[u-boot.git] / lib / fdtdec.c

/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <serial.h>
#include <libfdt.h>
#include <fdtdec.h>

/* we need the generic GPIO interface here */
#include <asm-generic/gpio.h>

DECLARE_GLOBAL_DATA_PTR;

/*
 * Here are the type we know about. One day we might allow drivers to
 * register. For now we just put them here. The COMPAT macro allows us to
 * turn this into a sparse list later, and keeps the ID with the name.
 */
#define COMPAT(id, name) name
static const char * const compat_names[COMPAT_COUNT] = {
	COMPAT(UNKNOWN, "<none>"),
};

const char *fdtdec_get_compatible(enum fdt_compat_id id)
{
	/* We allow reading of the 'unknown' ID for testing purposes */
	assert(id >= 0 && id < COMPAT_COUNT);
	return compat_names[id];
}

/**
 * Look in the FDT for an alias with the given name and return its node.
 *
 * @param blob	FDT blob
 * @param name	alias name to look up
 * @return node offset if found, or an error code < 0 otherwise
 */
static int find_alias_node(const void *blob, const char *name)
{
	const char *path;
	int alias_node;

	debug("find_alias_node: %s\n", name);
	alias_node = fdt_path_offset(blob, "/aliases");
	if (alias_node < 0)
		return alias_node;
	path = fdt_getprop(blob, alias_node, name, NULL);
	if (!path)
		return -FDT_ERR_NOTFOUND;
	return fdt_path_offset(blob, path);
}

fdt_addr_t fdtdec_get_addr(const void *blob, int node,
		const char *prop_name)
{
	const fdt_addr_t *cell;
	int len;

	debug("get_addr: %s\n", prop_name);
	cell = fdt_getprop(blob, node, prop_name, &len);
	if (cell && (len == sizeof(fdt_addr_t) ||
			len == sizeof(fdt_addr_t) * 2))
		return fdt_addr_to_cpu(*cell);
	return FDT_ADDR_T_NONE;
}

s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
		s32 default_val)
{
	const s32 *cell;
	int len;

	debug("get_size: %s\n", prop_name);
	cell = fdt_getprop(blob, node, prop_name, &len);
	if (cell && len >= sizeof(s32))
		return fdt32_to_cpu(cell[0]);
	return default_val;
}

int fdtdec_get_is_enabled(const void *blob, int node)
{
	const char *cell;

	/*
	 * It should say "okay", so only allow that. Some fdts use "ok" but
	 * this is a bug. Please fix your device tree source file. See here
	 * for discussion:
	 *
	 * http://www.mail-archive.com/[email protected]/msg71598.html
	 */
	cell = fdt_getprop(blob, node, "status", NULL);
	if (cell)
		return 0 == strcmp(cell, "okay");
	return 1;
}

enum fdt_compat_id fd_dec_lookup(const void *blob, int node)
{
	enum fdt_compat_id id;

	/* Search our drivers */
	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
		if (0 == fdt_node_check_compatible(blob, node,
				compat_names[id]))
			return id;
	return COMPAT_UNKNOWN;
}

int fdtdec_next_compatible(const void *blob, int node,
		enum fdt_compat_id id)
{
	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
}

int fdtdec_next_alias(const void *blob, const char *name,
		enum fdt_compat_id id, int *upto)
{
#define MAX_STR_LEN 20
	char str[MAX_STR_LEN + 20];
	int node, err;

	/* snprintf() is not available */
	assert(strlen(name) < MAX_STR_LEN);
	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
	node = find_alias_node(blob, str);
	if (node < 0)
		return node;
	err = fdt_node_check_compatible(blob, node, compat_names[id]);
	if (err < 0)
		return err;
	if (err)
		return -FDT_ERR_NOTFOUND;
	(*upto)++;
	return node;
}

/* TODO: Can we tighten this code up a little? */
int fdtdec_find_aliases_for_id(const void *blob, const char *name,
			enum fdt_compat_id id, int *node_list, int maxcount)
{
	int name_len = strlen(name);
	int nodes[maxcount];
	int num_found = 0;
	int offset, node;
	int alias_node;
	int count;
	int i, j;

	/* find the alias node if present */
	alias_node = fdt_path_offset(blob, "/aliases");

