iio: adc: clear reference voltage bits before configuring vref

[PATCH v1] iio: adc: clear reference voltage bits before configuring vref

Posted by Billy Tsai 3 months, 2 weeks ago

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.

Change-Id: I03c036436f376ced8a19fa5d407b7bbb377ae721
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 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 1d5fd5f534b8..8ab29948214a 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)
-- 
2.25.1

Re: [PATCH v1] iio: adc: clear reference voltage bits before configuring vref

Posted by Jonathan Cameron 3 months, 1 week ago

On Tue, 21 Oct 2025 13:39:18 +0800
Billy Tsai <billy_tsai@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.
> 
> Change-Id: I03c036436f376ced8a19fa5d407b7bbb377ae721
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Make sure the patch title includes the part/driver name.

iio: adc: aspeed: ..

+ the stuff Andy raised already.

Actual change looks correct to me.

> ---
>  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 1d5fd5f534b8..8ab29948214a 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)

Re: [PATCH v1] iio: adc: clear reference voltage bits before configuring vref

Posted by Andy Shevchenko 3 months, 2 weeks ago

On Tue, Oct 21, 2025 at 01:39:18PM +0800, Billy Tsai 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.

> Change-Id: I03c036436f376ced8a19fa5d407b7bbb377ae721

What is this?

...

Shouldn't be a Fixes tag provided?

-- 
With Best Regards,
Andy Shevchenko