simpler generation of HID device tables

2 files changed, 345 insertions, 307 deletions

diff --git a/tools/gen_usb_descriptor.py b/tools/gen_usb_descriptor.py
index f782f9afc..82d2daf0f 100644
--- a/tools/gen_usb_descriptor.py
+++ b/tools/gen_usb_descriptor.py
@@ -12,7 +12,7 @@ ALL_DEVICES='CDC,MSC,AUDIO,HID'
 ALL_DEVICES_SET=frozenset(ALL_DEVICES.split(','))
 DEFAULT_DEVICES='CDC,MSC,AUDIO,HID'
 
-ALL_HID_DEVICES='KEYBOARD,MOUSE,CONSUMER,SYS_CONTROL,GAMEPAD,DIGITIZER,XAC_COMPATIBLE_GAMEPAD'
+ALL_HID_DEVICES='KEYBOARD,MOUSE,CONSUMER,SYS_CONTROL,GAMEPAD,DIGITIZER,XAC_COMPATIBLE_GAMEPAD,RAW'
 ALL_HID_DEVICES_SET=frozenset(ALL_HID_DEVICES.split(','))
 # Digitizer works on Linux but conflicts with mouse, so omit it.
 DEFAULT_HID_DEVICES='KEYBOARD,MOUSE,CONSUMER,GAMEPAD'
@@ -28,20 +28,20 @@ parser.add_argument('--pid', type=lambda x: int(x, 16),
                     help='product id')
 parser.add_argument('--serial_number_length', type=int, default=32,
                     help='length needed for the serial number in digits')
-parser.add_argument('--devices', type=lambda l: frozenset(l.split(',')), default=DEFAULT_DEVICES,
+parser.add_argument('--devices', type=lambda l: tuple(l.split(',')), default=DEFAULT_DEVICES,
                     help='devices to include in descriptor (AUDIO includes MIDI support)')
-parser.add_argument('--hid_devices', type=lambda l: frozenset(l.split(',')), default=DEFAULT_HID_DEVICES,
+parser.add_argument('--hid_devices', type=lambda l: tuple(l.split(',')), default=DEFAULT_HID_DEVICES,
                     help='HID devices to include in HID report descriptor')
 parser.add_argument('--output_c_file', type=argparse.FileType('w'), required=True)
 parser.add_argument('--output_h_file', type=argparse.FileType('w'), required=True)
 
 args = parser.parse_args()
 
-unknown_devices = list(args.devices - ALL_DEVICES_SET)
+unknown_devices = list(frozenset(args.devices) - ALL_DEVICES_SET)
 if unknown_devices:
     raise ValueError("Unknown device(s)", unknown_devices)
 
-unknown_hid_devices = list(args.hid_devices - ALL_HID_DEVICES_SET)
+unknown_hid_devices = list(frozenset(args.hid_devices) - ALL_HID_DEVICES_SET)
 if unknown_hid_devices:
     raise ValueError("Unknown HID devices(s)", unknown_hid_devices)
 
@@ -160,29 +160,27 @@ msc_interfaces = [
     )
 ]
 
-# Sort by Report ID for consistency.
-hid_devices = sorted(args.hid_devices, key=lambda name: hid_report_descriptors.REPORT_IDS[name])
+# When there's only one hid_device, it shouldn't have a report id.
+# Otherwise, report ids are assigned sequentially:
+# args.hid_devices[0] has report_id 1
+# args.hid_devices[1] has report_id 2
+# etc.
 
-# When there's only one hid_device, it can't be in a composite descriptor.
-# It has no report id (indicated by 0), so remove the existing one.
-
-#if len(hid_devices) == 1:
-if False:
-    name = hid_devices[0]
+if len(args.hid_devices) == 1:
+    name = args.hid_devices[0]
     combined_hid_report_descriptor = hid.ReportDescriptor(
         description=name,
-        report_descriptor=hid_report_descriptors.remove_report_id(
-            hid_report_descriptors.REPORT_DESCRIPTORS[name].report_descriptor))
-    hid_report_ids_dict = { name : 0 }
+        report_descriptor=bytes(hid_report_descriptors.REPORT_DESCRIPTOR_FUNCTIONS[name](0)))
 else:
+    report_id = 1
+    concatenated_descriptors = bytearray()
+    for name in args.hid_devices:
+        concatenated_descriptors.extend(
+            bytes(hid_report_descriptors.REPORT_DESCRIPTOR_FUNCTIONS[name](report_id)))
+        report_id += 1
     combined_hid_report_descriptor = hid.ReportDescriptor(
-    description="MULTIDEVICE",
-    report_descriptor=b''.join(
-        hid_report_descriptors.REPORT_DESCRIPTORS[name].report_descriptor for name in hid_devices ))
-    hid_report_ids_dict = { name: hid_report_descriptors.REPORT_IDS[name] for name in hid_devices }
-
-hid_report_lengths_dict = { name: hid_report_descriptors.REPORT_LENGTHS[name] for name in hid_devices }
-hid_max_report_length = max(hid_report_lengths_dict.values())
+        description="MULTIDEVICE",
+        report_descriptor=bytes(concatenated_descriptors))
 
