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arm64: dts: qcom: qcs615: Set LDO12A regulator to HPM to avoid boot hang

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On certain platforms (e.g., QCS615), consumers of LDO12A—such as PCIe,
UFS, and eMMC—may draw more than 10mA of current during boot. This can
exceed the regulator's limit in Low Power Mode (LPM), triggering current
limit protection and causing the system to hang.

To address this, there are two possible approaches:
a) Set the regulator's initial mode to High Performance Mode (HPM) in
   the device tree.
b) Keep the default LPM setting and have each consumer driver explicitly
   set its current load.

Since some regulators are shared among multiple consumers, and setting
the current must be coordinated across all of them, we will initially
adopt option a by setting the regulator to HPM. We can later migrate to
option b when the timing is appropriate and all consumer drivers are
ready.

Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
Signed-off-by: Tingguo Cheng <quic_tingguoc@quicinc.com>
Link: https://lore.kernel.org/r/20250717072746.987298-1-quic_ziyuzhan@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
This commit is contained in:
Ziyue Zhang
2025-08-11 16:47:35 -05:00
committed by Bjorn Andersson
parent 84f3849d05
commit fba47ba8c8
1 changed files with 1 additions and 4 deletions
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arch/arm64/boot/dts/qcom/qcs615-ride.dts
+1 -4
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@@ -246,10 +246,7 @@
regulator-name = "vreg_l12a";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1890000>;
regulator-initial-mode = <RPMH_REGULATOR_MODE_LPM>;
regulator-allow-set-load;
regulator-allowed-modes = <RPMH_REGULATOR_MODE_LPM
RPMH_REGULATOR_MODE_HPM>;
regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
};
vreg_l13a: ldo13 {