Re: [RFC PATCH v3 4/5] arm64: dts: mediatek: mt8173-elm-hana: Mark touchscreens and trackpads as fail

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Il 06/12/23 03:55, Chen-Yu Tsai ha scritto:
On Tue, Dec 5, 2023 at 6:22 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:

Il 04/12/23 17:50, Doug Anderson ha scritto:
Hi,

On Sun, Dec 3, 2023 at 10:59 PM Chen-Yu Tsai <wenst@xxxxxxxxxxxx> wrote:

On Sat, Dec 2, 2023 at 8:58 AM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:

Hi,

On Tue, Nov 28, 2023 at 12:45 AM Chen-Yu Tsai <wenst@xxxxxxxxxxxx> wrote:

@@ -44,6 +46,7 @@ trackpad2: trackpad@2c {
                  reg = <0x2c>;
                  hid-descr-addr = <0x0020>;
                  wakeup-source;
+               status = "fail-needs-probe";

While doing this, you could also remove the hack where the trackpad
IRQ pinctrl is listed under i2c4.

Sure. I do think we can do away with it though. According to at least one
schematic, the interrupt line has pull-ups on both sides of the voltage
shifter.

BTW, The touchscreen doesn't have pinctrl entries. This has pull-ups on
both sides of the voltage shifter as well.

I dunno if the convention is different on Mediatek boards, but at
least on boards I've been involved with in the past we've always put
pinctrl entries just to make things explicit. This meant that we
didn't rely on the firmware/bootrom/defaults to leave pulls in any
particular state. ...otherwise those external pull-ups could be
fighting with internal pull-downs, right?


MediaTek boards aren't special and there's no good reason for those to rely on
firmware/bootrom/defaults - so there is no good reason to avoid declaring any
relevant pinctrl entry.

I think this should be migrated to use the proper GPIO bindings: the
GPIO_PULL_UP / GPIO_PULL_DOWN / GPIO_BIAS_DISABLE flags.

But that's a different discussion.


100% agreed.

Cheers,
Angelo





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