Re: [PATCH v5 2/2] iio: adc: add Axiado SARADC driver

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Mon, Aug 10, 2026 at 07:49:36AM -0700, Petar Stepanovic wrote:
> Add support for the SARADC controller found on Axiado AX3000 and
> AX3005 SoCs.
> 
> The driver supports single-shot voltage reads through the IIO
> subsystem. The number of available input channels is selected from
> the SoC match data, allowing AX3000 and AX3005 variants to use the
> same driver.

...

> +/* MANUAL_CTRL register fields */

^^^

> +#define AX_SARADC_MANUAL_CTRL_ENABLE	BIT(0)
> +#define AX_SARADC_MANUAL_CTRL_CH_SEL_MASK	GENMASK(4, 1)
> +
> +#define AX_RESOLUTION_BITS	10
> +#define AX_SARADC_CONV_CYCLES	13
> +#define AX_SARADC_CONV_DELAY_MARGIN_US	10
> +
> +struct axiado_saradc {
> +	struct regmap *regmap;
> +	struct mutex lock; /* Serializes ADC conversions. */

Choose the same style for all single-line comments (here is a period present
while in the above, for instance, there is none).

> +	unsigned long clk_rate;
> +	int vref_uV;
> +};

...

> +static int axiado_saradc_conversion(struct axiado_saradc *info,
> +				    struct iio_chan_spec const *chan, int *val)
> +{
> +	unsigned long usecs;
> +	unsigned int regval;
> +	int ret;
> +
> +	guard(mutex)(&info->lock);
> +
> +	/* Select the channel to be used and trigger conversion */
> +	ret = regmap_write(info->regmap, AX_SARADC_MANUAL_CTRL_REG,
> +			   AX_SARADC_MANUAL_CTRL_ENABLE |
> +			   FIELD_PREP(AX_SARADC_MANUAL_CTRL_CH_SEL_MASK, chan->channel));
> +	if (ret)
> +		return ret;
> +
> +	/* Hardware requires 13 conversion cycles at clk_rate */

> +	usecs = DIV_ROUND_UP(AX_SARADC_CONV_CYCLES * USEC_PER_SEC,
> +			     info->clk_rate);

I think it's okay to have this on a single line (83 characters).

> +	fsleep(usecs + AX_SARADC_CONV_DELAY_MARGIN_US);
> +
> +	ret = regmap_read(info->regmap, AX_SARADC_DOUT_REG, &regval);
> +
> +	/* Best effort to stop manual conversion. */
> +	regmap_write(info->regmap, AX_SARADC_MANUAL_CTRL_REG, 0);
> +
> +	if (ret)
> +		return ret;
> +
> +	*val = regval & GENMASK(AX_RESOLUTION_BITS - 1, 0);
> +
> +	return 0;
> +}

...

> +	soc_data = device_get_match_data(dev);
> +	if (!soc_data)
> +		return dev_err_probe(dev, -EINVAL, "failed to get match data\n");

-ENODATA

-- 
With Best Regards,
Andy Shevchenko