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Ubuntu 20.04

My laptop has touchscreen device which enables touching function. I can view its info by command less /proc/bus/input/devices. It looks like:

I: Bus=0018 Vendor=06cb Product=1a1b Version=0100
N: Name="06CB:00 06CB:1A1B"
P: Phys=i2c-06CB:00
S: Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-2/i2c-06CB:00/0018:06CB:1A1B.0002/input/input14
U: Uniq=
H: Handlers=mouse2 event6
B: PROP=2
B: EV=1b
B: KEY=400 0 0 0 0 0
B: ABS=260800000000003
B: MSC=20

I can view the touching event log by sudo cat /dev/input/event6. So I can believe my ubuntu 20.04 has well support about touch-screen. And I expect lsusb should includes the touch-screen device info. But it doesn't. The output is:

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 13d3:56f2 IMC Networks USB camera
Bus 001 Device 003: ID 8087:0026 Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Do I mis-understand something? Any suggestion will be helpful. Thanks in advance.

I tried lspci:

00:00.0 Host bridge: Intel Corporation Device 9b61 (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 02)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 0c)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Comet Lake Thermal Subsytem
00:14.0 USB controller: Intel Corporation Device 02ed
00:14.2 RAM memory: Intel Corporation Device 02ef
00:14.3 Network controller: Intel Corporation Wireless-AC 9462
00:15.0 Serial bus controller [0c80]: Intel Corporation Serial IO I2C Host Controller
00:15.1 Serial bus controller [0c80]: Intel Corporation Comet Lake Serial IO I2C Host Controller
00:16.0 Communication controller: Intel Corporation Comet Lake Management Engine Interface
00:1d.0 PCI bridge: Intel Corporation Device 02b0 (rev f0)
00:1e.0 Communication controller: Intel Corporation Device 02a8
00:1e.3 Serial bus controller [0c80]: Intel Corporation Device 02ab
00:1f.0 ISA bridge: Intel Corporation Device 0284
00:1f.3 Audio device: Intel Corporation Device 02c8
00:1f.4 SMBus: Intel Corporation Device 02a3
00:1f.5 Serial bus controller [0c80]: Intel Corporation Comet Lake SPI (flash) Controller
01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983

It seems that no touch screen device included. Any further suggestion please? Thanks~

2
  • 1
    The first result indicates a PCI device, not USB. So, try lspci instead. May 10 at 7:25
  • So what is the real problem? Does the touchscreen work?
    – Pilot6
    May 10 at 10:58

1 Answer 1

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The reason lsusb or lspci don't show the touchpad is that the device is not connected directly to USB or PCI. It is connected to i2c bus.

You can see it in Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-2/i2c-06CB:00/0018:06CB:1A1B.0002/input/input14

The i2c controller is connected to the PCI bus and you can see it too.

00:15.0 Serial bus controller [0c80]: Intel Corporation Serial IO I2C Host Controller
00:15.1 Serial bus controller [0c80]: Intel Corporation Comet Lake Serial IO I2C Host Controller   

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