Hello again, I realize this is partially spec help, my apologies. I'm not aware of a better
place to potentially ask for guidance.
Interesting to note is that Windows fails to enumerate but Linux falls back to USB2.
On Windows, enumeration fails early enough I get no useful message.
The code is in Rust. If that is problematic I can rewrite it, but it is very close to C. The
USB HS descriptors work just fine. I suspect I have made a mistake in the companion
descriptors. It is hard to find good isochronous examples.
Thanks in advance.
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#[derive(Debug)]
#[repr(C, packed)]
pub struct usb_functionfs_ep_descs {
intf: usb_interface_descriptor,
sink: usb_endpoint_descriptor,
source: usb_endpoint_descriptor,
intf_alt1: usb_interface_descriptor,
isoc_sink: usb_endpoint_descriptor,
isoc_source: usb_endpoint_descriptor,
}
// Per example this is not packed.
#[derive(Debug)]
pub struct usb_functionfs_ss_ep_descs {
intf: usb_interface_descriptor,
sink: usb_endpoint_descriptor,
sink_comp: usb_ss_ep_comp_descriptor,
source: usb_endpoint_descriptor,
source_comp: usb_ss_ep_comp_descriptor,
intf_alt1: usb_interface_descriptor,
isoc_sink: usb_endpoint_descriptor,
isoc_sink_comp: usb_ss_ep_comp_descriptor,
isoc_source: usb_endpoint_descriptor,
isoc_source_comp: usb_ss_ep_comp_descriptor,
}
#[derive(Debug)]
#[repr(C, packed)]
pub struct usb_functionfs_descriptors {
header: usb_functionfs_descs_head_v2,
fs_count: u32,
hs_count: u32,
ss_count: u32,
fs_descs: usb_functionfs_ep_descs,
hs_descs: usb_functionfs_ep_descs,
ss_descs: usb_functionfs_ss_ep_descs,
}
pub const fn descriptors() -> usb_functionfs_descriptors {
usb_functionfs_descriptors {
header: usb_functionfs_descs_head_v2 {
magic: FUNCTIONFS_DESCRIPTORS_MAGIC_V2.to_le(),
flags: (functionfs_flags_FUNCTIONFS_HAS_FS_DESC |
functionfs_flags_FUNCTIONFS_HAS_HS_DESC |
functionfs_flags_FUNCTIONFS_HAS_SS_DESC).to_le(),
length: (mem::size_of::<usb_functionfs_descriptors>() as u32).to_le(),
},
fs_count: 6u32.to_le(),
hs_count: 6u32.to_le(),
ss_count: 10u32.to_le(),
fs_descs: usb_functionfs_ep_descs {
intf: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 0,
bAlternateSetting: 0,
bNumEndpoints: 2,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 1,
},
sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 1 | USB_DIR_IN as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 0,
bInterval: 0,
bRefresh: 0,
bSynchAddress: 0,
},
source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 2 | USB_DIR_OUT as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 0,
bInterval: 0,
bRefresh: 0,
bSynchAddress: 0,
},
intf_alt1: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 1,
bAlternateSetting: 1,
bNumEndpoints: 2,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 2,
},
isoc_sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 3 | USB_DIR_IN as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
isoc_source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 4 | USB_DIR_OUT as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
},
hs_descs: usb_functionfs_ep_descs {
intf: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 0,
bAlternateSetting: 0,
bNumEndpoints: 4,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 1,
},
sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 1 | USB_DIR_IN as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 512u16.to_le(),
bInterval: 0,
bRefresh: 0,
bSynchAddress: 0,
},
source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 2 | USB_DIR_OUT as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 512u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
intf_alt1: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 1,
bAlternateSetting: 1,
bNumEndpoints: 2,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 2,
},
isoc_sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 3 | USB_DIR_IN as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
isoc_source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 4 | USB_DIR_OUT as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
},
ss_descs: usb_functionfs_ss_ep_descs {
intf: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 0,
bAlternateSetting: 0,
bNumEndpoints: 4,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 1,
},
sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 1 | USB_DIR_IN as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 1024u16.to_le(),
bInterval: 0,
bRefresh: 0,
bSynchAddress: 0,
},
sink_comp: usb_ss_ep_comp_descriptor {
bLength: USB_DT_SS_EP_COMP_SIZE as u8,
bDescriptorType: USB_DT_SS_ENDPOINT_COMP as u8,
bMaxBurst: 0,
bmAttributes: 0,
wBytesPerInterval: 0,
},
source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 2 | USB_DIR_OUT as u8,
bmAttributes: USB_ENDPOINT_XFER_BULK as u8,
wMaxPacketSize: 1024u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
source_comp: usb_ss_ep_comp_descriptor {
bLength: USB_DT_SS_EP_COMP_SIZE as u8,
bDescriptorType: USB_DT_SS_ENDPOINT_COMP as u8,
bMaxBurst: 0,
bmAttributes: 0,
wBytesPerInterval: 0,
},
intf_alt1: usb_interface_descriptor {
bLength: mem::size_of::<usb_interface_descriptor>() as u8,
bDescriptorType: USB_DT_INTERFACE as u8,
bInterfaceNumber: 1,
bAlternateSetting: 1,
bNumEndpoints: 2,
bInterfaceClass: USB_CLASS_VENDOR_SPEC as u8,
bInterfaceSubClass: 0,
bInterfaceProtocol: 0,
iInterface: 2,
},
isoc_sink: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 3 | USB_DIR_IN as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
isoc_sink_comp: usb_ss_ep_comp_descriptor {
bLength: USB_DT_SS_EP_COMP_SIZE as u8,
bDescriptorType: USB_DT_SS_ENDPOINT_COMP as u8,
bMaxBurst: 0,
bmAttributes: 0,
wBytesPerInterval: 0,
},
isoc_source: usb_endpoint_descriptor {
bLength: mem::size_of::<usb_endpoint_descriptor>() as u8,
bDescriptorType: USB_DT_ENDPOINT as u8,
bEndpointAddress: 4 | USB_DIR_OUT as u8,
bmAttributes: (USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC | USB_ENDPOINT_USAGE_DATA) as u8,
wMaxPacketSize: 256u16.to_le(),
bInterval: 1,
bRefresh: 0,
bSynchAddress: 0,
},
isoc_source_comp: usb_ss_ep_comp_descriptor {
bLength: USB_DT_SS_EP_COMP_SIZE as u8,
bDescriptorType: USB_DT_SS_ENDPOINT_COMP as u8,
bMaxBurst: 0,
bmAttributes: 0,
wBytesPerInterval: 0,
},
},
}
}