	/*
	 * start with nothing, and we can assume that the root node can't
	 * match
	 */
	memset(nodes, '\0', sizeof(nodes));

	/* First find all the compatible nodes */
	for (node = count = 0; node >= 0 && count < maxcount;) {
		node = fdtdec_next_compatible(blob, node, id);
		if (node >= 0)
			nodes[count++] = node;
	}
	if (node >= 0)
		debug("%s: warning: maxcount exceeded with alias '%s'\n",
		       __func__, name);

	/* Now find all the aliases */
	memset(node_list, '\0', sizeof(*node_list) * maxcount);

	for (offset = fdt_first_property_offset(blob, alias_node);
			offset > 0;
			offset = fdt_next_property_offset(blob, offset)) {
		const struct fdt_property *prop;
		const char *path;
		int number;
		int found;

		node = 0;
		prop = fdt_get_property_by_offset(blob, offset, NULL);
		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
		if (prop->len && 0 == strncmp(path, name, name_len))
			node = fdt_path_offset(blob, prop->data);
		if (node <= 0)
			continue;

		/* Get the alias number */
		number = simple_strtoul(path + name_len, NULL, 10);
		if (number < 0 || number >= maxcount) {
			debug("%s: warning: alias '%s' is out of range\n",
			       __func__, path);
			continue;
		}

		/* Make sure the node we found is actually in our list! */
		found = -1;
		for (j = 0; j < count; j++)
			if (nodes[j] == node) {
				found = j;
				break;
			}

		if (found == -1) {
			debug("%s: warning: alias '%s' points to a node "
				"'%s' that is missing or is not compatible "
				" with '%s'\n", __func__, path,
				fdt_get_name(blob, node, NULL),
			       compat_names[id]);
			continue;
		}

		/*
		 * Add this node to our list in the right place, and mark
		 * it as done.
		 */
		if (fdtdec_get_is_enabled(blob, node)) {
			node_list[number] = node;
			if (number >= num_found)
				num_found = number + 1;
		}
		nodes[j] = 0;
	}

	/* Add any nodes not mentioned by an alias */
	for (i = j = 0; i < maxcount; i++) {
		if (!node_list[i]) {
			for (; j < maxcount; j++)
				if (nodes[j] &&
					fdtdec_get_is_enabled(blob, nodes[j]))
					break;

			/* Have we run out of nodes to add? */
			if (j == maxcount)
				break;

			assert(!node_list[i]);
			node_list[i] = nodes[j++];
			if (i >= num_found)
				num_found = i + 1;
		}
	}

	return num_found;
}

/*
 * This function is a little odd in that it accesses global data. At some
 * point if the architecture board.c files merge this will make more sense.
 * Even now, it is common code.
 */
int fdtdec_check_fdt(void)
{
	/* We must have an fdt */
	if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob))
		panic("No valid fdt found - please append one to U-Boot\n"
			"binary or define CONFIG_OF_EMBED\n");
	return 0;
}

int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
{
	const u32 *phandle;
	int lookup;

	phandle = fdt_getprop(blob, node, prop_name, NULL);
	if (!phandle)
		return -FDT_ERR_NOTFOUND;

	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
	return lookup;
}

/**
 * Look up a property in a node and check that it has a minimum length.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param min_len	minimum property length in bytes
 * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
			found, or -FDT_ERR_BADLAYOUT if not enough data
 * @return pointer to cell, which is only valid if err == 0
 */
static const void *get_prop_check_min_len(const void *blob, int node,
		const char *prop_name, int min_len, int *err)
{
	const void *cell;
	int len;

	debug("%s: %s\n", __func__, prop_name);
	cell = fdt_getprop(blob, node, prop_name, &len);
	if (!cell)
		*err = -FDT_ERR_NOTFOUND;
	else if (len < min_len)
		*err = -FDT_ERR_BADLAYOUT;
	else
		*err = 0;
	return cell;
}

int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
		u32 *array, int count)
{
	const u32 *cell;
	int i, err = 0;

	debug("%s: %s\n", __func__, prop_name);
	cell = get_prop_check_min_len(blob, node, prop_name,
				      sizeof(u32) * count, &err);
	if (!err) {
		for (i = 0; i < count; i++)
			array[i] = fdt32_to_cpu(cell[i]);
	}
	return err;
}

int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
{
	const s32 *cell;
	int len;

	debug("%s: %s\n", __func__, prop_name);
	cell = fdt_getprop(blob, node, prop_name, &len);
	return cell != NULL;
}

