Update keyboard report descriptor for USB compliance (#21626)
Running the "HID Tests" suite of the USB 3 Command Verifier (USB3CV) tool resulted in the following error: (HID: 3.2.61) The report descriptor returned in response to a GetDescriptor(Report) must be compliant with the HID specification. Byte Number: 37h ( 55d) Data Field: 91 02 Mnemonic: Output Value: (Variable) Errors: Error: LOGICAL MAX MUST be bounded by Report Size The error stems from the fact that logical minimum and maximum are global items, which means that the next item in a report descriptor inherits the value from the previously set value. In this case the status leds item inherited the logical minimum (=0) and maximum (=255) from the keycodes item. As the status leds set a report size of 1 bit, wich can only hold a boolean, it becomes clear that this range would never fit. The fix is straightforward, we just define a appropriate logical maximum (=1), the mismatch is solved and our keyboard now passes the compliance tests. Defining the logical minimum is redundant in this case but is kept to form a logical block.
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@ -93,6 +93,8 @@ const USB_Descriptor_HIDReport_Datatype_t PROGMEM KeyboardReport[] = {
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HID_RI_USAGE_PAGE(8, 0x08), // LED
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HID_RI_USAGE_MINIMUM(8, 0x01), // Num Lock
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HID_RI_USAGE_MAXIMUM(8, 0x05), // Kana
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HID_RI_LOGICAL_MINIMUM(8, 0x00),
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HID_RI_LOGICAL_MAXIMUM(8, 0x01),
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HID_RI_REPORT_COUNT(8, 0x05),
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HID_RI_REPORT_SIZE(8, 0x01),
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HID_RI_OUTPUT(8, HID_IOF_DATA | HID_IOF_VARIABLE | HID_IOF_ABSOLUTE | HID_IOF_NON_VOLATILE),
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@ -435,6 +435,8 @@ const PROGMEM uchar keyboard_hid_report[] = {
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0x05, 0x08, // Usage Page (LED)
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0x19, 0x01, // Usage Minimum (Num Lock)
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0x29, 0x05, // Usage Maximum (Kana)
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0x15, 0x00, // Logical Minimum (0)
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0x25, 0x01, // Logical Maximum (1)
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0x95, 0x05, // Report Count (5)
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0x75, 0x01, // Report Size (1)
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0x91, 0x02, // Output (Data, Variable, Absolute)
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