I'm developing a custom HID-compliant UPS based on Arduino Micro. When I connect it to Apple OSX (I'm using Macbook as a host machine) or Windows 10 VM machine, my "UPS" is correctly determined by the operating system and I can also report remaining battery capacity and other parameters back to the host.
However, when I plug it to Ubuntu 18.04 LTS, it is not working (not showing up in the Power settings). At the same time, the commercial APC UPS works just fine under Ubuntu. Posting of lsusb is below:
abratchik@ubuntu-parallels-vm:~$ lsusb
Bus 001 Device 003: ID 203a:fffa
Bus 001 Device 002: ID 203a:fffa
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 203a:fff9
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 004: ID 2341:8036 Arduino SA Leonardo (CDC ACM, HID)
Bus 002 Device 006: ID 051d:0003 American Power Conversion UPS
Bus 002 Device 003: ID 203a:fffe
Bus 002 Device 002: ID 203a:fffc
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
abratchik@ubuntu-parallels-vm:~$ lsusb -t
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 5000M
|__ Port 1: Dev 2, If 0, Class=Video, Driver=uvcvideo, 5000M
|__ Port 1: Dev 2, If 1, Class=Video, Driver=uvcvideo, 5000M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
|__ Port 1: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 1: Dev 2, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 3, If 0, Class=Hub, Driver=hub/15p, 12M
|__ Port 5: Dev 4, If 2, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 5: Dev 4, If 0, Class=Communications, Driver=cdc_acm, 12M
|__ Port 5: Dev 4, If 1, Class=CDC Data, Driver=cdc_acm, 12M
|__ Port 4: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 12M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/15p, 480M
|__ Port 1: Dev 2, If 0, Class=Printer, Driver=usblp, 480M
|__ Port 2: Dev 3, If 0, Class=Printer, Driver=usblp, 480M
In the first printout, my custom UPS is coming with ID 2341:8036 and APC UPS is 051d:0003. Second printout also shows both of them identified correctly as HID device (Bus 02 port 5 interface 2 for my UPS and port 4 interface 0 for APC) and both are using usbhid driver, which is also correct and as expected.
However, APC is correctly detected by Ubuntu as UPS while my UPS is not showing up at all:
parallels-vm:~$ upower -e
/org/freedesktop/UPower/devices/line_power_ADP0
/org/freedesktop/UPower/devices/battery_BAT0
/org/freedesktop/UPower/devices/ups_hiddev3
/org/freedesktop/UPower/devices/DisplayDevice
abratchik@ubuntu-parallels-vm:~$ upower -i /org/freedesktop/UPower/devices/ups_hiddev3
native-path: /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2.4/2-2.4:1.0/usbmisc/hiddev3
vendor: American Power Conversion
model: Smart-UPS C 1500 FW:UPS 10.0 / ID=1005
serial: 3S1838X02676
power supply: yes
updated: Thu 03 Dec 2020 10:00:04 AM +04 (-11 seconds ago)
has history: yes
has statistics: yes
ups
present: yes
state: fully-charged
warning-level: none
time to empty: 2.0 hours
percentage: 100%
icon-name: 'battery-full-charged-symbolic'
Also RX/TX LEDs are not blinking on Arduino board so looks like there is no exchange between the board and the VM. The same board is working just fine under OSX and Windows 10 as I mentioned above.
When I check communication during the handshake between my device and the host with Wireshark, it seems like all events are stopping after usbhid driver gets the HID descriptor. But the descriptor itself can be correctly dumped using the usbhid-dump utility and parsing of it also works perfectly fine. I suspect if the descriptor were an issue it would not work under OSX and Windows as well.
dmesg also gives nothing unnusual about my device - messages during the handshake look the same as APC:
[239474.147682] usb 2-2.6: New USB device found, idVendor=2341, idProduct=8036, bcdDevice= 1.00
[239474.147684] usb 2-2.6: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[239474.147685] usb 2-2.6: Product: Arduino Leonardo
[239474.147686] usb 2-2.6: Manufacturer: Arduino LLC
[239474.147687] usb 2-2.6: SerialNumber: HIDKN
[239474.194582] cdc_acm 2-2.6:1.0: ttyACM0: USB ACM device
[239474.209496] hid-generic 0003:2341:8036.0038: hiddev2,hidraw2: USB HID v1.01 Device [Arduino LLC Arduino Leonardo] on usb-0000:00:1d.0-2.6/input2
[239581.283918] usb 2-2.4: new full-speed USB device number 35 using uhci_hcd
[239581.397670] usb 2-2.4: New USB device found, idVendor=051d, idProduct=0003, bcdDevice= 1.06
[239581.397674] usb 2-2.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[239581.397675] usb 2-2.4: Product: Smart-UPS C 1500 FW:UPS 10.0 / ID=1005
[239581.397676] usb 2-2.4: Manufacturer: American Power Conversion
[239581.397676] usb 2-2.4: SerialNumber: 3S1838X02676
[239581.481215] hid-generic 0003:051D:0003.0039: hiddev3,hidraw3: USB HID v1.00 Device [American Power Conversion Smart-UPS C 1500 FW:UPS 10.0 / ID=1005] on
I googled a bit and found that many articles on this subject are referring to usbhid-ups driver, which is not installed by default and requires some configuration as I understood. I really would like to avoid this and make my UPS fully "plug-and-play", similar to APC UPS. Already lost of ideas what could be different for my UPS, except may be Vendor ID/Product ID but that would be my last option to try and change these. Any hint what I'm missing is much appreciated.