Linux on TrekStor SurfTab wintron 7.0

Linux 4.12~rc6

Get Linux 4.12~rc6 from kernel.org

Fixing timing problems

Add clocksource=tsc to your kernel cmdline to fix issues with timing, timekeeping and a lot of other time related things

Installing wireless drivers

By now the rtl8723bs driver made it into the staging area of linux. Just enable the staging driver or use my kernel config from here and it will work out of the box.

The wireless driver seems to be stable and gives me acceptable throughput at around 20 Mbit/s.

In theory this card also supports Bluetooth via hciattach but I couldn't get it working. Supposably this driver works but as I said I had no luck with it. More precisely I couldn't get the module to talk to me via the serial bus. There is probably an additional GPIO on the SOC needed to enable it.

Getting the touchscreen working

The touchscreen driver is now part of the kernel, too. Again, either enable the driver yourself or use my kernel config.

You will still need firmware for it though. The firmware is pretty easy to find eg. here. Just move it to /lib/firmware/silead/, reboot and you should be ready to go.

Battery monitoring

The battery monitoring works pretty well. You will need to enable the axp288_fuel_gauge driver in the kernel configuration (mine has it already enabled, obviously) and then it will just work out of the box.

It will show up in /sys/class/power_supply/axp288_fuel_gaugeand cat /sys/class/power_supply/axp288_fuel_gauge/capacity will give you a correct capacity indication.

Note that I get a lot of

axp288_fuel_gauge axp288_fuel_gauge: ADC charge current read failed:-19

in my dmesg though and charge current monitoring doesn't work.

TODO

Sound

The sound chip on this SoC is a rt5651 which seems to be somewhat supported in the newest kernel git 4.5-rc1+ but it still doesn't work on the wintron though because of some missing DAIs. @Manawyrm tested a recent kernel. You can take a look at the bootlog here. We wrote an ALSA mailinglist post about this. You can view it here

Upate: I compiled a new kernel with a patch provided by an Intel developer (thanks Pierre!) and now we are getting somewhere. You can find the new logs [here] (https://github.com/TobleMiner/wintron7.0/tree/master/logs/4.5.0-rc2-ARCH-tsys-audio-intel-dirty) There are still some errors but the compress DAI is now properly initialized. But as soon as I try to use ALSA the intel_sst_acpi driver fails to download required firmware to the audio chipset. We got in touch with the people on alsa-devel again and are now waitig for a response.

Bluetooth

Look above @Installing wireless drivers

Camera

The camera is of very low quality and I've not looked into getting it working yet. It doesn't look like the camera is a USB camera thus getting it working might be pretty hard and is of low priority to me.

OLD STUFF

Linux 4.4.0

Get Linux 4.4.0 from kernel.org

Fixing timing problems

Add clocksource=tsc to your kernel cmdline to fix issues with timing, timekeeping and a lot of other time related things

Installing wireless drivers

Get driver for SDIO WiFi card from https://github.com/hadess/rtl8723bs
Apply patches from 'patches' directory of driver to kernel
Build and install the driver

Theoretically this card also supports Bluetooth via hciattach but I couldn't get it working. Supposably this driver works but as I said I had no luck with it. More precisely I couldn't get the module to talk to me via the serial bus. I'm always getting

Realtek Bluetooth init uart with init speed:115200, final_speed:115200, type:HCI UART H5
Realtek Bluetooth :Realtek hciattach version 2.5
Realtek Bluetooth :3-wire sync pattern resend : 1, len: 8
Realtek Bluetooth :3-wire sync pattern resend : 2, len: 8
Realtek Bluetooth :3-wire sync pattern resend : 3, len: 8
...

Getting the touchscreen working

Get touchscreen driver from https://github.com/onitake/gslx680-acpi
Run ./fwtool -c GSL_TS_CFG_NEW_WINTRON_70.h -2 -m 1680 -w 1024 -h 600 -t 10 /lib/firmware/silead_ts.fw to convert and install the firmware for the touchscreen driver
Build and install the driver
By default the touchscreen is not calibrated so you will have to calibrate the touchscreen using xinput_calibrator.