/* * 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 #include #include #include #include #include #include #include #include #include #include "of_private.h" LIST_HEAD(aliases_lookup); struct device_node *of_root; EXPORT_SYMBOL(of_root); struct device_node *of_chosen; struct device_node *of_aliases; struct device_node *of_stdout; struct kset *of_kset; /* * Used to protect the of_aliases, to hold off addition of nodes to sysfs. * This mutex must be held whenever modifications are being made to the * device tree. The of_{attach,detach}_node() and * of_{add,remove,update}_property() helpers make sure this happens. */ DEFINE_MUTEX(of_mutex); /* use when traversing tree through the child, sibling, * or parent members of struct device_node. */ DEFINE_RAW_SPINLOCK(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); #ifdef CONFIG_NUMA int __weak of_node_to_nid(struct device_node *np) { return numa_node_id(); } #endif #ifndef CONFIG_OF_DYNAMIC static void of_node_release(struct kobject *kobj) { /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */ } #endif /* CONFIG_OF_DYNAMIC */ struct kobj_type of_node_ktype = { .release = of_node_release, }; static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t offset, size_t count) { struct property *pp = container_of(bin_attr, struct property, attr); return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); } static const char *safe_name(struct kobject *kobj, const char *orig_name) { const char *name = orig_name; struct kernfs_node *kn; int i = 0; /* don't be a hero. After 16 tries give up */ while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) { sysfs_put(kn); if (name != orig_name) kfree(name); name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); } if (name != orig_name) pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", kobject_name(kobj), name); return name; } int __of_add_property_sysfs(struct device_node *np, struct property *pp) { int rc; /* Important: Don't leak passwords */ bool secure = strncmp(pp->name, "security-", 9) == 0; if (!IS_ENABLED(CONFIG_SYSFS)) return 0; if (!of_kset || !of_node_is_attached(np)) return 0; sysfs_bin_attr_init(&pp->attr); pp->attr.attr.name = safe_name(&np->kobj, pp->name); pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO; pp->attr.size = secure ? 0 : pp->length; pp->attr.read = of_node_property_read; rc = sysfs_create_bin_file(&np->kobj, &pp->attr); WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name); return rc; } int __of_attach_node_sysfs(struct device_node *np) { const char *name; struct property *pp; int rc; if (!IS_ENABLED(CONFIG_SYSFS)) return 0; if (!of_kset) return 0; np->kobj.kset = of_kset; if (!np->parent) { /* Nodes without parents are new top level trees */ rc = kobject_add(&np->kobj, NULL, "%s", safe_name(&of_kset->kobj, "base")); } else { name = safe_name(&np->parent->kobj, kbasename(np->full_name)); if (!name || !name[0]) return -EINVAL; rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name); } if (rc) return rc; for_each_property_of_node(np, pp) __of_add_property_sysfs(np, pp); return 0; } static int __init of_init(void) { struct device_node *np; /* Create the kset, and register existing nodes */ mutex_lock(&of_mutex); of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj); if (!of_kset) { mutex_unlock(&of_mutex); return -ENOMEM; } for_each_of_allnodes(np) __of_attach_node_sysfs(np); mutex_unlock(&of_mutex); /* Symlink in /proc as required by userspace ABI */ if (of_root) proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); return 0; } core_initcall(of_init); static struct property *__of_find_property(const struct device_node *np, const char *name, int *lenp) { struct property *pp; if (!np) return NULL; for (pp = np->properties; pp; pp = pp->next) { if (of_prop_cmp(pp->name, name) == 0) { if (lenp) *lenp = pp->length; break; } } return pp; } struct property *of_find_property(const struct device_node *np, const char *name, int *lenp) { struct property *pp; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); pp = __of_find_property(np, name, lenp); raw_spin_unlock_irqrestore(&devtree_lock, flags); return pp; } EXPORT_SYMBOL(of_find_property); struct device_node *__of_find_all_nodes(struct device_node *prev) { struct device_node *np; if (!prev) { np = of_root; } else if (prev->child) { np = prev->child; } else { /* Walk back up looking for a sibling, or the end of the structure */ np = prev; while (np->parent && !np->sibling) np = np->parent; np = np->sibling; /* Might be null at the end of the tree */ } return np; } /** * 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); np = __of_find_all_nodes(prev); of_node_get(np); of_node_put(prev); raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; } /* * 