touchpad does not work on some snow chromebooks

[jenneron]

This patch is the fix, so i decided to post it here

From 170fa62ecc113a44cf33591c7b38643eaf457c55 Mon Sep 17 00:00:00 2001
From: Anton Bambura <jenneron@protonmail.com>
Date: Wed, 5 Jan 2022 16:13:53 +0200
Subject: [PATCH] ARM: dts: exynos: snow: add atmel mxt touchpad

Add Atmel mXT touchpad (like peach chromebooks) as it is used in
some revisions (probably rev5 only).

Signed-off-by: Anton Bambura <jenneron@protonmail.com>
---
 arch/arm/boot/dts/exynos5250-snow-common.dtsi | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm/boot/dts/exynos5250-snow-common.dtsi b/arch/arm/boot/dts/exynos5250-snow-common.dtsi
index c952a6151..83c1a3a4e 100644
--- a/arch/arm/boot/dts/exynos5250-snow-common.dtsi
+++ b/arch/arm/boot/dts/exynos5250-snow-common.dtsi
@@ -446,6 +446,21 @@ trackpad@67 {
        interrupt-parent = <&gpx1>;
        wakeup-source;
    };
+
+   /* Atmel mXT which is used in some revisions */
+   trackpad@4b {
+       compatible = "atmel,maxtouch";
+       reg = <0x4b>;
+       interrupt-parent = <&gpx1>;
+       interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+       wakeup-source;
+       linux,gpio-keymap = <KEY_RESERVED
+                    KEY_RESERVED
+                    KEY_RESERVED   /* GPIO0 */
+                    KEY_RESERVED   /* GPIO1 */
+                    KEY_RESERVED   /* GPIO2 */
+                    BTN_LEFT>;     /* GPIO3 */
+   };
 };

 /*
-- 
2.34.1

[hexdump0815]

@jenneron - thanks a lot ... to make sure it does not get forgotten: https://github.com/hexdump0815/linux-mainline-and-mali-generic-stable-kernel/commit/faa7e00b0806e2f75e45ed4630c843dca4adb1f2

[pbgapski]

I have tried the patched dtb provided by @jenneron and it fixed my touchpad issues. See https://github.com/hexdump0815/imagebuilder/issues/26#issuecomment-1009885113 for details.