On Thu, Oct 18, 2018 at 10:39 AM Hans de Goede [off-list ref] wrote:

Hi,

On 18-10-18 10:10, Benjamin Tissoires wrote:

quoted

On Wed, Oct 17, 2018 at 10:15 PM Rob Herring [off-list ref] wrote:

quoted

On Fri, Oct 12, 2018 at 04:24:11PM +0200, Benjamin Tissoires wrote:

quoted

Some new touchpads IC are connected through PS/2 and I2C. On some of these
new IC, the I2C part doesn't have all of the information available.
We need to be able to forward the touchpad parameters from PS/2 and
thus, we need those new optional properties.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1628715
Signed-off-by: Benjamin Tissoires <redacted>
---
  Documentation/devicetree/bindings/input/elan_i2c.txt | 8 ++++++++
  1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/elan_i2c.txt b/Documentation/devicetree/bindings/input/elan_i2c.txt
index 797607460735..ace6bcb0b4eb 100644
--- a/Documentation/devicetree/bindings/input/elan_i2c.txt
+++ b/Documentation/devicetree/bindings/input/elan_i2c.txt

@@ -13,6 +13,14 @@ Optional properties:
    pinctrl binding [1]).
  - vcc-supply: a phandle for the regulator supplying 3.3V power.
  - elan,trackpoint: touchpad can support a trackpoint (boolean)
+- elan,clickpad: touchpad is a clickpad (the entire surface is a button)

quoted

+- elan,max_x: the maximum reported value on the X axis
+- elan,max_y: the maximum reported value on the Y axis
+- elan,min_x: the minimum reported value on the X axis
+- elan,min_y: the minimum reported value on the Y axis
+- elan,x_res: the resolution of the X axis (in units per mm)
+- elan,y_res: the resolution of the Y axis (in units per mm)
+- elan,width: max reported width of a blob

Can't we use standard touchscreen properties here? (Yes, I get this is a
touchpad, not touchscreen).

Hey Rob,

Well, there is that (it's a touchpad driver) and we can't also really
use the of_touchscreen.c implementation.
If both concerns are not an issue, we can then move the [min/max/res]
properties to the touchscreen ones.

Regarding 'elan,width', this is something missing from the standard ts
properties, and AFAICT, this controls the maximum reported
width/height of a touch.
I should probably rename them to max_width, max_height.

Hans, do you think we should add such properties to of_touchscreen.c
too? (the width/height ones)

Are there touchscreens which report finger/touch width / height ? if so
then it probably does make sense.

Well, it's pretty common for hid-multitouch touchscreens to report
such properties (it's a way to indicate the palm). Don't know about
the touchscreens that rely on of_touchscreen though.

Note that for historical reasons
Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

Looks like your sentence is not finished here :)

Also the touchscreen bindings have: touchscreen-x-mm and touchscreen-y-mm
rather then res, which can then be used to calculate the resolution.

yeah, that's fine, I would need to convert to mm, then go back to res.
Extra effort, but that's the price to pay.

Cheers,
Benjamin