Re: [PATCH v3 3/4] iio: dac: ad3530r: parameterize DAC resolution

Andy Shevchenko <[email protected]> Mon, 17 Aug 2026 14:15:26 +0300

Newsgroups	org.kernel.vger.linux-iio,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
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 17, 2026 at 02:37:13PM +0800, Kim Seer Paller wrote:
> In preparation for adding the AD5710R/AD5711R, which support selectable
> 12-/16-bit resolution, add a per-chip resolution field and use it in the
> raw read/write and scale paths instead of assuming 16 bits. Drop
> AD3530R_REG_VAL_MASK and AD3530R_DAC_MAX_VAL, which hardcoded the 16-bit
> width and are now unused.

...

>  	case IIO_CHAN_INFO_RAW:
> -		if (val < 0 || val > AD3530R_DAC_MAX_VAL)
> +		if (val < 0 || val > (1 << st->chip_info->resolution) - 1)

		if (val < 0 || val > (BIT(st->chip_info->resolution) - 1))

OR

		if (val < 0 || val > GENMASK(st->chip_info->resolution - 1, 0))

One (GENMASK) works for 32, another (BIT) for 0. While it's tempting to use
BIT() for readability, the 0 is unlikely is correct, but 32 might be.

>  			return -EINVAL;

-- 
With Best Regards,
Andy Shevchenko