diff options
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/Makefile | 1 | ||||
-rw-r--r-- | drivers/of/base.c | 65 |
2 files changed, 66 insertions, 0 deletions
diff --git a/drivers/of/Makefile b/drivers/of/Makefile new file mode 100644 index 00000000000..cddbe840e30 --- /dev/null +++ b/drivers/of/Makefile @@ -0,0 +1 @@ +obj-y = base.o diff --git a/drivers/of/base.c b/drivers/of/base.c new file mode 100644 index 00000000000..723d80d704e --- /dev/null +++ b/drivers/of/base.c @@ -0,0 +1,65 @@ +/* + * Procedures for creating, accessing and interpreting the device tree. + * + * Paul Mackerras August 1996. + * Copyright (C) 1996-2005 Paul Mackerras. + * + * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. + * {engebret|bergner}@us.ibm.com + * + * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net + * + * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/module.h> +#include <linux/of.h> + +int of_n_addr_cells(struct device_node *np) +{ + const int *ip; + + do { + if (np->parent) + np = np->parent; + ip = of_get_property(np, "#address-cells", NULL); + if (ip) + return *ip; + } while (np->parent); + /* No #address-cells property for the root node */ + return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; +} +EXPORT_SYMBOL(of_n_addr_cells); + +int of_n_size_cells(struct device_node *np) +{ + const int *ip; + + do { + if (np->parent) + np = np->parent; + ip = of_get_property(np, "#size-cells", NULL); + if (ip) + return *ip; + } while (np->parent); + /* No #size-cells property for the root node */ + return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; +} +EXPORT_SYMBOL(of_n_size_cells); + +/* + * Find a property with a given name for a given node + * and return the value. + */ +const void *of_get_property(const struct device_node *np, const char *name, + int *lenp) +{ + struct property *pp = of_find_property(np, name, lenp); + + return pp ? pp->value : NULL; +} +EXPORT_SYMBOL(of_get_property); |