Re: [PATCH 2/2] regulator: qcom_usb_vbus: add support for qcom,pm4125-vbus-reg

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 5/20/26 11:07 AM, Rakesh Kota wrote:
> The PM4125 PMIC uses a different register layout for USB VBUS control
> compared to PM8150B. On PM4125, CMD_OTG is at offset 0x50, OTG_CFG is
> at 0x56, and offset 0x52 is a 2-bit VBOOST voltage selector rather than
> a current-limit selector.
> 
> Introduce per-compatible regulator descriptor data to accommodate these
> differences. This keeps the existing PM8150B current-limit logic intact
> while adding a dedicated voltage-selector path for PM4125.
> 
> Signed-off-by: Rakesh Kota <rakesh.kota@oss.qualcomm.com>
> ---
>  drivers/regulator/qcom_usb_vbus-regulator.c | 102 ++++++++++++++++++++++++----
>  1 file changed, 88 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/regulator/qcom_usb_vbus-regulator.c b/drivers/regulator/qcom_usb_vbus-regulator.c
> index cd94ed67621fee9f6d7a0327054db0ebab6cc7ee..3d425452a0b35b35c4b454f84eb28e87cc8ba4f8 100644
> --- a/drivers/regulator/qcom_usb_vbus-regulator.c
> +++ b/drivers/regulator/qcom_usb_vbus-regulator.c
> @@ -20,10 +20,35 @@
>  #define OTG_CFG				0x53
>  #define OTG_EN_SRC_CFG			BIT(1)
>  
> +#define PM4125_CMD_OTG			0x50

This register is named differently

> +#define PM4125_VBOOST_CFG		0x52
> +#define PM4125_VBOOST_CFG_MASK		GENMASK(1, 0)
> +#define PM4125_OTG_CFG			0x56

And so is this one


> +#define PM4125_OTG_EN_SRC_CFG          BIT(0)
> +
> +struct qcom_usb_vbus_reg_data {
> +	u16 cmd_otg;
> +	u16 otg_cfg;
> +	u8  otg_en_src_cfg;
> +	u16 csel_reg;
> +	u8 csel_mask;
> +	const unsigned int *curr_table;
> +	unsigned int n_current_limits;
> +	u16 vsel_reg;
> +	u8 vsel_mask;
> +	const unsigned int *volt_table;
> +	unsigned int n_voltages;
> +	const struct regulator_ops *ops;
> +};

And because they're so different, keeping them in a single driver starts to
look a little odd

> +
>  static const unsigned int curr_table[] = {
>  	500000, 1000000, 1500000, 2000000, 2500000, 3000000,
>  };

And I think there's current-limiting on this PMIC too, except in a differnt
peripheral (@1300)

Konrad