1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c
new file mode 100644
index 000000000..7899607fb
--- /dev/null
+++ b/drivers/irqchip/irqchip.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2012 Thomas Petazzoni
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/irqchip.h>
+#include <linux/platform_device.h>
+
+/*
+ * This special of_device_id is the sentinel at the end of the
+ * of_device_id[] array of all irqchips. It is automatically placed at
+ * the end of the array by the linker, thanks to being part of a
+ * special section.
+ */
+static const struct of_device_id
+irqchip_of_match_end __used __section("__irqchip_of_table_end");
+
+extern struct of_device_id __irqchip_of_table[];
+
+void __init irqchip_init(void)
+{
+	of_irq_init(__irqchip_of_table);
+	acpi_probe_device_table(irqchip);
+}
+
+int platform_irqchip_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *par_np = of_irq_find_parent(np);
+	of_irq_init_cb_t irq_init_cb = of_device_get_match_data(&pdev->dev);
+
+	if (!irq_init_cb) {
+		of_node_put(par_np);
+		return -EINVAL;
+	}
+
+	if (par_np == np)
+		par_np = NULL;
+
+	/*
+	 * If there's a parent interrupt controller and  none of the parent irq
+	 * domains have been registered, that means the parent interrupt
+	 * controller has not been initialized yet.  it's not time for this
+	 * interrupt controller to initialize. So, defer probe of this
+	 * interrupt controller. The actual initialization callback of this
+	 * interrupt controller can check for specific domains as necessary.
+	 */
+	if (par_np && !irq_find_matching_host(par_np, DOMAIN_BUS_ANY)) {
+		of_node_put(par_np);
+		return -EPROBE_DEFER;
+	}
+
+	return irq_init_cb(np, par_np);
+}
+EXPORT_SYMBOL_GPL(platform_irqchip_probe);