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); /* * arch_match_cpu_phys_id - Match the given logical CPU and physical id * * @cpu: logical cpu index of a core/thread * @phys_id: physical identifier of a core/thread * * CPU logical to physical index mapping is architecture specific. * However this __weak function provides a default match of physical * id to logical cpu index. phys_id provided here is usually values read * from the device tree which must match the hardware internal registers. * * Returns true if the physical identifier and the logical cpu index * correspond to the same core/thread, false otherwise. */ bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id) { return (u32)phys_id == cpu; } /** * Checks if the given "prop_name" property holds the physical id of the * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not * NULL, local thread number within the core is returned in it. */ static bool __of_find_n_match_cpu_property(struct device_node *cpun, const char *prop_name, int cpu, unsigned int *thread) { const __be32 *cell; int ac, prop_len, tid; u64 hwid; ac = of_n_addr_cells(cpun); cell = of_get_property(cpun, prop_name, &prop_len); if (!cell || !ac) return false; prop_len /= sizeof(*cell) * ac; for (tid = 0; tid < prop_len; tid++) { hwid = of_read_number(cell, ac); if (arch_match_cpu_phys_id(cpu, hwid)) { if (thread) *thread = tid; return true; } cell += ac; } return false; } /* * arch_find_n_match_cpu_physical_id - See if the given device node is * for the cpu corresponding to logical cpu 'cpu'. Return true if so, * else false. If 'thread' is non-NULL, the local thread number within the * core is returned in it. */ bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun, int cpu, unsigned int *thread) { /* Check for non-standard "ibm,ppc-interrupt-server#s" property * for thread ids on PowerPC. If it doesn't exist fallback to * standard "reg" property. */ if (IS_ENABLED(CONFIG_PPC) && __of_find_n_match_cpu_property(cpun, "ibm,ppc-interrupt-server#s", cpu, thread)) return true; if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread)) return true; return false; } /** * of_get_cpu_node - Get device node associated with the given logical CPU * * @cpu: CPU number(logical index) for which device node is required * @thread: if not NULL, local thread number within the physical core is * returned * * The main purpose of this function is to retrieve the device node for the * given logical CPU index. It should be used to initialize the of_node in * cpu device. Once of_node in cpu device is populated, all the further * references can use that instead. * * CPU logical to physical index mapping is architecture specific and is built * before booting secondary cores. This function uses arch_match_cpu_phys_id * which can be overridden by architecture specific implementation. * * Returns a node pointer for the logical cpu if found, else NULL. */ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) { struct device_node *cpun; for_each_node_by_type(cpun, "cpu") { if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread)) return cpun; } return NULL; } EXPORT_SYMBOL(of_get_cpu_node); /** * __of_device_is_compatible() - Check if the node matches given constraints * @device: pointer to node * @compat: required compatible string, NULL or "" for any match * @type: required device_type value, NULL or "" for any match * @name: required node name, NULL or "" for any match * * Checks if the given @compat, @type and @name strings match the * properties of the given @device. A constraints can be skipped by * passing NULL or an empty string as the constraint. * * Returns 0 for no match, and a positive integer on match. The return * value is a relative score with larger values indicating better * matches. The score is weighted for the most specific compatible value * to get the highest score. Matching type is next, followed by matching * name. Practically speaking, this results in the following priority * order for matches: * * 1. specific compatible && type && name * 2. specific compatible && type * 3. specific compatible && name * 4. specific compatible * 5. general compatible && type && name * 6. general compatible && type * 7. general compatible && name * 8. general compatible * 9. type && name * 10. type * 11. name */ static int __of_device_is_compatible(const struct device_node *device, const char *compat, const char *type, const char *name) { struct property *prop; const char *cp; int index = 0, score = 0; /* Compatible match has highest priority */ if (compat && compat[0]) { prop = __of_find_property(device, "compatible", NULL); for (cp = of_prop_next_string(prop, NULL); cp; cp = of_prop_next_string(prop, cp), index++) { if (of_compat_cmp(cp, compat, strlen(compat)) == 0) { score = INT_MAX/2 - (index << 2); break; } } if (!score) return 0; } /* Matching type is better than matching name */ if (type && type[0]) { if (!device->type || of_node_cmp(type, device->type)) return 0; score += 2; } /* Matching name is a bit better than not */ if (name && name[0]) { if (!device->name || of_node_cmp(name, device->name)) return 0; score++; } return score; } /** 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) { unsigned long flags; int res; raw_spin_lock_irqsave(&devtree_lock, flags); res = __of_device_is_compatible(device, compat, NULL, NULL); raw_spin_unlock_irqrestore(&devtree_lock, flags); return res; } 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, with locks already held * * Returns 1 if the status property is absent or set to "okay" or "ok", * 0 otherwise */ static int __of_device_is_available(const struct device_node *device) { const char *status; int statlen; if (!device) return 0; 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; } /** * 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) { unsigned long flags; int res; raw_spin_lock_irqsave(&devtree_lock, flags); res = __of_device_is_available(device); raw_spin_unlock_irqrestore(&devtree_lock, flags); return res; } 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; unsigned long flags; if (!node) return NULL; raw_spin_lock_irqsave(&devtree_lock, flags); np = of_node_get(node->parent); raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; unsigned long flags; if (!node) return NULL; raw_spin_lock_irqsave(&devtree_lock, flags); parent = of_node_get(node->parent); of_node_put(node); raw_spin_unlock_irqrestore(&devtree_lock, flags); return parent; } EXPORT_SYMBOL(of_get_next_parent); static struct device_node *__of_get_next_child(const struct device_node *node, struct device_node *prev) { struct device_node *next; if (!node) return NULL; next = prev ? prev->sibling : node->child; for (; next; next = next->sibling) if (of_node_get(next)) break; of_node_put(prev); return next; } #define __for_each_child_of_node(parent, child) \ for (child = __of_get_next_child(parent, NULL); child != NULL; \ child = __of_get_next_child(parent, child)) /** * 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); next = __of_get_next_child(node, prev); raw_spin_unlock_irqrestore(&devtree_lock, flags); return next; } EXPORT_SYMBOL(of_get_next_child); /** * of_get_next_available_child - Find the next available child node * @node: parent node * @prev: previous child of the parent node, or NULL to get first * * This function is like of_get_next_child(), except that it * automatically skips any disabled nodes (i.e. status = "disabled"). */ struct device_node *of_get_next_available_child(const struct device_node *node, struct device_node *prev) { struct device_node *next; unsigned long flags; if (!node) return NULL; raw_spin_lock_irqsave(&devtree_lock, flags); next = prev ? prev->sibling : node->child; for (; next; next = next->sibling) { if (!__of_device_is_available(next)) continue; if (of_node_get(next)) break; } of_node_put(prev); raw_spin_unlock_irqrestore(&devtree_lock, flags); return next; } EXPORT_SYMBOL(of_get_next_available_child); /** * of_get_child_by_name - Find the child node by name for a given parent * @node: parent node * @name: child name to look for. * * This function looks for child node for given matching name * * Returns a node pointer if found, with refcount incremented, use * of_node_put() on it when done. * Returns NULL if node is not found. */ struct device_node *of_get_child_by_name(const struct device_node *node, const char *name) { struct device_node *child; for_each_child_of_node(node, child) if (child->name && (of_node_cmp(child->name, name) == 0)) break; return child; } EXPORT_SYMBOL(of_get_child_by_name); static struct device_node *__of_find_node_by_path(struct device_node *parent, const char *path) { struct device_node *child; int len = strchrnul(path, '/') - path; if (!len) return NULL; __for_each_child_of_node(parent, child) { const char *name = strrchr(child->full_name, '/'); if (WARN(!name, "malformed device_node %s\n", child->full_name)) continue; name++; if (strncmp(path, name, len) == 0 && (strlen(name) == len)) return child; } return NULL; } /** * of_find_node_by_path - Find a node matching a full OF path * @path: Either the full path to match, or if the path does not * start with '/', the name of a property of the /aliases * node (an alias). In the case of an alias, the node * matching the alias' value will be returned. * * Valid paths: * /foo/bar Full path * foo Valid alias * foo/bar Valid alias + relative path * * 