pinctrl: stm32: check irq controller availability at probe

It is not guaranteed that the IRQ controller driver is probed before
the pin controller driver gets probed.
Considering this, check for the irq domain availability during probe
and return EPROBE_DEFER if needed.

Signed-off-by: Fabien Dessenne <[e-mail]>
Acked-by: Alexandre TORGUE <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/stm32/pinctrl-stm32.c

···
 	return 0;
 }
 
+static struct irq_domain *stm32_pctrl_get_irq_domain(struct device_node *np)
+{
+	struct device_node *parent;
+	struct irq_domain *domain;
+
+	if (!of_find_property(np, "interrupt-parent", NULL))
+		return NULL;
+
+	parent = of_irq_find_parent(np);
+	if (!parent)
+		return ERR_PTR(-ENXIO);
+
+	domain = irq_find_host(parent);
+	if (!domain)
+		/* domain not registered yet */
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return domain;
+}
+
 static int stm32_pctrl_dt_setup_irq(struct platform_device *pdev,
 			   struct stm32_pinctrl *pctl)
 {
-	struct device_node *np = pdev->dev.of_node, *parent;
+	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
 	struct regmap *rm;
 	int offset, ret, i;
 	int mask, mask_width;
-
-	parent = of_irq_find_parent(np);
-	if (!parent)
-		return -ENXIO;
-
-	pctl->domain = irq_find_host(parent);
-	if (!pctl->domain)
-		return -ENXIO;
 
 	pctl->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 	if (IS_ERR(pctl->regmap))
···
 
 	platform_set_drvdata(pdev, pctl);
 
+	/* check for IRQ controller (may require deferred probe) */
+	pctl->domain = stm32_pctrl_get_irq_domain(np);
+	if (IS_ERR(pctl->domain))
+		return PTR_ERR(pctl->domain);
+
 	/* hwspinlock is optional */
 	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);
 	if (hwlock_id < 0) {
···
 		return -EINVAL;
 	}
 
-	if (of_find_property(np, "interrupt-parent", NULL)) {
+	if (pctl->domain) {
 		ret = stm32_pctrl_dt_setup_irq(pdev, pctl);
 		if (ret)
 			return ret;