[PATCH v4 9/9] arm64: dts: mediatek: mt8192-asurada-spherion: Add Synaptics trackpad's supply

[Chen-Yu Tsai <wenst@chromium.org>]

The Synaptics trackpad, like the Elan trackpad option, is fed from the
system 3.3V power rail. Add it to the trackpad device node.

Also add the correct post-power-on delay, even though in practice it is
not required. The Synaptics trackpad requires 100ms after power-on (or
deasserting the reset, whichever comes later) to fully initialize. The
power is always on and the reset pin is not routed out, so the
implementation could try skipping the delay.

Cc: <stable+noautosel@kernel.org> # Without driver changes only lengthens probe time
Fixes: 925ebc0cd55c ("arm64: dts: mt8192-asurada-spherion: Add Synaptics trackpad support")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
I think this shouldn't be backported, as backporting it without the
driver enhancements just delays the trackpad probing with no real
gains.
---
 arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts b/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
index 68caf4c58cfe..8adbfc307fca 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
@@ -94,6 +94,8 @@ trackpad@2c {
 		hid-descr-addr = <0x20>;
 		interrupts-extended = <&pio 15 IRQ_TYPE_LEVEL_LOW>;
 		wakeup-source;
+		vdd-supply = <&pp3300_u>;
+		post-power-on-delay-ms = <100>;
 		status = "fail-needs-probe";
 	};
 };
-- 
2.55.0.679.g6767b8d81c-goog