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 = NULL; struct property *pp; unsigned long flags; if (strcmp(path, "/") == 0) return of_node_get(of_root); /* The path could begin with an alias */ if (*path != '/') { char *p = strchrnul(path, '/'); int len = p - path; /* of_aliases must not be NULL */ if (!of_aliases) return NULL; for_each_property_of_node(of_aliases, pp) { if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { np = of_find_node_by_path(pp->value); break; } } if (!np) return NULL; path = p; } /* Step down the tree matching path components */ raw_spin_lock_irqsave(&devtree_lock, flags); if (!np) np = of_node_get(of_root); while (np && *path == '/') { path++; /* Increment past '/' delimiter */ np = __of_find_node_by_path(np, path); path = strchrnul(path, '/'); } raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes_from(from, np) if (np->name && (of_node_cmp(np->name, name) == 0) && of_node_get(np)) break; of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes_from(from, np) if (np->type && (of_node_cmp(np->type, type) == 0) && of_node_get(np)) break; of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes_from(from, np) if (__of_device_is_compatible(np, compatible, type, NULL) && of_node_get(np)) break; of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); 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; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes_from(from, np) { for (pp = np->properties; pp; pp = pp->next) { if (of_prop_cmp(pp->name, prop_name) == 0) { of_node_get(np); goto out; } } } out: of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } EXPORT_SYMBOL(of_find_node_with_property); static const struct of_device_id *__of_match_node(const struct of_device_id *matches, const struct device_node *node) { const struct of_device_id *best_match = NULL; int score, best_score = 0; if (!matches) return NULL; for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) { score = __of_device_is_compatible(node, matches->compatible, matches->type, matches->name); if (score > best_score) { best_match = matches; best_score = score; } } return best_match; } /** * 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) { const struct of_device_id *match; unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); match = __of_match_node(matches, node); raw_spin_unlock_irqrestore(&devtree_lock, flags); return match; } EXPORT_SYMBOL(of_match_node); /** * of_find_matching_node_and_match - 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 * @match Updated to point at the matches entry which matched * * Returns a node pointer with refcount incremented, use * of_node_put() on it when done. */ struct device_node *of_find_matching_node_and_match(struct device_node *from, const struct of_device_id *matches, const struct of_device_id **match) { struct device_node *np; const struct of_device_id *m; unsigned long flags; if (match) *match = NULL; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes_from(from, np) { m = __of_match_node(matches, np); if (m && of_node_get(np)) { if (match) *match = m; break; } } of_node_put(from); raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } EXPORT_SYMBOL(of_find_matching_node_and_match); /** * 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; unsigned long flags; if (!handle) return NULL; raw_spin_lock_irqsave(&devtree_lock, flags); for_each_of_allnodes(np) if (np->phandle == handle) break; of_node_get(np); raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; } EXPORT_SYMBOL(of_find_node_by_phandle); /** * of_property_count_elems_of_size - Count the number of elements in a property * * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @elem_size: size of the individual element * * Search for a property in a device node and count the number of elements of * size elem_size in it. Returns number of elements on sucess, -EINVAL if the * property does not exist or its length does not match a multiple of elem_size * and -ENODATA if the property does not have a value. */ int of_property_count_elems_of_size(const struct device_node *np, const char *propname, int elem_size) { struct property *prop = of_find_property(np, propname, NULL); if (!prop) return -EINVAL; if (!prop->value) return -ENODATA; if (prop->length % elem_size != 0) { pr_err("size of %s in node %s is not a multiple of %d\n", propname, np->full_name, elem_size); return -EINVAL; } return prop->length / elem_size; } EXPORT_SYMBOL_GPL(of_property_count_elems_of_size); /** * of_find_property_value_of_size * * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @len: requested length of property value * * Search for a property in a device node and valid the requested size. * Returns the property