The PMH0101 PMIC introduces BIDIR_LVL_SHIFTER modules that provide
bidirectional voltage translation between 1.2 V and 1.8 V power
domains, targeting open-drain signal buses such as I2C. Each level
shifter shares its two physical pins with a corresponding pair of GPIO
modules, and its enable state is centrally managed by AOP firmware as
a shared RPMh "XOB" resource.

This series adds kernel support for controlling these level shifters
through the pinctrl subsystem. Patches are ordered from infrastructure
to driver to bindings:

Patch 1 (soc: qcom: rpmh) extends the RPMh driver to accept write
commands from devices that are not children of the RPMh controller.
The existing write path assumes the caller is a child of the RSC device;
however, the SPMI GPIO driver sits under the SPMI controller bus. Two
new APIs are introduced — rpmh_get_ctrlr_dev() for resolving the
controller from a "qcom,rpmh" DT phandle, and rpmh_write_ctrlr() /
rpmh_write_async_ctrlr() which accept the controller device pointer
directly rather than deriving it through the device parent chain.

Patch 2 (dt-bindings) documents the new "level-shifter" function, the
qcom,1p2v-1p8v-ls-en property, the qcom,rpmh phandle, and the
qcom,pmic-id string required on pmh0101 nodes. The pmh0101 conditional
block is split out from pmih0108 and given its own required properties.

Patch 3 (pinctrl: qcom: spmi-gpio, rearchitect) refactors the driver's
group and function registration to use the generic pinctrl group and
function APIs (pinctrl_generic_add_group, pinmux_generic_add_function).
The previous design treated every pin as its own group with access to
all functions. The new design allows multi-pin groups with restricted
function sets, which is a prerequisite for exposing the level-shifter
function that is tied to specific GPIO pairs only.

Patch 4 (pinctrl: qcom: spmi-gpio, level-shifter) builds on the above
to introduce the "level-shifter" function. When selected, both GPIO
pads in the pair are disabled (high-impedance), and the RPMh XOB vote
for the level shifter is controlled separately via the new
qcom,1p2v-1p8v-ls-en pinconf parameter, allowing enable and disable
to be represented as distinct pinctrl states with the same function and
group.

With all these changes, the BIDIR_LVL_SHIFTER in PMH0101 could be
controlled with following settings:

    &pmh0101_gpios {
    	qcom,rpmh = <&apps_rsc>;
    	qcom,pmic-id = "B_E0";

    	pmh0101-ls1-en {
    	        groups = "gpio11, gpio12";
    	        function = "level-shifter";
    	        qcom,1p2v-1p8v-ls-en = <1>;
    	};

    	pmh0101-ls1-dis {
    	        groups = "gpio11, gpio12";
    	        function = "level-shifter";
    	        qcom,1p2v-1p8v-ls-en = <0>;
    	};
    };

Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
---
Changes in v2:
Add following change to address review comments from Sashiko AI:

- PATCH 1, in drivers/soc/qcom/rpmh.c
  1. Add rpmh_put_device() wrapper to avoid casting put_device directly to
     void (*)(void *) in devm_add_action_or_reset(), which would trigger a
     CFI kernel panic on indirect call type mismatch.
  2. Add device_link_add() with DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_PM_RUNTIME
     in rpmh_get_ctrlr_dev() to enforce probe/remove ordering and runtime PM
     suspend/resume ordering between the RPMH controller and non-child consumer
     devices, preventing use-after-free and hardware state machine violations on unbind.

- PATCH 2, in Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.yaml
  1. Make qcom,rpmh and qcom,pmic-id optional for qcom,pmh0101-gpio by removing
     them from the required list in the if/then conditional block. Update property
     descriptions to clarify they are only needed when the level-shifter function is used.

- PATCH 3, in drivers/pinctrl/qcom/Kconfig
  1. Add select GENERIC_PINCTRL_GROUPS and select GENERIC_PINMUX_FUNCTIONS to
     PINCTRL_QCOM_SPMI_PMIC to declare explicit dependencies on the generic pinctrl
     APIs (pinctrl_generic_add_group(), pinmux_generic_add_function(), etc.) used by the driver.

- PATCH 3, in drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
  1. Switch from devm_pinctrl_register() to devm_pinctrl_register_and_init() + pinctrl_enable()
     to defer hog application until after all pin groups, functions, are fully registered,
     fixing a probe sequence bug where hogs would be applied against an incomplete pinctrl state.

