Upstream status GTA04 4.20

Generally a lot of things are useable, so in many cases patches can be developed on top of mainline

USB

Modem-Port:
- working, but suboptimal pm
- phy reset workaround missing, giving additional 10mA suspend current if ehci-omap is loaded requires off-mode-enabled (which is enabled in mainline only via a debugfs file)
- wwan-on-off missing (on gta04a4/5 gpio186 needs to be manually triggered via userspace to enable/disable modem
OTG-Port
- working but some feature missing:
  - id pin status sysfs file missing
  - b_host hacks missing
  - The minimum level the vbus voltage is allowed to drop to while increasing charging current is higher on mainline

mostly working
libertas (GTA04A4)
- Mainline has low transfer rate (100KByte/s)
  - Reason: sdio irq not enabled, that should be a simple one-liner patch to dtb. But somehow it is not working easily. Letux kernels have our own workaround giving higher transfer rates.
- higher power consumption when device is up but not connected (connect to save power), probably not wise to uptream that without cleanly solving the irq problem
wl18xx (GTA04A5): working in mainline as well as in letux

problematic
GTA04A4
- reset handling bt vs wlan is missing, so problems arise if one tries to use bluetooth without wlan
- h4 serdev additions are missing (is in discussion with upstream, probably hci_uart will be replaced by a new bt_uart), so pm is not working
GTA04A5
- device tree for hcill is missing (things should be ready for uptream)

if soc is in too deep powersave, reading out the hdq status fails, there are patches to the clock framework in letux-kernel to fix this

off mode needs to be manually enabled via debugfs, that is a lower power mode in the soc which reduces suspend current by around 5mA and helps with some ehci problems.


    uname -r | grep -E 'letux' || xinput set-prop "TSC2007 Touchscreen"  "Evdev Axis Calibration" 256 3840 3840 256

missing, no support for applications using accelerometer via evdev, they are required to use iio