value 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. * */ static void *of_find_property_value_of_size(const struct device_node *np, const char *propname, u32 len) { struct property *prop = of_find_property(np, propname, NULL); if (!prop) return ERR_PTR(-EINVAL); if (!prop->value) return ERR_PTR(-ENODATA); if (len > prop->length) return ERR_PTR(-EOVERFLOW); return prop->value; } /** * of_property_read_u32_index - Find and read a u32 from a multi-value 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 u32 in the list of values * @out_value: pointer to return value, modified only if no error. * * Search for a property in a device node and read nth 32-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 u32 value can be decoded. */ int of_property_read_u32_index(const struct device_node *np, const char *propname, u32 index, u32 *out_value) { const u32 *val = of_find_property_value_of_size(np, propname, ((index + 1) * sizeof(*out_value))); if (IS_ERR(val)) return PTR_ERR(val); *out_value = be32_to_cpup(((__be32 *)val) + index); return 0; } EXPORT_SYMBOL_GPL(of_property_read_u32_index); /** * of_property_read_u8_array - Find and read an array of u8 from a property. * * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_values: pointer to return value, modified only if return value is 0. * @sz: number of array elements to read * * Search for a property in a device node and read 8-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. * * dts entry of array should be like: * property = /bits/ 8 <0x50 0x60 0x70>; * * The out_values is modified only if a valid u8 value can be decoded. */ int of_property_read_u8_array(const struct device_node *np, const char *propname, u8 *out_values, size_t sz) { const u8 *val = of_find_property_value_of_size(np, propname, (sz * sizeof(*out_values))); if (IS_ERR(val)) return PTR_ERR(val); while (sz--) *out_values++ = *val++; return 0; } EXPORT_SYMBOL_GPL(of_property_read_u8_array); /** * of_property_read_u16_array - Find and read an array of u16 from a property. * * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_values: pointer to return value, modified only if return value is 0. * @sz: number of array elements to read * * Search for a property in a device node and read 16-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. * * dts entry of array should be like: * property = /bits/ 16 <0x5000 0x6000 0x7000>; * * The out_values is modified only if a valid u16 value can be decoded. */ int of_property_read_u16_array(const struct device_node *np, const char *propname, u16 *out_values, size_t sz) { const __be16 *val = of_find_property_value_of_size(np, propname, (sz * sizeof(*out_values))); if (IS_ERR(val)) return PTR_ERR(val); while (sz--) *out_values++ = be16_to_cpup(val++); return 0; } EXPORT_SYMBOL_GPL(of_property_read_u16_array); /** * 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_values: pointer to return value, modified only if return value is 0. * @sz: number of array elements to read * * 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_values 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) { const __be32 *val = of_find_property_value_of_size(np, propname, (sz * sizeof(*out_values))); if (IS_ERR(val)) return PTR_ERR(val); 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) { const __be32 *val = of_find_property_value_of_size(np, propname, sizeof(*out_value)); if (IS_ERR(val)) return PTR_ERR(val); *out_value = of_read_number(val, 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_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 = strnlen(p, end - 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_read_string_util() - Utility helper for parsing string properties * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_strs: output array of string pointers. * @sz: number of array elements to read. * @skip: Number of strings to skip over at beginning of list. * * Don't call this function directly. It is a utility helper for the * of_property_read_string*() family of functions. */ int of_property_read_string_helper(struct device_node *np, const char *propname, const char **out_strs, size_t sz, int skip) { struct property *prop = of_find_property(np, propname, NULL); int l = 0, i = 0; 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 && (!out_strs || i < skip + sz); i++, p += l) { l = strnlen(p, end - p) + 1; if (p + l > end) return -EILSEQ; if (out_strs && i >= skip) *out_strs++ = p; } i -= skip; return i <= 0 ? -ENODATA : i; } EXPORT_SYMBOL_GPL(of_property_read_string_helper); void of_print_phandle_args(const char *msg, const struct of_phandle_args *args) { int i; printk("%s %s", msg, of_node_full_name(args->np)); for (i = 0; i < args->args_count; i++) printk(i ? ",%08x" : ":%08x", args->args[i]); printk("\n"); } static int __of_parse_phandle_with_args(const struct device_node *np, const char *list_name, const char *cells_name, int cell_count, int index, struct of_phandle_args *out_args) { const __be32 *list, *list_end; int rc = 0, 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 -ENOENT; list_end = list + size / sizeof(*list); /* Loop over the phandles until all the requested entry is found */ while (list < list_end) { rc = -EINVAL; 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. * * This is not needed if the cell count is hard-coded * (i.e. cells_name not set, but cell_count is set), * except when we're going to return the found node * below. */ if (cells_name || cur_index == index) { node = of_find_node_by_phandle(phandle); if (!node) { pr_err("%s: could not find phandle\n", np->full_name); goto err; } } if (cells_name) { 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); goto err; } } else { count = cell_count; } /* * 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); goto err; } } /* * 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. */ rc = -ENOENT; if (cur_index == index) { if (!phandle) goto err; 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++); } else { of_node_put(node); } /* Found it! return success */ return 0; } of_node_put(node); node = NULL; list += count; cur_index++; } /* * Unlock node before returning result; will be one of: * -ENOENT : index is for empty phandle * -EINVAL : parsing error on data * [1..n] : Number of phandle (count mode; when index = -1) */ rc = index < 0 ? cur_index : -ENOENT; err: if (node) of_node_put(node); return rc; } /** * 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(const struct device_node *np, const char *phandle_name, int index) { struct of_phandle_args args; if (index < 0) return NULL; if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0, index, &args)) return NULL; return args.np; } 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(const struct device_node *np, const char *list_name, const char *cells_name, int index, struct of_phandle_args *out_args) { if (index < 0) return -EINVAL; return __of_parse_phandle_with_args(np, list_name, cells_name, 0, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_args); /** * of_parse_phandle_with_fixed_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 * @cell_count: number of argument cells following the phandle * @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 { * } * * phandle2: node2 { * } * * node3 { * list = <&phandle1 0 2 &phandle2 2 3>; * } * * To get a device_node of the `node2' node you may call this: * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args); */ int of_parse_phandle_with_fixed_args(const struct device_node *np, const char *list_name, int cell_count, int index, struct of_phandle_args *out_args) { if (index < 0) return -EINVAL; return __of_parse_phandle_with_args(np, list_name, NULL, cell_count, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_fixed_args); /** * of_count_phandle_with_args() - Find the number of phandles references in a property * @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 * * Returns the number of phandle + argument tuples within a property. It * is a typical pattern to encode a list of phandle and variable * arguments into a single property. The number of arguments is encoded * by a property in the phandle-target node. For example, a gpios * property would contain a list of GPIO specifies consisting of a * phandle and 1 or more arguments. The number of arguments are * determined by the #gpio-cells property in the node pointed to by the * phandle. */ int of_count_phandle_with_args(const struct device_node *np, const char *list_name, const char *cells_name) { return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1, NULL); } EXPORT_SYMBOL(of_count_phandle_with_args); /** * __of_add_property - Add a property to a node without lock operations */ int __of_add_property(struct device_node *np, struct property *prop) { struct property **next; prop->next = NULL; next = &np->properties; while (*next) { if (strcmp(prop->name, (*next)->name) == 0) /* duplicate ! don't insert it */ return -EEXIST; next = &(*next)->next; } *next = prop; return 0; } /** * of_add_property - Add a property to a node */ int of_add_property(struct device_node *np, struct property *prop) { unsigned long flags; int rc; mutex_lock(&of_mutex); raw_spin_lock_irqsave(&devtree_lock, flags); rc = __of_add_property(np, prop); raw_spin_unlock_irqrestore(&devtree_lock, flags); if (!rc) __of_add_property_sysfs(np, prop); mutex_unlock(&of_mutex); if (!rc) of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL); return