[PATCH 1/2] powerpc/44x: Change GPIO driver to a proper platform driver

[PATCH 1/2] powerpc/44x: Change GPIO driver to a proper platform driver

[Christophe Leroy]

In order to drop legacy-of-mm-gpiochip dependency, first change the
44x GPIO driver to a proper platform driver.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/platforms/44x/gpio.c | 83 +++++++++++++++++--------------
 1 file changed, 46 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/platforms/44x/gpio.c b/arch/powerpc/platforms/44x/gpio.c
index 08ab76582568..a025b3248342 100644
--- a/arch/powerpc/platforms/44x/gpio.c
+++ b/arch/powerpc/platforms/44x/gpio.c
@@ -18,6 +18,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/types.h>
 #include <linux/slab.h>
+#include <linux/platform_device.h>
 
 #define GPIO_MASK(gpio)		(0x80000000 >> (gpio))
 #define GPIO_MASK2(gpio)	(0xc0000000 >> ((gpio) * 2))
@@ -155,42 +156,50 @@ ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 	return 0;
 }
 
-static int __init ppc4xx_add_gpiochips(void)
+static int ppc4xx_gpio_probe(struct platform_device *ofdev)
 {
-	struct device_node *np;
-
-	for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {
-		int ret;
-		struct ppc4xx_gpio_chip *ppc4xx_gc;
-		struct of_mm_gpio_chip *mm_gc;
-		struct gpio_chip *gc;
-
-		ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);
-		if (!ppc4xx_gc) {
-			ret = -ENOMEM;
-			goto err;
-		}
-
-		spin_lock_init(&ppc4xx_gc->lock);
-
-		mm_gc = &ppc4xx_gc->mm_gc;
-		gc = &mm_gc->gc;
-
-		gc->ngpio = 32;
-		gc->direction_input = ppc4xx_gpio_dir_in;
-		gc->direction_output = ppc4xx_gpio_dir_out;
-		gc->get = ppc4xx_gpio_get;
-		gc->set = ppc4xx_gpio_set;
-
-		ret = of_mm_gpiochip_add_data(np, mm_gc, ppc4xx_gc);
-		if (ret)
-			goto err;
-		continue;
-err:
-		pr_err("%pOF: registration failed with status %d\n", np, ret);
-		kfree(ppc4xx_gc);
-		/* try others anyway */
-	}
-	return 0;
+	struct device *dev = &ofdev->dev;
+	struct device_node *np = dev->of_node;
+	struct ppc4xx_gpio_chip *chip;
+	struct of_mm_gpio_chip *mm_gc;
+	struct gpio_chip *gc;
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	spin_lock_init(&chip->lock);
+
+	mm_gc = &chip->mm_gc;
+	gc = &mm_gc->gc;
+
+	gc->ngpio = 32;
+	gc->direction_input = ppc4xx_gpio_dir_in;
+	gc->direction_output = ppc4xx_gpio_dir_out;
+	gc->get = ppc4xx_gpio_get;
+	gc->set = ppc4xx_gpio_set;
+
+	return of_mm_gpiochip_add_data(np, mm_gc, chip);
+}
+
+static const struct of_device_id ppc4xx_gpio_match[] = {
+	{
+		.compatible = "ibm,ppc4xx-gpio",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ppc4xx_gpio_match);
+
+static struct platform_driver ppc4xx_gpio_driver = {
+	.probe		= ppc4xx_gpio_probe,
+	.driver		= {
+		.name	= "ppc4xx-gpio",
+		.of_match_table	= ppc4xx_gpio_match,
+	},
+};
+
+static int __init ppc4xx_gpio_init(void)
+{
+	return platform_driver_register(&ppc4xx_gpio_driver);
 }
-arch_initcall(ppc4xx_add_gpiochips);
+arch_initcall(ppc4xx_gpio_init);
-- 
2.49.0

[PATCH 2/2] powerpc/44x: Drop legacy-of-mm-gpiochip.h header

[Christophe Leroy]

Remove legacy-of-mm-gpiochip.h header file. The above mentioned
file provides an OF API that's deprecated. There is no agnostic
alternatives to it and we have to open code the logic which was
hidden behind of_mm_gpiochip_add_data(). Note, most of the GPIO
drivers are using their own labeling schemas and resource retrieval
that only a few may gain of the code deduplication, so whenever
alternative is appear we can move drivers again to use that one.

As a side effect this change fixes a potential memory leak on
an error path, if of_mm_gpiochip_add_data() fails.

