* [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4
@ 2021-11-15 3:01 yangcong
2021-11-15 15:40 ` Doug Anderson
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: yangcong @ 2021-11-15 3:01 UTC (permalink / raw)
To: dianders, philipchen, agross, bjorn.andersson, robh+dt, swboyd
Cc: devicetree, linux-arm-msm, linux-kernel, yangcong
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 <yangcong5@huaqin.corp-partner.google.com>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4
2021-11-15 3:01 [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4 yangcong
@ 2021-11-15 15:40 ` Doug Anderson
2021-11-15 23:45 ` Stephen Boyd
2021-11-20 23:55 ` (subset) " Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Doug Anderson @ 2021-11-15 15:40 UTC (permalink / raw)
To: yangcong
Cc: philipchen, agross, bjorn.andersson, robh+dt, swboyd, devicetree,
linux-arm-msm, linux-kernel
Hi,
On Sun, Nov 14, 2021 at 7:02 PM yangcong
<yangcong5@huaqin.corp-partner.google.com> 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 <yangcong5@huaqin.corp-partner.google.com>
> ---
> 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 <dianders@chromium.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4
2021-11-15 3:01 [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4 yangcong
2021-11-15 15:40 ` Doug Anderson
@ 2021-11-15 23:45 ` Stephen Boyd
2021-11-20 23:55 ` (subset) " Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Stephen Boyd @ 2021-11-15 23:45 UTC (permalink / raw)
To: agross, bjorn.andersson, dianders, philipchen, robh+dt, yangcong
Cc: devicetree, linux-arm-msm, linux-kernel
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 <yangcong5@huaqin.corp-partner.google.com>
> ---
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: (subset) [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4
2021-11-15 3:01 [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4 yangcong
2021-11-15 15:40 ` Doug Anderson
2021-11-15 23:45 ` Stephen Boyd
@ 2021-11-20 23:55 ` Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Bjorn Andersson @ 2021-11-20 23:55 UTC (permalink / raw)
To: yangcong, robh+dt, dianders, agross, philipchen, swboyd
Cc: linux-arm-msm, linux-kernel, devicetree
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 <bjorn.andersson@linaro.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-11-15 3:01 [PATCH] arm64: dts: sc7180: Fix ps8640 power sequence for Homestar rev4 yangcong
2021-11-15 15:40 ` Doug Anderson
2021-11-15 23:45 ` Stephen Boyd
2021-11-20 23:55 ` (subset) " Bjorn Andersson
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