diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 458 |
1 files changed, 389 insertions, 69 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 89e888a78899..32e969d95319 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -21,8 +21,10 @@ #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" @@ -35,6 +37,12 @@ struct device_node *of_chosen; struct device_node *of_aliases; static struct device_node *of_stdout; +static struct kset *of_kset; + +/* + * Used to protect the of_aliases; but also overloaded to hold off addition of + * nodes to sysfs + */ DEFINE_MUTEX(of_aliases_mutex); /* use when traversing tree through the allnext, child, sibling, @@ -92,14 +100,14 @@ int __weak of_node_to_nid(struct device_node *np) struct device_node *of_node_get(struct device_node *node) { if (node) - kref_get(&node->kref); + kobject_get(&node->kobj); return node; } EXPORT_SYMBOL(of_node_get); -static inline struct device_node *kref_to_device_node(struct kref *kref) +static inline struct device_node *kobj_to_device_node(struct kobject *kobj) { - return container_of(kref, struct device_node, kref); + return container_of(kobj, struct device_node, kobj); } /** @@ -109,16 +117,15 @@ static inline struct device_node *kref_to_device_node(struct kref *kref) * In of_node_put() this function is passed to kref_put() * as the destructor. */ -static void of_node_release(struct kref *kref) +static void of_node_release(struct kobject *kobj) { - struct device_node *node = kref_to_device_node(kref); + struct device_node *node = kobj_to_device_node(kobj); struct property *prop = node->properties; /* We should never be releasing nodes that haven't been detached. */ if (!of_node_check_flag(node, OF_DETACHED)) { pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); dump_stack(); - kref_init(&node->kref); return; } @@ -151,11 +158,154 @@ static void of_node_release(struct kref *kref) void of_node_put(struct device_node *node) { if (node) - kref_put(&node->kref, of_node_release); + kobject_put(&node->kobj); } EXPORT_SYMBOL(of_node_put); +#else +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; +} + +static 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; + + 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; +} + +static int __of_node_add(struct device_node *np) +{ + const char *name; + struct property *pp; + int rc; + + np->kobj.kset = of_kset; + if (!np->parent) { + /* Nodes without parents are new top level trees */ + rc = kobject_add(&np->kobj, NULL, 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; +} + +int of_node_add(struct device_node *np) +{ + int rc = 0; + + BUG_ON(!of_node_is_initialized(np)); + + /* + * Grab the mutex here so that in a race condition between of_init() and + * of_node_add(), node addition will still be consistent. + */ + mutex_lock(&of_aliases_mutex); + if (of_kset) + rc = __of_node_add(np); + else + /* This scenario may be perfectly valid, but report it anyway */ + pr_info("of_node_add(%s) before of_init()\n", np->full_name); + mutex_unlock(&of_aliases_mutex); + return rc; +} + +#if defined(CONFIG_OF_DYNAMIC) +static void of_node_remove(struct device_node *np) +{ + struct property *pp; + + BUG_ON(!of_node_is_initialized(np)); + + /* only remove properties if on sysfs */ + if (of_node_is_attached(np)) { + for_each_property_of_node(np, pp) + sysfs_remove_bin_file(&np->kobj, &pp->attr); + kobject_del(&np->kobj); + } + + /* finally remove the kobj_init ref */ + of_node_put(np); +} +#endif + +static int __init of_init(void) +{ + struct device_node *np; + + /* Create the kset, and register existing nodes */ + mutex_lock(&of_aliases_mutex); + of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj); + if (!of_kset) { + mutex_unlock(&of_aliases_mutex); + return -ENOMEM; + } + for_each_of_allnodes(np) + __of_node_add(np); + mutex_unlock(&of_aliases_mutex); + + /* Symlink in /proc as required by userspace ABI */ + if (of_allnodes) + 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) { @@ -904,6 +1054,38 @@ struct device_node *of_find_node_by_phandle(phandle handle) 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. @@ -1498,6 +1680,10 @@ static int of_property_notify(int action, struct device_node *np, { struct of_prop_reconfig pr; + /* only call notifiers