Messages in this thread | | | From | Benjamin Tissoires <> | Subject | [PATCH v2 00/10] Fix Elan I2C touchpads in latest generation from Lenovo | Date | Tue, 21 May 2019 15:27:02 +0200 |
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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.
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
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