Re: [PATCH RESEND v6 5/5] regulator: axp20x: add support for the AXP318W

[Chen-Yu Tsai]

On Thu, Aug 13, 2026 at 5:31 AM Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>
> From: Andre Przywara <andre.przywara@xxxxxxx>
>
> The X-Powers AXP318W is a typical PMIC from X-Powers, featuring nine
> DC/DC converters and 28 LDOs, on the regulator side.
>
> Describe the chip's voltage settings and switch registers, how the
> voltages are encoded, and connect this to the MFD device via its
> regulator ID.
> We use just "318" for the internal identifiers, for easier typing and
> less churn. If something else other than the "AXP318W" shows up, that's
> an easy change, externally visible strings carry the additional letter
> already.
>
> Reviewed-by: Mark Brown <broonie@xxxxxxxxxx>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> Co-developed-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
>  drivers/regulator/axp20x-regulator.c | 324 ++++++++++++++++++++++++++++++++++-
>  include/linux/mfd/axp20x.h           |  45 +++++
>  2 files changed, 360 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
> index da891415efc0..9e81e2cb7542 100644
> --- a/drivers/regulator/axp20x-regulator.c
> +++ b/drivers/regulator/axp20x-regulator.c
> @@ -138,6 +138,29 @@
>  #define AXP313A_DCDC_V_OUT_MASK                GENMASK(6, 0)
>  #define AXP313A_LDO_V_OUT_MASK         GENMASK(4, 0)
>
> +#define AXP318_DCDC1_PFM_PWM_CTRL      BIT(7)
> +#define AXP318_DCDC23_POLYPHASE_CTRL   BIT(6)
> +#define AXP318_DCDC45_POLYPHASE_CTRL   BIT(7)
> +#define AXP318_DCDC1_V_OUT_MASK                GENMASK(4, 0)
> +#define AXP318_DCDC2_V_OUT_MASK                GENMASK(6, 0)
> +#define AXP318_LDO_V_OUT_MASK          GENMASK(4, 0)
> +#define AXP318_ELDO_V_OUT_MASK         GENMASK(5, 0)
> +#define AXP318_THRESHOLD_VOLTAGE       1540000
> +/*
> + * FIXME:
> + * Some LDOs of the AXP318 may be fed by different supplies and
> + * the documentation repeatedly warns that output voltage must
> + * be less than the supply, which is the case for any LDO really.
> + *
> + * The best way to let the framework handle this is to set the
> + * min_dropout_uV field. However the AXP318 documentation
> + * does not provide any information about this.
> + *
> + * Realistically, it can't be less than 1uV so use this
> + * for all LDOs until we know more.
> + */
> +#define AXP318_LDO_MIN_DROPOUT         1 /* uV */
> +
>  #define AXP717_DCDC1_NUM_VOLTAGES      88
>  #define AXP717_DCDC2_NUM_VOLTAGES      107
>  #define AXP717_DCDC3_NUM_VOLTAGES      103

[...]

> @@ -1430,6 +1704,20 @@ static int axp20x_set_dcdc_workmode(struct regulator_dev *rdev, int id, u32 work
>                 workmode <<= ffs(mask) - 1;
>                 break;
>
> +       case AXP318_ID:
> +               /*
> +                * Only DCDC1 has PWM control on the AXP318
> +                * The other DCDCs control DVM through bit 7 of the related
> +                * registers. Work mode could possibly extended to deal with
> +                * this but it is not how it is documented at the moment
> +                */

DVM bit is for turning on / off voltage ramp rate control. It is unrelated
to work mode. Please drop the comment.

> +               if (id != AXP318_DCDC1)
> +                       return -EINVAL;
> +               reg = AXP318_DCDC1_CONTROL;
> +               mask = AXP318_DCDC1_PFM_PWM_CTRL;
> +               workmode <<= ffs(mask) - 1;
> +               break;
> +
>         case AXP806_ID:
>                 /*
>                  * AXP806 DCDC regulator IDs have the same range as AXP22X.

[...]

> diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
> index 0191467de4ec..251f057ea76d 100644
> --- a/include/linux/mfd/axp20x.h
> +++ b/include/linux/mfd/axp20x.h
> @@ -128,6 +128,7 @@ enum axp20x_variants {
>  #define AXP318_DCDC7_CONTROL           0x18
>  #define AXP318_DCDC8_CONTROL           0x19
>  #define AXP318_DCDC9_CONTROL           0x1a
> +#define AXP318_DCDC_CONTROL1           0x1b

This could be moved to the previous patch for completeness.

[...]


Once fixed,

Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxxxx>