Messages in this thread | | | Date | Fri, 27 Jan 2023 21:37:42 +0530 | Subject | Re: [PATCH 6/6] regulator: qcom_smd: Add support to define the bootup voltage | From | Devi Priya <> |
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On 1/13/2023 9:07 PM, Konrad Dybcio wrote: > > > On 13.01.2023 16:03, devi priya wrote: >> Kernel does not know the initial voltage set by the bootloaders. >> During regulator registration, the voltage variable is just declared >> and it is zero. Based on that, the regulator framework considers current >> the voltage as zero and tries to bring up each regulator to minimum >> the supported voltage. >> >> This introduces a dip in the voltage during kernel boot and gets >> stabilized once the voltage scaling comes into picture. >> >> To avoid the voltage dip, adding support to define the >> bootup voltage set by the boodloaders and based on it, regulator >> framework understands that proper voltage is already set >> >> Co-developed-by: Praveenkumar I <quic_ipkumar@quicinc.com> >> Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com> >> Signed-off-by: devi priya <quic_devipriy@quicinc.com> >> --- > Or maybe hook it up to the spmi_regulator_common_get_voltage() > from the SPMI regulator driver and read the real voltage instead > of relying on hardcoded values thay may differ between boards? > > Konrad In IPQ9574, SPMI regulator is not used. We are using RPM-Glink communication and the regulators are controlled by RPM. In this case, we don't have an option to readback the bootup voltage and so, we have hardcoded the values
>> drivers/regulator/qcom_smd-regulator.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/regulator/qcom_smd-regulator.c b/drivers/regulator/qcom_smd-regulator.c >> index 1eb17d378897..49a36b07397c 100644 >> --- a/drivers/regulator/qcom_smd-regulator.c >> +++ b/drivers/regulator/qcom_smd-regulator.c >> @@ -800,6 +800,7 @@ struct rpm_regulator_data { >> u32 id; >> const struct regulator_desc *desc; >> const char *supply; >> + int boot_uV; /* To store the bootup voltage set by bootloaders */ >> }; >> >> static const struct rpm_regulator_data rpm_mp5496_regulators[] = { >> @@ -809,7 +810,7 @@ static const struct rpm_regulator_data rpm_mp5496_regulators[] = { >> }; >> >> static const struct rpm_regulator_data rpm_ipq9574_mp5496_regulators[] = { >> - { "s1", QCOM_SMD_RPM_SMPA, 1, &ipq9574_mp5496_smpa1, "s1" }, >> + { "s1", QCOM_SMD_RPM_SMPA, 1, &ipq9574_mp5496_smpa1, "s1", 875000 }, >> {} >> }; >> >> @@ -1394,6 +1395,9 @@ static int rpm_regulator_init_vreg(struct qcom_rpm_reg *vreg, struct device *dev >> vreg->type = rpm_data->type; >> vreg->id = rpm_data->id; >> >> + if (rpm_data->boot_uV) >> + vreg->uV = rpm_data->boot_uV; >> + >> memcpy(&vreg->desc, rpm_data->desc, sizeof(vreg->desc)); >> vreg->desc.name = rpm_data->name; >> vreg->desc.supply_name = rpm_data->supply; Best Regards, Devi Priya
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