[PATCH] gpio: sama5d2-piobu: remove platform_set_drvdata() + cleanup probe

[PATCH] gpio: sama5d2-piobu: remove platform_set_drvdata() + cleanup probe

[Alexandru Ardelean]

The platform_set_drvdata() call is only useful if we need to retrieve back
the private information.
Since the driver doesn't do that, it's not useful to have it.

This change also changes the probe order a bit, moving the
devm_gpiochip_add_data() as the last call. This means that when the
gpiochip is registered [and available to consumers], it should be
initialized.

It's still possible that the devm_gpiochip_add_data() call could fail,
leaving the chip in a partially initialized state, but that was possible
even before this change; it was just some other partially initialized
state.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---
 drivers/gpio/gpio-sama5d2-piobu.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/gpio/gpio-sama5d2-piobu.c b/drivers/gpio/gpio-sama5d2-piobu.c
index b7c950658170..dfaa069b1466 100644
--- a/drivers/gpio/gpio-sama5d2-piobu.c
+++ b/drivers/gpio/gpio-sama5d2-piobu.c
@@ -189,7 +189,6 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
 	if (!piobu)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, piobu);
 	piobu->chip.label = pdev->name;
 	piobu->chip.parent = &pdev->dev;
 	piobu->chip.of_node = pdev->dev.of_node;
@@ -210,12 +209,6 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
 		return PTR_ERR(piobu->regmap);
 	}
 
-	ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret);
-		return ret;
-	}
-
 	for (i = 0; i < PIOBU_NUM; ++i) {
 		ret = sama5d2_piobu_setup_pin(&piobu->chip, i);
 		if (ret) {
@@ -225,7 +218,7 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
 		}
 	}
 
-	return 0;
+	return devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
 }
 
 static const struct of_device_id sama5d2_piobu_ids[] = {
-- 
2.31.1

Re: [PATCH] gpio: sama5d2-piobu: remove platform_set_drvdata() + cleanup probe

[Alexandru Ardelean]

On Wed, 7 Jul 2021 at 16:51, Alexandru Ardelean <aardelean@deviqon.com> wrote:
>
> The platform_set_drvdata() call is only useful if we need to retrieve back
> the private information.
> Since the driver doesn't do that, it's not useful to have it.
>
> This change also changes the probe order a bit, moving the
> devm_gpiochip_add_data() as the last call. This means that when the
> gpiochip is registered [and available to consumers], it should be
> initialized.
>
> It's still possible that the devm_gpiochip_add_data() call could fail,
> leaving the chip in a partially initialized state, but that was possible
> even before this change; it was just some other partially initialized
> state.
>

Please disregard this.
It seems I have not taken into consideration the fact that interrupts
are enabled after the gpiochip is registered.

> Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
> ---
>  drivers/gpio/gpio-sama5d2-piobu.c | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/gpio/gpio-sama5d2-piobu.c b/drivers/gpio/gpio-sama5d2-piobu.c
> index b7c950658170..dfaa069b1466 100644
> --- a/drivers/gpio/gpio-sama5d2-piobu.c
> +++ b/drivers/gpio/gpio-sama5d2-piobu.c
> @@ -189,7 +189,6 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
>         if (!piobu)
>                 return -ENOMEM;
>
> -       platform_set_drvdata(pdev, piobu);
>         piobu->chip.label = pdev->name;
>         piobu->chip.parent = &pdev->dev;
>         piobu->chip.of_node = pdev->dev.of_node;
> @@ -210,12 +209,6 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
>                 return PTR_ERR(piobu->regmap);
>         }
>
> -       ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
> -       if (ret) {
> -               dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret);
> -               return ret;
> -       }
> -
>         for (i = 0; i < PIOBU_NUM; ++i) {
>                 ret = sama5d2_piobu_setup_pin(&piobu->chip, i);
>                 if (ret) {
> @@ -225,7 +218,7 @@ static int sama5d2_piobu_probe(struct platform_device *pdev)
>                 }
>         }
>
> -       return 0;
> +       return devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
>  }
>
>  static const struct of_device_id sama5d2_piobu_ids[] = {
> --
> 2.31.1
>