add other speed descriptor callback tud_descriptor_other_speed_configuration_cb()

example implement tud_descriptor_device_qualifier_cb() and
tud_descriptor_other_speed_configuration_cb() on high speed device to
fully compliant to usbcv

5 files changed, 284 insertions, 31 deletions

diff --git a/examples/device/cdc_dual_ports/src/usb_descriptors.c b/examples/device/cdc_dual_ports/src/usb_descriptors.c
index 02ccbcc9e..aa400d486 100644
--- a/examples/device/cdc_dual_ports/src/usb_descriptors.c
+++ b/examples/device/cdc_dual_ports/src/usb_descriptors.c
@@ -35,6 +35,9 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                            _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
@@ -42,7 +45,7 @@ tusb_desc_device_t const desc_device =
 {
     .bLength            = sizeof(tusb_desc_device_t),
     .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+    .bcdUSB             = USB_BCD,
 
     // Use Interface Association Descriptor (IAD) for CDC
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
@@ -51,7 +54,7 @@ tusb_desc_device_t const desc_device =
     .bDeviceProtocol    = MISC_PROTOCOL_IAD,
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
+    .idVendor           = USB_VID,
     .idProduct          = USB_PID,
     .bcdDevice          = 0x0100,
 
@@ -128,6 +131,8 @@ uint8_t const desc_fs_configuration[] =
 };
 
 #if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
 uint8_t const desc_hs_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
@@ -139,7 +144,44 @@ uint8_t const desc_hs_configuration[] =
   // 2nd CDC: Interface number, string index, EP notification address and size, EP data address (out, in) and size.
   TUD_CDC_DESCRIPTOR(ITF_NUM_CDC_1, 4, EPNUM_CDC_1_NOTIF, 8, EPNUM_CDC_1_OUT, EPNUM_CDC_1_IN, 512),
 };
-#endif
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier =
+{
+  .bLength            = sizeof(tusb_desc_device_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE,
+  .bcdUSB             = USB_BCD,
+
+  .bDeviceClass       = TUSB_CLASS_MISC,
+  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bNumConfigurations = 0x01,
+  .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void)
+{
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+
+  // if link speed is high return fullspeed config, and vice versa
+  return (tud_speed_get() == TUSB_SPEED_HIGH) ?  desc_fs_configuration : desc_hs_configuration;
+}
+
+#endif // highspeed
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
diff --git a/examples/device/cdc_msc/src/usb_descriptors.c b/examples/device/cdc_msc/src/usb_descriptors.c
index 3cf1eaf91..34537b8f0 100644
--- a/examples/device/cdc_msc/src/usb_descriptors.c
+++ b/examples/device/cdc_msc/src/usb_descriptors.c
@@ -35,32 +35,35 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                            _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
 tusb_desc_device_t const desc_device =
 {
-    .bLength            = sizeof(tusb_desc_device_t),
-    .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+  .bLength            = sizeof(tusb_desc_device_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE,
+  .bcdUSB             = USB_BCD,
 
-    // Use Interface Association Descriptor (IAD) for CDC
-    // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
-    .bDeviceClass       = TUSB_CLASS_MISC,
-    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
-    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+  // Use Interface Association Descriptor (IAD) for CDC
+  // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
+  .bDeviceClass       = TUSB_CLASS_MISC,
+  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
 
-    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
-    .idProduct          = USB_PID,
-    .bcdDevice          = 0x0100,
+  .idVendor           = USB_VID,
+  .idProduct          = USB_PID,
+  .bcdDevice          = 0x0100,
 
-    .iManufacturer      = 0x01,
-    .iProduct           = 0x02,
-    .iSerialNumber      = 0x03,
+  .iManufacturer      = 0x01,
+  .iProduct           = 0x02,
+  .iSerialNumber      = 0x03,
 
-    .bNumConfigurations = 0x01
+  .bNumConfigurations = 0x01
 };
 
 // Invoked when received GET DEVICE DESCRIPTOR
@@ -82,8 +85,6 @@ enum
   ITF_NUM_TOTAL
 };
 
-#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)
-
 #if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
   // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
   // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
@@ -126,6 +127,9 @@ enum
 
 #endif
 
+#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)
+
+// full speed configuration
 uint8_t const desc_fs_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
@@ -139,6 +143,9 @@ uint8_t const desc_fs_configuration[] =
 };
 
 #if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
+// high speed configuration
 uint8_t const desc_hs_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
@@ -150,7 +157,54 @@ uint8_t const desc_hs_configuration[] =
   // Interface number, string index, EP Out & EP In address, EP size
   TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 512),
 };
-#endif
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier =
+{
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+  .bcdUSB             = USB_BCD,
+
+  .bDeviceClass       = TUSB_CLASS_MISC,
+  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bNumConfigurations = 0x01,
+  .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void)
+{
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+
+  // if link speed is high return fullspeed config, and vice versa
+  // Note: the descriptor type is OHER_SPEED_CONFIG instead of CONFIG
+  memcpy(desc_other_speed_config,
+         (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_fs_configuration : desc_hs_configuration,
+         CONFIG_TOTAL_LEN);
+
+  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+  return desc_other_speed_config;
+}
+
+#endif // highspeed
 
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR
diff --git a/examples/device/cdc_msc_freertos/src/usb_descriptors.c b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
index c8dbcd415..f3ff305f8 100644
--- a/examples/device/cdc_msc_freertos/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_freertos/src/usb_descriptors.c
@@ -35,6 +35,9 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                            _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
@@ -42,7 +45,7 @@ tusb_desc_device_t const desc_device =
 {
     .bLength            = sizeof(tusb_desc_device_t),
     .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+    .bcdUSB             = USB_BCD,
 