rc; } int __of_remove_property(struct device_node *np, struct property *prop) { struct property **next; for (next = &np->properties; *next; next = &(*next)->next) { if (*next == prop) break; } if (*next == NULL) return -ENODEV; /* found the node */ *next = prop->next; prop->next = np->deadprops; np->deadprops = prop; return 0; } void __of_remove_property_sysfs(struct device_node *np, struct property *prop) { if (!IS_ENABLED(CONFIG_SYSFS)) return; /* at early boot, bail here and defer setup to of_init() */ if (of_kset && of_node_is_attached(np)) sysfs_remove_bin_file(&np->kobj, &prop->attr); } /** * of_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 of_remove_property(struct device_node *np, struct property *prop) { unsigned long flags; int rc; mutex_lock(&of_mutex); raw_spin_lock_irqsave(&devtree_lock, flags); rc = __of_remove_property(np, prop); raw_spin_unlock_irqrestore(&devtree_lock, flags); if (!rc) __of_remove_property_sysfs(np, prop); mutex_unlock(&of_mutex); if (!rc) of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL); return rc; } int __of_update_property(struct device_node *np, struct property *newprop, struct property **oldpropp) { struct property **next, *oldprop; for (next = &np->properties; *next; next = &(*next)->next) { if (of_prop_cmp((*next)->name, newprop->name) == 0) break; } *oldpropp = oldprop = *next; if (oldprop) { /* replace the node */ newprop->next = oldprop->next; *next = newprop; oldprop->next = np->deadprops; np->deadprops = oldprop; } else { /* new node */ newprop->next = NULL; *next = newprop; } return 0; } void __of_update_property_sysfs(struct device_node *np, struct property *newprop, struct property *oldprop) { if (!IS_ENABLED(CONFIG_SYSFS)) return; /* At early boot, bail out and defer setup to of_init() */ if (!of_kset) return; if (oldprop) sysfs_remove_bin_file(&np->kobj, &oldprop->attr); __of_add_property_sysfs(np, newprop); } /* * of_update_property - Update a property in a node, if the property does * not exist, add it. * * 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 of_update_property(struct device_node *np, struct property *newprop) { struct property *oldprop; unsigned long flags; int rc; if (!newprop->name) return -EINVAL; mutex_lock(&of_mutex); raw_spin_lock_irqsave(&devtree_lock, flags); rc = __of_update_property(np, newprop, &oldprop); raw_spin_unlock_irqrestore(&devtree_lock, flags); if (!rc) __of_update_property_sysfs(np, newprop, oldprop); mutex_unlock(&of_mutex); if (!rc) of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop); return rc; } 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, of_node_full_name(np)); } /** * 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_aliases = of_find_node_by_path("/aliases"); of_chosen = of_find_node_by_path("/chosen"); if (of_chosen == NULL) of_chosen = of_find_node_by_path("/chosen@0"); if (of_chosen) { /* linux,stdout-path and /aliases/stdout are for legacy compatibility */ const char *name = of_get_property(of_chosen, "stdout-path", NULL); if (!name) name = of_get_property(of_chosen, "linux,stdout-path", NULL); if (IS_ENABLED(CONFIG_PPC) && !name) name = of_get_property(of_aliases, "stdout", NULL); if (name) of_stdout = of_find_node_by_path(name); } 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; memset(ap, 0, sizeof(*ap) + len + 1); 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 the alias id for the given * device_node and alias stem. It returns the alias id if found. */ int of_alias_get_id(struct device_node *np, const char *stem) { struct alias_prop *app; int id = -ENODEV; mutex_lock(&of_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_mutex); return id; } EXPORT_SYMBOL_GPL(of_alias_get_id); const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur, u32 *pu) { const void *curv = cur; if (!prop) return NULL; if (!cur) { curv = prop->value; goto out_val; } curv += sizeof(*cur); if (curv >= prop->value + prop->length) return NULL; out_val: *pu = be32_to_cpup(curv); return curv; } EXPORT_SYMBOL_GPL(of_prop_next_u32); const char *of_prop_next_string(struct property *prop, const char *cur) { const void *curv = cur; if (!prop) return NULL; if (!cur) return prop->value; curv += strlen(cur) + 1; if (curv >= prop->value + prop->length) return NULL; return curv; } EXPORT_SYMBOL_GPL(of_prop_next_string); /** * of_console_check() - Test and setup console for DT setup * @dn - Pointer to device node * @name - Name to use for preferred console without index. ex. "ttyS" * @index - Index to use for preferred console. * * Check if the given device node matches the stdout-path property in the * /chosen node. If it does then register it as the preferred console and return * TRUE. Otherwise