diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 1262 |
1 files changed, 1262 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c new file mode 100644 index 00000000..58064498 --- /dev/null +++ b/drivers/of/base.c @@ -0,0 +1,1262 @@ +/* + * 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 and + * Grant Likely. + * + * 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/ctype.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/proc_fs.h> + +/** + * struct alias_prop - Alias property in 'aliases' node + * @link: List node to link the structure in aliases_lookup list + * @alias: Alias property name + * @np: Pointer to device_node that the alias stands for + * @id: Index value from end of alias name + * @stem: Alias string without the index + * + * The structure represents one alias property of 'aliases' node as + * an entry in aliases_lookup list. + */ +struct alias_prop { + struct list_head link; + const char *alias; + struct device_node *np; + int id; + char stem[0]; +}; + +static LIST_HEAD(aliases_lookup); + +struct device_node *allnodes; +struct device_node *of_chosen; +struct device_node *of_aliases; + +static DEFINE_MUTEX(of_aliases_mutex); + +/* 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 __be32 *ip; + + do { + if (np->parent) + np = np->parent; + ip = of_get_property(np, "#address-cells", NULL); + if (ip) + return be32_to_cpup(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 __be32 *ip; + + do { + if (np->parent) + np = np->parent; + ip = of_get_property(np, "#size-cells", NULL); + if (ip) + return be32_to_cpup(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); + +#if defined(CONFIG_OF_DYNAMIC) +/** + * of_node_get - Increment refcount of a node + * @node: Node to inc refcount, NULL is supported to + * simplify writing of callers + * + * Returns node. + */ +struct device_node *of_node_get(struct device_node *node) +{ + if (node) + kref_get(&node->kref); + return node; +} +EXPORT_SYMBOL(of_node_get); + +static inline struct device_node *kref_to_device_node(struct kref *kref) +{ + return container_of(kref, struct device_node, kref); +} + +/** + * of_node_release - release a dynamically allocated node + * @kref: kref element of the node to be released + * + * In of_node_put() this function is passed to kref_put() + * as the destructor. + */ +static void of_node_release(struct kref *kref) +{ + struct device_node *node = kref_to_device_node(kref); + struct property *prop = node->properties; + + /* We should never be releasing nodes that haven't been detached. */ + if (!of_node_check_flag(node, OF_DETACHED)) { + pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); + dump_stack(); + kref_init(&node->kref); + return; + } + + if (!of_node_check_flag(node, OF_DYNAMIC)) + return; + + while (prop) { + struct property *next = prop->next; + kfree(prop->name); + kfree(prop->value); + kfree(prop); + prop = next; + + if (!prop) { + prop = node->deadprops; + node->deadprops = NULL; + } + } + kfree(node->full_name); + kfree(node->data); + kfree(node); +} + +/** + * of_node_put - Decrement refcount of a node + * @node: Node to dec refcount, NULL is supported to + * simplify writing of callers + * + */ +void of_node_put(struct device_node *node) +{ + if (node) + kref_put(&node->kref, of_node_release); +} +EXPORT_SYMBOL(of_node_put); +#endif /* CONFIG_OF_DYNAMIC */ + +struct property *of_find_property(const struct device_node *np, + const char *name, + int *lenp) +{ + struct property *pp; + + if (!np) + return NULL; + + 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); + +/** + * of_find_all_nodes - Get next node in global list + * @prev: Previous node or NULL to start iteration + * of_node_put() will be called on it + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_all_nodes(struct device_node *prev) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = prev ? prev->allnext : allnodes; + for (; np != NULL; np = np->allnext) + if (of_node_get(np)) + break; + of_node_put(prev); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_all_nodes); + +/* + * 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); + +/** + * of_machine_is_compatible - Test root of device tree for a given compatible value + * @compat: compatible string to look for in root node's compatible property. + * + * Returns true if the root node has the given value in its + * compatible property. + */ +int of_machine_is_compatible(const char *compat) +{ + struct device_node *root; + int rc = 0; + + root = of_find_node_by_path("/"); + if (root) { + rc = of_device_is_compatible(root, compat); + of_node_put(root); + } + return rc; +} +EXPORT_SYMBOL(of_machine_is_compatible); + +/** + * of_device_is_available - check if a device is available for use + * + * @device: Node to check for availability + * + * Returns 1 if the status property is absent or set to "okay" or "ok", + * 0 otherwise + */ +int of_device_is_available(const struct