Re: [PATCH net-next v4 2/4] mfd: ac200: Add X-Powers AC200 support

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The AC200 driver resides in `drivers/mfd/` but fails to instantiate any child devices, violating MFD subsystem guidelines.
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--- Patch [2]: [PATCH net-next v4 2/4] mfd: ac200: Add X-Powers AC200 support ---
commit c3a5907d2032837edd51cf4fc8b2fb05a159740a
Author: James Hilliard <[email protected]>

mfd: ac200: Add X-Powers AC200 support
    
This patch introduces support for the X-Powers AC200 mixed-signal companion IC.
It provides shared register map access over I2C to be used by individual
function drivers. The core driver handles initialization, clock configuration,
and resetting of the chip.

> diff --git a/drivers/mfd/ac200.c b/drivers/mfd/ac200.c
> new file mode 100644
> index 0000000000000..798bb4173b14b
> --- /dev/null
> +++ b/drivers/mfd/ac200.c
[ ... ]
> +static int ac200_probe(struct i2c_client *client)
> +{
[ ... ]
> +	ret = regmap_write(ddata->regmap, AC200_SYS_CONTROL_REG, 0);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_write(ddata->regmap, AC200_SYS_CONTROL_REG,
> +			   AC200_SYS_CONTROL_CHIP_RESET_DEASSERT);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}

[Severity: Low]
Should this driver reside in drivers/mfd/ if it doesn't instantiate any child
devices?

The MFD subsystem guidelines explicitly state that placing a driver in
drivers/mfd/ is only permitted for devices that register multiple children
via the MFD API or of_platform_populate(). Here, ac200_probe() completes
successfully without calling devm_mfd_add_devices() or
devm_of_platform_populate().

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2