Re: [PATCH v3 2/3] iio: adc: mt6397-auxadc: add mt6397 PMIC AUXADC driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] iio: adc: early return on regmap error abandons hardware teardown
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commit 7889b991ac3807eea04917eed3e7986efc9451b3
Author: Ryan Brue <ryanbrue.dev@gmail.com>

iio: adc: mt6397-auxadc: add mt6397 PMIC AUXADC driver
    
The mt6397 AUXADC is a 10-bit ADC behind the SoC's PMIC wrapper. On boards
built around this PMIC it is the only way to read the battery. Add a driver
exposing the battery voltage and battery temperature channels.

> diff --git a/drivers/iio/adc/mt6397-auxadc.c b/drivers/iio/adc/mt6397-auxadc.c
> new file mode 100644
> index 0000000000000..d860cd3a89227
> --- /dev/null
> +++ b/drivers/iio/adc/mt6397-auxadc.c

[ ... ]

> +static int mt6397_auxadc_battemp_bias_off(struct mt6397_auxadc *adc)
> +{
> +	struct regmap *map = adc->regmap;
> +	int ret;
> +
> +	ret = regmap_clear_bits(map, MT6397_CHR_CON7, MT6397_CHR_CON7_BATON_TDET_EN);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_clear_bits(map, MT6397_AUXADC_CON0, MT6397_AUXADC_CON0_BUF_PWD_B);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_clear_bits(map, MT6397_AUXADC_CON0,
> +				 MT6397_AUXADC_CON0_BUF_PWD_ON);
> +}

[Severity: Medium]
Does returning early here abandon the hardware teardown? If clearing
MT6397_CHR_CON7 fails, the MT6397_AUXADC_CON0 bias buffers will remain
enabled. Since the caller relies on this function to provide unconditional
teardown even if earlier steps failed, should this function continue and
attempt to clear the remaining bits regardless of an error?

[ ... ]

> +static int mt6397_auxadc_isense_disable(struct mt6397_auxadc *adc)
> +{
> +	struct regmap *map = adc->regmap;
> +	int ret;
> +
> +	ret = regmap_clear_bits(map, MT6397_AUXADC_CON14,
> +				MT6397_AUXADC_CON14_CH0_NORM_SEL |
> +				MT6397_AUXADC_CON14_CH0_LBAT_SEL);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_clear_bits(map, MT6397_CHR_CON16,
> +				 MT6397_CHR_CON16_ADCIN_VSEN_EN |
> +				 MT6397_CHR_CON16_ADCIN_VBAT_EN);
> +}

[Severity: Medium]
Similarly, does returning early here prevent MT6397_CHR_CON16 from being
cleared if updating MT6397_AUXADC_CON14 fails?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260920-rbrue-suez-upstreaming-mt6397-auxadc-v3-0-c00edacbee64@gmail.com?part=2