device_node *device) +{ + const char *status; + int statlen; + + status = of_get_property(device, "status", &statlen); + if (status == NULL) + return 1; + + if (statlen > 0) { + if (!strcmp(status, "okay") || !strcmp(status, "ok")) + return 1; + } + + return 0; +} +EXPORT_SYMBOL(of_device_is_available); + +/** + * of_get_parent - Get a node's parent if any + * @node: Node to get parent + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_parent(const struct device_node *node) +{ + struct device_node *np; + + if (!node) + return NULL; + + read_lock(&devtree_lock); + np = of_node_get(node->parent); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_get_parent); + +/** + * of_get_next_parent - Iterate to a node's parent + * @node: Node to get parent of + * + * This is like of_get_parent() except that it drops the + * refcount on the passed node, making it suitable for iterating + * through a node's parents. + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_next_parent(struct device_node *node) +{ + struct device_node *parent; + + if (!node) + return NULL; + + read_lock(&devtree_lock); + parent = of_node_get(node->parent); + of_node_put(node); + read_unlock(&devtree_lock); + return parent; +} + +/** + * of_get_next_child - Iterate a node childs + * @node: parent node + * @prev: previous child of the parent node, or NULL to get first + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_next_child(const struct device_node *node, + struct device_node *prev) +{ + struct device_node *next; + + read_lock(&devtree_lock); + next = prev ? prev->sibling : node->child; + for (; next; next = next->sibling) + if (of_node_get(next)) + break; + of_node_put(prev); + read_unlock(&devtree_lock); + return next; +} +EXPORT_SYMBOL(of_get_next_child); + +/** + * of_find_node_by_path - Find a node matching a full OF path + * @path: The full path to match + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_path(const char *path) +{ + struct device_node *np = allnodes; + + read_lock(&devtree_lock); + for (; np; np = np->allnext) { + if (np->full_name && (of_node_cmp(np->full_name, path) == 0) + && of_node_get(np)) + break; + } + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_by_path); + +/** + * of_find_node_by_name - Find a node by its "name" property + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @name: The name string to match against + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_name(struct device_node *from, + const char *name) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) + if (np->name && (of_node_cmp(np->name, name) == 0) + && of_node_get(np)) + break; + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_by_name); + +/** + * of_find_node_by_type - Find a node by its "device_type" property + * @from: The node to start searching from, or NULL to start searching + * the entire device tree. The node you pass will not be + * searched, only the next one will; typically, you pass + * what the previous call returned. of_node_put() will be + * called on from for you. + * @type: The type string to match against + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_type(struct device_node *from, + const char *type) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) + if (np->type && (of_node_cmp(np->type, type) == 0) + && of_node_get(np)) + break; + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_by_type); + +/** + * of_find_compatible_node - Find a node based on type and one of the + * tokens in its "compatible" property + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @type: The type string to match "device_type" or NULL to ignore + * @compatible: The string to match to one of the tokens in the device + * "compatible" list. + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_compatible_node(struct device_node *from, + const char *type, const char *compatible) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + if (type + && !(np->type && (of_node_cmp(np->type, type) == 0))) + continue; + if (of_device_is_compatible(np, compatible) && of_node_get(np)) + break; + } + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_compatible_node); + +/** + * of_find_node_with_property - Find a node which has a property with + * the given name. + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @prop_name: The name of the property to look for. + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_with_property(struct device_node *from, + const char *prop_name) +{ + struct device_node *np; + struct property *pp; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + for (pp = np->properties; pp != 0; pp = pp->next) { + if (of_prop_cmp(pp->name, prop_name) == 0) { + of_node_get(np); + goto out; + } + } + } +out: + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_with_property); + +/** + * of_match_node - Tell if an device_node has a matching of_match structure + * @matches: array of of device match