 # ASF4 expects keyboard and generic devices to have both in and out endpoints,
 # and will fail (possibly silently) if both are not supplied.
@@ -343,6 +341,8 @@ h_file = args.output_h_file
 c_file.write("""\
 #include <stdint.h>
 
+#include "py/objtuple.h"
+#include "shared-bindings/usb_hid/Device.h"
 #include "{H_FILE_NAME}"
 
 """.format(H_FILE_NAME=h_file.name))
@@ -461,7 +461,9 @@ const uint8_t usb_desc_cfg[{configuration_length}];
 uint16_t usb_serial_number[{serial_number_length}];
 uint16_t const * const string_desc_arr [{string_descriptor_length}];
 
-const uint8_t hid_report_descriptor[{HID_REPORT_DESCRIPTOR_LENGTH}];
+const uint8_t hid_report_descriptor[{hid_report_descriptor_length}];
+
+#define USB_HID_NUM_DEVICES {hid_num_devices}
 
 // Vendor name included in Inquiry response, max 8 bytes
 #define CFG_TUD_MSC_VENDOR          "{msc_vendor}"
@@ -475,36 +477,11 @@ const uint8_t hid_report_descriptor[{HID_REPORT_DESCRIPTOR_LENGTH}];
         configuration_length=descriptor_length,
         max_configuration_length=max(hid_descriptor_length, descriptor_length),
         string_descriptor_length=len(pointers_to_strings),
-        HID_REPORT_DESCRIPTOR_LENGTH=len(bytes(combined_hid_report_descriptor)),
+        hid_report_descriptor_length=len(bytes(combined_hid_report_descriptor)),
+        hid_num_devices=len(args.hid_devices),
         msc_vendor=args.manufacturer[:8],
         msc_product=args.product[:16]))
 
-# #define the report ID's used in the combined HID descriptor
-for name, id in hid_report_ids_dict.items():
-    h_file.write("""\
-#define USB_HID_REPORT_ID_{name} {id}
-""".format(name=name,
-           id=id))
-
-h_file.write("\n")
-
-# #define the report sizes used in the combined HID descriptor
-for name, length in hid_report_lengths_dict.items():
-    h_file.write("""\
-#define USB_HID_REPORT_LENGTH_{name} {length}
-""".format(name=name,
-           length=length))
-
-h_file.write("\n")
-
-h_file.write("""\
-#define USB_HID_NUM_DEVICES {num_devices}
-#define USB_HID_MAX_REPORT_LENGTH {max_length}
-""".format(num_devices=len(hid_report_lengths_dict),
-           max_length=hid_max_report_length))
-
-
-
 # Write out the report descriptor and info
 c_file.write("""\
 const uint8_t hid_report_descriptor[{HID_DESCRIPTOR_LENGTH}] = {{
@@ -512,7 +489,55 @@ const uint8_t hid_report_descriptor[{HID_DESCRIPTOR_LENGTH}] = {{
 
 for b in bytes(combined_hid_report_descriptor):
     c_file.write("0x{:02x}, ".format(b))
+c_file.write("""\
+};
+
+""")
+
+# Write out USB HID report buffer definitions.
+for report_id, name in enumerate(args.hid_devices, start=1):
+    c_file.write("""\
+static uint8_t {name}_report_buffer[{report_length}];
+""".format(name=name.lower(), report_length=hid_report_descriptors.HID_DEVICE_DATA[name].report_length))
+
+# Write out table of device objects.
 c_file.write("""
+usb_hid_device_obj_t usb_hid_devices[] = {
+""");
+for report_id, name in enumerate(args.hid_devices, start=1):
+    device_data = hid_report_descriptors.HID_DEVICE_DATA[name]
+    c_file.write("""\
+    {{
+        .base          = {{ .type = &usb_hid_device_type }},
+        .report_buffer = {name}_report_buffer,
+        .report_id     = {report_id:},
+        .report_length = {report_length},
+        .usage_page    = {usage_page:#04x},
+        .usage         = {usage:#04x},
+    }},
+""".format(name=name.lower(), report_id=report_id,
+           report_length=device_data.report_length,
+           usage_page=device_data.usage_page,
+           usage=device_data.usage))
+c_file.write("""\
+};
+""")
+
+# Write out tuple of device objects.
+c_file.write("""
+mp_obj_tuple_t common_hal_usb_hid_devices = {{
+    .base = {{
+        .type = &mp_type_tuple,
+    }},
+    .len = {num_devices},
+    .items = {{
+""".format(num_devices=len(args.hid_devices)))
+for idx in range(len(args.hid_devices)):
+    c_file.write("""\
+         (mp_obj_t) &usb_hid_devices[{idx}],
+""".format(idx=idx))
+c_file.write("""\
+    },
 };
 """)
 
diff --git a/tools/hid_report_descriptors.py b/tools/hid_report_descriptors.py
index 4902657af..92c962d59 100644
--- a/tools/hid_report_descriptors.py
+++ b/tools/hid_report_descriptors.py
@@ -29,271 +29,284 @@ HID specific descriptors
 * Author(s): Dan Halbert
 """
 
