Re: [PATCH v2 2/4] dt-bindings: pinctrl: qcom,pmic-gpio: Add level-shifter function

[Fenglin Wu <fenglin.wu@oss.qualcomm.com>]

On 6/1/2026 7:30 PM, Krzysztof Kozlowski wrote:
> On 01/06/2026 07:00, Fenglin Wu wrote:
>> On 5/30/2026 6:29 PM, Krzysztof Kozlowski wrote:
>>> On Thu, May 28, 2026 at 06:05:36PM -0700, Fenglin Wu wrote:
>>>> Add the "level-shifter" function and add the required DT properties to
>>>> allow RPMh firmware to control the level-shifter. Introduce a custom
>>>> pinconf parameter "qcom,1p2v-1p8v-ls-en" for enabling or disabling the
>>>> level-shifter function.
>>> I don't get how PMIC, which is not a child of RPMh at all or not
>>> talking with RPMh RSC, needs to configure its pin via RPMh. It feels it
>>> is misrepresented.
>> The control for enabling or disabling the bi-directional level shifter
>> has been centralized in AOP, similar to how regulator resources are
>> managed. This allows it to be used on a serial bus shared by multiple
>> clients from different subsystems. Each subsystem can vote for its
>> enable state through RPMh commands, and AOP determines the final status
>> to turn the BIDIR_LVL_SHIFTER PMIC modules on or off. Additionally, each
>> bi-directional level shifter shares its physical pins with a pair of
>> PMIC GPIO modules and is mutually exclusive with other PMIC GPIO
>> functions, which means those PMIC GPIO functions must be disabled.
> So two completely independent hardware devices - PMIC and RPMh -
> configure the same hardware - level shifter and pin function?

Yes if we consider level shifter as a mux function of the GPIO pairs.

>
>> For these reasons, adding bi-directional level shifter software support
>> to the pinctrl-spmi-gpio driver is considered the best approach. Let me
>> know if you have a better suggestion.
>>
>>>> Additionally, add the "groups" property with the allowed group names
>>>> that can be used to control the level-shifter function on pmh0101.
>>>>
>>>> Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
>>>> ---
>>>>    .../bindings/pinctrl/qcom,pmic-gpio.yaml           | 66 +++++++++++++++++++++-
>>>>    include/dt-bindings/pinctrl/qcom,pmic-gpio.h       |  1 +
>>>>    2 files changed, 64 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.yaml b/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.yaml
>>>> index b8109e6c2a10..19dc61ddff2d 100644
>>>> --- a/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.yaml
>>>> +++ b/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.yaml
>>>> @@ -119,6 +119,21 @@ properties:
>>>>          The first cell will be used to define gpio number and the
>>>>          second denotes the flags for this gpio
>>>>    
>>>> +  qcom,rpmh:
>>>> +    description:
>>>> +      Phandle to the RPMh controller device. Required for PMICs when the
>>>> +      bidirectional level shifters is used (e.g., pmh0101), to enable
>>>> +      communication with RPMh firmware for level shifter control.
>>>> +    $ref: /schemas/types.yaml#/definitions/phandle
>>>> +
>>>> +  qcom,pmic-id:
>>>> +    description:
>>>> +      The ID of the PMIC which supports bidirectional level shifter function.
>>>> +      It is used as the RPMh resource name suffix to request control of the
>>>> +      level shifter to the RPMh firmware.
>>>> +    $ref: /schemas/types.yaml#/definitions/string
>>>> +    pattern: "^[A-N]_E[0-3]+$"
>>> You do not get instance IDs (it's explcitly documented in docs).
>> Okay. This is primarily for creating the resource names used to obtain
>> the rpmh addresses from the cmd-db for the level-shifter.
>>
>> I can change it to a different name if you still agree to add the
>> support in the pinctrl driver.
> ID or name, same thing. Still not allowed.

Okay. Then I don't know how could the driver be able to get the rpmh 
address from the cmd-db.

