Subject: [PATCH 5/7] gpio: ppc44x: Convert GPIO to generic MMIO

From: Rosen Penev <[email-masked]>
Date: Mon, 1 Jun 2026 22:01:29 -0700

Use gpio_generic_chip_init() to set up the PPC44x GPIO chip
instead of open-coding the basic get, set, locking and state handling.

Keep the PPC44x-specific direction callbacks because they still need to
program ODR and the OSR/TSR registers around the generic data and
direction registers.

Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <[email-masked]>
---
 drivers/gpio/gpio-ppc44x.c | 82 +++++++++++++++++---------------------
 1 file changed, 36 insertions(+), 46 deletions(-)

diff --git a/drivers/gpio/gpio-ppc44x.c b/drivers/gpio/gpio-ppc44x.c
index b30ca357ab74..6b4814ed12b5 100644
--- a/drivers/gpio/gpio-ppc44x.c
+++ b/drivers/gpio/gpio-ppc44x.c
@@ -11,10 +11,9 @@
 
 #include <linux/kernel.h>
 #include <linux/init.h>
-#include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/of.h>
-#include <linux/gpio/driver.h>
+#include <linux/gpio/generic.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
@@ -45,9 +44,8 @@ struct ppc4xx_gpio {
 };
 
 struct ppc4xx_gpio_chip {
-	struct gpio_chip gc;
+	struct gpio_generic_chip chip;
 	void __iomem *regs;
-	spinlock_t lock;
 };
 
 /*
@@ -56,55 +54,35 @@ struct ppc4xx_gpio_chip {
  * There are a maximum of 32 gpios in each gpio controller.
  */
 
-static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
-{
-	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
-	struct ppc4xx_gpio __iomem *regs = chip->regs;
-
-	return !!(in_be32(&regs->ir) & GPIO_MASK(gpio));
-}
-
 static inline void
 __ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 {
 	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
-	struct ppc4xx_gpio __iomem *regs = chip->regs;
+	struct gpio_generic_chip *gen_gc = &chip->chip;
 
 	if (val)
-		setbits32(&regs->or, GPIO_MASK(gpio));
+		gen_gc->sdata |= GPIO_MASK(gpio);
 	else
-		clrbits32(&regs->or, GPIO_MASK(gpio));
-}
+		gen_gc->sdata &= ~GPIO_MASK(gpio);
 
-static int ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
-{
-	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
-	unsigned long flags;
-
-	spin_lock_irqsave(&chip->lock, flags);
-
-	__ppc4xx_gpio_set(gc, gpio, val);
-
-	spin_unlock_irqrestore(&chip->lock, flags);
-
-	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
-
-	return 0;
+	gpio_generic_write_reg(gen_gc, gen_gc->reg_set, gen_gc->sdata);
 }
 
 static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 {
 	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+	struct gpio_generic_chip *gen_gc = &chip->chip;
 	struct ppc4xx_gpio __iomem *regs = chip->regs;
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	gpio_generic_chip_lock_irqsave(gen_gc, flags);
 
 	/* Disable open-drain function */
 	clrbits32(&regs->odr, GPIO_MASK(gpio));
 
 	/* Float the pin */
 	clrbits32(&regs->tcr, GPIO_MASK(gpio));
+	gen_gc->sdir &= ~GPIO_MASK(gpio);
 
 	/* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
 	if (gpio < 16) {
@@ -115,7 +93,7 @@ static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 		clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
 	}
 
-	spin_unlock_irqrestore(&chip->lock, flags);
+	gpio_generic_chip_unlock_irqrestore(gen_gc, flags);
 
 	return 0;
 }
@@ -124,10 +102,11 @@ static int
 ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 {
 	struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+	struct gpio_generic_chip *gen_gc = &chip->chip;
 	struct ppc4xx_gpio __iomem *regs = chip->regs;
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	gpio_generic_chip_lock_irqsave(gen_gc, flags);
 
 	/* First set initial value */
 	__ppc4xx_gpio_set(gc, gpio, val);
@@ -137,6 +116,7 @@ ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 
 	/* Drive the pin */
 	setbits32(&regs->tcr, GPIO_MASK(gpio));
+	gen_gc->sdir |= GPIO_MASK(gpio);
 
 	/* Bits 0-15 use TSRL, bits 16-31 use TSRH */
 	if (gpio < 16) {
@@ -147,7 +127,7 @@ ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 		clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
 	}
 
-	spin_unlock_irqrestore(&chip->lock, flags);
+	gpio_generic_chip_unlock_irqrestore(gen_gc, flags);
 
 	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
 
@@ -159,33 +139,43 @@ 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 gpio_generic_chip_config config;
 	struct gpio_chip *gc;
+	struct ppc4xx_gpio __iomem *regs;
+	int ret;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
-	spin_lock_init(&chip->lock);
-
-	gc = &chip->gc;
+	chip->regs = devm_platform_ioremap_resource(ofdev, 0);
+	if (IS_ERR(chip->regs))
+		return PTR_ERR(chip->regs);
 
-	gc->parent = dev;
+	regs = chip->regs;
+	config = (struct gpio_generic_chip_config) {
+		.dev = dev,
+		.sz = 4,
+		.dat = &regs->ir,
+		.set = &regs->or,
+		.dirout = &regs->tcr,
+		.flags = GPIO_GENERIC_BIG_ENDIAN |
+			 GPIO_GENERIC_BIG_ENDIAN_BYTE_ORDER,
+	};
+
+	ret = gpio_generic_chip_init(&chip->chip, &config);
+	if (ret)
+		return ret;
+
+	gc = &chip->chip.gc;
 	gc->fwnode = dev_fwnode(dev);
-	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;
 
 	gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
 	if (!gc->label)
 		return -ENOMEM;
 
-	chip->regs = devm_platform_ioremap_resource(ofdev, 0);
-	if (IS_ERR(chip->regs))
-		return PTR_ERR(chip->regs);
-
 	return devm_gpiochip_add_data(dev, gc, chip);
 }
 
-- 
2.54.0