        if(report->use_report_ids != 0) {
                *report_id = data[0];
        }       
        else {
                *report_id = 0;
        }


        report_des = usb_hid_report_find_description(report, *report_id, type);
        if(report_des == NULL) {
                return EINVAL;
        }

        /* read data */
        list_item = report_des->report_items.next;         
        while(list_item != &(report_des->report_items)) {

                item = list_get_instance(list_item, usb_hid_report_field_t, 
                                link);

                if(USB_HID_ITEM_FLAG_CONSTANT(item->item_flags) == 0) {
                        
                        if(USB_HID_ITEM_FLAG_VARIABLE(item->item_flags) == 0) {

                                // array
                                item->value = 
                                        usb_hid_translate_data(item, data);
                
                                item->usage = USB_HID_EXTENDED_USAGE(
                                    item->usages[item->value - item->physical_minimum]);

                                item->usage_page = USB_HID_EXTENDED_USAGE_PAGE(
                                    item->usages[item->value - item->physical_minimum]);

                                usb_hid_report_set_last_item (item->collection_path, 
                                    USB_HID_TAG_CLASS_GLOBAL, item->usage_page);

                                usb_hid_report_set_last_item (item->collection_path, 
                                    USB_HID_TAG_CLASS_LOCAL, item->usage);
                                
                        }
                        else {
                                // variable item
                                item->value = usb_hid_translate_data(item, data);                               
                        }                               
                }
                list_item = list_item->next;
        }
        
        return EOK;
        
}

/*---------------------------------------------------------------------------*/
/**
 * Translate data from the report as specified in report descriptor item
 *
 * @param item Report descriptor item with definition of translation
 * @param data Data to translate
 * @return Translated data
 */
int usb_hid_translate_data(usb_hid_report_field_t *item, const uint8_t *data)
{
        int resolution;
        int offset;
        int part_size;
        
        int32_t value=0;
        int32_t mask;
        const uint8_t *foo;

        // now only shot tags are allowed
        if(item->size > 32) {
                return 0;
        }

        if((item->physical_minimum == 0) && (item->physical_maximum == 0)){
                item->physical_minimum = item->logical_minimum;
                item->physical_maximum = item->logical_maximum;                 
        }
        

        if(item->physical_maximum == item->physical_minimum){
            resolution = 1;
        }
        else {
            resolution = (item->logical_maximum - item->logical_minimum) / 
                ((item->physical_maximum - item->physical_minimum) * 
                (usb_pow(10,(item->unit_exponent))));
        }

        offset = item->offset;
        // FIXME
        if((size_t)(offset/8) != (size_t)((offset+item->size-1)/8)) {
                
                part_size = ((offset+item->size)%8);

                size_t i=0;
                for(i=(size_t)(offset/8); i<=(size_t)(offset+item->size-1)/8; i++){
                        if(i == (size_t)(offset/8)) {
                                // the higher one
                                foo = data + i;
                                mask =  ((1 << (item->size-part_size))-1);
                                value = (*foo & mask) << part_size;
                        }
                        else if(i == ((offset+item->size-1)/8)){
                                // the lower one
                                foo = data + i;
                                mask =  ((1 << part_size)-1) << (8-part_size);
                                value += ((*foo & mask) >> (8-part_size));
                        }
                        else {
                                value = value << 8;
                                value += *(data + 1);
                        }
                }
        }
        else {          
                foo = data+(offset/8);
                mask =  ((1 << item->size)-1) << (8-((offset%8)+item->size));
                value = (*foo & mask) >> (8-((offset%8)+item->size));
        }

        if((item->logical_minimum < 0) || (item->logical_maximum < 0)){
                value = USB_HID_UINT32_TO_INT32(value, item->size);
        }

        return (int)(((value - item->logical_minimum) / resolution) + 
                item->physical_minimum);
        
}

/*---------------------------------------------------------------------------*/
/* OUTPUT API */

/** 
 * Allocates output report buffer for output report
 *
 * @param parser Report parsed structure
 * @param size Size of returned buffer
 * @param report_id Report id of created output report
 * @return Returns allocated output buffer for specified output
 */
uint8_t *usb_hid_report_output(usb_hid_report_t *report, size_t *size, 
        uint8_t report_id)
{
        if(report == NULL) {
                *size = 0;
                return NULL;
        }

        link_t *report_it = report->reports.next;
        usb_hid_report_description_t *report_des = NULL;
        while(report_it != &report->reports) {
                report_des = list_get_instance(report_it, 
                        usb_hid_report_description_t, link);
                
                if((report_des->report_id == report_id) && 
                        (report_des->type == USB_HID_REPORT_TYPE_OUTPUT)){
                        break;
                }

                report_it = report_it->next;
        }

        if(report_des == NULL){
                *size = 0;
                return NULL;
        }
        else {
                *size = (report_des->bit_length + (8 - 1))/8;
                uint8_t *ret = malloc((*size) * sizeof(uint8_t));
                memset(ret, 0, (*size) * sizeof(uint8_t));
                return ret;
        }
}


