Re: [PATCH v5 2/2] iio: adc: add Axiado SARADC driver
Andy Shevchenko <[email protected]>
| Newsgroups | org.kernel.vger.linux-kernel,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-iio |
|---|---|
| Organization | Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo |
| Message-ID | <[email protected]> |
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, ®val);
> +
> + /* 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