linux-kernel - Re: [PATCH] regulator:s5m8767 Fully convert to GPIO descriptors

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Message-ID: <bf80a815-a602-4bbe-a950-e8b6c1b0789a@kernel.org>
Date: Mon, 9 Dec 2024 20:50:07 +0100
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Song Chen <chensong_2000@....cn>, lgirdwood@...il.com,
 broonie@...nel.org, lee@...nel.org, linus.walleij@...aro.org, brgl@...ev.pl
Cc: linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
 linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH] regulator:s5m8767 Fully convert to GPIO descriptors

On 07/12/2024 07:16, Song Chen wrote:
>>>   		}
>>> -		pdata->buck_gpios[i] = gpio;
>>> +
>>> +		/* SET GPIO*/
>>
>> What is a SET GPIO?
>>
>>> +		snprintf(label, sizeof(label), "%s%d", "S5M8767 SET", i + 1);
>>
>> Why using "SET" as name, not the actual name it is used for? Buck DVS?
> 
> from below snippets:
> s5m8767_pmic_probe of drivers/regulator/s5m8767.c
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[0],
>                      "S5M8767 SET1");
>          if (ret)
>              return ret;
> 
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[1],
>                      "S5M8767 SET2");
>          if (ret)
>              return ret;
> 
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[2],
>                      "S5M8767 SET3");


Yeah, your code is fine.

> 
> and arch/arm/boot/dts/samsung/exynos5250-spring.dts
> 
>          s5m8767,pmic-buck-dvs-gpios = <&gpd1 0 GPIO_ACTIVE_LOW>, /* DVS1 */
>                            <&gpd1 1 GPIO_ACTIVE_LOW>, /* DVS2 */
>                            <&gpd1 2 GPIO_ACTIVE_LOW>; /* DVS3 */
> 
>          s5m8767,pmic-buck-ds-gpios = <&gpx2 3 GPIO_ACTIVE_LOW>, /* SET1 */
>                           <&gpx2 4 GPIO_ACTIVE_LOW>, /* SET2 */
>                           <&gpx2 5 GPIO_ACTIVE_LOW>; /* SET3 */
> 
>>
>>> +		gpiod_set_consumer_name(pdata->buck_gpios[i], label);
>>> +		gpiod_direction_output(pdata->buck_gpios[i],
>>> +					(pdata->buck_default_idx >> (2 - i)) & 0x1);
>>
>> This is not an equivalent code. You set values for GPIOs 0-1 even if
>> requesting GPIO 2 fails.
>>
>> On which board did you test it?
> 
> You are right ,it's not equivalent with original code, i will fix it. 
> but i have a question here:
> 
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[0],
>                      "S5M8767 SET1");
>          if (ret)
>              return ret;
> 
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[1],
>                      "S5M8767 SET2");
>          if (ret)
>              return ret;
> 
>          ret = devm_gpio_request(&pdev->dev, pdata->buck_gpios[2],
>                      "S5M8767 SET3");
>          if (ret)
>              return ret;
> 
> if it fails to request buck_gpios[2] after successfully requests 
> buck_gpios[0] and buck_gpios[1], the probe fails as well, should it call 
> gpiod_put to return gpio resource?


Aren't you using devm interface? Please read the API. You do not need to
put anything, unless you use some other interface and I missed the point
of the question.

Best regards,
Krzysztof