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MdeModulePkg ConPlatform: Support IAD-style USB input devices. 

Some multi-function input devices (e.g. combo keyboard and mouse)
present as IAD-style devices (https://www.usb.org/defined-class-codes,
https://learn.microsoft.com/en-us/windows-hardware/drivers/usbcon/usb-interface-association-descriptor).
Historically, multi-function devices would report a DeviceClass of 0,
indicating that interface matching should be done on the interface
descriptor rather than the global device descriptor.

IAD-style devices us DeviceClass of 0xEF, so they don't match
MatchUsbClass() for keyboard (DeviceClass=3, SubClass=1, Proto=1). If
they are treated as if they had a DeviceClass of zero, which is more
traditional for legacy multi-function devices, then the interface
descriptors are used instead and these types of devices will "just work"
without needing to add a custom USB device path to ConIn.

Signed-off-by: Aaron Pop <aaronpop@microsoft.com>
This commit is contained in:
John Schock 2023-05-26 16:50:41 -07:00 committed by mergify[bot]
parent 1b37b3659b
commit 472be4d139
1 changed files with 18 additions and 3 deletions
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21
MdeModulePkg/Universal/Console/ConPlatformDxe/ConPlatform.c
View File

@ -27,6 +27,15 @@ EFI_DRIVER_BINDING_PROTOCOL gConPlatformTextOutDriverBinding = {
NULL
};
//
// Values from Usb Inteface Association Descriptor Device
// Class Code and Usage Model specification (iadclasscode_r10.pdf)
// from Usb.org
//
#define USB_BASE_CLASS_MISCELLANEOUS 0xEF
#define USB_MISCELLANEOUS_SUBCLASS_COMMON 0x02
#define USB_MISCELLANEOUS_PROTOCOL_IAD 0x01
/**
Entrypoint of this module.
@ -808,10 +817,16 @@ MatchUsbClass (
DeviceClass = DevDesc.DeviceClass;
DeviceSubClass = DevDesc.DeviceSubClass;
DeviceProtocol = DevDesc.DeviceProtocol;
if (DeviceClass == 0) {
if ((DeviceClass == 0) ||
((DeviceClass == USB_BASE_CLASS_MISCELLANEOUS) &&
(DeviceSubClass == USB_MISCELLANEOUS_SUBCLASS_COMMON) &&
(DeviceProtocol == USB_MISCELLANEOUS_PROTOCOL_IAD)))
{
//
// If Class in Device Descriptor is set to 0, use the Class, SubClass and
// Protocol in Interface Descriptor instead.
// If Class in Device Descriptor is set to 0 (Device), or
// Class/SubClass/Protocol is 0xEF/0x02/0x01 (IAD), use the Class, SubClass
// and Protocol in Interface Descriptor instead.
//
Status = UsbIo->UsbGetInterfaceDescriptor (UsbIo, &IfDesc);
if (EFI_ERROR (Status)) {