/**
 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 * terminating item.
 *
 * @param blob		FDT blob to use
 * @param node		Node to look at
 * @param prop_name	Node property name
 * @param gpio		Array of gpio elements to fill from FDT. This will be
 *			untouched if either 0 or an error is returned
 * @param max_count	Maximum number of elements allowed
 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 */
static int fdtdec_decode_gpios(const void *blob, int node,
		const char *prop_name, struct fdt_gpio_state *gpio,
		int max_count)
{
	const struct fdt_property *prop;
	const u32 *cell;
	const char *name;
	int len, i;

	debug("%s: %s\n", __func__, prop_name);
	assert(max_count > 0);
	prop = fdt_get_property(blob, node, prop_name, &len);
	if (!prop) {
		debug("FDT: %s: property '%s' missing\n", __func__, prop_name);
		return -FDT_ERR_NOTFOUND;
	}

	/* We will use the name to tag the GPIO */
	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
	cell = (u32 *)prop->data;
	len /= sizeof(u32) * 3;		/* 3 cells per GPIO record */
	if (len > max_count) {
		debug("FDT: %s: too many GPIOs / cells for "
			"property '%s'\n", __func__, prop_name);
		return -FDT_ERR_BADLAYOUT;
	}

	/* Read out the GPIO data from the cells */
	for (i = 0; i < len; i++, cell += 3) {
		gpio[i].gpio = fdt32_to_cpu(cell[1]);
		gpio[i].flags = fdt32_to_cpu(cell[2]);
		gpio[i].name = name;
	}

	return len;
}

int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
		struct fdt_gpio_state *gpio)
{
	int err;

	debug("%s: %s\n", __func__, prop_name);
	gpio->gpio = FDT_GPIO_NONE;
	gpio->name = NULL;
	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
	return err == 1 ? 0 : err;
}

int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
{
	/*
	 * Return success if there is no GPIO defined. This is used for
	 * optional GPIOs)
	 */
	if (!fdt_gpio_isvalid(gpio))
		return 0;

