Hi, On Tue, May 21, 2019 at 3:27 PM Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: > > Hi, > > This is the v2 from https://lkml.org/lkml/2018/10/12/633 > > So I initially thought it would be easy to integrate the suggested changes > in the v1, but it turns our that the changes to have the touchscreen-width > and height parameters were quite hard to do. > > I finally postponed the issue by blacklisting the 2 laptops we knew were > not working and tried to devote more time to understand both drivers more. > > But it s the time where Lenovo is preparing the new models, and guess what, > they suffer from the same symptoms. I just received the confirmation from Lenovo that this series makes the new laptops working. Cheers, Benjamin > > So I took a few time to work on this and finally got my head around the > width and height problem. Once I got it, it was simple clear, but this also > means we can not really rely on a device tree property for that. > > So in the elan* drivers, the "traces" are simply how many antennas there > are on each axis. Which means that if a trace of 4 is reported in the > events, it means it is simply seen by 4 antennas. So the computation of the > width/height is the following: we take how many antennas there are, we > subtract one to have the number of holes between the antennas, and we > divide the number of unit we have in the axis by the value we just > computed. > This gives a rough 4mm on the P52, in both directions. > > And once you get that, you can just realize that the unit of the width and > height are just the same than the X and Y coordinates, so we can apply the > same resolution. > > So, in the end, that means that elan_i2c needs the information, or it will > not be able to convert the number of crossed antennas into a size, but this > is something specific to this touchpad. > > So here come, 7 months later the v2 on the subject. > > Cheers, > Benjamin > > Benjamin Tissoires (10): > Input: elantech - query the min/max information beforehand too > Input: elantech - add helper function elantech_is_buttonpad() > Input: elantech - detect middle button based on firmware version > dt-bindings: add more optional properties for elan_i2c touchpads > Input: elan_i2c - do not query the info if they are provided > Input: elantech/SMBus - export all capabilities from the PS/2 node > Input: elan_i2c - handle physical middle button > Input: elan_i2c - export true width/height > Input: elan_i2c - correct the width/size base value > Input: elantech: remove P52 from SMBus blacklist > > .../devicetree/bindings/input/elan_i2c.txt | 11 + > drivers/input/mouse/elan_i2c_core.c | 85 +++-- > drivers/input/mouse/elantech.c | 318 ++++++++++-------- > drivers/input/mouse/elantech.h | 8 + > 4 files changed, 251 insertions(+), 171 deletions(-) > > -- > 2.21.0 >
