Re: [PATCH v4] iio: adc: ad7280a: use cleanup helpers guard() and scoped_guard() for mutex locking

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

On Thu, Apr 23, 2026 at 10:26:48AM -0300, Lucas Ivars Cadima Ciziks wrote:
> Replace open-coded mutex_lock/unlock pairs with the cleanup-based
> guard() and scoped_guard() helpers in ad7280a_write_thresh(),
> ad7280_show_balance_timer(), ad7280_store_balance_sw(),
> ad7280_store_balance_timer() and ad7280_read_raw().
> 
> This removes the need for the err_unlock label and explicit
> mutex_unlock() calls, as the lock is now automatically released
> when the function returns or the guarded scope exits, regardless
> of the exit path.

...

>  	switch (m) {
> -	case IIO_CHAN_INFO_RAW:
> -		mutex_lock(&st->lock);
> +	case IIO_CHAN_INFO_RAW: {
> +		guard(mutex)(&st->lock);
> +
>  		if (chan->address == AD7280A_ALL_CELLS)
>  			ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
>  		else
>  			ret = ad7280_read_channel(st, chan->address >> 8,
>  						  chan->address & 0xFF);
> -		mutex_unlock(&st->lock);

Same idea of splitting devaddr + ch variables can be made for this entire
switch-case...

>  		if (ret < 0)
>  			return ret;

>  		*val = ret;
>  
>  		return IIO_VAL_INT;
> +	}
>  	case IIO_CHAN_INFO_SCALE:
>  		if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6_REG)

...as I assume that would benefit this code as well.
Perhaps it should be done as preparatory patch.

>  			*val = 4000;

-- 
With Best Regards,
Andy Shevchenko