structures to search in + * @node: the of device structure to match against + * + * Low level utility function used by device matching. + */ +const struct of_device_id *of_match_node(const struct of_device_id *matches, + const struct device_node *node) +{ + if (!matches) + return NULL; + + while (matches->name[0] || matches->type[0] || matches->compatible[0]) { + int match = 1; + if (matches->name[0]) + match &= node->name + && !strcmp(matches->name, node->name); + if (matches->type[0]) + match &= node->type + && !strcmp(matches->type, node->type); + if (matches->compatible[0]) + match &= of_device_is_compatible(node, + matches->compatible); + if (match) + return matches; + matches++; + } + return NULL; +} +EXPORT_SYMBOL(of_match_node); + +/** + * of_find_matching_node - Find a node based on an of_device_id match + * table. + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @matches: array of of device match structures to search in + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_matching_node(struct device_node *from, + const struct of_device_id *matches) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + if (of_match_node(matches, np) && of_node_get(np)) + break; + } + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_matching_node); + +/** + * of_modalias_node - Lookup appropriate modalias for a device node + * @node: pointer to a device tree node + * @modalias: Pointer to buffer that modalias value will be copied into + * @len: Length of modalias value + * + * Based on the value of the compatible property, this routine will attempt + * to choose an appropriate modalias value for a particular device tree node. + * It does this by stripping the manufacturer prefix (as delimited by a ',') + * from the first entry in the compatible list property. + * + * This routine returns 0 on success, <0 on failure. + */ +int of_modalias_node(struct device_node *node, char *modalias, int len) +{ + const char *compatible, *p; + int cplen; + + compatible = of_get_property(node, "compatible", &cplen); + if (!compatible || strlen(compatible) > cplen) + return -ENODEV; + p = strchr(compatible, ','); + strlcpy(modalias, p ? p + 1 : compatible, len); + return 0; +} +EXPORT_SYMBOL_GPL(of_modalias_node); + +/** + * of_find_node_by_phandle - Find a node given a phandle + * @handle: phandle of the node to find + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_phandle(phandle handle) +{ + struct device_node *np; + + read_lock(&devtree_lock); + for (np = allnodes; np; np = np->allnext) + if (np->phandle == handle) + break; + of_node_get(np); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_by_phandle); + +/** + * of_property_read_u32_array - Find and read an array of 32 bit integers + * from a property. + * + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @out_value: pointer to return value, modified only if return value is 0. + * + * Search for a property in a device node and read 32-bit value(s) from + * it. Returns 0 on success, -EINVAL if the property does not exist, + * -ENODATA if property does not have a value, and -EOVERFLOW if the + * property data isn't large enough. + * + * The out_value is modified only if a valid u32 value can be decoded. + */ +int of_property_read_u32_array(const struct device_node *np, + const char *propname, u32 *out_values, + size_t sz) +{ + struct property *prop = of_find_property(np, propname, NULL); + const __be32 *val; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if ((sz * sizeof(*out_values)) > prop->length) + return -EOVERFLOW; + + val = prop->value; + while (sz--) + *out_values++ = be32_to_cpup(val++); + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u32_array); + +/** + * of_property_read_u64 - Find and read a 64 bit integer from a property + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @out_value: pointer to return value, modified only if return value is 0. + * + * Search for a property in a device node and read a 64-bit value from + * it. Returns 0 on success, -EINVAL if the property does not exist, + * -ENODATA if property does not have a value, and -EOVERFLOW if the + * property data isn't large enough. + * + * The out_value is modified only if a valid u64 value can be decoded. + */ +int of_property_read_u64(const struct device_node *np, const char *propname, + u64 *out_value) +{ + struct property *prop = of_find_property(np, propname, NULL); + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (sizeof(*out_value) > prop->length) + return -EOVERFLOW; + *out_value = of_read_number(prop->value, 2); + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u64); + +/** + * of_property_read_string - Find and read a string from a property + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @out_string: pointer to null terminated return string, modified only if + * return value is 0. + * + * Search for a property in a device tree node and retrieve a null + * terminated