regmap: Allow setting IRQ domain name suffix

When multiple IRQ domains are created from the same device-tree node they
will get the same name based on the device-tree path. This will cause a
naming collision in debugFS when IRQ domain specific entries are created.

The regmap-IRQ creates per instance IRQ domains. This will lead to a
domain name conflict when a device which provides more than one
interrupt line uses the regmap-IRQ.

Add support for specifying an IRQ domain name suffix when creating a
regmap-IRQ controller.

Signed-off-by: Matti Vaittinen <[e-mail]>
Link: https://patch.msgid.link/776bc4[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regmap-irq.c

···
 }
 EXPORT_SYMBOL_GPL(regmap_irq_set_type_config_simple);
 
+static int regmap_irq_create_domain(struct fwnode_handle *fwnode, int irq_base,
+				    const struct regmap_irq_chip *chip,
+				    struct regmap_irq_chip_data *d)
+{
+	struct irq_domain_info info = {
+		.fwnode = fwnode,
+		.size = chip->num_irqs,
+		.hwirq_max = chip->num_irqs,
+		.virq_base = irq_base,
+		.ops = &regmap_domain_ops,
+		.host_data = d,
+		.name_suffix = chip->domain_suffix,
+	};
+
+	d->domain = irq_domain_instantiate(&info);
+	if (IS_ERR(d->domain)) {
+		dev_err(d->map->dev, "Failed to create IRQ domain\n");
+		return PTR_ERR(d->domain);
+	}
+
+	return 0;
+}
+
+
 /**
  * regmap_add_irq_chip_fwnode() - Use standard regmap IRQ controller handling
  *
···
 		}
 	}
 
-	if (irq_base)
-		d->domain = irq_domain_create_legacy(fwnode, chip->num_irqs,
-						     irq_base, 0,
-						     &regmap_domain_ops, d);
-	else
-		d->domain = irq_domain_create_linear(fwnode, chip->num_irqs,
-						     &regmap_domain_ops, d);
-	if (!d->domain) {
-		dev_err(map->dev, "Failed to create IRQ domain\n");
-		ret = -ENOMEM;
+	ret = regmap_irq_create_domain(fwnode, irq_base, chip, d);
+	if (ret)
 		goto err_alloc;
-	}
 
 	ret = request_threaded_irq(irq, NULL, regmap_irq_thread,
 				   irq_flags | IRQF_ONESHOT,

include/linux/regmap.h

···
  * struct regmap_irq_chip - Description of a generic regmap irq_chip.
  *
  * @name:        Descriptive name for IRQ controller.
+ * @domain_suffix: Name suffix to be appended to end of IRQ domain name. Needed
+ *		   when multiple regmap-IRQ controllers are created from same
+ *		   device.
  *
  * @main_status: Base main status register address. For chips which have
  *		 interrupts arranged in separate sub-irq blocks with own IRQ
···
  */
 struct regmap_irq_chip {
 	const char *name;
+	const char *domain_suffix;
 
 	unsigned int main_status;
 	unsigned int num_main_status_bits;