pinctrl: pic32: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition. Switch some call to use irqd_to_hwirq() in the
process.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230414-immutable-irqchips-2-v1-1-6b59a5186b00@linaro.org

Author: Linus Walleij

drivers/pinctrl/pinctrl-pic32.c

@@ -17,6 +17,7 @@
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/pinctrl/pinmux.h>
 #include <linux/platform_device.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -60,8 +61,8 @@ struct pic32_desc_function {
 
 struct pic32_gpio_bank {
 	void __iomem *reg_base;
+	int instance;
 	struct gpio_chip gpio_chip;
-	struct irq_chip irq_chip;
 	struct clk *clk;
 };
 
@@ -2008,12 +2009,14 @@ static void pic32_gpio_irq_mask(struct irq_data *data)
 	struct pic32_gpio_bank *bank = irqd_to_bank(data);
 
 	writel(BIT(PIC32_CNCON_ON), bank->reg_base + PIC32_CLR(CNCON_REG));
+	gpiochip_disable_irq(&bank->gpio_chip, irqd_to_hwirq(data));
 }
 
 static void pic32_gpio_irq_unmask(struct irq_data *data)
 {
 	struct pic32_gpio_bank *bank = irqd_to_bank(data);
 
+	gpiochip_enable_irq(&bank->gpio_chip, irqd_to_hwirq(data));
 	writel(BIT(PIC32_CNCON_ON), bank->reg_base + PIC32_SET(CNCON_REG));
 }
 
@@ -2030,7 +2033,7 @@ static unsigned int pic32_gpio_irq_startup(struct irq_data *data)
 static int pic32_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 {
 	struct pic32_gpio_bank *bank = irqd_to_bank(data);
-	u32 mask = BIT(data->hwirq);
+	u32 mask = irqd_to_hwirq(data);
 
 	switch (type & IRQ_TYPE_SENSE_MASK) {
 	case IRQ_TYPE_EDGE_RISING:
@@ -2122,14 +2125,7 @@ static void pic32_gpio_irq_handler(struct irq_desc *desc)
 			.owner = THIS_MODULE,				\
 			.can_sleep = 0,					\
 		},							\
-		.irq_chip = {						\
-			.name = "GPIO" #_bank,				\
-			.irq_startup = pic32_gpio_irq_startup,	\
-			.irq_ack = pic32_gpio_irq_ack,		\
-			.irq_mask = pic32_gpio_irq_mask,		\
-			.irq_unmask = pic32_gpio_irq_unmask,		\
-			.irq_set_type = pic32_gpio_irq_set_type,	\
-		},							\
+		.instance = (_bank),					\
 	}
 
 static struct pic32_gpio_bank pic32_gpio_banks[] = {
@@ -2145,6 +2141,24 @@ static struct pic32_gpio_bank pic32_gpio_banks[] = {
 	GPIO_BANK(9, PINS_PER_BANK),
 };
 
+static void pic32_gpio_irq_print_chip(struct irq_data *data, struct seq_file *p)
+{
+	struct pic32_gpio_bank *bank = irqd_to_bank(data);
+
+	seq_printf(p, "GPIO%d", bank->instance);
+}
+
+static const struct irq_chip pic32_gpio_irq_chip = {
+	.irq_startup = pic32_gpio_irq_startup,
+	.irq_ack = pic32_gpio_irq_ack,
+	.irq_mask = pic32_gpio_irq_mask,
+	.irq_unmask = pic32_gpio_irq_unmask,
+	.irq_set_type = pic32_gpio_irq_set_type,
+	.irq_print_chip = pic32_gpio_irq_print_chip,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int pic32_pinctrl_probe(struct platform_device *pdev)
 {
 	struct pic32_pinctrl *pctl;
@@ -2243,7 +2257,7 @@ static int pic32_gpio_probe(struct platform_device *pdev)
 	bank->gpio_chip.parent = &pdev->dev;
 
 	girq = &bank->gpio_chip.irq;
-	girq->chip = &bank->irq_chip;
+	gpio_irq_chip_set_chip(girq, &pic32_gpio_irq_chip);
 	girq->parent_handler = pic32_gpio_irq_handler;
 	girq->num_parents = 1;
 	girq->parents = devm_kcalloc(&pdev->dev, 1, sizeof(*girq->parents),