	if (gpio_request(gpio->gpio, gpio->name))
		return -1;
	return 0;
}
Commit	Line	Data
b5220bc6 SG	1	/*
	2	* Copyright (c) 2011 The Chromium OS Authors.
	3	* See file CREDITS for list of people who contributed to this
	4	* project.
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License as
	8	* published by the Free Software Foundation; either version 2 of
	9	* the License, or (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	19	* MA 02111-1307 USA
	20	*/
	21
	22	#include <common.h>
	23	#include <serial.h>
	24	#include <libfdt.h>
	25	#include <fdtdec.h>
	26
ed3ee5cd SG	27	/* we need the generic GPIO interface here */
	28	#include <asm-generic/gpio.h>
	29
b5220bc6 SG	30	DECLARE_GLOBAL_DATA_PTR;
	31
	32	/*
	33	* Here are the type we know about. One day we might allow drivers to
	34	* register. For now we just put them here. The COMPAT macro allows us to
	35	* turn this into a sparse list later, and keeps the ID with the name.
	36	*/
	37	#define COMPAT(id, name) name
	38	static const char * const compat_names[COMPAT_COUNT] = {
f88fe2de	39	COMPAT(UNKNOWN, "<none>"),
b5220bc6 SG	40	};
b5220bc6 SG	41
a53f4a29 SG	42	const char *fdtdec_get_compatible(enum fdt_compat_id id)
	43	{
	44	/* We allow reading of the 'unknown' ID for testing purposes */
	45	assert(id >= 0 && id < COMPAT_COUNT);
	46	return compat_names[id];
	47	}
	48
b5220bc6 SG	49	/**
	50	* Look in the FDT for an alias with the given name and return its node.
	51	*
	52	* @param blob FDT blob
	53	* @param name alias name to look up
	54	* @return node offset if found, or an error code < 0 otherwise
	55	*/
	56	static int find_alias_node(const void blob, const char name)
	57	{
	58	const char *path;
	59	int alias_node;
	60
	61	debug("find_alias_node: %s\n", name);
	62	alias_node = fdt_path_offset(blob, "/aliases");
	63	if (alias_node < 0)
	64	return alias_node;
	65	path = fdt_getprop(blob, alias_node, name, NULL);
	66	if (!path)
	67	return -FDT_ERR_NOTFOUND;
	68	return fdt_path_offset(blob, path);
	69	}
	70
	71	fdt_addr_t fdtdec_get_addr(const void *blob, int node,
	72	const char *prop_name)
	73	{
	74	const fdt_addr_t *cell;
	75	int len;
	76
	77	debug("get_addr: %s\n", prop_name);
	78	cell = fdt_getprop(blob, node, prop_name, &len);
	79	if (cell && (len == sizeof(fdt_addr_t) \|\|
	80	len == sizeof(fdt_addr_t) * 2))
	81	return fdt_addr_to_cpu(*cell);
	82	return FDT_ADDR_T_NONE;
	83	}
	84
	85	s32 fdtdec_get_int(const void blob, int node, const char prop_name,
	86	s32 default_val)
	87	{
	88	const s32 *cell;
	89	int len;
	90
	91	debug("get_size: %s\n", prop_name);
	92	cell = fdt_getprop(blob, node, prop_name, &len);
	93	if (cell && len >= sizeof(s32))
	94	return fdt32_to_cpu(cell[0]);
	95	return default_val;
	96	}
	97
f88fe2de	98	int fdtdec_get_is_enabled(const void *blob, int node)
b5220bc6 SG	99	{
	100	const char *cell;
	101
f88fe2de SG	102	/*
	103	* It should say "okay", so only allow that. Some fdts use "ok" but
	104	* this is a bug. Please fix your device tree source file. See here
	105	* for discussion:
	106	*
	107	* http://www.mail-archive.com/[email protected]/msg71598.html
	108	*/
b5220bc6 SG	109	cell = fdt_getprop(blob, node, "status", NULL);
b5220bc6 SG	110	if (cell)
f88fe2de SG	111	return 0 == strcmp(cell, "okay");
f88fe2de SG	112	return 1;
b5220bc6 SG	113	}
	114
	115	enum fdt_compat_id fd_dec_lookup(const void *blob, int node)
	116	{
	117	enum fdt_compat_id id;
	118
	119	/* Search our drivers */
	120	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
	121	if (0 == fdt_node_check_compatible(blob, node,
	122	compat_names[id]))
	123	return id;
	124	return COMPAT_UNKNOWN;
	125	}
	126
	127	int fdtdec_next_compatible(const void *blob, int node,
	128	enum fdt_compat_id id)
	129	{
	130	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
	131	}
	132
	133	int fdtdec_next_alias(const void blob, const char name,
	134	enum fdt_compat_id id, int *upto)
	135	{
	136	#define MAX_STR_LEN 20
	137	char str[MAX_STR_LEN + 20];
	138	int node, err;
	139
	140	/* snprintf() is not available */
	141	assert(strlen(name) < MAX_STR_LEN);
	142	sprintf(str, "%.s%d", MAX_STR_LEN, name, upto);
b5220bc6 SG	143	node = find_alias_node(blob, str);
	144	if (node < 0)
	145	return node;
	146	err = fdt_node_check_compatible(blob, node, compat_names[id]);
	147	if (err < 0)
	148	return err;
f88fe2de SG	149	if (err)
	150	return -FDT_ERR_NOTFOUND;
	151	(*upto)++;
	152	return node;
b5220bc6 SG	153	}
b5220bc6 SG	154
a53f4a29 SG	155	/* TODO: Can we tighten this code up a little? */
	156	int fdtdec_find_aliases_for_id(const void blob, const char name,
	157	enum fdt_compat_id id, int *node_list, int maxcount)
	158	{
	159	int name_len = strlen(name);
	160	int nodes[maxcount];
	161	int num_found = 0;
	162	int offset, node;
	163	int alias_node;
	164	int count;
	165	int i, j;
	166
	167	/* find the alias node if present */
	168	alias_node = fdt_path_offset(blob, "/aliases");
	169
	170	/*
	171	* start with nothing, and we can assume that the root node can't
	172	* match
	173	*/
	174	memset(nodes, '\0', sizeof(nodes));
	175
	176	/* First find all the compatible nodes */
	177	for (node = count = 0; node >= 0 && count < maxcount;) {
	178	node = fdtdec_next_compatible(blob, node, id);
	179	if (node >= 0)
	180	nodes[count++] = node;
	181	}
	182	if (node >= 0)
	183	debug("%s: warning: maxcount exceeded with alias '%s'\n",
	184	__func__, name);
	185
	186	/* Now find all the aliases */
	187	memset(node_list, '\0', sizeof(node_list) maxcount);
	188
	189	for (offset = fdt_first_property_offset(blob, alias_node);
	190	offset > 0;
	191	offset = fdt_next_property_offset(blob, offset)) {
	192	const struct fdt_property *prop;
	193	const char *path;
	194	int number;
	195	int found;
	196
	197	node = 0;
	198	prop = fdt_get_property_by_offset(blob, offset, NULL);
	199	path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
	200	if (prop->len && 0 == strncmp(path, name, name_len))
	201	node = fdt_path_offset(blob, prop->data);
	202	if (node <= 0)
	203	continue;
	204
	205	/* Get the alias number */
	206	number = simple_strtoul(path + name_len, NULL, 10);
	207	if (number < 0 \|\| number >= maxcount) {
	208	debug("%s: warning: alias '%s' is out of range\n",
	209	__func__, path);
	210	continue;
	211	}
	212
	213	/* Make sure the node we found is actually in our list! */
	214	found = -1;
	215	for (j = 0; j < count; j++)
	216	if (nodes[j] == node) {
	217	found = j;
	218	break;
219	}
220
221	if (found == -1) {
222	debug("%s: warning: alias '%s' points to a node "
223	"'%s' that is missing or is not compatible "
224	" with '%s'\n", __func__, path,
225	fdt_get_name(blob, node, NULL),
226	compat_names[id]);
227	continue;
228	}
229
230	/*
231	* Add this node to our list in the right place, and mark
232	* it as done.
233	*/
234	if (fdtdec_get_is_enabled(blob, node)) {
235	node_list[number] = node;
236	if (number >= num_found)
237	num_found = number + 1;
238	}
239	nodes[j] = 0;
240	}
241
242	/* Add any nodes not mentioned by an alias */
243	for (i = j = 0; i < maxcount; i++) {
244	if (!node_list[i]) {
245	for (; j < maxcount; j++)
246	if (nodes[j] &&
247	fdtdec_get_is_enabled(blob, nodes[j]))
248	break;
249
250	/* Have we run out of nodes to add? */
251	if (j == maxcount)
252	break;
253
254	assert(!node_list[i]);
255	node_list[i] = nodes[j++];
256	if (i >= num_found)
257	num_found = i + 1;
258	}
259	}
260
261	return num_found;
262	}
263
b5220bc6 SG	264	/*
	265	* This function is a little odd in that it accesses global data. At some
	266	* point if the architecture board.c files merge this will make more sense.
	267	* Even now, it is common code.
	268	*/
	269	int fdtdec_check_fdt(void)
	270	{
	271	/* We must have an fdt */
f88fe2de	272	if (((uintptr_t)gd->fdt_blob & 3) \|\| fdt_check_header(gd->fdt_blob))
b5220bc6 SG	273	panic("No valid fdt found - please append one to U-Boot\n"
	274	"binary or define CONFIG_OF_EMBED\n");
	275	return 0;
	276	}
d17da655 SG	277
	278	int fdtdec_lookup_phandle(const void blob, int node, const char prop_name)
	279	{
	280	const u32 *phandle;
	281	int lookup;
	282
	283	phandle = fdt_getprop(blob, node, prop_name, NULL);
