When powering up the ps8640, we need to deassert PD right
after we turn on the vdd33 regulator. Unfortunately, the vdd33
regulator takes some time (~4ms) to turn on. Add in the delay
for the vdd33 regulator so that when the driver deasserts PD
that the regulator has had time to ramp.
Signed-off-by: yangcong <[email protected]>
---
arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
index fb27106bbb4a..0de0c97f5728 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
@@ -15,3 +15,7 @@ / {
model = "Google Homestar (rev4+)";
compatible = "google,homestar", "qcom,sc7180";
};
+
+&pp3300_brij_ps8640 {
+ regulator-enable-ramp-delay = <4000>;
+};
--
2.25.1
Hi,
On Sun, Nov 14, 2021 at 7:02 PM yangcong
<[email protected]> wrote:
>
> When powering up the ps8640, we need to deassert PD right
> after we turn on the vdd33 regulator. Unfortunately, the vdd33
> regulator takes some time (~4ms) to turn on. Add in the delay
> for the vdd33 regulator so that when the driver deasserts PD
> that the regulator has had time to ramp.
>
> Signed-off-by: yangcong <[email protected]>
> ---
> arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
> index fb27106bbb4a..0de0c97f5728 100644
> --- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
> +++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-homestar-r4.dts
> @@ -15,3 +15,7 @@ / {
> model = "Google Homestar (rev4+)";
> compatible = "google,homestar", "qcom,sc7180";
> };
> +
> +&pp3300_brij_ps8640 {
> + regulator-enable-ramp-delay = <4000>;
> +};
It should have been pointed out somewhere in the post, but this patch
depends on Philip's most recent, which is:
https://lore.kernel.org/r/20211029152647.v3.4.If7aaa8e36f1269acae5488035bd62ce543756bf8@changeid/
This seems fine to me. Apparently this 4ms delay isn't needed
lazor-rev9 (at least they were happy with the signals on that board)
which is why this is a homestar change. That can make sense since the
components on the two boards may be different.
In any case:
Reviewed-by: Douglas Anderson <[email protected]>
Quoting yangcong (2021-11-14 19:01:55)
> When powering up the ps8640, we need to deassert PD right
> after we turn on the vdd33 regulator. Unfortunately, the vdd33
> regulator takes some time (~4ms) to turn on. Add in the delay
> for the vdd33 regulator so that when the driver deasserts PD
> that the regulator has had time to ramp.
>
> Signed-off-by: yangcong <[email protected]>
> ---
Reviewed-by: Stephen Boyd <[email protected]>
On Mon, 15 Nov 2021 11:01:55 +0800, yangcong wrote:
> When powering up the ps8640, we need to deassert PD right
> after we turn on the vdd33 regulator. Unfortunately, the vdd33
> regulator takes some time (~4ms) to turn on. Add in the delay
> for the vdd33 regulator so that when the driver deasserts PD
> that the regulator has had time to ramp.
>
>
> [...]
Applied, thanks!
[1/1] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4
commit: 96e1e3a15273a99d89b1389e4487e734c7d37d8e
Best regards,
--
Bjorn Andersson <[email protected]>