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

[Andy Shevchenko]

On Fri, Mar 13, 2026 at 06:02:16PM +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.
> 
> Changes made:
> - Introduce aspeed_adc_get_active_channels() to return the number of
>   channels that should be enabled by default
> - For battery sensing capable controllers, exclude the last channel
>   from the default channel enable mask
> - Enable the battery sensing channel only when explicitly accessed
>   via read_raw()
> - Replace hardcoded channel numbers with ASPEED_ADC_BATTERY_CHANNEL macro
> - Add helper functions for cleaner channel management

Why not series of patches each for the change made?

> This ensures optimal power efficiency for normal ADC operations while
> maintaining full functionality when battery sensing is needed.

-- 
With Best Regards,
Andy Shevchenko