soc: fsl: qe: Change GPIO driver to a proper platform driver

In order to be able to add interrupts to the GPIOs, first change the
QE GPIO driver to the proper platform driver in order to allow
initialisation to be done in the right order, otherwise the GPIOs
get added before the interrupts are registered.

Remove linux/of.h and linux/property.h which are unused.

And to improve readability and reduce risk of errors, add a macro to
transform a pin number into the mask that matches the associated bit
in registers.

Reviewed-by: Bartosz Golaszewski <[e-mail]>
Link: https://lore.kernel.org/r/b0b44802[e-mail]
Signed-off-by: Christophe Leroy <[e-mail]>

drivers/soc/fsl/qe/gpio.c

···
 #include <linux/spinlock.h>
 #include <linux/err.h>
 #include <linux/io.h>
-#include <linux/of.h>
 #include <linux/gpio/legacy-of-mm-gpiochip.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 #include <linux/slab.h>
 #include <linux/export.h>
-#include <linux/property.h>
+#include <linux/platform_device.h>
 
 #include <soc/fsl/qe/qe.h>
+
+#define PIN_MASK(gpio) (1UL << (QE_PIO_PINS - 1 - (gpio)))
 
 struct qe_gpio_chip {
 	struct of_mm_gpio_chip mm_gc;
···
 {
 	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
 	struct qe_pio_regs __iomem *regs = mm_gc->regs;
-	u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
+	u32 pin_mask = PIN_MASK(gpio);
 
 	return !!(ioread32be(&regs->cpdata) & pin_mask);
 }
···
 	struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
 	struct qe_pio_regs __iomem *regs = mm_gc->regs;
 	unsigned long flags;
-	u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
+	u32 pin_mask = PIN_MASK(gpio);
 
 	spin_lock_irqsave(&qe_gc->lock, flags);
 
···
 			break;
 		if (__test_and_clear_bit(i, mask)) {
 			if (test_bit(i, bits))
-				qe_gc->cpdata |= (1U << (QE_PIO_PINS - 1 - i));
+				qe_gc->cpdata |= PIN_MASK(i);
 			else
-				qe_gc->cpdata &= ~(1U << (QE_PIO_PINS - 1 - i));
+				qe_gc->cpdata &= ~PIN_MASK(i);
 		}
 	}
 
···
 }
 EXPORT_SYMBOL(qe_pin_set_gpio);
 
-static int __init qe_add_gpiochips(void)
+static int qe_gpio_probe(struct platform_device *ofdev)
 {
-	struct device_node *np;
+	struct device *dev = &ofdev->dev;
+	struct device_node *np = dev->of_node;
+	struct qe_gpio_chip *qe_gc;
+	struct of_mm_gpio_chip *mm_gc;
+	struct gpio_chip *gc;
 
-	for_each_compatible_node(np, NULL, "fsl,mpc8323-qe-pario-bank") {
-		int ret;
-		struct qe_gpio_chip *qe_gc;
-		struct of_mm_gpio_chip *mm_gc;
-		struct gpio_chip *gc;
+	qe_gc = devm_kzalloc(dev, sizeof(*qe_gc), GFP_KERNEL);
+	if (!qe_gc)
+		return -ENOMEM;
 
-		qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL);
-		if (!qe_gc) {
-			ret = -ENOMEM;
-			goto err;
-		}
+	spin_lock_init(&qe_gc->lock);
 
-		spin_lock_init(&qe_gc->lock);
+	mm_gc = &qe_gc->mm_gc;
+	gc = &mm_gc->gc;
 
-		mm_gc = &qe_gc->mm_gc;
-		gc = &mm_gc->gc;
+	mm_gc->save_regs = qe_gpio_save_regs;
+	gc->ngpio = QE_PIO_PINS;
+	gc->direction_input = qe_gpio_dir_in;
+	gc->direction_output = qe_gpio_dir_out;
+	gc->get = qe_gpio_get;
+	gc->set = qe_gpio_set;
+	gc->set_multiple = qe_gpio_set_multiple;
 
-		mm_gc->save_regs = qe_gpio_save_regs;
-		gc->ngpio = QE_PIO_PINS;
-		gc->direction_input = qe_gpio_dir_in;
-		gc->direction_output = qe_gpio_dir_out;
-		gc->get = qe_gpio_get;
-		gc->set = qe_gpio_set;
-		gc->set_multiple = qe_gpio_set_multiple;
-
-		ret = of_mm_gpiochip_add_data(np, mm_gc, qe_gc);
-		if (ret)
-			goto err;
-		continue;
-err:
-		pr_err("%pOF: registration failed with status %d\n",
-		       np, ret);
-		kfree(qe_gc);
-		/* try others anyway */
-	}
-	return 0;
+	return of_mm_gpiochip_add_data(np, mm_gc, qe_gc);
 }
-arch_initcall(qe_add_gpiochips);
+
+static const struct of_device_id qe_gpio_match[] = {
+	{
+		.compatible = "fsl,mpc8323-qe-pario-bank",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, qe_gpio_match);
+
+static struct platform_driver qe_gpio_driver = {
+	.probe		= qe_gpio_probe,
+	.driver		= {
+		.name	= "qe-gpio",
+		.of_match_table	= qe_gpio_match,
+	},
+};
+
+static int __init qe_gpio_init(void)
+{
+	return platform_driver_register(&qe_gpio_driver);
+}
+arch_initcall(qe_gpio_init);