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SAMD21 USB host not working

Open maxgerhardt opened this issue 2 months ago • 4 comments

Operating System

Windows 10

Commit SHA

331c263400dd5ccf77264cab1fa6bbd9f374b44e

Board

Adafruit Feather M0 (RFM95)

Firmware

https://github.com/maxgerhardt/samd21-usb-host-repro/

What happened ?

When starting up the TinyUSB stack configured for just USB host, and with only the CDC host driver enabled, no hubs, the enumeration of USB devices files with a timeout.

When using the same hardware with the USBHost library (https://github.com/arduino/ArduinoCore-samd/tree/master/libraries/USBHost/examples/USB_desc), it can enumerate the USB device just fine.

Starting USB Descriptor test
Initializing USB

01
--

Device descriptor: 
Descriptor Length:12
Descriptor type:01
USB version:0110
Device class:00
Device Subclass:00
Device Protocol:00
Max.packet size:40
Vendor  ID:10C4
Product ID:EA60
Revision ID:0100
..

How to reproduce ?

  • Download reference firmware repo in VSCode + PlatformIO extension
  • Plug in Adafruit Feather M0 via USB port, quickly double-press RESET button to get it into USB bootloader mode
  • Upload firmware via project tasks -> Upload
  • Unplug the USB cable from the Feather M0
  • Use a USB-to-UART adapter with VCC, GND and RX connected to "USB", "GND" and "TX1" of the Feather (gives the Feather power and can read debug logs)
  • use a micro USB OTG adapter to get a female USB-A port on on the Feather
  • plug in a device (example: CP2102 adapter)

Debug Log as txt file (LOG/CFG_TUSB_DEBUG=2)

TinyUSB Dual Device Info Example
Enabling USB clock
Setting USB handler
Beginning USB host
USBH init on controller 0, speed = Full
sizeof(usbh_data_t) = 28
sizeof(usbh_device_t) = 94
sizeof(hcd_event_t) = 12
sizeof(tuh_xfer_t) = 24
sizeof(tu_fifo_t) = 12
sizeof(tu_edpt_stream_t) = 20
Got 1 host drivers
CDC init
sizeof(cdch_interface_t) = 200
Initialized all drivers, now initing controller
Resetting USB controller
Done restting USB controller
Waiting for USB sync
Got USB sync
Enabling USB interrupts now
Beginning USB host done
[0:] USBH Device Attach
Full Speed
[0:0] Open EP0 with Size = 8
Get 8 byte of Device Descriptor
[0:0] Get Descriptor: 80 06 00 01 00 00 08 00
[:0] on EP 00 with 8 bytes: OK
[:0] on EP 80 with 8 bytes: OK
[0:0] Control data:
  0000:  12 01 10 01 00 00 00 40                          |.......@|
[:0] on EP 00 with 0 bytes: TIMEOUT

Screenshots

Image

I have checked existing issues, discussion and documentation

  • [x] I confirm I have checked existing issues, discussion and documentation.

maxgerhardt avatar Oct 11 '25 22:10 maxgerhardt

Note: The config of the project in regards to CFG_TUH_HUB matches what is being told about TIMEOUTS in exactly the original PR https://github.com/hathach/tinyusb/pull/2573.

I use the exact same pin mode setup and clock setup as the USBHost library (this, ref), since I work within the context of the Adafruit SAMD core and don't include the family.c of the SAMD21 family from this repo.

The board has a 32.768 kHz crystal oscillator on-board, which is used during clock setup as reference for the delay-locked-loop DFLL48M. (CRYSTALLESS is not defined for the variant in this section).

I have tried several things:

  • turning on the HCD_SAMD_FAKE_FNUM driver option
  • substituting the "local pad calibration" from the working USBHost library
  • starting USB peripheral in "forced FS mode" instead of "normal" mode (USB_HOST_CTRLB_SPDCONF_NORMAL)

None of which has made a difference.

maxgerhardt avatar Oct 11 '25 22:10 maxgerhardt

thanks for detailed report, can you do the quick check and run this repo stock example with cmake build e.g host/cdc_msc_hid or host/device_info to see if that works. Arduino core may need more glueing.

PS: I haven't tried to run tinyusb with host most on arduinocore either. Maybe this is time to add that support

hathach avatar Oct 12 '25 02:10 hathach

I compiled the host/device_info example from 331c263400dd5ccf77264cab1fa6bbd9f374b44e for the feather_m0_express, with the addition that I changed

https://github.com/hathach/tinyusb/blob/331c263400dd5ccf77264cab1fa6bbd9f374b44e/hw/bsp/samd21/boards/feather_m0_express/board.h#L47-L49

to be

// UART
#define UART_SERCOM           0
#define UART_RX_PIN           11
#define UART_TX_PIN           10

This seems to be a bug in all SAMD board.h, the UART_SERCOM is left undefined so it doesn't trigger the right code to activate UART logging, on top of that all RX / TX pins seem wrong; On the Feather M0 (and the same on my board), TX = PA10, RX = PA11, as schematics say.

I ran the example with examples\host\device_info\src\tusb_config.h modified with

#define CFG_TUSB_DEBUG        2

and

#define CFG_TUH_HUB                 0

to respect the issue as linked in the original PR.

Uploaded it over USB with bossac

C:\Users\Max\.platformio\packages\[email protected]\bossac --info --debug --port "COM40" --write --verify --reset --erase -U true "C:\Users\Max\temp\tinyusb\examples\build\feather_m0_express\host\device_info\RelWithDebInfo\device_info.bin"

Output over UART and when connecting the same USB device (USB-to-serial adapter) was

TinyUSB Device Info Example
USBH init on controller 0, speed = Auto
sizeof(usbh_data_t) = 28
sizeof(usbh_device_t) = 94
sizeof(hcd_event_t) = 12
sizeof(tuh_xfer_t) = 24
sizeof(tu_fifo_t) = 12
sizeof(tu_edpt_stream_t) = 20
[0:] USBH Device Attach
Full Speed
[0:0] Open EP0 with Size = 8
Get 8 byte of Device Descriptor
[0:0] Get Descriptor: 80 06 00 01 00 00 08 00
[:0] on EP 00 with 8 bytes: OK
[:0] on EP 80 with 8 bytes: OK
[0:0] Control data:
  0000:  12 01 10 01 00 00 00 40                          |.......@|
[:0] on EP 00 with 0 bytes: TIMEOUT

which is exactly equal to the one I got in my attempt with the Arduino USB core.

maxgerhardt avatar Oct 12 '25 11:10 maxgerhardt

thank you for confirmation, I will test and get back to you later. I think I tested with samd51 previously, will try with the M0 this time.

hathach avatar Oct 14 '25 17:10 hathach