powerpc/44x: Drop legacy-of-mm-gpiochip.h header

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 <[e-mail]>
Signed-off-by: Madhavan Srinivasan <[e-mail]>
Link: https://patch.msgid.link/2f8f16ea[e-mail]

arch/powerpc/platforms/44x/Kconfig

···
 	bool "PPC4xx GPIO support"
 	depends on 44x
 	select GPIOLIB
-	select OF_GPIO_MM_GPIOCHIP
 	help
 	  Enable gpiolib support for ppc440 based boards
 

arch/powerpc/platforms/44x/gpio.c

···
 #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>
···
 };
 
 struct ppc4xx_gpio_chip {
-	struct of_mm_gpio_chip mm_gc;
+	struct gpio_chip gc;
+	void __iomem *regs;
 	spinlock_t lock;
 };
 
···
 
 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));
 }
···
 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));
···
 
 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);
···
 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);
···
 	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);
···
 
 	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[] = {