Re: [PATCH v2 3/3] iio: adc: ti-ads1298: Remove unnecessary CONFIG2 write during init
From: Jonathan Cameron
Date: Thu May 07 2026 - 12:31:45 EST
On Thu, 7 May 2026 13:51:28 +0300
Md Shofiqul Islam <shofiqtest@xxxxxxxxx> wrote:
> The driver was enabling the internal test signal (INT_TEST), double
> amplitude (TEST_AMP), and fast frequency (TEST_FREQ_FAST) bits in
> CONFIG2 during initialization. These bits activate an internal square
> wave generator intended for device testing and calibration, not normal
> ECG operation.
>
> CONFIG2 defaults to having only the RESERVED bit set after reset, which
> is the correct value for normal operation. Remove the write entirely
> since it would just be writing the reset default value.
>
> Suggested-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
> Signed-off-by: Md Shofiqul Islam <shofiqtest@xxxxxxxxx>
Looks fine to me.
I'll pick it up once you've addressed comments on patch 2 that
are outstanding.
> ---
> drivers/iio/adc/ti-ads1298.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.c
> index 186bda3087..8957e873e1 100644
> --- a/drivers/iio/adc/ti-ads1298.c
> +++ b/drivers/iio/adc/ti-ads1298.c
> @@ -615,15 +615,6 @@ static int ads1298_init(struct iio_dev *indio_dev)
> if (!indio_dev->name)
> return -ENOMEM;
>
> - /* Enable internal test signal, double amplitude, double frequency */
> - ret = regmap_write(priv->regmap, ADS1298_REG_CONFIG2,
> - ADS1298_MASK_CONFIG2_RESERVED |
> - ADS1298_MASK_CONFIG2_INT_TEST |
> - ADS1298_MASK_CONFIG2_TEST_AMP |
> - ADS1298_MASK_CONFIG2_TEST_FREQ_FAST);
> - if (ret)
> - return ret;
> -
> val = ADS1298_MASK_CONFIG3_RESERVED; /* Must write 1 always */
> if (!priv->reg_vref) {
> /* Enable internal reference */