-from adafruit_usb_descriptor import hid
-
-def remove_report_id(report_descriptor_bytes):
-    #return report_descriptor_bytes
-    report_id_pos = report_descriptor_bytes.index(0x85)
-    return report_descriptor_bytes[:report_id_pos] + report_descriptor_bytes[report_id_pos + 2:]
+from collections import namedtuple
 
-REPORT_IDS = {
-    "KEYBOARD" : 1,
-    "MOUSE" : 2,
-    "CONSUMER" : 3,
-    "SYS_CONTROL" : 4,
-    "GAMEPAD" : 5,
-    "DIGITIZER" : 6,
-    "XAC_COMPATIBLE_GAMEPAD" : 7,
-    # RAW must not have a report ID, so it can't be used with other devices.
-    "RAW" : 0,
-    }
+from adafruit_usb_descriptor import hid
 
-# Byte count for each kind of report. Length does not include report ID in first byte.
-REPORT_LENGTHS = {
-    "KEYBOARD" : 8,
-    "MOUSE" : 4,
-    "CONSUMER" : 2,
-    "SYS_CONTROL" : 1,
-    "GAMEPAD" : 6,
-    "DIGITIZER" : 5,
-    "XAC_COMPATIBLE_GAMEPAD" : 3,
-    "RAW" : 64,
+# Information about each kind of device
+# report_length does not include report ID in first byte, if present when sent.
+DeviceData = namedtuple('DeviceData', ('report_length', 'usage_page', 'usage'))
+HID_DEVICE_DATA = {
+    "KEYBOARD" : DeviceData(report_length=8, usage_page=0x01, usage=0x06),    # Generic Desktop, Keyboard
+    "MOUSE" : DeviceData(report_length=4, usage_page=0x01, usage=0x02),       # Generic Desktop, Mouse
+    "CONSUMER" : DeviceData(report_length=2, usage_page=0x0C, usage=0x01),    # Consumer, Consumer Control
+    "SYS_CONTROL" : DeviceData(report_length=1, usage_page=0x01, usage=0x80), # Generic Desktop, Sys Control
+    "GAMEPAD" : DeviceData(report_length=6, usage_page=0x01, usage=0x05),     # Generic Desktop, Game Pad
+    "DIGITIZER" : DeviceData(report_length=5, usage_page=0x0D, usage=0x02),   # Digitizers, Pen
+    "XAC_COMPATIBLE_GAMEPAD" : DeviceData(report_length=3, usage_page=0x01, usage=0x05), # Generic Desktop, Game Pad
+    "RAW" : DeviceData(report_length=64, usage_page=0xFFAF, usage=0xAF),      # Vendor 0xFFAF "Adafruit", 0xAF
     }
 
