Re: [PATCH v2 4/7] thermal: exynos: simplify regulator (de)initialization

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 11/09/2023 15:34, Mateusz Majewski wrote:
> This does reduce the error granularity a bit, but the code
> simplification seems to be worth it.
> 
> Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
> ---
>  drivers/thermal/samsung/exynos_tmu.c | 33 +++++++---------------------
>  1 file changed, 8 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
> index ba9414b419ef..8451deb65f43 100644
> --- a/drivers/thermal/samsung/exynos_tmu.c
> +++ b/drivers/thermal/samsung/exynos_tmu.c
> @@ -157,7 +157,6 @@ enum soc_type {
>   * @reference_voltage: reference voltage of amplifier
>   *	in the positive-TC generator block
>   *	0 < reference_voltage <= 31
> - * @regulator: pointer to the TMU regulator structure.
>   * @tzd: pointer to thermal_zone_device structure
>   * @ntrip: number of supported trip points.
>   * @enabled: current status of TMU device
> @@ -183,7 +182,6 @@ struct exynos_tmu_data {
>  	u16 temp_error1, temp_error2;
>  	u8 gain;
>  	u8 reference_voltage;
> -	struct regulator *regulator;
>  	struct thermal_zone_device *tzd;
>  	unsigned int ntrip;
>  	bool enabled;
> @@ -994,42 +992,34 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>  	 * TODO: Add regulator as an SOC feature, so that regulator enable
>  	 * is a compulsory call.
>  	 */
> -	data->regulator = devm_regulator_get_optional(&pdev->dev, "vtmu");
> -	if (!IS_ERR(data->regulator)) {
> -		ret = regulator_enable(data->regulator);
> -		if (ret) {
> -			dev_err(&pdev->dev, "failed to enable vtmu\n");
> -			return ret;
> -		}
> -	} else {
> -		if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
> +	ret = devm_regulator_get_enable_optional(&pdev->dev, "vtmu");
> +	if (ret) {
> +		if (ret == -EPROBE_DEFER)
>  			return -EPROBE_DEFER;
> -		dev_info(&pdev->dev, "Regulator node (vtmu) not found\n");
> +		dev_info(&pdev->dev, "Failed to get regulator node (vtmu)\n");

This is not equivalent. If regulator is provided and enable fails, the
old code is nicely returning error. Now, it will print misleading
message - failed to get regulator - and continue.

While this simplifies the code, it ignores important running condition -
having regulator enabled.

Best regards,
Krzysztof