arm64: dts: qcom: sc7180: Start the trogdor eDP/touchscreen regulator on
authorDouglas Anderson <dianders@chromium.org>
Fri, 9 Dec 2022 17:12:39 +0000 (09:12 -0800)
committerBjorn Andersson <andersson@kernel.org>
Wed, 28 Dec 2022 03:31:47 +0000 (21:31 -0600)
commit23ff866987de2910de4a1060e9b0e112376c0dd0
treeff0f15753c5a176ff58cc7614e12d32d78ef544d
parentf5b4811e8758fed76da4f54f6efa1452bc878595
arm64: dts: qcom: sc7180: Start the trogdor eDP/touchscreen regulator on

Now that we've added the `off-on-delay-us` for the touchpanel
regulator, we can see that we're actually hitting that delay at
bootup. I saw about 200 ms of delay.

Let's avoid that delay by starting the regulator on. We'll only do
this for eDP devices for the time being.

NOTE: we _won't_ do this for homestar. Homestar's panel really likes
to be power cycled. It's why the Linux driver for this panel has a
pm_runtime_put_sync_suspend() when the panel is being unprepared but
the normal panel-edp driver doesn't. It's also why this hardware has a
separate power rail for eDP vs. touchscreen, unlike all the other
trogdor boards. We won't start homestar's regulator on. While this
could mean a slight delay on homestar, it is probably a _correct_
delay. The bootloader might have left the regulator on (it does so in
dev and recovery modes), so if we turned the regulator off at probe
time and we actually hit the delay then we were probably violating T12
in the panel spec.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221209091234.v3.3.I7050a61ba3a48e44b86053f265265b5e3c0cee31@changeid
arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar.dtsi
arch/arm64/boot/dts/qcom/sc7180-trogdor-parade-ps8640.dtsi
arch/arm64/boot/dts/qcom/sc7180-trogdor-ti-sn65dsi86.dtsi