On Mon, Jul 13, 2015 at 5:24 PM, Gregor Riepl [off-list ref] wrote:

quoted

The firmware has to be calibrated by the vendor for each chip-panel
combination. If you change the panel even if you keep the same chip it
is very likely to need some calibration. This might be the reason why
the finger ID is not working properly.

Thinking about the device parameters... Wouldn't it be possible to read them
from the Silead controller? According to comments in the firmware shipped with
the old Android platform driver by Basewin, all the configurable parameters
are contained in the firmware.[1]

I don't have a complete data sheet, but maybe we could just read back the
panel width and height and number of tracking points from a hardware register?

That would not solve the problem of transferring the correct, platform
specific firmware image to the device, however.

In the datasheet there is no register map. Silead gave us a partial
register map in order to implement the driver. In the map they
provided there is no register for resolution or anything that would
help with this issue. The information in [1] is incomplete and can not
be considered reliable since the vendor does not say anything about
it.

Regards,
Robert

[1]
https://code.google.com/p/yuandao-n90-window-dual-core-2/source/browse/drivers/input/touchscreen/gslx680_ts.h
- the comments are in Chinese, a translation can be found here:
https://github.com/jabjoe/sunxi-gslx680/blob/master/firmware/firmware_information.txt