[FFe] Provide access to GPIO to default user

[Dave Jones]

At present, access to the GPIO pins is provided to the dialout group by the udev rules from the rpi.gpio-common package. However, rpi.gpio is a single GPIO library, and the device(s) it provides access to are not specific to it. Moreover, the interface used is deprecated and the /dev/gpiochip* interface is now the favoured mechanism for controlling the GPIO pins.

The choice of the dialout group appears reasonable (historically it's used to provide access to the serial ports, and indeed the serial ports are part of the GPIO header on Raspberry Pi devices), but the rules should be extended to cover the modern /dev/gpiochip* devices, the related /dev/spidev* and /dev/i2c-* devices, and should be placed in a central location (i.e. ubuntu-raspi-settings) rather than in a specific GPIO library (like rpi.gpio).

Related to this is LP: #1923363 which seeks to ensure equal access across images (the default user is currently granted "dialout" group membership on the pi server images, but not the desktop ones).

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-settings - 21.04.3

---------------
ubuntu-settings (21.04.3) hirsute; urgency=medium

  [ William 'jawn-smith' Wilson ]
  * Adding 99-gpio.rules udev rules for Raspberry Pi GPIO functionality
    (LP: #1923672)

  [ Dave Jones ]
  * Replace netplan eth0 renaming rules for raspi with networkd link unit
    (LP: #1922266)

 -- Dave Jones <email address hidden> Tue, 13 Apr 2021 23:02:42 +0100

[Dave Jones (waveform)]

Targetting to Impish and Jammy as apparently ubuntu-settings lost the 21.04.3 changes in 21.10.1 (which was based on 21.04.2).

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-settings - 22.04.1

---------------
ubuntu-settings (22.04.1) jammy; urgency=medium

  * Reinstate changes from 21.04.3:
    - Adding 99-gpio.rules udev rules for Raspberry Pi GPIO functionality
      (LP: #1923672)
    - Replace netplan eth0 renaming rules for raspi with networkd link unit
      (LP: #1922266)
  * Override initramfs compression to lz4 to prevent OOM on 512MB platforms,
    and add a dependency on lz4 to d/control (LP: #1950214)
  * d/control: Correct spelling of raspberry

 -- Dave Jones <email address hidden> Wed, 15 Dec 2021 15:29:10 +0100