[POWERPC] Move of_device allocation into of_device.[ch]

Extract generic of_device allocation code from of_platform_device_create()
and move it into of_device.[ch], called of_device_alloc(). Also, there's now
of_device_free() which puts the device node.

This way, bus drivers that build on of_platform (like ibmebus will) can
build upon this code instead of reinventing the wheel.

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/of_device.c b/arch/powerpc/kernel/of_device.c
index 8f3db32..3388ad6 100644
--- a/arch/powerpc/kernel/of_device.c
+++ b/arch/powerpc/kernel/of_device.c
@@ -7,8 +7,88 @@
 #include <linux/slab.h>
 
 #include <asm/errno.h>
+#include <asm/dcr.h>
 #include <asm/of_device.h>
 
+static void of_device_make_bus_id(struct of_device *dev)
+{
+	static atomic_t bus_no_reg_magic;
+	struct device_node *node = dev->node;
+	char *name = dev->dev.bus_id;
+	const u32 *reg;
+	u64 addr;
+	int magic;
+
+	/*
+	 * If it's a DCR based device, use 'd' for native DCRs
+	 * and 'D' for MMIO DCRs.
+	 */
+#ifdef CONFIG_PPC_DCR
+	reg = of_get_property(node, "dcr-reg", NULL);
+	if (reg) {
+#ifdef CONFIG_PPC_DCR_NATIVE
+		snprintf(name, BUS_ID_SIZE, "d%x.%s",
+			 *reg, node->name);
+#else /* CONFIG_PPC_DCR_NATIVE */
+		addr = of_translate_dcr_address(node, *reg, NULL);
+		if (addr != OF_BAD_ADDR) {
+			snprintf(name, BUS_ID_SIZE,
+				 "D%llx.%s", (unsigned long long)addr,
+				 node->name);
+			return;
+		}
+#endif /* !CONFIG_PPC_DCR_NATIVE */
+	}
+#endif /* CONFIG_PPC_DCR */
+
+	/*
+	 * For MMIO, get the physical address
+	 */
+	reg = of_get_property(node, "reg", NULL);
+	if (reg) {
+		addr = of_translate_address(node, reg);
+		if (addr != OF_BAD_ADDR) {
+			snprintf(name, BUS_ID_SIZE,
+				 "%llx.%s", (unsigned long long)addr,
+				 node->name);
+			return;
+		}
+	}
+
+	/*
+	 * No BusID, use the node name and add a globally incremented
+	 * counter (and pray...)
+	 */
+	magic = atomic_add_return(1, &bus_no_reg_magic);
+	snprintf(name, BUS_ID_SIZE, "%s.%d", node->name, magic - 1);
+}
+
+struct of_device *of_device_alloc(struct device_node *np,
+				  const char *bus_id,
+				  struct device *parent)
+{
+	struct of_device *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	dev->node = of_node_get(np);
+	dev->dev.dma_mask = &dev->dma_mask;
+	dev->dev.parent = parent;
+	dev->dev.release = of_release_dev;
+	dev->dev.archdata.of_node = np;
+	dev->dev.archdata.numa_node = of_node_to_nid(np);
+
+	if (bus_id)
+		strlcpy(dev->dev.bus_id, bus_id, BUS_ID_SIZE);
+	else
+		of_device_make_bus_id(dev);
+
+	return dev;
+}
+EXPORT_SYMBOL(of_device_alloc);
+
 ssize_t of_device_get_modalias(struct of_device *ofdev,
 				char *str, ssize_t len)
 {