[PATCH v2 6/7] arm64: dts: mediatek: mt8173-elm-hana: Unmark trackpad supply as always-on
Chen-Yu Tsai
wenst at chromium.org
Fri Jul 3 04:55:59 PDT 2026
Up until now, the MT8173 elm/hana device tree has set the dedicated
regulator supplying the trackpad as always-on, simply because the Elan
driver was missing proper delays. As a result the delay for the
Synaptics trackpad was also omitted, as it was not strictly required
under such a model and delayed the availability of the trackpad to the
user.
The Elan driver recently gained proper delays after power up, with
opportunistic skipping of the delay when the regulator was originally
on. The I2C HID driver gained similar opportunistic delay skipping.
So has the I2C OF component prober library.
Now fix the device tree to have the regulator not be always on, and
let the I2C HID device have the correct post-power-on delay time.
Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
---
arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi | 8 +-------
arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 1 -
2 files changed, 1 insertion(+), 8 deletions(-)
diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi
index 1004eb8ea52c..b9e311fcd9a0 100644
--- a/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi
@@ -62,13 +62,7 @@ trackpad2: trackpad at 2c {
pinctrl-0 = <&trackpad_irq>;
reg = <0x2c>;
hid-descr-addr = <0x0020>;
- /*
- * The trackpad needs a post-power-on delay of 100ms,
- * but at time of writing, the power supply for it on
- * this board is always on. The delay is therefore not
- * added to avoid impacting the readiness of the
- * trackpad.
- */
+ post-power-on-delay-ms = <100>;
vdd-supply = <&mt6397_vgp6_reg>;
wakeup-source;
status = "fail-needs-probe";
diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
index a0573bc359fb..6b9f47f515c7 100644
--- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
@@ -1093,7 +1093,6 @@ mt6397_vgp6_reg: ldo_vgp6 {
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-enable-ramp-delay = <218>;
- regulator-always-on;
};
mt6397_vibr_reg: ldo_vibr {
--
2.55.0.rc0.799.gd6f94ed593-goog
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