of/platform: Assign MSI domain to platform device

As for PCI, we're able to populate the msi_domain field at probe time,
provided that the device tree has an "msi-parent" property.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-9-git-send-email-marc.zyngier@arm.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/of/irq.c

@@ -18,6 +18,7 @@
  * driver.
  */
 
+#include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/list.h>
 #include <linux/module.h>
@@ -576,3 +577,23 @@ void __init of_irq_init(const struct of_device_id *matches)
 		kfree(desc);
 	}
 }
+
+/**
+ * of_msi_configure - Set the msi_domain field of a device
+ * @dev: device structure to associate with an MSI irq domain
+ * @np: device node for that device
+ */
+void of_msi_configure(struct device *dev, struct device_node *np)
+{
+	struct device_node *msi_np;
+	struct irq_domain *d;
+
+	msi_np = of_parse_phandle(np, "msi-parent", 0);
+	if (!msi_np)
+		return;
+
+	d = irq_find_matching_host(msi_np, DOMAIN_BUS_PLATFORM_MSI);
+	if (!d)
+		d = irq_find_host(msi_np);
+	dev_set_msi_domain(dev, d);
+}

drivers/of/platform.c

@@ -184,6 +184,7 @@ static struct platform_device *of_platform_device_create_pdata(
 	dev->dev.bus = &platform_bus_type;
 	dev->dev.platform_data = platform_data;
 	of_dma_configure(&dev->dev, dev->dev.of_node);
+	of_msi_configure(&dev->dev, dev->dev.of_node);
 
 	if (of_device_add(dev) != 0) {
 		of_dma_deconfigure(&dev->dev);

include/linux/irqdomain.h

@@ -55,6 +55,7 @@ struct irq_data;
 enum irq_domain_bus_token {
 	DOMAIN_BUS_ANY		= 0,
 	DOMAIN_BUS_PCI_MSI,
+	DOMAIN_BUS_PLATFORM_MSI,
 };
 
 /**

include/linux/of_irq.h

@@ -74,6 +74,7 @@ static inline int of_irq_to_resource_table(struct device_node *dev,
  */
 extern unsigned int irq_of_parse_and_map(struct device_node *node, int index);
 extern struct device_node *of_irq_find_parent(struct device_node *child);
+extern void of_msi_configure(struct device *dev, struct device_node *np);
 
 #else /* !CONFIG_OF */
 static inline unsigned int irq_of_parse_and_map(struct device_node *dev,