Simplify probe by using devm_regulator_get_enable_read_voltage() to
get, enable and read the regulator voltage in a single call.

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;
-- 
2.43.0

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;

On Wed, Feb 11, 2026 at 10:18:28AM +0200, Antoniu Miclaus wrote:
> Simplify probe by using devm_regulator_get_enable_read_voltage() to
> get, enable and read the regulator voltage in a single call.

One nit-pick below, otherwise LGTM,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

...

>  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;
>  };

Haven't noticed, but I believe this is not the best place to put a new member.
Does `pahole` agree with me or with you?

...

>  		/* temp -= 0.222 * VDD */
> -		temp -= 222 * div_s64(ret, MILLI);
> +		temp -= 222 * (data->vdd_uV / MILLI);

Just a side note: Here is a possible loss in precision, wouldn't be better to
have it as

		temp -= 222 * data->vdd_uV / MILLI;

?

Note, if you agree this needs to be checked with the datasheet, etc. and sent
in a separate patch. For now the original way seems okay to me.

-- 
With Best Regards,
Andy Shevchenko