lkml.org 
[lkml]   [2023]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 6/6] regulator: qcom_smd: Add support to define the bootup voltage
From


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

\
 
 \ /
  Last update: 2023-03-26 23:58    [W:0.137 / U:0.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site