Integrated webcam not working on Dell Latitude 7640 running Ubuntu 23.04

(I was invited here to raise this is as a new question)

I have a Dell Latitude 7640 laptop (2023) running Ubuntu 23.04.

The integrated webcam is not recognized, though an external one works fine. The integrated camera is described by the manufacturer as "FHD/IR Camera with ExpressSign-In + Intelligent Privacy, Temporal Noise Reduction, Camera Shutter, Mic" and works well on Windows (Windows no longer installed on my machine).

Without the external webcam plugged in, asking

sudo lshw -C video

produces

  *-display                 
   description: VGA compatible controller
   product: Raptor Lake-P [Iris Xe Graphics]
   vendor: Intel Corporation
   physical id: 2
   bus info: pci@0000:00:02.0
   logical name: /dev/fb0
   version: 04
   width: 64 bits
   clock: 33MHz
   capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
   configuration: depth=32 driver=i915 latency=0 mode=1920x1200 resolution=1920,1200 visual=truecolor xres=1920 yres=1200
   resources: iomemory:600-5ff iomemory:400-3ff irq:201 memory:6055000000-6055ffffff memory:4000000000-400fffffff ioport:3000(size=64) memory:c0000-dffff memory:4010000000-4016ffffff memory:4020000000-40ffffffff

And

ls -l /dev/vid*;id

returns

ls: cannot access '/dev/vid*': No such file or directory
uid=1000(user) gid=1000(user) groups=1000(user),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),122(lpadmin),135(lxd),136(sambashare)

With an external webcam plugged in, asking lsusb I get

Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 003: ID 0a5c:5843 Broadcom Corp. 58200
Bus 002 Device 002: ID 8086:0b63 Intel Corp. USB Bridge
Bus 002 Device 007: ID 0c45:6367 Microdia USB 2.0 Camera
Bus 002 Device 004: ID 8087:0033 Intel Corp. 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Following the request below by @Raffles, without the external webcam plugged in I asked inxi -Fxz and got the following:

System:
Kernel: 6.2.0-24-generic arch: x86_64 bits: 64 compiler: N/A
Desktop: Cinnamon v: 5.6.7 Distro: Ubuntu 23.04 (Lunar Lobster)
Machine:
Type: Laptop System: Dell product: Latitude 7640 v: N/A
serial: <superuser required>
Mobo: Dell model: 0982JK v: A00 serial: <superuser required> UEFI: Dell
v: 1.4.1 date: 05/31/2023
Battery:
ID-1: BAT0 charge: 49.4 Wh (87.6%) condition: 56.4/57.0 Wh (98.9%)
volts: 12.5 min: 11.4 model: BYD DELL 047T034 status: discharging
CPU:
Info: 10-core (2-mt/8-st) model: 13th Gen Intel Core i7-1365U bits: 64
type: MST AMCP arch: Raptor Lake rev: 3 cache: L1: 928 KiB L2: 6.5 MiB
L3: 12 MiB
Speed (MHz): avg: 2508 high: 2700 min/max: 400/5200:3900 cores: 1: 2700
2: 2700 3: 2700 4: 2700 5: 2700 6: 2700 7: 400 8: 2700 9: 2700 10: 2700
11: 2700 12: 2700 bogomips: 64512
Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
Device-1: Intel Raptor Lake-P [Iris Xe Graphics] vendor: Dell driver: i915
v: kernel bus-ID: 0000:00:02.0
Display: x11 server: X.Org v: 1.21.1.7 with: Xwayland v: 22.1.8 driver: X:
loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915
resolution: 1920x1200~60Hz
API: OpenGL v: 4.6 Mesa 23.0.2 renderer: Mesa Intel Graphics (RPL-P)
direct-render: Yes
Audio:
Device-1: Intel vendor: Dell driver: intel-ipu6 bus-ID: 0000:00:05.0
Device-2: Intel vendor: Dell driver: snd_hda_intel v: kernel
bus-ID: 0000:00:1f.3
Sound API: ALSA v: k6.2.0-24-generic running: yes
Sound Server-1: PulseAudio v: 16.1 running: no
Sound Server-2: PipeWire v: 0.3.65 running: yes
Network:
Device-1: Intel driver: iwlwifi v: kernel port: N/A bus-ID: 0000:00:14.3
IF: wlp0s20f3 state: up mac: <filter>
Bluetooth:
Device-1: Intel type: USB driver: btusb v: 0.8 bus-ID: 3-10:4
Report: hciconfig ID: hci0 rfk-id: 0 state: up address: <filter>
RAID:
Hardware-1: Intel Volume Management Device NVMe RAID Controller Intel
driver: vmd v: 0.6 bus-ID: 0000:00:0e.0
Drives:
Local Storage: total: 953.87 GiB used: 345.01 GiB (36.2%)
ID-1: /dev/nvme0n1 vendor: Samsung model: PM9B1 NVMe 1024GB
size: 953.87 GiB temp: 35.9 C
Partition:
ID-1: / size: 937.33 GiB used: 344.94 GiB (36.8%) fs: ext4
dev: /dev/nvme0n1p2
ID-2: /boot/efi size: 511 MiB used: 68 MiB (13.3%) fs: vfat
dev: /dev/nvme0n1p1
Swap:
ID-1: swap-1 type: file size: 2 GiB used: 0 KiB (0.0%) file: /swapfile
Sensors:
System Temperatures: cpu: 37.0 C mobo: N/A
Fan Speeds (RPM): N/A
Info:
Processes: 325 Uptime: 43m Memory: 30.69 GiB used: 3.1 GiB (10.1%)
Init: systemd target: graphical (5) Compilers: gcc: 12.2.0 Packages: 2665
Shell: Bash v: 5.2.15 inxi: 3.3.25

Suggestions welcome!

A solution was posted here for the webcam on Dell 7340 / 7440 running 22.04. This solution has worked for me too, so I am reproducing it for easier reference.

Install the IPU6/IPU6EP stack manually:

sudo add-apt-repository ppa:oem-solutions-group/intel-ipu6
sudo apt install linux-modules-ipu6-generic-hwe-22.04 linux-modules-ivsc-generic-hwe-22.04
sudo apt install libcamhal-ipu6ep0
sudo reboot 

Add the video group to your user if this isn't done automatically.

Your integrated webcam should work on Zoom, Skype and OBS now, though not necessarily on Cheese.