[Text copied from commit 34064c8267a6 ("powerpc/8xx: Drop
legacy-of-mm-gpiochip.h header")]

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/platforms/44x/Kconfig |  1 -
 arch/powerpc/platforms/44x/gpio.c  | 33 +++++++++++++++++-------------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/Kconfig
index 35a1f4b9f827..fc79f8466933 100644
--- a/arch/powerpc/platforms/44x/Kconfig
+++ b/arch/powerpc/platforms/44x/Kconfig
@@ -231,7 +231,6 @@ config PPC4xx_GPIO
 	bool "PPC4xx GPIO support"
 	depends on 44x
 	select GPIOLIB
-	select OF_GPIO_MM_GPIOCHIP
 	help
 	  Enable gpiolib support for ppc440 based boards
 
diff --git a/arch/powerpc/platforms/44x/gpio.c b/arch/powerpc/platforms/44x/gpio.c
index a025b3248342..aea0d913b59d 100644
--- a/arch/powerpc/platforms/44x/gpio.c
+++ b/arch/powerpc/platforms/44x/gpio.c
@@ -14,7 +14,6 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/of.h>
-#include <linux/gpio/legacy-of-mm-gpiochip.h>
 #include <linux/gpio/driver.h>
 #include <linux/types.h>
 #include <linux/slab.h>
@@ -46,7 +45,8 @@ struct ppc4xx_gpio {
 };
 
 struct ppc4xx_gpio_chip {
-	struct of_mm_gpio_chip mm_gc;
+	struct gpio_chip gc;
+	void __iomem *regs;
 	spinlock_t lock;
 };
 
@@ -58,8 +58,8 @@ struct ppc4xx_gpio_chip {
 
 static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 {
-	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
-	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+	struct ppc4xx_gpio __iomem *regs = chip->regs;
 
 	return !!(in_be32(&regs->ir) & GPIO_MASK(gpio));
 }
@@ -67,8 +67,8 @@ static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 static inline void
 __ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 {
-	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
-	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+	struct ppc4xx_gpio __iomem *regs = chip->regs;
 
 	if (val)
 		setbits32(&regs->or, GPIO_MASK(gpio));
@@ -94,9 +94,8 @@ static int ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 
 static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 {
-	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
 	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
-	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+	struct ppc4xx_gpio __iomem *regs = chip->regs;
 	unsigned long flags;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -124,9 +123,8 @@ static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 static int
 ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 {
-	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
 	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
-	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+	struct ppc4xx_gpio __iomem *regs = chip->regs;
 	unsigned long flags;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -161,7 +159,6 @@ static int ppc4xx_gpio_probe(struct platform_device *ofdev)
 	struct device *dev = &ofdev->dev;
 	struct device_node *np = dev->of_node;
 	struct ppc4xx_gpio_chip *chip;
-	struct of_mm_gpio_chip *mm_gc;
 	struct gpio_chip *gc;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
@@ -170,16 +167,24 @@ static int ppc4xx_gpio_probe(struct platform_device *ofdev)
 
 	spin_lock_init(&chip->lock);
 
-	mm_gc = &chip->mm_gc;
-	gc = &mm_gc->gc;
+	gc = &chip->gc;
 
+	gc->base = -1;
 	gc->ngpio = 32;
 	gc->direction_input = ppc4xx_gpio_dir_in;
 	gc->direction_output = ppc4xx_gpio_dir_out;
 	gc->get = ppc4xx_gpio_get;
 	gc->set = ppc4xx_gpio_set;
 
-	return of_mm_gpiochip_add_data(np, mm_gc, chip);
+	gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
+	if (!gc->label)
+		return -ENOMEM;
+
+	chip->regs = devm_of_iomap(dev, np, 0, NULL);
+	if (IS_ERR(chip->regs))
+		return PTR_ERR(chip->regs);
+
+	return devm_gpiochip_add_data(dev, gc, chip);
 }
 
 static const struct of_device_id ppc4xx_gpio_match[] = {
-- 
2.49.0

Re: [PATCH 1/2] powerpc/44x: Change GPIO driver to a proper platform driver

[Linus Walleij]

On Mon, Aug 18, 2025 at 2:17 PM Christophe Leroy
<christophe.leroy@csgroup.eu> wrote:

> In order to drop legacy-of-mm-gpiochip dependency, first change the
> 44x GPIO driver to a proper platform driver.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH 1/2] powerpc/44x: Change GPIO driver to a proper platform driver

[Madhavan Srinivasan]

On Mon, 18 Aug 2025 14:17:34 +0200, Christophe Leroy wrote:
> In order to drop legacy-of-mm-gpiochip dependency, first change the
> 44x GPIO driver to a proper platform driver.
> 
> 

Applied to powerpc/next.

[1/2] powerpc/44x: Change GPIO driver to a proper platform driver
      https://git.kernel.org/powerpc/c/1044dbaf2a77c9e1143753a620d830943da6a193
[2/2] powerpc/44x: Drop legacy-of-mm-gpiochip.h header
      https://git.kernel.org/powerpc/c/d2ad26e7b67e5a3d73221daf8207e848dd819bd4

Thanks