     // Use Interface Association Descriptor (IAD) for CDC
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
@@ -52,7 +55,7 @@ tusb_desc_device_t const desc_device =
 
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
+    .idVendor           = USB_VID,
     .idProduct          = USB_PID,
     .bcdDevice          = 0x0100,
 
@@ -82,8 +85,6 @@ enum
   ITF_NUM_TOTAL
 };
 
-#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)
-
 #if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
   // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
   // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
@@ -114,6 +115,8 @@ enum
 
 #endif
 
+#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MSC_DESC_LEN)
+
 uint8_t const desc_fs_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
@@ -127,6 +130,9 @@ uint8_t const desc_fs_configuration[] =
 };
 
 #if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
+// high speed configuration
 uint8_t const desc_hs_configuration[] =
 {
   // Config number, interface count, string index, total length, attribute, power in mA
@@ -138,7 +144,54 @@ uint8_t const desc_hs_configuration[] =
   // Interface number, string index, EP Out & EP In address, EP size
   TUD_MSC_DESCRIPTOR(ITF_NUM_MSC, 5, EPNUM_MSC_OUT, EPNUM_MSC_IN, 512),
 };
-#endif
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier =
+{
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+  .bcdUSB             = USB_BCD,
+
+  .bDeviceClass       = TUSB_CLASS_MISC,
+  .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+  .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bNumConfigurations = 0x01,
+  .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void)
+{
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+
+  // if link speed is high return fullspeed config, and vice versa
+  // Note: the descriptor type is OHER_SPEED_CONFIG instead of CONFIG
+  memcpy(desc_other_speed_config,
+         (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_fs_configuration : desc_hs_configuration,
+         CONFIG_TOTAL_LEN);
+
+  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+  return desc_other_speed_config;
+}
+
+#endif // highspeed
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
diff --git a/examples/device/hid_composite/src/usb_descriptors.c b/examples/device/hid_composite/src/usb_descriptors.c
index b9a6e7292..e760b20ba 100644
--- a/examples/device/hid_composite/src/usb_descriptors.c
+++ b/examples/device/hid_composite/src/usb_descriptors.c
@@ -36,6 +36,9 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                            _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
@@ -43,13 +46,13 @@ tusb_desc_device_t const desc_device =
 {
     .bLength            = sizeof(tusb_desc_device_t),
     .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+    .bcdUSB             = USB_BCD,
     .bDeviceClass       = 0x00,
     .bDeviceSubClass    = 0x00,
     .bDeviceProtocol    = 0x00,
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
+    .idVendor           = USB_VID,
     .idProduct          = USB_PID,
     .bcdDevice          = 0x0100,
 
@@ -111,12 +114,62 @@ uint8_t const desc_configuration[] =
   TUD_HID_DESCRIPTOR(ITF_NUM_HID, 0, HID_ITF_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 5)
 };
 
+#if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier =
+{
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+  .bcdUSB             = USB_BCD,
+
+  .bDeviceClass       = 0x00,
+  .bDeviceSubClass    = 0x00,
+  .bDeviceProtocol    = 0x00,
+
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bNumConfigurations = 0x01,
+  .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void)
+{
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+
+  // other speed config is basically configuration with type = OHER_SPEED_CONFIG
+  memcpy(desc_other_speed_config, desc_configuration, CONFIG_TOTAL_LEN);
+  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+  // this example use the same configuration for both high and full speed mode
+  return desc_other_speed_config;
+}
+
+#endif // highspeed
+
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
 uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 {
   (void) index; // for multiple configurations
+
+  // This example use the same configuration for both high and full speed mode
   return desc_configuration;
 }
 
diff --git a/examples/device/hid_composite_freertos/src/usb_descriptors.c b/examples/device/hid_composite_freertos/src/usb_descriptors.c
index b9a6e7292..791813fdf 100644
--- a/examples/device/hid_composite_freertos/src/usb_descriptors.c
+++ b/examples/device/hid_composite_freertos/src/usb_descriptors.c
@@ -36,6 +36,9 @@
 #define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | \
                            _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
 
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
@@ -43,13 +46,13 @@ tusb_desc_device_t const desc_device =
 {
     .bLength            = sizeof(tusb_desc_device_t),
     .bDescriptorType    = TUSB_DESC_DEVICE,
-    .bcdUSB             = 0x0200,
+    .bcdUSB             = USB_BCD,
     .bDeviceClass       = 0x00,
     .bDeviceSubClass    = 0x00,
     .bDeviceProtocol    = 0x00,
     .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
 
-    .idVendor           = 0xCafe,
+    .idVendor           = USB_VID,
     .idProduct          = USB_PID,
     .bcdDevice          = 0x0100,
 
@@ -111,6 +114,54 @@ uint8_t const desc_configuration[] =
   TUD_HID_DESCRIPTOR(ITF_NUM_HID, 0, HID_ITF_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 5)
 };
 
+#if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier =
+{
+  .bLength            = sizeof(tusb_desc_device_qualifier_t),
+  .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+  .bcdUSB             = USB_BCD,
+
+  .bDeviceClass       = 0x00,
+  .bDeviceSubClass    = 0x00,
+  .bDeviceProtocol    = 0x00,
+
+  .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+  .bNumConfigurations = 0x01,
+  .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void)
+{
+  return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+
+  // other speed config is basically configuration with type = OHER_SPEED_CONFIG
+  memcpy(desc_other_speed_config, desc_configuration, CONFIG_TOTAL_LEN);
+  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+  // this example use the same configuration for both high and full speed mode
+  return desc_other_speed_config;
+}
+
+#endif // highspeed
+
 // Invoked when received GET CONFIGURATION DESCRIPTOR
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete