IEEE 1275 defined a standard "status" property to indicate the operational
status of a device.  The property has four possible values: okay, disabled,
fail, fail-xxx.  The absence of this property means the operational status
of the device is unknown or okay.

This adds a function called of_device_is_available that checks the state
of the status property of a device.  If the property is absent or set to
either "okay" or "ok", it returns 1.  Otherwise it returns 0.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Iterating through a device node's parents is simple enough, but dealing
with the refcounts properly is a little ugly, and replicating that logic
is asking for someone to get it wrong or forget it all together, eg:

while (dn != NULL) {
	/* loop body */
	tmp = of_get_parent(dn);
	of_node_put(dn);
	dn = tmp;
}

So add of_get_next_parent(), inspired by of_get_next_child().  The
contract is that it returns the parent and drops the reference on the
current node, this makes the loop look like:

while (dn != NULL) {
	/* loop body */
	dn = of_get_next_parent(dn);
}

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Similar to of_find_compatible_node(), of_find_matching_node() and
for_each_matching_node() allow you to iterate over the device tree
looking for specific nodes, except that they take of_device_id
tables instead of strings.

This also moves of_match_node() from driver/of/device.c to
driver/of/base.c to colocate it with the of_find_matching_node which
depends on it.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Add for_each_child_of_node() to encapsulate the common idiom of
iterating over the children of a device_node.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

remove asm/bitops.h includes

including asm/bitops directly may cause compile errors. don't include it
and include linux/bitops instead. next patch will deny including asm header
directly.

Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

They were only needed for backwards compatibility and all in tree uses
have now been changed.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This creates linux/of.h and includes asm/prom.h from it.

We also include linux/of.h from asm/prom.h while we transition.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>