/*************************************************************************** * 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 */ /** */ /** Device HID Class */ /** */ /**************************************************************************/ /**************************************************************************/ #define UX_SOURCE_CODE /* Include necessary system files. */ #include "ux_api.h" #include "ux_device_class_hid.h" #include "ux_device_stack.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _ux_device_class_hid_descriptor_send PORTABLE C */ /* 6.1.8 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function sends back the class descriptor required by the host. */ /* */ /* INPUT */ /* */ /* descriptor_type Descriptor type */ /* descriptor_index Index of descriptor */ /* host_length Length requested by host */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* (ux_slave_dcd_function) DCD dispatch function */ /* _ux_device_stack_transfer_request Process transfer request */ /* _ux_utility_memory_copy Memory copy */ /* */ /* CALLED BY */ /* */ /* Application */ /* Device Stack */ /* */ /**************************************************************************/ UINT _ux_device_class_hid_descriptor_send(UX_SLAVE_CLASS_HID *hid, ULONG descriptor_type, ULONG request_index, ULONG host_length) { UX_SLAVE_DCD *dcd; UX_SLAVE_DEVICE *device; UX_SLAVE_TRANSFER *transfer_request; UX_SLAVE_ENDPOINT *endpoint; UCHAR * device_framework; UCHAR * device_framework_end; ULONG descriptor_length; UINT status = UX_ERROR; ULONG length; UCHAR interface_number = 0xFF; UX_PARAMETER_NOT_USED(request_index); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_DEVICE_CLASS_HID_DESCRIPTOR_SEND, hid, descriptor_type, request_index, 0, UX_TRACE_DEVICE_CLASS_EVENTS, 0, 0) /* Get the pointer to the DCD. */ dcd = &_ux_system_slave -> ux_system_slave_dcd; /* Get the pointer to the device. */ device = &_ux_system_slave -> ux_system_slave_device; /* Get the control endpoint associated with the device. */ endpoint = &device -> ux_slave_device_control_endpoint; /* Get the pointer to the transfer request associated with the endpoint. */ transfer_request = &endpoint -> ux_slave_endpoint_transfer_request; /* Set the direction to OUT. */ transfer_request -> ux_slave_transfer_request_phase = UX_TRANSFER_PHASE_DATA_OUT; /* Shift the descriptor type in the low byte field. */ descriptor_type = (UCHAR) ((descriptor_type >> 8) & 0xff); /* What type of descriptor do we need to return? */ switch (descriptor_type) { case UX_DEVICE_CLASS_HID_DESCRIPTOR_HID: /* We should have a HID descriptor as part of the config descriptor. */ device_framework = _ux_system_slave -> ux_system_slave_device_framework; device_framework_end = device_framework + _ux_system_slave -> ux_system_slave_device_framework_length; /* Parse the device framework and locate the HID descriptor. There is only one HID descriptor. */ while (device_framework < device_framework_end) { /* Get the type of the current descriptor. */ descriptor_type = *(device_framework + 1); /* And its length. */ descriptor_length = (ULONG) *device_framework; /* Save interface number for later check. */ if (descriptor_type == UX_INTERFACE_DESCRIPTOR_ITEM) interface_number = *(device_framework + 2); /* Check if this is a HID report descriptor. */ if ((descriptor_type == UX_DEVICE_CLASS_HID_DESCRIPTOR_HID) && (interface_number == (UCHAR)request_index)) { /* Ensure the host does not demand a length beyond our descriptor (Windows does that) and do not return more than what is allowed. */ if (descriptor_length < host_length) length = descriptor_length; else length = host_length; /* Check buffer length, since descriptor length may exceed buffer... */ if (length > UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH) { /* Error trap. */ _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_MEMORY_INSUFFICIENT); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_MEMORY_INSUFFICIENT, hid, 0, 0, UX_TRACE_ERRORS, 0, 0) /* Stall the endpoint. */ status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint); break; } /* Copy the device descriptor into the transfer request memory. */ _ux_utility_memory_copy(transfer_request -> ux_slave_transfer_request_data_pointer, device_framework, length); /* Use case of memcpy is verified. */ /* We can return the configuration descriptor. */ status = _ux_device_stack_transfer_request(transfer_request, length, host_length); break; } /* Point to the next descriptor. */ device_framework += descriptor_length; } /* Stall the endpoint if not found or corrupt. */ if (device_framework >= device_framework_end) status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint); break; case UX_DEVICE_CLASS_HID_DESCRIPTOR_REPORT: /* Get the length of entire configuration descriptor. */ descriptor_length = hid -> ux_device_class_hid_report_length; /* Ensure the host does not demand a length beyond our descriptor (Windows does that) and do not return more than what is allowed. */ if (descriptor_length < host_length) length = descriptor_length; else length = host_length; /* Check buffer length, since total descriptors length may exceed buffer... */ if (length > UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH) { /* Error trap. */ _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_MEMORY_INSUFFICIENT); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_MEMORY_INSUFFICIENT, hid, 0, 0, UX_TRACE_ERRORS, 0, 0) /* Stall the endpoint. */ status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint); break; } /* Copy the device descriptor into the transfer request memory. */ _ux_utility_memory_copy(transfer_request -> ux_slave_transfer_request_data_pointer, hid -> ux_device_class_hid_report_address, length); /* Use case of memcpy is verified. */ /* We can return the report descriptor. */ status = _ux_device_stack_transfer_request(transfer_request, length, host_length); break; case UX_DEVICE_CLASS_HID_DESCRIPTOR_PHYSICAL: /* Not treated for now. Fall through and Stall endpoint. */ default: /* Stall the endpoint. */ dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint); return(UX_ERROR); } /* Return the status to the caller. */ return(status); }