irqchip/exiu: Implement ACPI support

Expose the existing EXIU hierarchical irqchip domain code to permit
the interrupt controller to be used as the irqchip component of a
GPIO controller on ACPI systems, or as the target of ordinary
interrupt resources.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 68 insertions, 8 deletions

diff --git a/drivers/irqchip/irq-sni-exiu.c b/drivers/irqchip/irq-sni-exiu.c
index fef7c2437dfb..30a323a2b332 100644
--- a/drivers/irqchip/irq-sni-exiu.c
+++ b/drivers/irqchip/irq-sni-exiu.c
@@ -20,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
 
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 
@@ -134,9 +135,13 @@ static int exiu_domain_translate(struct irq_domain *domain,
 
                 *hwirq = fwspec->param[1] - info->spi_base;
                 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
-                return 0;
+        } else {
+                if (fwspec->param_count != 2)
+                        return -EINVAL;
+                *hwirq = fwspec->param[0];
+                *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
         }
-        return -EINVAL;
+        return 0;
 }
 
 static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
@@ -147,16 +152,21 @@ static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
         struct exiu_irq_data *info = dom->host_data;
         irq_hw_number_t hwirq;
 
-        if (fwspec->param_count != 3)
-                return -EINVAL; /* Not GIC compliant */
-        if (fwspec->param[0] != GIC_SPI)
-                return -EINVAL; /* No PPI should point to this domain */
+        parent_fwspec = *fwspec;
+        if (is_of_node(dom->parent->fwnode)) {
+                if (fwspec->param_count != 3)
+                        return -EINVAL; /* Not GIC compliant */
+                if (fwspec->param[0] != GIC_SPI)
+                        return -EINVAL; /* No PPI should point to this domain */
 
+                hwirq = fwspec->param[1] - info->spi_base;
+        } else {
+                hwirq = fwspec->param[0];
+                parent_fwspec.param[0] = hwirq + info->spi_base + 32;
+        }
         WARN_ON(nr_irqs != 1);
-        hwirq = fwspec->param[1] - info->spi_base;
         irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
 
-        parent_fwspec = *fwspec;
         parent_fwspec.fwnode = dom->parent->fwnode;
         return irq_domain_alloc_irqs_parent(dom, virq, nr_irqs, &parent_fwspec);
 }
@@ -245,3 +255,53 @@ out_unmap:
         return -ENOMEM;
 }
 IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_dt_init);
+
+#ifdef CONFIG_ACPI
+static int exiu_acpi_probe(struct platform_device *pdev)
+{
+        struct irq_domain *domain;
+        struct exiu_irq_data *data;
+        struct resource *res;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "failed to parse memory resource\n");
+                return -ENXIO;
+        }
+
+        data = exiu_init(dev_fwnode(&pdev->dev), res);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
+        domain = acpi_irq_create_hierarchy(0, NUM_IRQS, dev_fwnode(&pdev->dev),
+                                           &exiu_domain_ops, data);
+        if (!domain) {
+                dev_err(&pdev->dev, "failed to create IRQ domain\n");
+                goto out_unmap;
+        }
+
+        dev_info(&pdev->dev, "%d interrupts forwarded\n", NUM_IRQS);
+
+        return 0;
+
+out_unmap:
+        iounmap(data->base);
+        kfree(data);
+        return -ENOMEM;
+}
+
+static const struct acpi_device_id exiu_acpi_ids[] = {
+        { "SCX0008" },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, exiu_acpi_ids);
+
+static struct platform_driver exiu_driver = {
+        .driver = {
+                .name = "exiu",
+                .acpi_match_table = exiu_acpi_ids,
+        },
+        .probe = exiu_acpi_probe,
+};
+builtin_platform_driver(exiu_driver);
+#endif