-KEYBOARD_WITH_ID = hid.ReportDescriptor(
-    description="KEYBOARD",
-    report_descriptor=bytes([
-        # Regular keyboard
-        0x05, 0x01,                 # Usage Page (Generic Desktop)
-        0x09, 0x06,                 # Usage (Keyboard)
-        0xA1, 0x01,                 # Collection (Application)
-        0x85, REPORT_IDS["KEYBOARD"], #   Report ID (1)
-        0x05, 0x07,                 #   Usage Page (Keyboard)
-        0x19, 224,                  #   Usage Minimum (224)
-        0x29, 231,                  #   Usage Maximum (231)
-        0x15, 0x00,                 #   Logical Minimum (0)
-        0x25, 0x01,                 #   Logical Maximum (1)
-        0x75, 0x01,                 #   Report Size (1)
-        0x95, 0x08,                 #   Report Count (8)
-        0x81, 0x02,                 #   Input (Data, Variable, Absolute)
-        0x81, 0x01,                 #   Input (Constant)
-        0x19, 0x00,                 #   Usage Minimum (0)
-        0x29, 101,                  #   Usage Maximum (101)
-        0x15, 0x00,                 #   Logical Minimum (0)
-        0x25, 101,                  #   Logical Maximum (101)
-        0x75, 0x08,                 #   Report Size (8)
-        0x95, 0x06,                 #   Report Count (6)
-        0x81, 0x00,                 #   Input (Data, Array)
-        0x05, 0x08,                 #   Usage Page (LED)
-        0x19, 0x01,                 #   Usage Minimum (1)
-        0x29, 0x05,                 #   Usage Maximum (5)
-        0x15, 0x00,                 #   Logical Minimum (0)
-        0x25, 0x01,                 #   Logical Maximum (1)
-        0x75, 0x01,                 #   Report Size (1)
-        0x95, 0x05,                 #   Report Count (5)
-        0x91, 0x02,                 #   Output (Data, Variable, Absolute)
-        0x95, 0x03,                 #   Report Count (3)
-        0x91, 0x01,                 #   Output (Constant)
-        0xC0,                       # End Collection
-    ]))
+def keyboard_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["KEYBOARD"]
+    return hid.ReportDescriptor(
+        description="KEYBOARD",
+        report_descriptor=bytes(
+            # Regular keyboard
+            (0x05, data.usage_page,      # Usage Page (Generic Desktop)
+             0x09, data.usage,           # Usage (Keyboard)
+             0xA1, 0x01,                 # Collection (Application)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x05, 0x07,                 #   Usage Page (Keyboard)
+             0x19, 224,                  #   Usage Minimum (224)
+             0x29, 231,                  #   Usage Maximum (231)
+             0x15, 0x00,                 #   Logical Minimum (0)
+             0x25, 0x01,                 #   Logical Maximum (1)
+             0x75, 0x01,                 #   Report Size (1)
+             0x95, 0x08,                 #   Report Count (8)
+             0x81, 0x02,                 #   Input (Data, Variable, Absolute)
+             0x81, 0x01,                 #   Input (Constant)
+             0x19, 0x00,                 #   Usage Minimum (0)
+             0x29, 101,                  #   Usage Maximum (101)
+             0x15, 0x00,                 #   Logical Minimum (0)
+             0x25, 101,                  #   Logical Maximum (101)
+             0x75, 0x08,                 #   Report Size (8)
+             0x95, 0x06,                 #   Report Count (6)
+             0x81, 0x00,                 #   Input (Data, Array)
+             0x05, 0x08,                 #   Usage Page (LED)
+             0x19, 0x01,                 #   Usage Minimum (1)
+             0x29, 0x05,                 #   Usage Maximum (5)
+             0x15, 0x00,                 #   Logical Minimum (0)
+             0x25, 0x01,                 #   Logical Maximum (1)
+             0x75, 0x01,                 #   Report Size (1)
+             0x95, 0x05,                 #   Report Count (5)
+             0x91, 0x02,                 #   Output (Data, Variable, Absolute)
+             0x95, 0x03,                 #   Report Count (3)
+             0x91, 0x01,                 #   Output (Constant)
+             0xC0,                       # End Collection
+            )))
 
-MOUSE_WITH_ID = hid.ReportDescriptor(
-    description="MOUSE",
-    report_descriptor=bytes([
-        # Regular mouse
-        0x05, 0x01,        # Usage Page (Generic Desktop)
-        0x09, 0x02,        # Usage (Mouse)
-        0xA1, 0x01,        # Collection (Application)
-        0x09, 0x01,        #   Usage (Pointer)
-        0xA1, 0x00,        #   Collection (Physical)
-        0x85, REPORT_IDS["MOUSE"], # Report ID (n)
-        0x05, 0x09,        #     Usage Page (Button)
-        0x19, 0x01,        #     Usage Minimum (0x01)
-        0x29, 0x05,        #     Usage Maximum (0x05)
-        0x15, 0x00,        #     Logical Minimum (0)
-        0x25, 0x01,        #     Logical Maximum (1)
-        0x95, 0x05,        #     Report Count (5)
-        0x75, 0x01,        #     Report Size (1)
-        0x81, 0x02,        #     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0x95, 0x01,        #     Report Count (1)
-        0x75, 0x03,        #     Report Size (3)
-        0x81, 0x01,        #     Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0x05, 0x01,        #     Usage Page (Generic Desktop Ctrls)
-        0x09, 0x30,        #     Usage (X)
-        0x09, 0x31,        #     Usage (Y)
-        0x15, 0x81,        #     Logical Minimum (-127)
-        0x25, 0x7F,        #     Logical Maximum (127)
-        0x75, 0x08,        #     Report Size (8)
-        0x95, 0x02,        #     Report Count (2)
-        0x81, 0x06,        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
-        0x09, 0x38,        #     Usage (Wheel)
-        0x15, 0x81,        #     Logical Minimum (-127)
-        0x25, 0x7F,        #     Logical Maximum (127)
-        0x75, 0x08,        #     Report Size (8)
-        0x95, 0x01,        #     Report Count (1)
-        0x81, 0x06,        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
-        0xC0,              #   End Collection
-        0xC0,              # End Collection
-    ]))
+def mouse_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["MOUSE"]
+    return hid.ReportDescriptor(
+        description="MOUSE",
+        report_descriptor=bytes(
+            # Regular mouse
+            (0x05, data.usage_page, # Usage Page (Generic Desktop)
+             0x09, data.usage,  # Usage (Mouse)
+             0xA1, 0x01,        # Collection (Application)
+             0x09, 0x01,        #   Usage (Pointer)
+             0xA1, 0x00,        #   Collection (Physical)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x05, 0x09,        #     Usage Page (Button)
+             0x19, 0x01,        #     Usage Minimum (0x01)
+             0x29, 0x05,        #     Usage Maximum (0x05)
+             0x15, 0x00,        #     Logical Minimum (0)
+             0x25, 0x01,        #     Logical Maximum (1)
+             0x95, 0x05,        #     Report Count (5)
+             0x75, 0x01,        #     Report Size (1)
+             0x81, 0x02,        #     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0x95, 0x01,        #     Report Count (1)
+             0x75, 0x03,        #     Report Size (3)
+             0x81, 0x01,        #     Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0x05, 0x01,        #     Usage Page (Generic Desktop Ctrls)
+             0x09, 0x30,        #     Usage (X)
+             0x09, 0x31,        #     Usage (Y)
+             0x15, 0x81,        #     Logical Minimum (-127)
+             0x25, 0x7F,        #     Logical Maximum (127)
+             0x75, 0x08,        #     Report Size (8)
+             0x95, 0x02,        #     Report Count (2)
+             0x81, 0x06,        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+             0x09, 0x38,        #     Usage (Wheel)
+             0x15, 0x81,        #     Logical Minimum (-127)
+             0x25, 0x7F,        #     Logical Maximum (127)
+             0x75, 0x08,        #     Report Size (8)
+             0x95, 0x01,        #     Report Count (1)
+             0x81, 0x06,        #     Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+             0xC0,              #   End Collection
+             0xC0,              # End Collection
+            )))
 
