Re: [PATCH v2 3/3] iio: adc: aspeed: Reserve battery sensing channel for on-demand use

Billy Tsai
2026-03-20T03:41:43Z

On Mon, Mar 16, 2026 at 11:00:48AM +0800, Billy Tsai wrote:
> > For controllers with battery sensing capability (AST2600/AST2700), the
> > last channel uses a different circuit design optimized for battery
> > voltage measurement. This channel should not be enabled by default
> > along with other channels to avoid potential interference and power
> > efficiency issues.
> > This ensures optimal power efficiency for normal ADC operations while
> > maintaining full functionality when battery sensing is needed.

>...

> > + /*
> > + * After enable a new channel need to wait some time for adc stable

> ADC

Got it.

> > + * Experiment result is 1ms.
> > + */
> > + mdelay(1);

> Why atomic? If not required, use fsleep(). Otherwise explain.

Good point.

This path is sleepable, so mdelay() is not required. I’ll switch it to
fsleep(1000) in v2.

I’ll also take a look at other mdelay() users in the driver and clean them
up in a separate patch if appropriate.

> > + }

Thanks

Billy Tsai