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

[Krzysztof Kozlowski <krzk@kernel.org>]

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?

> 
> 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.

> 
>>> +
>>>   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?

Best regards,
Krzysztof