Re: [PATCH v2] iio: magnetometer: si7210: use devm_regulator_get_enable_read_voltage()

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 11 Feb 2026 10:18:28 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Simplify probe by using devm_regulator_get_enable_read_voltage() to
> get, enable and read the regulator voltage in a single call.
This needs to state that this is a functional change, but in real
deployments it is very rare for VDD to change after initial probe.

Note I once had a board where it did depending on driver
probe ordering as devices had slightly different requirements and
it was cut and paste from the driver I wrote for that which probably
led to so many drivers assuming it was dynamic.

Jonathan

> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
> Changes in v2:
>  - use vdd_uV naming convention
>  - remove unnecessary div_s64() for 32-bit division
>  drivers/iio/magnetometer/si7210.c | 21 +++++++--------------
>  1 file changed, 7 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/iio/magnetometer/si7210.c b/drivers/iio/magnetometer/si7210.c
> index 27e3feba7a0f..8b98dd4dafa4 100644
> --- a/drivers/iio/magnetometer/si7210.c
> +++ b/drivers/iio/magnetometer/si7210.c
> @@ -128,13 +128,13 @@ static const struct regmap_config si7210_regmap_conf = {
>  struct si7210_data {
>  	struct regmap *regmap;
>  	struct i2c_client *client;
> -	struct regulator *vdd;
>  	struct mutex fetch_lock; /* lock for a single measurement fetch */
>  	s8 temp_offset;
>  	s8 temp_gain;
>  	s8 scale_20_a[A_REGS_COUNT];
>  	s8 scale_200_a[A_REGS_COUNT];
>  	u8 curr_scale;
> +	unsigned int vdd_uV;
>  };
>  
>  static const struct iio_chan_spec si7210_channels[] = {
> @@ -221,12 +221,8 @@ static int si7210_read_raw(struct iio_dev *indio_dev,
>  		temp *= (1 + (data->temp_gain / 2048));
>  		temp += (int)(MICRO / 16) * data->temp_offset;
>  
> -		ret = regulator_get_voltage(data->vdd);
> -		if (ret < 0)
> -			return ret;
> -
>  		/* temp -= 0.222 * VDD */
> -		temp -= 222 * div_s64(ret, MILLI);
> +		temp -= 222 * (data->vdd_uV / MILLI);
>  
>  		*val = div_s64(temp, MILLI);
>  
> @@ -396,14 +392,11 @@ static int si7210_probe(struct i2c_client *client)
>  		return dev_err_probe(&client->dev, PTR_ERR(data->regmap),
>  				     "failed to register regmap\n");
>  
> -	data->vdd = devm_regulator_get(&client->dev, "vdd");
> -	if (IS_ERR(data->vdd))
> -		return dev_err_probe(&client->dev, PTR_ERR(data->vdd),
> -				     "failed to get VDD regulator\n");
> -
> -	ret = regulator_enable(data->vdd);
> -	if (ret)
> -		return ret;
> +	ret = devm_regulator_get_enable_read_voltage(&client->dev, "vdd");
> +	if (ret < 0)
> +		return dev_err_probe(&client->dev, ret,
> +				     "Failed to get vdd regulator\n");
> +	data->vdd_uV = ret;
>  
>  	indio_dev->name = dev_name(&client->dev);
>  	indio_dev->modes = INDIO_DIRECT_MODE;