string value (pointer to data, not a copy). Returns 0 on + * success, -EINVAL if the property does not exist, -ENODATA if property + * does not have a value, and -EILSEQ if the string is not null-terminated + * within the length of the property data. + * + * The out_string pointer is modified only if a valid string can be decoded. + */ +int of_property_read_string(struct device_node *np, const char *propname, + const char **out_string) +{ + struct property *prop = of_find_property(np, propname, NULL); + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) >= prop->length) + return -EILSEQ; + *out_string = prop->value; + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_string); + +/** + * of_property_read_string_index - Find and read a string from a multiple + * strings property. + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @index: index of the string in the list of strings + * @out_string: pointer to null terminated return string, modified only if + * return value is 0. + * + * Search for a property in a device tree node and retrieve a null + * terminated string value (pointer to data, not a copy) in the list of strings + * contained in that property. + * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if + * property does not have a value, and -EILSEQ if the string is not + * null-terminated within the length of the property data. + * + * The out_string pointer is modified only if a valid string can be decoded. + */ +int of_property_read_string_index(struct device_node *np, const char *propname, + int index, const char **output) +{ + struct property *prop = of_find_property(np, propname, NULL); + int i = 0; + size_t l = 0, total = 0; + const char *p; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) >= prop->length) + return -EILSEQ; + + p = prop->value; + + for (i = 0; total < prop->length; total += l, p += l) { + l = strlen(p) + 1; + if (i++ == index) { + *output = p; + return 0; + } + } + return -ENODATA; +} +EXPORT_SYMBOL_GPL(of_property_read_string_index); + +/** + * of_property_match_string() - Find string in a list and return index + * @np: pointer to node containing string list property + * @propname: string list property name + * @string: pointer to string to search for in string list + * + * This function searches a string list property and returns the index + * of a specific string value. + */ +int of_property_match_string(struct device_node *np, const char *propname, + const char *string) +{ + struct property *prop = of_find_property(np, propname, NULL); + size_t l; + int i; + const char *p, *end; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + + p = prop->value; + end = p + prop->length; + + for (i = 0; p < end; i++, p += l) { + l = strlen(p) + 1; + if (p + l > end) + return -EILSEQ; + pr_debug("comparing %s with %s\n", string, p); + if (strcmp(string, p) == 0) + return i; /* Found it; return index */ + } + return -ENODATA; +} +EXPORT_SYMBOL_GPL(of_property_match_string); + +/** + * of_property_count_strings - Find and return the number of strings from a + * multiple strings property. + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device tree node and retrieve the number of null + * terminated string contain in it. Returns the number of strings on + * success, -EINVAL if the property does not exist, -ENODATA if property + * does not have a value, and -EILSEQ if the string is not null-terminated + * within the length of the property data. + */ +int of_property_count_strings(struct device_node *np, const char *propname) +{ + struct property *prop = of_find_property(np, propname, NULL); + int i = 0; + size_t l = 0, total = 0; + const char *p; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) >= prop->length) + return -EILSEQ; + + p = prop->value; + + for (i = 0; total < prop->length; total += l, p += l, i++) + l = strlen(p) + 1; + + return i; +} +EXPORT_SYMBOL_GPL(of_property_count_strings); + +/** + * of_parse_phandle - Resolve a phandle property to a device_node pointer + * @np: Pointer to device node holding phandle property + * @phandle_name: Name of property holding a phandle value + * @index: For properties holding a table of phandles, this is the index into + * the table + * + * Returns the device_node pointer with refcount incremented. Use + * of_node_put() on it when done. + */ +struct device_node * +of_parse_phandle(struct device_node *np, const char *phandle_name, int index) +{ + const __be32 *phandle; + int size; + + phandle = of_get_property(np, phandle_name, &size); + if ((!phandle) || (size < sizeof(*phandle) * (index + 1))) + return NULL; + + return of_find_node_by_phandle(be32_to_cpup(phandle + index)); +} +EXPORT_SYMBOL(of_parse_phandle); + +/** + * of_parse_phandle_with_args() - Find a node pointed by phandle in a list + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @cells_name: property name that specifies phandles' arguments count + * @index: index of