return FALSE. */ bool of_console_check(struct device_node *dn, char *name, int index) { if (!dn || dn != of_stdout || console_set_on_cmdline) return false; return !add_preferred_console(name, index, NULL); } EXPORT_SYMBOL_GPL(of_console_check); /** * of_find_next_cache_node - Find a node's subsidiary cache * @np: node of type "cpu" or "cache" * * Returns a node pointer with refcount incremented, use * of_node_put() on it when done. Caller should hold a reference * to np. */ struct device_node *of_find_next_cache_node(const struct device_node *np) { struct device_node *child; const phandle *handle; handle = of_get_property(np, "l2-cache", NULL); if (!handle) handle = of_get_property(np, "next-level-cache", NULL); if (handle) return of_find_node_by_phandle(be32_to_cpup(handle)); /* OF on pmac has nodes instead of properties named "l2-cache" * beneath CPU nodes. */ if (!strcmp(np->type, "cpu")) for_each_child_of_node(np, child) if (!strcmp(child->type, "cache")) return child; return NULL; } /** * of_graph_parse_endpoint() - parse common endpoint node properties * @node: pointer to endpoint device_node * @endpoint: pointer to the OF endpoint data structure * * The caller should hold a reference to @node. */ int of_graph_parse_endpoint(const struct device_node *node, struct of_endpoint *endpoint) { struct device_node *port_node = of_get_parent(node); WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n", __func__, node->full_name); memset(endpoint, 0, sizeof(*endpoint)); endpoint->local_node = node; /* * It doesn't matter whether the two calls below succeed. * If they don't then the default value 0 is used. */ of_property_read_u32(port_node, "reg", &endpoint->port); of_property_read_u32(node, "reg", &endpoint->id); of_node_put(port_node); return 0; } EXPORT_SYMBOL(of_graph_parse_endpoint); /** * of_graph_get_next_endpoint() - get next endpoint node * @parent: pointer to the parent device node * @prev: previous endpoint node, or NULL to get first * * Return: An 'endpoint' node pointer with refcount incremented. Refcount * of the passed @prev node is not decremented, the caller have to use * of_node_put() on it when done. */ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, struct device_node *prev) { struct device_node *endpoint; struct device_node *port; if (!parent) return NULL; /* * Start by locating the port node. If no previous endpoint is specified * search for the first port node, otherwise get the previous endpoint * parent port node. */ if (!prev) { struct device_node *node; node = of_get_child_by_name(parent, "ports"); if (node) parent = node; port = of_get_child_by_name(parent, "port"); of_node_put(node); if (!port) { pr_err("%s(): no port node found in %s\n", __func__, parent->full_name); return NULL; } } else { port = of_get_parent(prev); if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n", __func__, prev->full_name)) return NULL; /* * Avoid dropping prev node refcount to 0 when getting the next * child below. */ of_node_get(prev); } while (1) { /* * Now that we have a port node, get the next endpoint by * getting the next child. If the previous endpoint is NULL this * will return the first child. */ endpoint = of_get_next_child(port, prev); if (endpoint) { of_node_put(port); return endpoint; } /* No more endpoints under this port, try the next one. */ prev = NULL; do { port = of_get_next_child(parent, port); if (!port) return NULL; } while (of_node_cmp(port->name, "port")); } } EXPORT_SYMBOL(of_graph_get_next_endpoint); /** * of_graph_get_remote_port_parent() - get remote port's parent node * @node: pointer to a local endpoint device_node * * Return: Remote device node associated with remote endpoint node linked * to @node. Use of_node_put() on it when done. */ struct device_node *of_graph_get_remote_port_parent( const struct device_node *node) { struct device_node *np; unsigned int depth; /* Get remote endpoint node. */ np = of_parse_phandle(node, "remote-endpoint", 0); /* Walk 3 levels up only if there is 'ports' node. */ for (depth = 3; depth && np; depth--) { np = of_get_next_parent(np); if (depth == 2 && of_node_cmp(np->name, "ports")) break; } return np; } EXPORT_SYMBOL(of_graph_get_remote_port_parent); /** * of_graph_get_remote_port() - get remote port node * @node: pointer to a local endpoint device_node * * Return: Remote port node associated with remote endpoint node linked * to @node. Use of_node_put() on it when done. */ struct device_node *of_graph_get_remote_port(const struct device_node *node) { struct device_node *np; /* Get remote endpoint node. */ np = of_parse_phandle(node, "remote-endpoint", 0); if (!np) return NULL; return of_get_next_parent(np); } EXPORT_SYMBOL(of_graph_get_remote_port);