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Diffstat (limited to 'kernel/drivers/of/base.c')
| -rw-r--r-- | kernel/drivers/of/base.c | 2276 |
1 files changed, 2276 insertions, 0 deletions
diff --git a/kernel/drivers/of/base.c b/kernel/drivers/of/base.c new file mode 100644 index 000000000..f0650265f --- /dev/null +++ b/kernel/drivers/of/base.c @@ -0,0 +1,2276 @@ +/* + * 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/console.h> +#include <linux/ctype.h> +#include <linux/cpu.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_graph.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/proc_fs.h> + +#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; +static const char *of_stdout_options; + +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; +} + +void __init of_core_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); + pr_err("devicetree: failed to register existing nodes\n"); + return; + } + 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"); +} + +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 a positive integer 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 true if the status property is absent or set to "okay" or "ok", + * false otherwise + */ +static bool __of_device_is_available(const struct device_node *device) +{ + const char *status; + int statlen; + + if (!device) + return false; + + status = __of_get_property(device, "status", &statlen); + if (status == NULL) + return true; + + if (statlen > 0) { + if (!strcmp(status, "okay") || !strcmp(status, "ok")) + return true; + } + + return false; +} + +/** + * of_device_is_available - check if a device is available for use + * + * @device: Node to check for availability + * + * Returns true if the status property is absent or set to "okay" or "ok", + * false otherwise + */ +bool of_device_is_available(const struct device_node *device) +{ + unsigned long flags; + bool 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_device_is_big_endian - check if a device has BE registers + * + * @device: Node to check for endianness + * + * Returns true if the device has a "big-endian" property, or if the kernel + * was compiled for BE *and* the device has a "native-endian" property. + * Returns false otherwise. + * + * Callers would nominally use ioread32be/iowrite32be if + * of_device_is_big_endian() == true, or readl/writel otherwise. + */ +bool of_device_is_big_endian(const struct device_node *device) +{ + if (of_property_read_bool(device, "big-endian")) + return true; + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && + of_property_read_bool(device, "native-endian")) + return true; + return false; +} +EXPORT_SYMBOL(of_device_is_big_endian); + +/** + * 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. Returns NULL when prev is the last child. Decrements the + * refcount of prev. + */ +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; + + len = strcspn(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_opts_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. + * @opts: Address of a pointer into which to store the start of + * an options string appended to the end of the path with + * a ':' separator. + * + * 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_opts_by_path(const char *path, const char **opts) +{ + struct device_node *np = NULL; + struct property *pp; + unsigned long flags; + const char *separator = strchr(path, ':'); + + if (opts) + *opts = separator ? separator + 1 : NULL; + + if (strcmp(path, "/") == 0) + return of_node_get(of_root); + + /* The path could begin with an alias */ + if (*path != '/') { + int len; + const char *p = separator; + + if (!p) + p = strchrnul(path, '/'); + 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, '/'); + if (separator && separator < path) + break; + } + raw_spin_unlock_irqrestore(&devtree_lock, flags); + return np; +} +EXPORT_SYMBOL(of_find_node_opts_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 a 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_u64_array - Find and read an array of 64 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 64-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 u64 value can be decoded. + */ +int of_property_read_u64_array(const struct device_node *np, + const char *propname, u64 *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++ = of_read_number(val, 2); + val += 2; + } + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u64_array); + +/** + * 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_helper() - 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->np + * 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->np + * 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 the 'aliases' node + * + * The function scans all the properties of the 'aliases' node and populates + * the global lookup table with the properties. It returns the + * number of alias properties found, or an error code in case of failure. + * + * @dt_alloc: An allocator that provides a virtual address to memory + * for storing 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_opts_by_path(name, &of_stdout_options); + } + + 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); + +/** + * of_alias_get_highest_id - Get highest alias id for the given stem + * @stem: Alias stem to be examined + * + * The function travels the lookup table to get the highest alias id for the + * given alias stem. It returns the alias id if found. + */ +int of_alias_get_highest_id(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 (app->id > id) + id = app->id; + } + mutex_unlock(&of_mutex); + + return id; +} +EXPORT_SYMBOL_GPL(of_alias_get_highest_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, + kstrdup(of_stdout_options, GFP_KERNEL)); +} +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_port_by_id() - get the port matching a given id + * @parent: pointer to the parent device node + * @id: id of the port + * + * Return: A 'port' node pointer with refcount incremented. The caller + * has to use of_node_put() on it when done. + */ +struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id) +{ + struct device_node *node, *port; + + node = of_get_child_by_name(parent, "ports"); + if (node) + parent = node; + + for_each_child_of_node(parent, port) { + u32 port_id = 0; + + if (of_node_cmp(port->name, "port") != 0) + continue; + of_property_read_u32(port, "reg", &port_id); + if (id == port_id) + break; + } + + of_node_put(node); + + return port; +} +EXPORT_SYMBOL(of_graph_get_port_by_id); + +/** + * 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 decremented. + */ +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; + } + + 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); |