a phandle to parse out + * @out_args: optional pointer to output arguments structure (will be filled) + * + * This function is useful to parse lists of phandles and their arguments. + * Returns 0 on success and fills out_args, on error returns appropriate + * errno value. + * + * Caller is responsible to call of_node_put() on the returned out_args->node + * pointer. + * + * Example: + * + * phandle1: node1 { + * #list-cells = <2>; + * } + * + * phandle2: node2 { + * #list-cells = <1>; + * } + * + * node3 { + * list = <&phandle1 1 2 &phandle2 3>; + * } + * + * To get a device_node of the `node2' node you may call this: + * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); + */ +int of_parse_phandle_with_args(struct device_node *np, const char *list_name, + const char *cells_name, int index, + struct of_phandle_args *out_args) +{ + const __be32 *list, *list_end; + int size, cur_index = 0; + uint32_t count = 0; + struct device_node *node = NULL; + phandle phandle; + + /* Retrieve the phandle list property */ + list = of_get_property(np, list_name, &size); + if (!list) + return -EINVAL; + list_end = list + size / sizeof(*list); + + /* Loop over the phandles until all the requested entry is found */ + while (list < list_end) { + count = 0; + + /* + * If phandle is 0, then it is an empty entry with no + * arguments. Skip forward to the next entry. + */ + phandle = be32_to_cpup(list++); + if (phandle) { + /* + * Find the provider node and parse the #*-cells + * property to determine the argument length + */ + node = of_find_node_by_phandle(phandle); + if (!node) { + pr_err("%s: could not find phandle\n", + np->full_name); + break; + } + if (of_property_read_u32(node, cells_name, &count)) { + pr_err("%s: could not get %s for %s\n", + np->full_name, cells_name, + node->full_name); + break; + } + + /* + * Make sure that the arguments actually fit in the + * remaining property data length + */ + if (list + count > list_end) { + pr_err("%s: arguments longer than property\n", + np->full_name); + break; + } + } + + /* + * All of the error cases above bail out of the loop, so at + * this point, the parsing is successful. If the requested + * index matches, then fill the out_args structure and return, + * or return -ENOENT for an empty entry. + */ + if (cur_index == index) { + if (!phandle) + return -ENOENT; + + if (out_args) { + int i; + if (WARN_ON(count > MAX_PHANDLE_ARGS)) + count = MAX_PHANDLE_ARGS; + out_args->np = node; + out_args->args_count = count; + for (i = 0; i < count; i++) + out_args->args[i] = be32_to_cpup(list++); + } + return 0; + } + + of_node_put(node); + node = NULL; + list += count; + cur_index++; + } + + /* Loop exited without finding a valid entry; return an error */ + if (node) + of_node_put(node); + return -EINVAL; +} +EXPORT_SYMBOL(of_parse_phandle_with_args); + +/** + * prom_add_property - Add a property to a node + */ +int prom_add_property(struct device_node *np, struct property *prop) +{ + struct property **next; + unsigned long flags; + + prop->next = NULL; + write_lock_irqsave(&devtree_lock, flags); + next = &np->properties; + while (*next) { + if (strcmp(prop->name, (*next)->name) == 0) { + /* duplicate ! don't insert it */ + write_unlock_irqrestore(&devtree_lock, flags); + return -1; + } + next = &(*next)->next; + } + *next = prop; + write_unlock_irqrestore(&devtree_lock, flags); + +#ifdef CONFIG_PROC_DEVICETREE + /* try to add to proc as well if it was initialized */ + if (np->pde) + proc_device_tree_add_prop(np->pde, prop); +#endif /* CONFIG_PROC_DEVICETREE */ + + return 0; +} + +/** + * prom_remove_property - Remove a property from a node. + * + * Note that we don't actually remove it, since we have given out + * who-knows-how-many pointers to the data using get-property. + * Instead we just move the property to the "dead properties" + * list, so it won't be found any more. + */ +int prom_remove_property(struct device_node *np, struct property *prop) +{ + struct property **next; + unsigned long flags; + int found = 0; + + write_lock_irqsave(&devtree_lock, flags); + next = &np->properties; + while (*next) { + if (*next == prop) { + /* found the node */ + *next = prop->next; + prop->next = np->deadprops; + np->deadprops = prop; + found = 1; + break; + } + next = &(*next)->next; + } + write_unlock_irqrestore(&devtree_lock, flags); + + if (!found) + return -ENODEV; + +#ifdef CONFIG_PROC_DEVICETREE + /* try to remove the proc node as well */ + if (np->pde) + proc_device_tree_remove_prop(np->pde, prop); +#endif /* CONFIG_PROC_DEVICETREE */ + + return 0; +} + +/* + * prom_update_property - Update a property in a node. + * + * Note that we don't actually remove it, since we have given out + * who-knows-how-many pointers to the data using get-property. + * Instead we just move the property to the "dead properties" list, + * and add the new property to the property list + */ +int prom_update_property(struct