Re: [PATCH V2] iio: magnetometer: mag3110: add optional vdd/vddio regulator operation support

[Phil Reid]

G'day Anson,

On 10/12/2018 3:17 PM, Anson Huang wrote:
> The magnetometer's power supply could be controlled by regulator
> on some platforms, such as i.MX6Q-SABRESD board, the mag3110's
> power supply is controlled by a GPIO fixed regulator, need to make
> sure the regulator is enabled before any communication with mag3110,
> this patch adds optional vdd/vddio regulator operation support.

[snip]

> +
> +	data->vdd_reg = devm_regulator_get_optional(&client->dev, "vdd");
> +	if (!IS_ERR(data->vdd_reg)) {
> +		ret = regulator_enable(data->vdd_reg);
> +		if (ret) {
> +			dev_err(&client->dev, "failed to enable VDD regulator\n");
> +			return ret;
> +		}
> +	} else if (data->vdd_reg == ERR_PTR(-EPROBE_DEFER)) {
> +		return -EPROBE_DEFER;
> +	}
> +
IANAE, but normally the return pattern for devm_regulator_get_optional

if (!IS_ERR(reg)) {
    regulator_enable ...
} else {
    ret = PTR_ERR(reg);
    if (ret != -ENODEV)
        return ret;
}



--
Regards
Phil