linux-kernel - Re: [PATCH v3 10/12] i2c: qcom-geni: Use resources helper APIs in runtime PM functions

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Message-ID: <fcb56bf2-aa0a-4812-8ef4-b92ad7478096@oss.qualcomm.com>
Date: Wed, 4 Feb 2026 11:16:46 +0530
From: Praveen Talari <praveen.talari@....qualcomm.com>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>,
        Andi Shyti <andi.shyti@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley
 <conor+dt@...nel.org>,
        Mukesh Kumar Savaliya <mukesh.savaliya@....qualcomm.com>,
        Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, linux-arm-msm@...r.kernel.org,
        linux-i2c@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, bryan.odonoghue@...aro.org,
        dmitry.baryshkov@....qualcomm.com, bjorn.andersson@....qualcomm.com
Cc: prasad.sodagudi@....qualcomm.com, quic_vtanuku@...cinc.com,
        aniket.randive@....qualcomm.com, chandana.chiluveru@....qualcomm.com
Subject: Re: [PATCH v3 10/12] i2c: qcom-geni: Use resources helper APIs in
 runtime PM functions

Hi Konrad,

On 2/3/2026 4:43 PM, Konrad Dybcio wrote:
> On 1/30/26 5:48 PM, Praveen Talari wrote:
>> Hi Konrad,
>>
>> On 1/30/2026 5:35 PM, Konrad Dybcio wrote:
>>> On 1/12/26 11:47 AM, Praveen Talari wrote:
>>>> To manage GENI serial engine resources during runtime power management,
>>>> drivers currently need to call functions for ICC, clock, and
>>>> SE resource operations in both suspend and resume paths, resulting in
>>>> code duplication across drivers.
>>>>
>>>> The new geni_se_resources_activate() and geni_se_resources_deactivate()
>>>> helper APIs addresses this issue by providing a streamlined method to
>>>> enable or disable all resources based, thereby eliminating redundancy
>>>> across drivers.
>>>>
>>>> Signed-off-by: Praveen Talari <praveen.talari@....qualcomm.com>
>>>> ---
>>>> v1->v2:
>>>> Bjorn:
>>>> - Remove geni_se_resources_state() API.
>>>> - Used geni_se_resources_activate() and geni_se_resources_deactivate()
>>>>     to enable/disable resources.
>>>> ---
>>>>    drivers/i2c/busses/i2c-qcom-geni.c | 28 +++++-----------------------
>>>>    1 file changed, 5 insertions(+), 23 deletions(-)
>>>>
>>>> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
>>>> index a4b13022e508..b0a18e3d57d9 100644
>>>> --- a/drivers/i2c/busses/i2c-qcom-geni.c
>>>> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
>>>> @@ -1160,18 +1160,15 @@ static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
>>>>        struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
>>>>          disable_irq(gi2c->irq);
>>>> -    ret = geni_se_resources_off(&gi2c->se);
>>>> +
>>>> +    ret = geni_se_resources_deactivate(&gi2c->se);
>>>
>>> This calls dev_pm_opp_set_rate(se->dev, 0), dropping the performance state
>>
>> This does not apply to I²C, since I²C lacks an OPP table, so the callback is only relevant for SPI and UART. All the refactored APIs were added as generic interfaces shared across I²C, SPI, and UART.
> 
> Does the i2c mode not require any ratesetting on the SE clock, or

Yes, it is not needed since we are updating clock related values in SE 
register like I2C_SCL_COUNTERS.

Thanks,
Praveen Talari

> any >= LOWSVS RPMh vote on the power rail?
> 
> Konrad