linux-kernel - [PATCH] gpio: gpio-stmpe: fully use convert probe to device-managed

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Message-Id: <20210516061425.8757-1-aardelean@deviqon.com>
Date:   Sun, 16 May 2021 09:14:25 +0300
From:   Alexandru Ardelean <aardelean@...iqon.com>
To:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     linus.walleij@...aro.org, bgolaszewski@...libre.com,
        alexandre.torgue@...s.st.com, mcoquelin.stm32@...il.com,
        Alexandru Ardelean <aardelean@...iqon.com>
Subject: [PATCH] gpio: gpio-stmpe: fully use convert probe to device-managed

The driver doesn't look like it can be built as a kmod, so leaks cannot
happen via a rmmod mechanism.
The remove hook was removed via commit 3b52bb960ec6 ("gpio: stmpe: make
it explicitly non-modular").

The IRQ is registered via devm_request_threaded_irq(), making the driver
only partially device-managed.

In any case all resources should be made device-managed, mostly as a good
practice. That way at least the unwinding on error is happening in reverse
order (as the probe).

This change also removes platform_set_drvdata() since the information is
never retrieved to be used in the driver.

Signed-off-by: Alexandru Ardelean <aardelean@...iqon.com>
---

I'm not sure if this should be marked with a Fixes tag.
But if so, it should probably be for commit 3b52bb960ec6 (also mentioned in
the comment above).

 drivers/gpio/gpio-stmpe.c | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index b94ef8181428..dd4d58b4ae49 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -449,6 +449,11 @@ static void stmpe_init_irq_valid_mask(struct gpio_chip *gc,
 	}
 }
 
+static void stmpe_gpio_disable(void *stmpe)
+{
+	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+}
+
 static int stmpe_gpio_probe(struct platform_device *pdev)
 {
 	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
@@ -461,7 +466,7 @@ static int stmpe_gpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	stmpe_gpio = kzalloc(sizeof(*stmpe_gpio), GFP_KERNEL);
+	stmpe_gpio = devm_kzalloc(&pdev->dev, sizeof(*stmpe_gpio), GFP_KERNEL);
 	if (!stmpe_gpio)
 		return -ENOMEM;
 
@@ -489,7 +494,11 @@ static int stmpe_gpio_probe(struct platform_device *pdev)
 
 	ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
 	if (ret)
-		goto out_free;
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev, stmpe_gpio_disable, stmpe);
+	if (ret)
+		return ret;
 
 	if (irq > 0) {
 		struct gpio_irq_chip *girq;
@@ -499,7 +508,7 @@ static int stmpe_gpio_probe(struct platform_device *pdev)
 				"stmpe-gpio", stmpe_gpio);
 		if (ret) {
 			dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
-			goto out_disable;
+			return ret;
 		}
 
 		girq = &stmpe_gpio->chip.irq;
@@ -514,22 +523,7 @@ static int stmpe_gpio_probe(struct platform_device *pdev)
 		girq->init_valid_mask = stmpe_init_irq_valid_mask;
 	}
 
-	ret = gpiochip_add_data(&stmpe_gpio->chip, stmpe_gpio);
-	if (ret) {
-		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
-		goto out_disable;
-	}
-
-	platform_set_drvdata(pdev, stmpe_gpio);
-
-	return 0;
-
-out_disable:
-	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
-	gpiochip_remove(&stmpe_gpio->chip);
-out_free:
-	kfree(stmpe_gpio);
-	return ret;
+	return devm_gpiochip_add_data(&pdev->dev, &stmpe_gpio->chip, stmpe_gpio);
 }
 
 static struct platform_driver stmpe_gpio_driver = {
-- 
2.31.1