if the node is attached */ + if (!of_node_is_attached(np)) + return 0; + pr.dn = np; pr.prop = prop; return of_reconfig_notify(action, &pr); @@ -1511,11 +1697,31 @@ static int of_property_notify(int action, struct device_node *np, #endif /** + * __of_add_property - Add a property to a node without lock operations + */ +static 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) { - struct property **next; unsigned long flags; int rc; @@ -1523,27 +1729,16 @@ int of_add_property(struct device_node *np, struct property *prop) if (rc) return rc; - prop->next = NULL; raw_spin_lock_irqsave(&devtree_lock, flags); - next = &np->properties; - while (*next) { - if (strcmp(prop->name, (*next)->name) == 0) { - /* duplicate ! don't insert it */ - raw_spin_unlock_irqrestore(&devtree_lock, flags); - return -1; - } - next = &(*next)->next; - } - *next = prop; + rc = __of_add_property(np, prop); raw_spin_unlock_irqrestore(&devtree_lock, flags); + if (rc) + return rc; -#ifdef CONFIG_PROC_DEVICETREE - /* try to add to proc as well if it was initialized */ - if (np->pde) - proc_device_tree_add_prop(np->pde, prop); -#endif /* CONFIG_PROC_DEVICETREE */ + if (of_node_is_attached(np)) + __of_add_property_sysfs(np, prop); - return 0; + return rc; } /** @@ -1583,11 +1778,11 @@ int of_remove_property(struct device_node *np, struct property *prop) if (!found) return -ENODEV; -#ifdef CONFIG_PROC_DEVICETREE - /* try to remove the proc node as well */ - if (np->pde) - proc_device_tree_remove_prop(np->pde, prop); -#endif /* CONFIG_PROC_DEVICETREE */ + /* at early boot, bail hear and defer setup to of_init() */ + if (!of_kset) + return 0; + + sysfs_remove_bin_file(&np->kobj, &prop->attr); return 0; } @@ -1633,15 +1828,16 @@ int of_update_property(struct device_node *np, struct property *newprop) next = &(*next)->next; } raw_spin_unlock_irqrestore(&devtree_lock, flags); - if (!found) return -ENODEV; -#ifdef CONFIG_PROC_DEVICETREE - /* try to add to proc as well if it was initialized */ - if (np->pde) - proc_device_tree_update_prop(np->pde, newprop, oldprop); -#endif /* CONFIG_PROC_DEVICETREE */ + /* At early boot, bail out and defer setup to of_init() */ + if (!of_kset) + return found ? 0 : -ENODEV; + + /* Update the sysfs attribute */ + sysfs_remove_bin_file(&np->kobj, &oldprop->attr); + __of_add_property_sysfs(np, newprop); return 0; } @@ -1677,22 +1873,6 @@ int of_reconfig_notify(unsigned long action, void *p) return notifier_to_errno(rc); } -#ifdef CONFIG_PROC_DEVICETREE -static void of_add_proc_dt_entry(struct device_node *dn) -{ - struct proc_dir_entry *ent; - - ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde); - if (ent) - proc_device_tree_add_node(dn, ent); -} -#else -static void of_add_proc_dt_entry(struct device_node *dn) -{ - return; -} -#endif - /** * of_attach_node - Plug a device node into the tree and global list. */ @@ -1710,24 +1890,13 @@ int of_attach_node(struct device_node *np) np->allnext = of_allnodes; np->parent->child = np; of_allnodes = np; + of_node_clear_flag(np, OF_DETACHED); raw_spin_unlock_irqrestore(&devtree_lock, flags); - of_add_proc_dt_entry(np); + of_node_add(np); return 0; } -#ifdef CONFIG_PROC_DEVICETREE -static void of_remove_proc_dt_entry(struct device_node *dn) -{ - proc_remove(dn->pde); -} -#else -static void of_remove_proc_dt_entry(struct device_node *dn) -{ - return; -} -#endif - /** * of_detach_node - "Unplug" a node from the device tree. * @@ -1783,7 +1952,7 @@ int of_detach_node(struct device_node *np) of_node_set_flag(np, OF_DETACHED); raw_spin_unlock_irqrestore(&devtree_lock, flags); - of_remove_proc_dt_entry(np); + of_node_remove(np); return rc; } #endif /* defined(CONFIG_OF_DYNAMIC) */ @@ -1819,9 +1988,9 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) of_chosen = of_find_node_by_path("/chosen@0"); if (of_chosen) { - const char *name; - - name = of_get_property(of_chosen, "linux,stdout-path", NULL); + const char *name = of_get_property(of_chosen, "stdout-path", NULL); + if (!name) + name = of_get_property(of_chosen, "linux,stdout-path", NULL); if (name) of_stdout = of_find_node_by_path(name); } @@ -1982,3 +2151,154 @@ struct device_node *of_find_next_cache_node(const struct device_node *np) 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); |