pinctrl: stmfx: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition.

This driver rolls it's own resource handling and does not
use GPIOCHIP_IRQ_RESOURCE_HELPERS.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230403-immutable-irqchips-v1-8-503788a7f6e6@linaro.org

Author: Linus Walleij

drivers/pinctrl/pinctrl-stmfx.c

@@ -85,7 +85,6 @@ struct stmfx_pinctrl {
 	struct pinctrl_dev *pctl_dev;
 	struct pinctrl_desc pctl_desc;
 	struct gpio_chip gpio_chip;
-	struct irq_chip irq_chip;
 	struct mutex lock; /* IRQ bus lock */
 	unsigned long gpio_valid_mask;
 	/* Cache of IRQ_GPI_* registers for bus_lock */
@@ -427,6 +426,7 @@ static void stmfx_pinctrl_irq_mask(struct irq_data *data)
 	u32 mask = get_mask(data->hwirq);
 
 	pctl->irq_gpi_src[reg] &= ~mask;
+	gpiochip_disable_irq(gpio_chip, irqd_to_hwirq(data));
 }
 
 static void stmfx_pinctrl_irq_unmask(struct irq_data *data)
@@ -436,6 +436,7 @@ static void stmfx_pinctrl_irq_unmask(struct irq_data *data)
 	u32 reg = get_reg(data->hwirq);
 	u32 mask = get_mask(data->hwirq);
 
+	gpiochip_enable_irq(gpio_chip, irqd_to_hwirq(data));
 	pctl->irq_gpi_src[reg] |= mask;
 }
 
@@ -592,6 +593,26 @@ static irqreturn_t stmfx_pinctrl_irq_thread_fn(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void stmfx_pinctrl_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
+	struct stmfx_pinctrl *pctl = gpiochip_get_data(gpio_chip);
+
+	seq_printf(p, dev_name(pctl->dev));
+}
+
+static const struct irq_chip stmfx_pinctrl_irq_chip = {
+	.irq_mask = stmfx_pinctrl_irq_mask,
+	.irq_unmask = stmfx_pinctrl_irq_unmask,
+	.irq_set_type = stmfx_pinctrl_irq_set_type,
+	.irq_bus_lock = stmfx_pinctrl_irq_bus_lock,
+	.irq_bus_sync_unlock = stmfx_pinctrl_irq_bus_sync_unlock,
+	.irq_request_resources = stmfx_gpio_irq_request_resources,
+	.irq_release_resources = stmfx_gpio_irq_release_resources,
+	.irq_print_chip = stmfx_pinctrl_irq_print_chip,
+	.flags = IRQCHIP_IMMUTABLE,
+};
+
 static int stmfx_pinctrl_gpio_function_enable(struct stmfx_pinctrl *pctl)
 {
 	struct pinctrl_gpio_range *gpio_range;
@@ -678,17 +699,8 @@ static int stmfx_pinctrl_probe(struct platform_device *pdev)
 	pctl->gpio_chip.ngpio = pctl->pctl_desc.npins;
 	pctl->gpio_chip.can_sleep = true;
 
-	pctl->irq_chip.name = dev_name(pctl->dev);
-	pctl->irq_chip.irq_mask = stmfx_pinctrl_irq_mask;
-	pctl->irq_chip.irq_unmask = stmfx_pinctrl_irq_unmask;
-	pctl->irq_chip.irq_set_type = stmfx_pinctrl_irq_set_type;
-	pctl->irq_chip.irq_bus_lock = stmfx_pinctrl_irq_bus_lock;
-	pctl->irq_chip.irq_bus_sync_unlock = stmfx_pinctrl_irq_bus_sync_unlock;
-	pctl->irq_chip.irq_request_resources = stmfx_gpio_irq_request_resources;
-	pctl->irq_chip.irq_release_resources = stmfx_gpio_irq_release_resources;
-
 	girq = &pctl->gpio_chip.irq;
-	girq->chip = &pctl->irq_chip;
+	gpio_irq_chip_set_chip(girq, &stmfx_pinctrl_irq_chip);
 	/* This will let us handle the parent IRQ in the driver */
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;
@@ -710,7 +722,7 @@ static int stmfx_pinctrl_probe(struct platform_device *pdev)
 	ret = devm_request_threaded_irq(pctl->dev, irq, NULL,
 					stmfx_pinctrl_irq_thread_fn,
 					IRQF_ONESHOT,
-					pctl->irq_chip.name, pctl);
+					dev_name(pctl->dev), pctl);
 	if (ret) {
 		dev_err(pctl->dev, "cannot request irq%d\n", irq);
 		return ret;