- PATCH 4, in drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
  1. Guard pad->is_enabled = true in pmic_gpio_pinconf_pin_set() to skip the assignment
     when pad->function == PMIC_GPIO_FUNC_INDEX_LEVEL_SHIFTER, preventing pinconf
     application from re-enabling GPIO pads that were explicitly disabled by the
     level-shifter mux path.
  2. Call cmd_db_ready() before cmd_db_read_addr() in pmic_gpio_register_level_shifters()
     to propagate -EPROBE_DEFER when the command DB is not yet initialized, instead of
     incorrectly returning -ENODEV which causes a permanent probe failure.
  3. Add qcom,rpmh / qcom,pmic-id DT property check before calling pmic_gpio_register_level_shifters()
     add make the level shifter function registration optional to match with the DT binding change.

- Link to v1: https://patch.msgid.link/20260527-pinctrl-level-shifter-v1-0-1965461d0a7c@oss.qualcomm.com

---
Fenglin Wu (4):
      soc: qcom: rpmh: Allow non-child devices to issue write commands
      dt-bindings: pinctrl: qcom,pmic-gpio: Add level-shifter function
      pinctrl: qcom: spmi-gpio: Rearchitect for flexible group support
      pinctrl: qcom: spmi-gpio: Add level-shifter function support

 .../bindings/pinctrl/qcom,pmic-gpio.yaml           |  66 +-
 drivers/pinctrl/qcom/Kconfig                       |   2 +
 drivers/pinctrl/qcom/pinctrl-spmi-gpio.c           | 796 ++++++++++++++++-----
 drivers/soc/qcom/rpmh.c                            | 173 ++++-
 include/dt-bindings/pinctrl/qcom,pmic-gpio.h       |   1 +
 include/soc/qcom/rpmh.h                            |  21 +
 6 files changed, 845 insertions(+), 214 deletions(-)
---
base-commit: b8f192cec7dcb2e4f04ee57ab78d51777b0a5729
change-id: 20260527-pinctrl-level-shifter-929b286f583d

Best regards,
--  
Fenglin Wu <fenglin.wu@oss.qualcomm.com>

On Fri, May 29, 2026 at 3:05 AM Fenglin Wu <fenglin.wu@oss.qualcomm.com> wrote:

> The PMH0101 PMIC introduces BIDIR_LVL_SHIFTER modules that provide
> bidirectional voltage translation between 1.2 V and 1.8 V power
> domains, targeting open-drain signal buses such as I2C. Each level
> shifter shares its two physical pins with a corresponding pair of GPIO
> modules, and its enable state is centrally managed by AOP firmware as
> a shared RPMh "XOB" resource.
(...)

This cover letter has a *very* long text mass, something Andy
Shevchenko strikingly dubbed "Dostoyevsky commitlogs".

It adds completely obvious descriptions of what every
patch does breaking the rule of "don't comment the obvious".

This is usually a sign of LLM AI-assisted commit message.
It also contains emdashes and other obvious signs of AI.

In that case, please use the Assisted-by tag, because the
LLM can then read this comment of mine and learn from it.
https://github.com/torvalds/linux/blob/master/Documentation/process/coding-assistants.rst

Yours,
Linus Walleij

On 5/30/2026 4:25 AM, Linus Walleij wrote:
> On Fri, May 29, 2026 at 3:05 AM Fenglin Wu <fenglin.wu@oss.qualcomm.com> wrote:
>
>> The PMH0101 PMIC introduces BIDIR_LVL_SHIFTER modules that provide
>> bidirectional voltage translation between 1.2 V and 1.8 V power
>> domains, targeting open-drain signal buses such as I2C. Each level
>> shifter shares its two physical pins with a corresponding pair of GPIO
>> modules, and its enable state is centrally managed by AOP firmware as
>> a shared RPMh "XOB" resource.
> (...)
>
> This cover letter has a *very* long text mass, something Andy
> Shevchenko strikingly dubbed "Dostoyevsky commitlogs".
>
> It adds completely obvious descriptions of what every
> patch does breaking the rule of "don't comment the obvious".
>
> This is usually a sign of LLM AI-assisted commit message.
> It also contains emdashes and other obvious signs of AI.
>
> In that case, please use the Assisted-by tag, because the
> LLM can then read this comment of mine and learn from it.
> https://github.com/torvalds/linux/blob/master/Documentation/process/coding-assistants.rst
>
> Yours,
> Linus Walleij

Thanks. I did use claude-4-6-sonnet for assistance. I will add following 
tag in all of the patches:

"Assisted-by: Claude:claude-4-6-sonnet"