# ALSA Scarlett2 Control Panel Installation

## Prerequisites

### Linux Kernel

You need to be running a Linux Kernel that has the ALSA Scarlett2
Protocol Driver. Use `uname -r` to check what kernel version you are
running.

- Use at least version 5.14 for Scarlett Gen 3 support and bug fixes
  for the Gen 2 support.
- For Clarett+ 8Pre support, you need 6.1.
- For the other Clarett USB and Clarett+ models, you need 6.7.
- For the level meters to work, you need 6.7.

If you don't have 6.7, you can get the driver from here and build it
for your current kernel:

https://github.com/geoffreybennett/scarlett-gen2/releases/tag/v6.5.11c1

### Gtk4

You need a Linux distribution with Gtk4 development libraries. If it
doesn't have them natively, try the Flatpak instructions below.

## Enabling the Driver

As of Linux 6.7 the driver is enabled by default and you can skip this
section.

If you're running a kernel before 6.7, the driver needs to be enabled
at module load time with the `device_setup=1` option to
insmod/modprobe. Create a file /etc/modprobe.d/scarlett.conf
containing the appropriate line for your device:

Scarlett Gen 2:

- 6i6: `options snd_usb_audio vid=0x1235 pid=0x8203 device_setup=1`
- 18i8: `options snd_usb_audio vid=0x1235 pid=0x8204 device_setup=1`
- 18i20: `options snd_usb_audio vid=0x1235 pid=0x8201 device_setup=1`

Scarlett Gen 3:

- Solo: `options snd_usb_audio vid=0x1235 pid=0x8211 device_setup=1`
- 2i2: `options snd_usb_audio vid=0x1235 pid=0x8210 device_setup=1`
- 4i4: `options snd_usb_audio vid=0x1235 pid=0x8212 device_setup=1`
- 8i6: `options snd_usb_audio vid=0x1235 pid=0x8213 device_setup=1`
- 18i8: `options snd_usb_audio vid=0x1235 pid=0x8214 device_setup=1`
- 18i20: `options snd_usb_audio vid=0x1235 pid=0x8215 device_setup=1`

Clarett+:

- 8Pre: `options snd_usb_audio vid=0x1235 pid=0x820c device_setup=1`

Or you can use a sledgehammer:
```
options snd_usb_audio device_setup=1,1,1,1
```
to pass that option to the first 4 USB audio devices.

To see if the driver is present and enabled: `dmesg | grep -i -A 5 -B
5 focusrite` should display information like:

```
New USB device found, idVendor=1235, idProduct=8215, bcdDevice= 6.0b
Product: Scarlett 18i20 USB
Focusrite Scarlett Gen 2/3 Mixer Driver enabled pid=0x8215
```

If the driver is disabled you’ll see a message like:

```
Focusrite Scarlett Gen 2/3 Mixer Driver disabled; use options
snd_usb_audio vid=0x1235 pid=0x8215 device_setup=1 to enable and
report any issues to g@b4.vu
```

### Firmware

As of Linux 6.8, firmware updates of all the supported interfaces can
be done through Linux. This is mandatory for Scarlett 4th Gen and
Vocaster interfaces (unless you've already updated it using the
manufacturer's software), and optional for Scarlett 2nd and 3rd Gen,
Clarett USB, and Clarett+ interfaces.

Download the firmware from
https://github.com/geoffreybennett/scarlett2-firmware and place in
`/usr/lib/firmware/scarlett2` or use the RPM/deb package.

## Building and Running

On Fedora, these packages need to be installed:

```
sudo dnf -y install alsa-lib-devel gtk4-devel openssl-devel
```

On OpenSUSE:

```
sudo zypper in git alsa-devel gtk4-devel libopenssl-devel
```

On Ubuntu:

```
sudo apt -y install git make gcc libgtk-4-dev libasound2-dev libssl-dev
```

To download from github:

```
git clone https://github.com/geoffreybennett/alsa-scarlett-gui
cd alsa-scarlett-gui
```

To build:

```
cd src
make -j4
```

To run:

```
./alsa-scarlett-gui
```

You can install it into `/usr/local` (binary, desktop file, and icon)
with:

```
sudo make install
```

And uninstall with:

```
sudo make uninstall
```

Continue on to reading [USAGE.md](USAGE.md) for usage information and
known issues.

## Flatpak

With Flatpak, in any distro:

```
flatpak-builder --user --install --force-clean flatpak-build \
    vu.b4.alsa-scarlett-gui.yml
```

Be sure to use `flatpak-build` as the directory where the flatpak is
built or hence you risk bundling the artifacts when committing!

If you get messages like these:

```
Failed to init: Unable to find sdk org.gnome.Sdk version 45
Failed to init: Unable to find runtime org.gnome.Platform version 45
```

Then install them:

```
flatpak install org.gnome.Sdk
flatpak install org.gnome.Platform
```

If you get:

```
Looking for matches…
error: No remote refs found for ‘org.gnome.Sdk’
```

Then:

```
flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
```