HID preparsed data - bit arrays

NTDEV
1

Hello,

On two devices I’ve found something rather odd with the HID preparsed
data APIs. On one device,

Usage Page (Vendor-Defined 1) 06 00 FF
        Report Size (1) 75 01
        Report Count (16) 95 10
        Logical Maximum (1) 25 01
        Physical Maximum (1) 45 01
        Usage (Vendor-Defined 1) 09 01
*Input* (Data,Var,Abs,NWrp,Lin,Pref,NNul,Bit) 81 02

On another,

Report Size (1) 75 01
    Report Count (2) 95 02
*Input* (Data,Var,Abs,NWrp,Lin,Pref,NNul,Bit) 81 02
    Usage (Mute) 09 E2
    Usage (Undefined) 09 00
*Input* (Data,Var,Rel,NWrp,Lin,Pref,NNul,Bit) 81 06
    Usage Page (Telephony Devices) 05 0B
    Usage (Hook Switch) 09 20
    Report Count (1) 95 01
*Input* (Data,Var,Rel,NWrp,Lin,Pref,NNul,Bit) 81 06
    Usage Page (Consumer Devices) 05 0C
    Usage (Undefined) 09 00
    Report Count (3) 95 03

In both cases, Report Size (1) means the Input segment shows up in
HidP_GetButtonCaps, not HidP_GetValueCaps.

However, these are multiple bits with a single Usage (Vendor Defined in
the first, Undefined in the second). The data index does not show up as
a range, and HIDP_BUTTON_CAPS does not provide ReportCount like
HIDP_VALUE_CAPS does.

Because there are multiple bits, calling HidP_SetData fails with
HIDP_STATUS_IS_VALUE_ARRAY.

If I do try calling HidP_SetUsageValueArray, it fails with
HIDP_STATUS_USAGE_NOT_FOUND, unsurprisingly, because the segment was
returned in HidP_GetButtonCaps.

Is there something I am missing? Neither method seems to be able to
introspect or otherwise interact with this array of buttons.

Thanks!

James