-CONSUMER_WITH_ID = hid.ReportDescriptor(
-    description="CONSUMER",
-    report_descriptor=bytes([
-        # Consumer ("multimedia") keys
-        0x05, 0x0C,        # Usage Page (Consumer)
-        0x09, 0x01,        # Usage (Consumer Control)
-        0xA1, 0x01,        # Collection (Application)
-        0x85, REPORT_IDS["CONSUMER"], # Report ID (n)
-        0x75, 0x10,        #   Report Size (16)
-        0x95, 0x01,        #   Report Count (1)
-        0x15, 0x01,        #   Logical Minimum (1)
-        0x26, 0x8C, 0x02,  #   Logical Maximum (652)
-        0x19, 0x01,        #   Usage Minimum (Consumer Control)
-        0x2A, 0x8C, 0x02,  #   Usage Maximum (AC Send)
-        0x81, 0x00,        #   Input (Data,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0xC0,              # End Collection
-    ]))
+def consumer_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["CONSUMER"]
+    return hid.ReportDescriptor(
+        description="CONSUMER",
+        report_descriptor=bytes(
+            # Consumer ("multimedia") keys
+            (0x05, data.usage_page, # Usage Page (Consumer)
+             0x09, data.usage,  # Usage (Consumer Control)
+             0xA1, 0x01,        # Collection (Application)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x75, 0x10,        #   Report Size (16)
+             0x95, 0x01,        #   Report Count (1)
+             0x15, 0x01,        #   Logical Minimum (1)
+             0x26, 0x8C, 0x02,  #   Logical Maximum (652)
+             0x19, 0x01,        #   Usage Minimum (Consumer Control)
+             0x2A, 0x8C, 0x02,  #   Usage Maximum (AC Send)
+             0x81, 0x00,        #   Input (Data,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0xC0,              # End Collection
+            )))
 
-SYS_CONTROL_WITH_ID = hid.ReportDescriptor(
-    description="SYS_CONTROL",
-    report_descriptor=bytes([
-        # Power controls
-        0x05, 0x01,        # Usage Page (Generic Desktop Ctrls)
-        0x09, 0x80,        # Usage (Sys Control)
-        0xA1, 0x01,        # Collection (Application)
-        0x85, REPORT_IDS["SYS_CONTROL"], # Report ID (n)
-        0x75, 0x02,        #   Report Size (2)
-        0x95, 0x01,        #   Report Count (1)
-        0x15, 0x01,        #   Logical Minimum (1)
-        0x25, 0x03,        #   Logical Maximum (3)
-        0x09, 0x82,        #   Usage (Sys Sleep)
-        0x09, 0x81,        #   Usage (Sys Power Down)
-        0x09, 0x83,        #   Usage (Sys Wake Up)
-        0x81, 0x60,        #   Input (Data,Array,Abs,No Wrap,Linear,No Preferred State,Null State)
-        0x75, 0x06,        #   Report Size (6)
-        0x81, 0x03,        #   Input (Const,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0xC0,              # End Collection
-    ]))
+def sys_control_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["SYS_CONTROL"]
+    return hid.ReportDescriptor(
+        description="SYS_CONTROL",
+        report_descriptor=bytes(
+            # Power controls
+            (0x05, data.usage_page, # Usage Page (Generic Desktop Ctrls)
+             0x09, data.usage,  # Usage (Sys Control)
+             0xA1, 0x01,        # Collection (Application)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x75, 0x02,        #   Report Size (2)
+             0x95, 0x01,        #   Report Count (1)
+             0x15, 0x01,        #   Logical Minimum (1)
+             0x25, 0x03,        #   Logical Maximum (3)
+             0x09, 0x82,        #   Usage (Sys Sleep)
+             0x09, 0x81,        #   Usage (Sys Power Down)
+             0x09, 0x83,        #   Usage (Sys Wake Up)
+             0x81, 0x60,        #   Input (Data,Array,Abs,No Wrap,Linear,No Preferred State,Null State)
+             0x75, 0x06,        #   Report Size (6)
+             0x81, 0x03,        #   Input (Const,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0xC0,              # End Collection
+            )))
 
