Scarlett Gen 2 USB2.0 fix

This release is for Gen 2 devices only. One major fix: making the driver work with USB 2 ports (ehci host driver), a few tidyups, and a different initialisation sequence that is hopefully compatible with Gen 2 and Gen 3 devices.

Please test and report back if it works or not for you.

Better Gen 3 18i8, 18i20 support

This release (should) improve support for Gen 3 18i8 and 18i20:

• The master HW control and outputs with the volume control set to HW should now move along with the actual HW knob.
• Add mute and dim button controls

The features previously added should also still work:

• Gen 2 support
• Gen 3 4i4 and 8i6 support
• Mixing/routing, Line/Inst, Pad, Air, MSD options

You need to enable the driver at module load time with the device_setup=1 option to insmod/modprobe. In /etc/modprobe.d/scarlett.conf, something like one of these lines should do it:

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

Test Focusrite Scarlett Gen 3 4i4, 8i6, 18i8, 18i20 Support

This is a testing release; it might not work, and it might break your system. I can say that it at least boots and the Fedora RPM sees my Gen 3 4i4 and Gen 2 18i20. I don't have a Gen 3 8i6, 18i8, or 18i20 to test with. If you're willing to try it, please get in contact and provide feedback!

This release adds support for Gen 3 8i6, 18i8, and 18i20, including 18i8 and 18i20 Main/Alt speaker switching.

These things should still work for the Gen 3 4i4 and hopefully others too:

• same mixing/routing, line/inst, pad options as for Gen 2 devices
• enable/disable "Air" to make your guitars and vocals sound instantly brighter and more spacious
• enable/disable Mass Storage Device (MSD) mode

As for the Gen 2 driver, you need to enable the driver at module load time with the device_setup=1 option to insmod/modprobe. In /etc/modprobe.d/scarlett.conf, something like one of these lines should do it:

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

Enabling MSD mode seems to me to be something that you would never want to do, so once you disable it the control gets hidden (use device_setup=3 if you really want to make it reappear).

5.7.1s1 Focusrite Scarlett Gen 3 4i4 Support

This release adds support for the Gen 3 4i4 including:

• same mixing/routing, line/inst, pad options as for Gen 2 devices
• enable/disable "Air" to make your guitars and vocals sound instantly brighter and more spacious
• enable/disable Mass Storage Device (MSD) mode

As for the Gen 2 driver, you need to enable the driver at module load time with the device_setup=1 option to insmod/modprobe. In /etc/modprobe.d/scarlett.conf, something like one of these lines should do it:

options snd_usb_audio device_setup=1,1,1,1
options snd_usb_audio vid=0x1235 pid=0x8212 device_setup=1

Enabling MSD mode seems to me to be something that you would never want to do, so once you disable it the control gets hidden (use device_setup=3 if you really want to make it reappear).

5.4rc6 Focusrite Scarlett Gen 2 6i6 fix

Changes from 5.4rc6:

• Fix the 6i6 mixer/routing setup. Thanks to xkr47 for spotting the issue.

Focusrite Scarlett 6i6/18i8/18i20 Gen 2 ALSA mixer driver Test 6

This release adds no new features. The changes are:

• Fix checkpatch.pl warnings, fix other typos etc.
• Cancel delayed work on suspend
• Run kmalloc outside the mutex
• Use device_setup option instead of scarlett_gen2_mixer_enable
• Fix issue where the config save delayed work would be cancelled and not restarted if a scarlett2_*_ctl_put() function was called and the parameter value was not changed
• Rename definitions and functions for consistency; move private free/suspend functions above their use so pre-declaration isn't necessary
• Initialise pointers as "NULL" not "0"
• Add code to use snd_usb_pipe_sanity_check() to verify pipe (commented out as that's added in 5.3)

Note: by default, this new mixer driver will not be enabled and a kernel message "Focusrite Scarlett Gen 2 Mixer Driver disabled; use options snd_usb_audio device_setup=1 to enable and report any issues to g@b4.vu" will be output.

Create a file /etc/modprobe.d/scarlett.conf containing the line "options snd_usb_audio device_setup=1" (then unload/reload the driver or reboot) to enable it.

If you have more than one USB audio device and you still see the "...Mixer Driver disabled..." message, then you probably need to change "device_setup=1" to e.g. "device_setup=1,1,1,1" to ensure that the option gets applied to this driver.

Focusrite Scarlett 6i6/18i8/18i20 Gen 2 ALSA mixer driver Test 5

This release adds:

• Support for controlling mute/dim (18i20 only)
• Replace timer with delayed work
• Remove extra scarlett2-specific fields from struct usb_mixer_interface
• Add mixer driver enable module parameter

By default, this new mixer driver will not be enabled and a kernel message "Focusrite Scarlett Gen 2 Mixer Driver disabled; use options snd_usb_audio scarlett_gen2_mixer_enable=1 to enable and report any issues to g@b4.vu" will be output.

Create a file /etc/modprobe.d/scarlett.conf containing the line "options snd_usb_audio scarlett_gen2_mixer_enable=1" (then unload/reload the driver or reboot) to enable it.

Focusrite Scarlett 6i6/18i8/18i20 Gen 2 ALSA mixer driver Test 4

Test 4 of Focusrite Scarlett Gen 2 ALSA mixer driver.

• Add support for the 6i6 (untested)

Focusrite Scarlett 18i8/18i20 Gen 2 ALSA mixer driver Test 3

Test 3 of Focusrite Scarlett Gen 2 ALSA mixer driver.

• Add support for the 18i8
• Save configuration parameters to NVRAM
• Implemented feedback from Takashi's email 24/Apr/2019
• Moved private field from struct snd_usb_audio to struct usb_mixer_interface
• Added timer and buffer fields to struct usb_mixer_interface
• Other small code fixes/cleanups/improvements

Focusrite Scarlett 18i20 Gen 2 ALSA mixer driver Test 2

Test 2 of Focusrite Scarlett 18i20 Gen 2 ALSA mixer driver.
This release fixes the mux-setting USB messages so the assignments are done in the same order as the Windows driver and the meters work better now.
Also reformatted code for Linux kernel style.
Submitted to alsa-devel: https://mailman.alsa-project.org/pipermail/alsa-devel/2019-April/147270.html