/*************************************************************************** * Copyright (c) 2024 Microsoft Corporation * Copyright (c) 2026-present Eclipse ThreadX contributors * * This program and the accompanying materials are made available under the * terms of the MIT License which is available at * https://opensource.org/licenses/MIT. * * SPDX-License-Identifier: MIT **************************************************************************/ /**************************************************************************/ /**************************************************************************/ /** */ /** USBX Component */ /** */ /** HID Class */ /** */ /**************************************************************************/ /**************************************************************************/ /* Include necessary system files. */ #define UX_SOURCE_CODE #include "ux_api.h" #include "ux_host_class_hid.h" #include "ux_host_stack.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _ux_host_class_hid_report_compress PORTABLE C */ /* 6.1 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function will compress a client report into a report buffer. */ /* */ /* INPUT */ /* */ /* hid Pointer to HID class */ /* client_report Pointer to client report */ /* report_buffer Pointer to report buffer */ /* report_length Length of report */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* None */ /* */ /* CALLED BY */ /* */ /* HID Class */ /* */ /**************************************************************************/ UINT _ux_host_class_hid_report_compress(UX_HOST_CLASS_HID *hid, UX_HOST_CLASS_HID_CLIENT_REPORT *client_report, UCHAR *report_buffer, ULONG report_length) { UX_HOST_CLASS_HID_REPORT *hid_report; UX_HOST_CLASS_HID_FIELD *hid_field; ULONG field_usage; ULONG field_report_count; ULONG field_report_size; ULONG *client_buffer; ULONG client_value; UCHAR value; ULONG data_offset_bit; UCHAR is_valid_usage; UX_PARAMETER_NOT_USED(hid); UX_PARAMETER_NOT_USED(report_length); /* Get the report pointer from the caller. */ hid_report = client_report -> ux_host_class_hid_client_report; /* Get the pointer to the user buffer. */ client_buffer = client_report -> ux_host_class_hid_client_report_buffer; /* Get the first field associated with the report. */ hid_field = hid_report -> ux_host_class_hid_report_field; /* Set data offset bit. */ data_offset_bit = 0; /* We need to compress each field defined in the report. */ while (hid_field != UX_NULL) { /* Each report field has a report count value. This count is used to extract values from the incoming report and build each usage/value instance. */ for (field_report_count = 0; field_report_count < hid_field -> ux_host_class_hid_field_report_count; field_report_count++) { /* Ensure the usage in the client buffer is valid. How we determine this depends on whether the field is VARIABLE or ARRAY. */ is_valid_usage = UX_FALSE; if (hid_field -> ux_host_class_hid_field_value & UX_HOST_CLASS_HID_ITEM_VARIABLE) { /* Go through the usage array to try and find the client's usage. */ for (field_usage = 0; field_usage < hid_field -> ux_host_class_hid_field_number_usage; field_usage++) { /* Is this a usage we've recorded? */ if (*client_buffer == hid_field -> ux_host_class_hid_field_usages[field_usage]) { /* Yes, this is a valid usage. */ is_valid_usage = UX_TRUE; break; } } } else { /* Is the usage page valid? */ if (((*client_buffer & 0xffff0000) >> 16) == hid_field -> ux_host_class_hid_field_usage_page) { /* Is the usage in the min and max range? */ if ((*client_buffer & 0xffff) >= hid_field -> ux_host_class_hid_field_usage_min && (*client_buffer & 0xffff) <= hid_field -> ux_host_class_hid_field_usage_max) { /* Yes, this is a valid usage. */ is_valid_usage = UX_TRUE; } } } /* Is the usage invalid? */ if (is_valid_usage == UX_FALSE) { /* Error trap. */ _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_HOST_CLASS_HID_REPORT_ERROR); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_HOST_CLASS_HID_REPORT_ERROR, hid, 0, 0, UX_TRACE_ERRORS, 0, 0) return(UX_HOST_CLASS_HID_REPORT_ERROR); } /* Skip the usage and point the buffer to the value. */ client_buffer++; /* Read the client value. */ client_value = *client_buffer++; /* Build the value field in the report buffer bit by bit. */ for (field_report_size = hid_field -> ux_host_class_hid_field_report_size; field_report_size > 0; field_report_size--) { /* Isolate each bit from the report value. */ value = (UCHAR) client_value & 1; /* Shift the isolated bit to its right space in the report byte. */ value = (UCHAR)(value << data_offset_bit); /* Update the report with the bit value. */ *report_buffer |= value; /* Move to next bit. */ data_offset_bit++; /* Are we on a byte boundary. */ if ((data_offset_bit & 7) == 0) { /* If so increment the report address. */ report_buffer++; /* Reset offset bit. */ data_offset_bit = 0; } /* Move to the next bit. */ client_value = client_value >> 1; } } /* Move to the next field. */ hid_field = hid_field -> ux_host_class_hid_field_next_field; } /* Return successful completion. */ return(UX_SUCCESS); }