of: Make device nodes kobjects so they show up in sysfs

Device tree nodes are already treated as objects, and we already want to
expose them to userspace which is done using the /proc filesystem today.
Right now the kernel has to do a lot of work to keep the /proc view in
sync with the in-kernel representation. If device_nodes are switched to
be kobjects then the device tree code can be a whole lot simpler. It
also turns out that switching to using /sysfs from /proc results in
smaller code and data size, and the userspace ABI won't change if
/proc/device-tree symlinks to /sys/firmware/devicetree/base.

v7: Add missing sysfs_bin_attr_init()
v6: Add __of_add_property() early init fixes from Pantelis
v5: Rename firmware/ofw to firmware/devicetree
    Fix updating property values in sysfs
v4: Fixed build error on Powerpc
    Fixed handling of dynamic nodes on powerpc
v3: Fixed handling of duplicate attribute and child node names
v2: switch to using sysfs bin_attributes which solve the problem of
    reporting incorrect property size.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/of.h b/include/linux/of.h
index b3d0f6d86e3b..bd45be5bd565 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -18,7 +18,7 @@
 #include <linux/types.h>
 #include <linux/bitops.h>
 #include <linux/errno.h>
-#include <linux/kref.h>
+#include <linux/kobject.h>
 #include <linux/mod_devicetable.h>
 #include <linux/spinlock.h>
 #include <linux/topology.h>
@@ -37,6 +37,7 @@ struct property {
         struct property *next;
         unsigned long _flags;
         unsigned int unique_id;
+        struct bin_attribute attr;
 };
 
 #if defined(CONFIG_SPARC)
@@ -57,7 +58,7 @@ struct device_node {
         struct  device_node *next;      /* next device of same type */
         struct  device_node *allnext;   /* next in list of all nodes */
         struct  proc_dir_entry *pde;    /* this node's proc directory */
-        struct  kref kref;
+        struct  kobject kobj;
         unsigned long _flags;
         void    *data;
 #if defined(CONFIG_SPARC)
@@ -74,6 +75,8 @@ struct of_phandle_args {
         uint32_t args[MAX_PHANDLE_ARGS];
 };
 
+extern int of_node_add(struct device_node *node);
+
 #ifdef CONFIG_OF_DYNAMIC
 extern struct device_node *of_node_get(struct device_node *node);
 extern void of_node_put(struct device_node *node);
@@ -187,6 +190,8 @@ static inline const char *of_node_full_name(const struct device_node *np)
         return np ? np->full_name : "<no-node>";
 }
 
+#define for_each_of_allnodes(dn) \
+        for (dn = of_allnodes; dn; dn = dn->allnext)
 extern struct device_node *of_find_node_by_name(struct device_node *from,
         const char *name);
 extern struct device_node *of_find_node_by_type(struct device_node *from,