Maybe just like what Dmitry suggested, register a separate, RPMh-based 
GPIO driver for those GPIOs associated with the level shifter function, 
would be a better approach?

Re: [PATCH v2 1/4] soc: qcom: rpmh: Allow non-child devices to issue 
write commands - Dmitry Baryshkov 
<https://lore.kernel.org/linux-arm-msm/4ac5hjmr6divqs4myhcw5sveuboj265sw2jwslbivrfwh5e7ce@6d7ajvgikkgt/>

>
>>>> +
>>>>    additionalProperties: false
>>>>    
>>>>    required:
>>>> @@ -330,6 +345,22 @@ allOf:
>>>>              contains:
>>>>                enum:
>>>>                  - qcom,pmh0101-gpio
>>>> +    then:
>>>> +      properties:
>>>> +        gpio-line-names:
>>>> +          minItems: 18
>>>> +          maxItems: 18
>>>> +        gpio-reserved-ranges:
>>>> +          minItems: 1
>>>> +          maxItems: 9
>>>> +        qcom,rpmh: true
>>>> +        qcom,pmic-id: true
>>>> +
>>>> +  - if:
>>>> +      properties:
>>>> +        compatible:
>>>> +          contains:
>>>> +            enum:
>>>>                  - qcom,pmih0108-gpio
>>>>        then:
>>>>          properties:
>>>> @@ -523,6 +554,19 @@ $defs:
>>>>            items:
>>>>              pattern: '^gpio([0-9]+)$'
>>>>    
>>>> +      groups:
>>>> +        $ref: /schemas/types.yaml#/definitions/string-array
>>>> +        description:
>>>> +          List of GPIO groups to apply properties to. Only valid for
>>>> +          function "level-shifter" on pmh0101. Valid groups are
>>>> +          gpio11, gpio12; gpio13, gpio14; gpio15, gpio16; gpio17, gpio18.
>>>> +        items:
>>>> +          enum:
>>>> +            - gpio11, gpio12
>>>> +            - gpio13, gpio14
>>>> +            - gpio15, gpio16
>>>> +            - gpio17, gpio18
>>>> +
>>>>          function:
>>>>            items:
>>>>              - enum:
>>>> @@ -536,6 +580,7 @@ $defs:
>>>>                  - dtest4
>>>>                  - func3  # supported by LV/MV GPIO subtypes
>>>>                  - func4  # supported by LV/MV GPIO subtypes
>>>> +              - level-shifter  # supported only by pmh0101
>>>>    
>>>>          bias-disable: true
>>>>          bias-pull-down: true
>>>> @@ -592,9 +637,24 @@ $defs:
>>>>              configured as digital input.
>>>>            enum: [1, 2, 3, 4]
>>>>    
>>>> -    required:
>>>> -      - pins
>>>> -      - function
>>>> +      qcom,1p2v-1p8v-ls-en:
>>>> +        $ref: /schemas/types.yaml#/definitions/uint32
>>>> +        description:
>>>> +          Enable or disable the bidirectional 1.2V/1.8V level shifter
>>>> +          associated with the specified GPIO group. When set to 1, an RPMh
>>>> +          vote is sent to AOP to enable the level shifter. When set to 0,
>>>> +          the vote is withdrawn. Only valid when function is "level-shifter"
>>>> +          and groups is a level-shifter GPIO pair (e.g., "gpio11, gpio12"
>>>> +          on pmh0101).
>>> And there are no generic pinconf properties defining the voltage?
>> The 1.2V and 1.8V voltages on each side of the bidirectional level
>> shifter are not configurable. They are fixed in the hardware with
>> built-in reference voltages at each side of the pins. I am adding this
>> custom pinconf parameter mainly to control its enabling status. Also, I
>> am adding "1p2v-1p8v" in the parameter name to provide additional
>> clarity for users about the "level-shifter" function.
> So there are or there are not?

There is not such generic pinconf parameter based what I saw here:

https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/tree/drivers/pinctrl/pinconf-generic.c#n173

>
> Best regards,
> Krzysztof