i2c/of: Allow device node to be passed via i2c_board_info

The struct device_node *of_node pointer is moving out of dev->archdata
and into the struct device proper.  of_i2c.c needs to set the of_node
pointer before the device is registered.  Since the i2c subsystem
doesn't allow 2 stage allocation and registration of i2c devices, the
of_node pointer needs to be passed via the i2c_board_info structure
so that it is set prior to registration.

This patch adds of_node to struct i2c_board_info (conditional on
CONFIG_OF), sets of_node in i2c_new_device(), and modifies of_i2c.c
to use the new parameter.  The calling of dev_archdata_set_node()
from of_i2c will be removed in a subsequent patch when of_node is
removed from archdata and all users are converted over.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/i2c/i2c-core.c

@@ -387,6 +387,9 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 	client->dev.parent = &client->adapter->dev;
 	client->dev.bus = &i2c_bus_type;
 	client->dev.type = &i2c_client_type;
+#ifdef CONFIG_OF
+	client->dev.of_node = info->of_node;
+#endif
 
 	dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
 		     client->addr);

drivers/of/of_i2c.c

@@ -43,6 +43,7 @@ void of_register_i2c_devices(struct i2c_adapter *adap,
 		info.addr = be32_to_cpup(addr);
 
 		dev_archdata_set_node(&dev_ad, node);
+		info.of_node = node;
 		info.archdata = &dev_ad;
 
 		request_module("%s", info.type);

include/linux/i2c.h

@@ -34,6 +34,7 @@
 #include <linux/device.h>	/* for struct device */
 #include <linux/sched.h>	/* for completion */
 #include <linux/mutex.h>
+#include <linux/of.h>		/* for struct device_node */
 
 extern struct bus_type i2c_bus_type;
 
@@ -251,6 +252,9 @@ struct i2c_board_info {
 	unsigned short	addr;
 	void		*platform_data;
 	struct dev_archdata	*archdata;
+#ifdef CONFIG_OF
+	struct device_node *of_node;
+#endif
 	int		irq;
 };