[mirror_ubuntu-bionic-kernel.git] / drivers / of / base.c

/*
 * 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>
#include <linux/spinlock.h>

/* use when traversing tree through the allnext, child, sibling,
 * or parent members of struct device_node.
 */
DEFINE_RWLOCK(devtree_lock);

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);

struct property *of_find_property(const struct device_node *np,
				  const char *name,
				  int *lenp)
{
	struct property *pp;

	read_lock(&devtree_lock);
	for (pp = np->properties; pp != 0; pp = pp->next) {
		if (of_prop_cmp(pp->name, name) == 0) {
			if (lenp != 0)
				*lenp = pp->length;
			break;
		}
	}
	read_unlock(&devtree_lock);

	return pp;
}
EXPORT_SYMBOL(of_find_property);

/*
 * 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);

/** Checks if the given "compat" string matches one of the strings in
 * the device's "compatible" property
 */
int of_device_is_compatible(const struct device_node *device,
		const char *compat)
{
	const char* cp;
	int cplen, l;

	cp = of_get_property(device, "compatible", &cplen);
	if (cp == NULL)
		return 0;
	while (cplen > 0) {
		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
			return 1;
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
	}

	return 0;
}
EXPORT_SYMBOL(of_device_is_compatible);
Commit	Line	Data
97e873e5 SR	1	/*
	2	* Procedures for creating, accessing and interpreting the device tree.
	3	*
	4	* Paul Mackerras August 1996.
	5	* Copyright (C) 1996-2005 Paul Mackerras.
	6	*
	7	* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
	8	* {engebret\|bergner}@us.ibm.com
	9	*
	10	* Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
	11	*
	12	* Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell.
	13	*
	14	* This program is free software; you can redistribute it and/or
	15	* modify it under the terms of the GNU General Public License
	16	* as published by the Free Software Foundation; either version
	17	* 2 of the License, or (at your option) any later version.
	18	*/
	19	#include <linux/module.h>
	20	#include <linux/of.h>
581b605a SR	21	#include <linux/spinlock.h>
	22
	23	/* use when traversing tree through the allnext, child, sibling,
	24	* or parent members of struct device_node.
	25	*/
	26	DEFINE_RWLOCK(devtree_lock);
97e873e5 SR	27
	28	int of_n_addr_cells(struct device_node *np)
	29	{
	30	const int *ip;
	31
	32	do {
	33	if (np->parent)
	34	np = np->parent;
	35	ip = of_get_property(np, "#address-cells", NULL);
	36	if (ip)
	37	return *ip;
	38	} while (np->parent);
	39	/* No #address-cells property for the root node */
	40	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
	41	}
	42	EXPORT_SYMBOL(of_n_addr_cells);
	43
	44	int of_n_size_cells(struct device_node *np)
	45	{
	46	const int *ip;
	47
	48	do {
	49	if (np->parent)
	50	np = np->parent;
	51	ip = of_get_property(np, "#size-cells", NULL);
	52	if (ip)
	53	return *ip;
	54	} while (np->parent);
	55	/* No #size-cells property for the root node */
	56	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
	57	}
	58	EXPORT_SYMBOL(of_n_size_cells);
	59
581b605a SR	60	struct property of_find_property(const struct device_node np,
	61	const char *name,
	62	int *lenp)
	63	{
	64	struct property *pp;
	65
	66	read_lock(&devtree_lock);
	67	for (pp = np->properties; pp != 0; pp = pp->next) {
	68	if (of_prop_cmp(pp->name, name) == 0) {
	69	if (lenp != 0)
	70	*lenp = pp->length;
	71	break;
	72	}
	73	}
	74	read_unlock(&devtree_lock);
	75
	76	return pp;
	77	}
	78	EXPORT_SYMBOL(of_find_property);
	79
97e873e5 SR	80	/*
	81	* Find a property with a given name for a given node
	82	* and return the value.
	83	*/
	84	const void of_get_property(const struct device_node np, const char *name,
	85	int *lenp)
	86	{
	87	struct property *pp = of_find_property(np, name, lenp);
	88
	89	return pp ? pp->value : NULL;
	90	}
	91	EXPORT_SYMBOL(of_get_property);
0081cbc3 SR	92
	93	/** Checks if the given "compat" string matches one of the strings in
	94	* the device's "compatible" property
	95	*/
	96	int of_device_is_compatible(const struct device_node *device,
	97	const char *compat)
	98	{
	99	const char* cp;
	100	int cplen, l;
	101
	102	cp = of_get_property(device, "compatible", &cplen);
	103	if (cp == NULL)
	104	return 0;
	105	while (cplen > 0) {
	106	if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
	107	return 1;
	108	l = strlen(cp) + 1;
	109	cp += l;
	110	cplen -= l;
	111	}
	112
	113	return 0;
	114	}
	115	EXPORT_SYMBOL(of_device_is_compatible);