/** Frees output report buffer
 *
 * @param output Output report buffer
 * @return void
 */
void usb_hid_report_output_free(uint8_t *output)

{
        if(output != NULL) {
                free (output);
        }
}

/** Makes the output report buffer for data given in the report structure
 *
 * @param parser Opaque report parser structure
 * @param path Usage path specifing which parts of output will be set
 * @param flags Usage path structure comparison flags
 * @param buffer Output buffer
 * @param size Size of output buffer
 * @return Error code
 */
int usb_hid_report_output_translate(usb_hid_report_t *report, 
        uint8_t report_id, uint8_t *buffer, size_t size)
{
        link_t *item;   
        int32_t value=0;
        int offset;
        int length;
        int32_t tmp_value;
        
        if(report == NULL) {
                return EINVAL;
        }

        if(report->use_report_ids != 0) {
                buffer[0] = report_id;          
        }

        usb_hid_report_description_t *report_des;
        report_des = usb_hid_report_find_description (report, report_id, 
                USB_HID_REPORT_TYPE_OUTPUT);
        
        if(report_des == NULL){
                return EINVAL;
        }

        usb_hid_report_field_t *report_item;    
        item = report_des->report_items.next;   
        while(item != &report_des->report_items) {
                report_item = list_get_instance(item, usb_hid_report_field_t, link);

                if(USB_HID_ITEM_FLAG_VARIABLE(report_item->item_flags) == 0) {
                                        
                        // array
                        value = usb_hid_translate_data_reverse(report_item, 
                                report_item->value);

                        offset = report_item->offset;
                        length = report_item->size;
                }
                else {
                        // variable item
                        value  = usb_hid_translate_data_reverse(report_item, 
                                report_item->value);

                        offset = report_item->offset;
                        length = report_item->size;
                }

                usb_log_debug("\ttranslated value: %x\n", value);

                if((offset/8) == ((offset+length-1)/8)) {
                        // je to v jednom bytu
                        if(((size_t)(offset/8) >= size) || 
                                ((size_t)(offset+length-1)/8) >= size) {
                                break; // TODO ErrorCode
                        }
                        size_t shift = 8 - offset%8 - length;
                        value = value << shift;                                                 
                        value = value & (((1 << length)-1) << shift);
                                
                        uint8_t mask = 0;
                        mask = 0xff - (((1 << length) - 1) << shift);
                        buffer[offset/8] = (buffer[offset/8] & mask) | value;
                }
                else {
                        int i = 0;
                        uint8_t mask = 0;
                        for(i = (offset/8); i <= ((offset+length-1)/8); i++) {
                                if(i == (offset/8)) {
                                        tmp_value = value;
                                        tmp_value = tmp_value & 
                                                ((1 << (8-(offset%8)))-1);

                                        tmp_value = tmp_value << (offset%8);
        
                                        mask = ~(((1 << (8-(offset%8)))-1) << 
                                                        (offset%8));

                                        buffer[i] = (buffer[i] & mask) | 
                                                tmp_value;
                                }
                                else if (i == ((offset + length -1)/8)) {
                                        
                                        value = value >> (length - 
                                                ((offset + length) % 8));

                                        value = value & ((1 << (length - 
                                                ((offset + length) % 8))) - 1);
                                
                                        mask = (1 << (length - 
                                                ((offset + length) % 8))) - 1;

                                        buffer[i] = (buffer[i] & mask) | value;
                                }
                                else {
                                        buffer[i] = value & (0xFF << i);
                                }
                        }
                }

                // reset value
                report_item->value = 0;
                
                item = item->next;
        }
        
        return EOK;
}

/*---------------------------------------------------------------------------*/
/**
 * Translate given data for putting them into the outoput report
 * @param item Report item structure
 * @param value Value to translate
 * @return ranslated value
 */
uint32_t usb_hid_translate_data_reverse(usb_hid_report_field_t *item, 
        int value)
{
        int ret=0;
        int resolution;

        if(USB_HID_ITEM_FLAG_CONSTANT(item->item_flags)) {
                ret = item->logical_minimum;
        }

        if((item->physical_minimum == 0) && (item->physical_maximum == 0)){
                item->physical_minimum = item->logical_minimum;
                item->physical_maximum = item->logical_maximum;                 
        }
        