-GAMEPAD_WITH_ID = hid.ReportDescriptor(
-    description="GAMEPAD",
-    report_descriptor=bytes([
-        # Gamepad with 16 buttons and two joysticks
-        0x05, 0x01,        # Usage Page (Generic Desktop Ctrls)
-        0x09, 0x05,        # Usage (Game Pad)
-        0xA1, 0x01,        # Collection (Application)
-        0x85, REPORT_IDS["GAMEPAD"], # Report ID (n)
-        0x05, 0x09,        #   Usage Page (Button)
-        0x19, 0x01,        #   Usage Minimum (Button 1)
-        0x29, 0x10,        #   Usage Maximum (Button 16)
-        0x15, 0x00,        #   Logical Minimum (0)
-        0x25, 0x01,        #   Logical Maximum (1)
-        0x75, 0x01,        #   Report Size (1)
-        0x95, 0x10,        #   Report Count (16)
-        0x81, 0x02,        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0x05, 0x01,        #   Usage Page (Generic Desktop Ctrls)
-        0x15, 0x81,        #   Logical Minimum (-127)
-        0x25, 0x7F,        #   Logical Maximum (127)
-        0x09, 0x30,        #   Usage (X)
-        0x09, 0x31,        #   Usage (Y)
-        0x09, 0x32,        #   Usage (Z)
-        0x09, 0x35,        #   Usage (Rz)
-        0x75, 0x08,        #   Report Size (8)
-        0x95, 0x04,        #   Report Count (4)
-        0x81, 0x02,        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0xC0,              # End Collection
-    ]))
+def gamepad_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["GAMEPAD"]
+    return hid.ReportDescriptor(
+        description="GAMEPAD",
+        report_descriptor=bytes(
+            # Gamepad with 16 buttons and two joysticks
+            (0x05, data.usage_page, # Usage Page (Generic Desktop Ctrls)
+             0x09, data.usage,  # Usage (Game Pad)
+             0xA1, 0x01,        # Collection (Application)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x05, 0x09,        #   Usage Page (Button)
+             0x19, 0x01,        #   Usage Minimum (Button 1)
+             0x29, 0x10,        #   Usage Maximum (Button 16)
+             0x15, 0x00,        #   Logical Minimum (0)
+             0x25, 0x01,        #   Logical Maximum (1)
+             0x75, 0x01,        #   Report Size (1)
+             0x95, 0x10,        #   Report Count (16)
+             0x81, 0x02,        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0x05, 0x01,        #   Usage Page (Generic Desktop Ctrls)
+             0x15, 0x81,        #   Logical Minimum (-127)
+             0x25, 0x7F,        #   Logical Maximum (127)
+             0x09, 0x30,        #   Usage (X)
+             0x09, 0x31,        #   Usage (Y)
+             0x09, 0x32,        #   Usage (Z)
+             0x09, 0x35,        #   Usage (Rz)
+             0x75, 0x08,        #   Report Size (8)
+             0x95, 0x04,        #   Report Count (4)
+             0x81, 0x02,        #   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0xC0,              # End Collection
+            )))
 