device_node *np, + struct property *newprop, + struct property *oldprop) +{ + struct property **next; + unsigned long flags; + int found = 0; + + write_lock_irqsave(&devtree_lock, flags); + next = &np->properties; + while (*next) { + if (*next == oldprop) { + /* found the node */ + newprop->next = oldprop->next; + *next = newprop; + oldprop->next = np->deadprops; + np->deadprops = oldprop; + found = 1; + break; + } + next = &(*next)->next; + } + write_unlock_irqrestore(&devtree_lock, flags); + + if (!found) + return -ENODEV; + +#ifdef CONFIG_PROC_DEVICETREE + /* try to add to proc as well if it was initialized */ + if (np->pde) + proc_device_tree_update_prop(np->pde, newprop, oldprop); +#endif /* CONFIG_PROC_DEVICETREE */ + + return 0; +} + +#if defined(CONFIG_OF_DYNAMIC) +/* + * Support for dynamic device trees. + * + * On some platforms, the device tree can be manipulated at runtime. + * The routines in this section support adding, removing and changing + * device tree nodes. + */ + +/** + * of_attach_node - Plug a device node into the tree and global list. + */ +void of_attach_node(struct device_node *np) +{ + unsigned long flags; + + write_lock_irqsave(&devtree_lock, flags); + np->sibling = np->parent->child; + np->allnext = allnodes; + np->parent->child = np; + allnodes = np; + write_unlock_irqrestore(&devtree_lock, flags); +} + +/** + * of_detach_node - "Unplug" a node from the device tree. + * + * The caller must hold a reference to the node. The memory associated with + * the node is not freed until its refcount goes to zero. + */ +void of_detach_node(struct device_node *np) +{ + struct device_node *parent; + unsigned long flags; + + write_lock_irqsave(&devtree_lock, flags); + + parent = np->parent; + if (!parent) + goto out_unlock; + + if (allnodes == np) + allnodes = np->allnext; + else { + struct device_node *prev; + for (prev = allnodes; + prev->allnext != np; + prev = prev->allnext) + ; + prev->allnext = np->allnext; + } + + if (parent->child == np) + parent->child = np->sibling; + else { + struct device_node *prevsib; + for (prevsib = np->parent->child; + prevsib->sibling != np; + prevsib = prevsib->sibling) + ; + prevsib->sibling = np->sibling; + } + + of_node_set_flag(np, OF_DETACHED); + +out_unlock: + write_unlock_irqrestore(&devtree_lock, flags); +} +#endif /* defined(CONFIG_OF_DYNAMIC) */ + +static void of_alias_add(struct alias_prop *ap, struct device_node *np, + int id, const char *stem, int stem_len) +{ + ap->np = np; + ap->id = id; + strncpy(ap->stem, stem, stem_len); + ap->stem[stem_len] = 0; + list_add_tail(&ap->link, &aliases_lookup); + pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n", + ap->alias, ap->stem, ap->id, np ? np->full_name : NULL); +} + +/** + * of_alias_scan - Scan all properties of 'aliases' node + * + * The function scans all the properties of 'aliases' node and populate + * the the global lookup table with the properties. It returns the + * number of alias_prop found, or error code in error case. + * + * @dt_alloc: An allocator that provides a virtual address to memory + * for the resulting tree + */ +void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) +{ + struct property *pp; + + of_chosen = of_find_node_by_path("/chosen"); + if (of_chosen == NULL) + of_chosen = of_find_node_by_path("/chosen@0"); + of_aliases = of_find_node_by_path("/aliases"); + if (!of_aliases) + return; + + for_each_property_of_node(of_aliases, pp) { + const char *start = pp->name; + const char *end = start + strlen(start); + struct device_node *np; + struct alias_prop *ap; + int id, len; + + /* Skip those we do not want to proceed */ + if (!strcmp(pp->name, "name") || + !strcmp(pp->name, "phandle") || + !strcmp(pp->name, "linux,phandle")) + continue; + + np = of_find_node_by_path(pp->value); + if (!np) + continue; + + /* walk the alias backwards to extract the id and work out + * the 'stem' string */ + while (isdigit(*(end-1)) && end > start) + end--; + len = end - start; + + if (kstrtoint(end, 10, &id) < 0) + continue; + + /* Allocate an alias_prop with enough space for the stem */ + ap = dt_alloc(sizeof(*ap) + len + 1, 4); + if (!ap) + continue; + ap->alias = start; + of_alias_add(ap, np, id, start, len); + } +} + +/** + * of_alias_get_id - Get alias id for the given device_node + * @np: Pointer to the given device_node + * @stem: Alias stem of the given device_node + * + * The function travels the lookup table to get alias id for the given + * device_node and alias stem. It returns the alias id if find it. + */ +int of_alias_get_id(struct device_node *np, const char *stem) +{ + struct alias_prop *app; + int id = -ENODEV; + + mutex_lock(&of_aliases_mutex); + list_for_each_entry(app, &aliases_lookup, link) { + if (strcmp(app->stem, stem) != 0) + continue; + + if (np == app->np) { + id = app->id; + break; + } + } + mutex_unlock(&of_aliases_mutex); + + return id; +} +EXPORT_SYMBOL_GPL(of_alias_get_id); |