	284	if (!phandle)
	285	return -FDT_ERR_NOTFOUND;
	286
	287	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
	288	return lookup;
	289	}
	290
	291	/**
	292	* Look up a property in a node and check that it has a minimum length.
	293	*
	294	* @param blob FDT blob
	295	* @param node node to examine
	296	* @param prop_name name of property to find
	297	* @param min_len minimum property length in bytes
	298	* @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not
	299	found, or -FDT_ERR_BADLAYOUT if not enough data
	300	* @return pointer to cell, which is only valid if err == 0
	301	*/
	302	static const void get_prop_check_min_len(const void blob, int node,
	303	const char prop_name, int min_len, int err)
	304	{
	305	const void *cell;
	306	int len;
	307
	308	debug("%s: %s\n", __func__, prop_name);
	309	cell = fdt_getprop(blob, node, prop_name, &len);
	310	if (!cell)
	311	*err = -FDT_ERR_NOTFOUND;
	312	else if (len < min_len)
	313	*err = -FDT_ERR_BADLAYOUT;
	314	else
	315	*err = 0;
	316	return cell;
	317	}
	318
	319	int fdtdec_get_int_array(const void blob, int node, const char prop_name,
	320	u32 *array, int count)
	321	{
	322	const u32 *cell;
	323	int i, err = 0;
	324
	325	debug("%s: %s\n", __func__, prop_name);
	326	cell = get_prop_check_min_len(blob, node, prop_name,
	327	sizeof(u32) * count, &err);
	328	if (!err) {
	329	for (i = 0; i < count; i++)
	330	array[i] = fdt32_to_cpu(cell[i]);
	331	}
	332	return err;
	333	}
	334
	335	int fdtdec_get_bool(const void blob, int node, const char prop_name)
	336	{
	337	const s32 *cell;
	338	int len;
	339
	340	debug("%s: %s\n", __func__, prop_name);
341	cell = fdt_getprop(blob, node, prop_name, &len);
342	return cell != NULL;
343	}
ed3ee5cd SG	344
	345	/**
	346	* Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
	347	* terminating item.
	348	*
	349	* @param blob FDT blob to use
	350	* @param node Node to look at
	351	* @param prop_name Node property name
	352	* @param gpio Array of gpio elements to fill from FDT. This will be
	353	* untouched if either 0 or an error is returned
	354	* @param max_count Maximum number of elements allowed
	355	* @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
	356	* be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
	357	*/
	358	static int fdtdec_decode_gpios(const void *blob, int node,
	359	const char prop_name, struct fdt_gpio_state gpio,
	360	int max_count)
	361	{
	362	const struct fdt_property *prop;
	363	const u32 *cell;
	364	const char *name;
	365	int len, i;
	366
	367	debug("%s: %s\n", __func__, prop_name);
	368	assert(max_count > 0);
	369	prop = fdt_get_property(blob, node, prop_name, &len);
	370	if (!prop) {
	371	debug("FDT: %s: property '%s' missing\n", __func__, prop_name);
	372	return -FDT_ERR_NOTFOUND;
	373	}
	374
	375	/* We will use the name to tag the GPIO */
	376	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
	377	cell = (u32 *)prop->data;
	378	len /= sizeof(u32) * 3; /* 3 cells per GPIO record */
	379	if (len > max_count) {
	380	debug("FDT: %s: too many GPIOs / cells for "
	381	"property '%s'\n", __func__, prop_name);
	382	return -FDT_ERR_BADLAYOUT;
	383	}
	384
	385	/* Read out the GPIO data from the cells */
	386	for (i = 0; i < len; i++, cell += 3) {
	387	gpio[i].gpio = fdt32_to_cpu(cell[1]);
	388	gpio[i].flags = fdt32_to_cpu(cell[2]);
	389	gpio[i].name = name;
	390	}
	391
	392	return len;
	393	}
	394
	395	int fdtdec_decode_gpio(const void blob, int node, const char prop_name,
	396	struct fdt_gpio_state *gpio)
	397	{
	398	int err;
	399
	400	debug("%s: %s\n", __func__, prop_name);
	401	gpio->gpio = FDT_GPIO_NONE;
	402	gpio->name = NULL;
	403	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
	404	return err == 1 ? 0 : err;
	405	}
	406
	407	int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
408	{
409	/*
410	* Return success if there is no GPIO defined. This is used for
411	* optional GPIOs)
412	*/
413	if (!fdt_gpio_isvalid(gpio))
414	return 0;
415
416	if (gpio_request(gpio->gpio, gpio->name))
417	return -1;
418	return 0;
419	}