-DIGITIZER_WITH_ID = hid.ReportDescriptor(
-    description="DIGITIZER",
-    report_descriptor=bytes([
-        # Digitizer (used as an absolute pointer)
-        0x05, 0x0D,        # Usage Page (Digitizers)
-        0x09, 0x02,        # Usage (Pen)
-        0xA1, 0x01,        # Collection (Application)
-        0x85, REPORT_IDS["DIGITIZER"], # Report ID (n)
-        0x09, 0x01,        #   Usage (Stylus)
-        0xA1, 0x00,        #   Collection (Physical)
-        0x09, 0x32,        #     Usage (In-Range)
-        0x09, 0x42,        #     Usage (Tip Switch)
-        0x09, 0x44,        #     Usage (Barrel Switch)
-        0x09, 0x45,        #     Usage (Eraser Switch)
-        0x15, 0x00,        #     Logical Minimum (0)
-        0x25, 0x01,        #     Logical Maximum (1)
-        0x75, 0x01,        #     Report Size (1)
-        0x95, 0x04,        #     Report Count (4)
-        0x81, 0x02,        #     Input (Data,Var,Abs)
-        0x75, 0x04,        #     Report Size (4) -- Filler
-        0x95, 0x01,        #     Report Count (1) -- Filler
-        0x81, 0x01,        #     Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
-        0x05, 0x01,        #     Usage Page (Generic Desktop Ctrls)
-        0x15, 0x00,        #     Logical Minimum (0)
-        0x26, 0xff, 0x7f,  #     Logical Maximum (32767)
-        0x09, 0x30,        #     Usage (X)
-        0x09, 0x31,        #     Usage (Y)
-        0x75, 0x10,        #     Report Size (16)
-        0x95, 0x02,        #     Report Count (2)
-        0x81, 0x02,        #     Input (Data,Var,Abs)
-        0xC0,              #   End Collection
-        0xC0,              # End Collection
-    ]))
+def digitizer_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["DIGITIZER"]
+    return hid.ReportDescriptor(
+        description="DIGITIZER",
+        report_descriptor=bytes(
+            # Digitizer (used as an absolute pointer)
+            (0x05, data.usage_page, # Usage Page (Digitizers)
+             0x09, data.usage,  # Usage (Pen)
+             0xA1, 0x01,        # Collection (Application)
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x09, 0x01,        #   Usage (Stylus)
+             0xA1, 0x00,        #   Collection (Physical)
+             0x09, 0x32,        #     Usage (In-Range)
+             0x09, 0x42,        #     Usage (Tip Switch)
+             0x09, 0x44,        #     Usage (Barrel Switch)
+             0x09, 0x45,        #     Usage (Eraser Switch)
+             0x15, 0x00,        #     Logical Minimum (0)
+             0x25, 0x01,        #     Logical Maximum (1)
+             0x75, 0x01,        #     Report Size (1)
+             0x95, 0x04,        #     Report Count (4)
+             0x81, 0x02,        #     Input (Data,Var,Abs)
+             0x75, 0x04,        #     Report Size (4) -- Filler
+             0x95, 0x01,        #     Report Count (1) -- Filler
+             0x81, 0x01,        #     Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+             0x05, 0x01,        #     Usage Page (Generic Desktop Ctrls)
+             0x15, 0x00,        #     Logical Minimum (0)
+             0x26, 0xff, 0x7f,  #     Logical Maximum (32767)
+             0x09, 0x30,        #     Usage (X)
+             0x09, 0x31,        #     Usage (Y)
+             0x75, 0x10,        #     Report Size (16)
+             0x95, 0x02,        #     Report Count (2)
+             0x81, 0x02,        #     Input (Data,Var,Abs)
+             0xC0,              #   End Collection
+             0xC0,              # End Collection
+            )))
 
-XAC_COMPATIBLE_GAMEPAD_WITH_ID = hid.ReportDescriptor(
-    description="XAC",
-    report_descriptor=bytes([
-        # This descriptor mimics the simple joystick from PDP that the XBox likes
-        0x05, 0x01,         #  Usage Page (Desktop),
-        0x09, 0x05,         #  Usage (Gamepad),
-        0xA1, 0x01,         #  Collection (Application),
-        0x85, REPORT_IDS["XAC_COMPATIBLE_GAMEPAD"], # Report ID (n)
-        0x15, 0x00,         #      Logical Minimum (0),
-        0x25, 0x01,         #      Logical Maximum (1),
-        0x35, 0x00,         #      Physical Minimum (0),
-        0x45, 0x01,         #      Physical Maximum (1),
-        0x75, 0x01,         #      Report Size (1),
-        0x95, 0x08,         #      Report Count (8),
-        0x05, 0x09,         #      Usage Page (Button),
-        0x19, 0x01,         #      Usage Minimum (01h),
-        0x29, 0x08,         #      Usage Maximum (08h),
-        0x81, 0x02,         #      Input (Variable),
-        0x05, 0x01,         #      Usage Page (Desktop),
-        0x26, 0xFF, 0x00,   #      Logical Maximum (255),
-        0x46, 0xFF, 0x00,   #      Physical Maximum (255),
-        0x09, 0x30,         #      Usage (X),
-        0x09, 0x31,         #      Usage (Y),
-        0x75, 0x08,         #      Report Size (8),
-        0x95, 0x02,         #      Report Count (2),
-        0x81, 0x02,         #      Input (Variable),
-        0xC0                #  End Collection
-    ]))
+def xac_compatible_gamepad_hid_descriptor(report_id):
+    data = HID_DEVICE_DATA["XAC_COMPATIBLE_GAMEPAD"]
+    return hid.ReportDescriptor(
+        description="XAC",
+        report_descriptor=bytes(
+            # This descriptor mimics the simple joystick from PDP that the XBox likes
+            (0x05, data.usage_page,  #  Usage Page (Desktop),
+             0x09, data.usage,       #  Usage (Gamepad),
+             0xA1, 0x01,             #  Collection (Application),
+            ) +
+            ((0x85, report_id) if report_id != 0 else ()) +
+            (0x15, 0x00,         #      Logical Minimum (0),
+             0x25, 0x01,         #      Logical Maximum (1),
+             0x35, 0x00,         #      Physical Minimum (0),
+             0x45, 0x01,         #      Physical Maximum (1),
+             0x75, 0x01,         #      Report Size (1),
+             0x95, 0x08,         #      Report Count (8),
+             0x05, 0x09,         #      Usage Page (Button),
+             0x19, 0x01,         #      Usage Minimum (01h),
+             0x29, 0x08,         #      Usage Maximum (08h),
+             0x81, 0x02,         #      Input (Variable),
+             0x05, 0x01,         #      Usage Page (Desktop),
+             0x26, 0xFF, 0x00,   #      Logical Maximum (255),
+             0x46, 0xFF, 0x00,   #      Physical Maximum (255),
+             0x09, 0x30,         #      Usage (X),
+             0x09, 0x31,         #      Usage (Y),
+             0x75, 0x08,         #      Report Size (8),
+             0x95, 0x02,         #      Report Count (2),
+             0x81, 0x02,         #      Input (Variable),
+             0xC0                #  End Collection
+            )))
 
