[PATCH v3] iio: adc: aspeed: clear reference voltage bits before configuring vref

[Jonathan Cameron]

On Tue, 3 Mar 2026 10:38:26 +0800
Billy Tsai <billy_tsai at aspeedtech.com> wrote:

> Ensures the reference voltage bits are cleared in the ADC engine
> control register before configuring the voltage reference. This
> avoids potential misconfigurations caused by residual bits.
> 
> Fixes: 1b5ceb55fec2 ("iio: adc: aspeed: Support ast2600 adc.")
> Signed-off-by: Billy Tsai <billy_tsai at aspeedtech.com>
Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan

> ---
> Changes in v3:
> - Added the missing Fixes: tag
> 
> Changes in v2:
> - Remove Gerrit Change-Id's
> ---
>  drivers/iio/adc/aspeed_adc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
> index 4be44c524b4d..83a9885b9ae4 100644
> --- a/drivers/iio/adc/aspeed_adc.c
> +++ b/drivers/iio/adc/aspeed_adc.c
> @@ -415,6 +415,7 @@ static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
>  	}
>  	adc_engine_control_reg_val =
>  		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
> +	adc_engine_control_reg_val &= ~ASPEED_ADC_REF_VOLTAGE;
>  
>  	ret = devm_regulator_get_enable_read_voltage(data->dev, "vref");
>  	if (ret < 0 && ret != -ENODEV)
> 
> ---
> base-commit: af4e9ef3d78420feb8fe58cd9a1ab80c501b3c08
> change-id: 20260303-adc-47e5bfdf89c9
> 
> Best regards,