        // variable item
        if(item->physical_maximum == item->physical_minimum){
            resolution = 1;
        }
        else {
            resolution = (item->logical_maximum - item->logical_minimum) /
                ((item->physical_maximum - item->physical_minimum) *
                (usb_pow(10,(item->unit_exponent))));
        }

        ret = ((value - item->physical_minimum) * resolution) + 
                item->logical_minimum;

        usb_log_debug("\tvalue(%x), resolution(%x), phymin(%x) logmin(%x), \
                ret(%x)\n", value, resolution, item->physical_minimum, 
                item->logical_minimum, ret);
        
        if((item->logical_minimum < 0) || (item->logical_maximum < 0)){
                return USB_HID_INT32_TO_UINT32(ret, item->size);
        }
        return (int32_t)0 + ret;
}

/*---------------------------------------------------------------------------*/
/**
 * Clones given state table
 *
 * @param item State table to clone
 * @return Pointer to the cloned item
 */
usb_hid_report_item_t *usb_hid_report_item_clone(
        const usb_hid_report_item_t *item)
{
        usb_hid_report_item_t *new_report_item;
        
        if(!(new_report_item = malloc(sizeof(usb_hid_report_item_t)))) {
                return NULL;
        }                                       
        memcpy(new_report_item,item, sizeof(usb_hid_report_item_t));
        link_initialize(&(new_report_item->link));

        return new_report_item;
}

/*---------------------------------------------------------------------------*/
/**
 * Function for sequence walking through the report. Returns next field in the
 * report or the first one when no field is given.
 *
 * @param report Searched report structure
 * @param field Current field. If NULL is given, the first one in the report
 * is returned. Otherwise the next one i nthe list is returned.
 * @param path Usage path specifying which fields wa are interested in. 
 * @param flags Flags defining mode of usage paths comparison
 * @param type Type of report we search.
 * @retval NULL if no field is founded
 * @retval Pointer to the founded report structure when founded
 */
usb_hid_report_field_t *usb_hid_report_get_sibling(usb_hid_report_t *report, 
        usb_hid_report_field_t *field, usb_hid_report_path_t *path, int flags, 
        usb_hid_report_type_t type)
{
        usb_hid_report_description_t *report_des = 
                usb_hid_report_find_description(report, path->report_id, type);

        link_t *field_it;
        
        if(report_des == NULL){
                return NULL;
        }

        if(field == NULL){
                field_it = report_des->report_items.next;
        }
        else {
                field_it = field->link.next;
        }

        while(field_it != &report_des->report_items) {
                field = list_get_instance(field_it, usb_hid_report_field_t, 
                        link);

                if(USB_HID_ITEM_FLAG_CONSTANT(field->item_flags) == 0) {
                        usb_hid_report_path_append_item (
                                field->collection_path, field->usage_page, 
                                field->usage);

                        if(usb_hid_report_compare_usage_path(
                                field->collection_path, path, flags) == EOK){

                                usb_hid_report_remove_last_item(
                                        field->collection_path);

                                return field;
                        }
                        usb_hid_report_remove_last_item (
                                field->collection_path);
                }
                field_it = field_it->next;
        }

        return NULL;
}

/*---------------------------------------------------------------------------*/
/**
 * Returns next report_id of report of specified type. If zero is given than
 * first report_id of specified type is returned (0 is not legal value for
 * repotr_id)
 *
 * @param report_id Current report_id, 0 if there is no current report_id
 * @param type Type of searched report
 * @param report Report structure inwhich we search
 * @retval 0 if report structure is null or there is no specified report
 * @retval report_id otherwise
 */
uint8_t usb_hid_get_next_report_id(usb_hid_report_t *report, 
        uint8_t report_id, usb_hid_report_type_t type)
{
        if(report == NULL){
                return 0;
        }

        usb_hid_report_description_t *report_des;
        link_t *report_it;
        
        if(report_id > 0) {
                report_it = usb_hid_report_find_description(report, report_id, 
                        type)->link.next;               
        }
        else {
                report_it = report->reports.next;
        }

        while(report_it != &report->reports) {
                report_des = list_get_instance(report_it, 
                        usb_hid_report_description_t, link);

                if(report_des->type == type){
                        return report_des->report_id;
                }
        }

        return 0;
}

/*---------------------------------------------------------------------------*/
/**
 * Reset all local items in given state table
 *
 * @param report_item State table containing current state of report
 * descriptor parsing
 *
 * @return void
 */
void usb_hid_report_reset_local_items(usb_hid_report_item_t *report_item)
{
        if(report_item == NULL) {
                return;
        }
        
        report_item->usages_count = 0;
        memset(report_item->usages, 0, USB_HID_MAX_USAGES);
        
        report_item->extended_usage_page = 0;
        report_item->usage_minimum = 0;
        report_item->usage_maximum = 0;
        report_item->designator_index = 0;
        report_item->designator_minimum = 0;
        report_item->designator_maximum = 0;
        report_item->string_index = 0;
        report_item->string_minimum = 0;
        report_item->string_maximum = 0;

        return;
}
/**
 * @}
 */