-RAW = hid.ReportDescriptor(
-    description="RAW",
-    report_descriptor=bytes([
-        # Provide vendor-defined
-        0x06, 0xAF, 0xFF,   #  Usage Page (Vendor 0xFFAF "Adafruit"),
-        0x09, 0xAF,         #  Usage (AF),
-        0xA1, 0x01,         #  Collection (Application),
-        0x75, 0x08,         #      Report Size (8),
-        0x15, 0x00,         #      Logical Minimum (0),
-        0x26, 0xFF, 0x00    #      Logical Maximum (255),
-        0x95, 0x08,         #      Report Count (8),
-        0x09, 0x01          #      Usage(xxx)
-        0x81, 0x02          #      Input (Variable)
-        0x95, 0x08,         #      Report Count (8),
-        0x09, 0x02,         #      Usage(xxx)
-        0x91, 0x02,         #      Input (Variable)
-        0xC0                #  End Collection
-    ]))
+def raw_hid_descriptor(report_id):
+    if report_id != 0:
+        raise ValueError("raw hid must not have a report id")
+    data = HID_DEVICE_DATA["RAW"]
+    return hid.ReportDescriptor(
+        description="RAW",
+        report_descriptor=bytes(
+            # Provide vendor-defined
+            # This is a two-byte page value.
+            (0x06, data.usage_page & 0xff, (data.usage_page >> 8) & 0xff, #  Usage Page (Vendor 0xFFAF "Adafruit"),
+             0x09, data.usage,         #  Usage (AF),
+             0xA1, 0x01,         #  Collection (Application),
+             0x75, 0x08,         #      Report Size (8),
+             0x15, 0x00,         #      Logical Minimum (0),
+             0x26, 0xFF, 0x00,   #      Logical Maximum (255),
+             0x95, 0x08,         #      Report Count (8),
+             0x09, 0x01,         #      Usage(xxx)
+             0x81, 0x02,         #      Input (Variable)
+             0x95, 0x08,         #      Report Count (8),
+             0x09, 0x02,         #      Usage(xxx)
+             0x91, 0x02,         #      Input (Variable)
+             0xC0                #  End Collection
+            )))
 
-# Byte count for each kind of report. Length does not include report ID in first byte.
-REPORT_DESCRIPTORS = {
-    "KEYBOARD" : KEYBOARD_WITH_ID,
-    "MOUSE" : MOUSE_WITH_ID,
-    "CONSUMER" : CONSUMER_WITH_ID,
-    "SYS_CONTROL" : SYS_CONTROL_WITH_ID,
-    "GAMEPAD" : GAMEPAD_WITH_ID,
-    "DIGITIZER" : DIGITIZER_WITH_ID,
-    "XAC_COMPATIBLE_GAMEPAD" : XAC_COMPATIBLE_GAMEPAD_WITH_ID,
-    "RAW" : RAW_WITH_ID,
-    }
+# Function to call for each kind of HID descriptor.
+REPORT_DESCRIPTOR_FUNCTIONS = {
+    "KEYBOARD" : keyboard_hid_descriptor,
+    "MOUSE" : mouse_hid_descriptor,
+    "CONSUMER" : consumer_hid_descriptor,
+    "SYS_CONTROL" : sys_control_hid_descriptor,
+    "GAMEPAD" : gamepad_hid_descriptor,
+    "DIGITIZER" : digitizer_hid_descriptor,
+    "XAC_COMPATIBLE_GAMEPAD" : xac_compatible_gamepad_hid_descriptor,
+    "RAW" : raw_hid_descriptor,
+}