diff options
Diffstat (limited to 'drivers/base/swnode.c')
| -rw-r--r-- | drivers/base/swnode.c | 1116 |
1 files changed, 1116 insertions, 0 deletions
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c new file mode 100644 index 0000000000..079bd14bde --- /dev/null +++ b/drivers/base/swnode.c @@ -0,0 +1,1116 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Software nodes for the firmware node framework. + * + * Copyright (C) 2018, Intel Corporation + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com> + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/property.h> +#include <linux/slab.h> + +#include "base.h" + +struct swnode { + struct kobject kobj; + struct fwnode_handle fwnode; + const struct software_node *node; + int id; + + /* hierarchy */ + struct ida child_ids; + struct list_head entry; + struct list_head children; + struct swnode *parent; + + unsigned int allocated:1; + unsigned int managed:1; +}; + +static DEFINE_IDA(swnode_root_ids); +static struct kset *swnode_kset; + +#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj) + +static const struct fwnode_operations software_node_ops; + +bool is_software_node(const struct fwnode_handle *fwnode) +{ + return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops; +} +EXPORT_SYMBOL_GPL(is_software_node); + +#define to_swnode(__fwnode) \ + ({ \ + typeof(__fwnode) __to_swnode_fwnode = __fwnode; \ + \ + is_software_node(__to_swnode_fwnode) ? \ + container_of(__to_swnode_fwnode, \ + struct swnode, fwnode) : NULL; \ + }) + +static inline struct swnode *dev_to_swnode(struct device *dev) +{ + struct fwnode_handle *fwnode = dev_fwnode(dev); + + if (!fwnode) + return NULL; + + if (!is_software_node(fwnode)) + fwnode = fwnode->secondary; + + return to_swnode(fwnode); +} + +static struct swnode * +software_node_to_swnode(const struct software_node *node) +{ + struct swnode *swnode = NULL; + struct kobject *k; + + if (!node) + return NULL; + + spin_lock(&swnode_kset->list_lock); + + list_for_each_entry(k, &swnode_kset->list, entry) { + swnode = kobj_to_swnode(k); + if (swnode->node == node) + break; + swnode = NULL; + } + + spin_unlock(&swnode_kset->list_lock); + + return swnode; +} + +const struct software_node *to_software_node(const struct fwnode_handle *fwnode) +{ + const struct swnode *swnode = to_swnode(fwnode); + + return swnode ? swnode->node : NULL; +} +EXPORT_SYMBOL_GPL(to_software_node); + +struct fwnode_handle *software_node_fwnode(const struct software_node *node) +{ + struct swnode *swnode = software_node_to_swnode(node); + + return swnode ? &swnode->fwnode : NULL; +} +EXPORT_SYMBOL_GPL(software_node_fwnode); + +/* -------------------------------------------------------------------------- */ +/* property_entry processing */ + +static const struct property_entry * +property_entry_get(const struct property_entry *prop, const char *name) +{ + if (!prop) + return NULL; + + for (; prop->name; prop++) + if (!strcmp(name, prop->name)) + return prop; + + return NULL; +} + +static const void *property_get_pointer(const struct property_entry *prop) +{ + if (!prop->length) + return NULL; + + return prop->is_inline ? &prop->value : prop->pointer; +} + +static const void *property_entry_find(const struct property_entry *props, + const char *propname, size_t length) +{ + const struct property_entry *prop; + const void *pointer; + + prop = property_entry_get(props, propname); + if (!prop) + return ERR_PTR(-EINVAL); + pointer = property_get_pointer(prop); + if (!pointer) + return ERR_PTR(-ENODATA); + if (length > prop->length) + return ERR_PTR(-EOVERFLOW); + return pointer; +} + +static int +property_entry_count_elems_of_size(const struct property_entry *props, + const char *propname, size_t length) +{ + const struct property_entry *prop; + + prop = property_entry_get(props, propname); + if (!prop) + return -EINVAL; + + return prop->length / length; +} + +static int property_entry_read_int_array(const struct property_entry *props, + const char *name, + unsigned int elem_size, void *val, + size_t nval) +{ + const void *pointer; + size_t length; + + if (!val) + return property_entry_count_elems_of_size(props, name, + elem_size); + + if (!is_power_of_2(elem_size) || elem_size > sizeof(u64)) + return -ENXIO; + + length = nval * elem_size; + + pointer = property_entry_find(props, name, length); + if (IS_ERR(pointer)) + return PTR_ERR(pointer); + + memcpy(val, pointer, length); + return 0; +} + +static int property_entry_read_string_array(const struct property_entry *props, + const char *propname, + const char **strings, size_t nval) +{ + const void *pointer; + size_t length; + int array_len; + + /* Find out the array length. */ + array_len = property_entry_count_elems_of_size(props, propname, + sizeof(const char *)); + if (array_len < 0) + return array_len; + + /* Return how many there are if strings is NULL. */ + if (!strings) + return array_len; + + array_len = min_t(size_t, nval, array_len); + length = array_len * sizeof(*strings); + + pointer = property_entry_find(props, propname, length); + if (IS_ERR(pointer)) + return PTR_ERR(pointer); + + memcpy(strings, pointer, length); + + return array_len; +} + +static void property_entry_free_data(const struct property_entry *p) +{ + const char * const *src_str; + size_t i, nval; + + if (p->type == DEV_PROP_STRING) { + src_str = property_get_pointer(p); + nval = p->length / sizeof(*src_str); + for (i = 0; i < nval; i++) + kfree(src_str[i]); + } + + if (!p->is_inline) + kfree(p->pointer); + + kfree(p->name); +} + +static bool property_copy_string_array(const char **dst_ptr, + const char * const *src_ptr, + size_t nval) +{ + int i; + + for (i = 0; i < nval; i++) { + dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL); + if (!dst_ptr[i] && src_ptr[i]) { + while (--i >= 0) + kfree(dst_ptr[i]); + return false; + } + } + + return true; +} + +static int property_entry_copy_data(struct property_entry *dst, + const struct property_entry *src) +{ + const void *pointer = property_get_pointer(src); + void *dst_ptr; + size_t nval; + + /* + * Properties with no data should not be marked as stored + * out of line. + */ + if (!src->is_inline && !src->length) + return -ENODATA; + + /* + * Reference properties are never stored inline as + * they are too big. + */ + if (src->type == DEV_PROP_REF && src->is_inline) + return -EINVAL; + + if (src->length <= sizeof(dst->value)) { + dst_ptr = &dst->value; + dst->is_inline = true; + } else { + dst_ptr = kmalloc(src->length, GFP_KERNEL); + if (!dst_ptr) + return -ENOMEM; + dst->pointer = dst_ptr; + } + + if (src->type == DEV_PROP_STRING) { + nval = src->length / sizeof(const char *); + if (!property_copy_string_array(dst_ptr, pointer, nval)) { + if (!dst->is_inline) + kfree(dst->pointer); + return -ENOMEM; + } + } else { + memcpy(dst_ptr, pointer, src->length); + } + + dst->length = src->length; + dst->type = src->type; + dst->name = kstrdup(src->name, GFP_KERNEL); + if (!dst->name) { + property_entry_free_data(dst); + return -ENOMEM; + } + + return 0; +} + +/** + * property_entries_dup - duplicate array of properties + * @properties: array of properties to copy + * + * This function creates a deep copy of the given NULL-terminated array + * of property entries. + */ +struct property_entry * +property_entries_dup(const struct property_entry *properties) +{ + struct property_entry *p; + int i, n = 0; + int ret; + + if (!properties) + return NULL; + + while (properties[n].name) + n++; + + p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL); + if (!p) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < n; i++) { + ret = property_entry_copy_data(&p[i], &properties[i]); + if (ret) { + while (--i >= 0) + property_entry_free_data(&p[i]); + kfree(p); + return ERR_PTR(ret); + } + } + + return p; +} +EXPORT_SYMBOL_GPL(property_entries_dup); + +/** + * property_entries_free - free previously allocated array of properties + * @properties: array of properties to destroy + * + * This function frees given NULL-terminated array of property entries, + * along with their data. + */ +void property_entries_free(const struct property_entry *properties) +{ + const struct property_entry *p; + + if (!properties) + return; + + for (p = properties; p->name; p++) + property_entry_free_data(p); + + kfree(properties); +} +EXPORT_SYMBOL_GPL(property_entries_free); + +/* -------------------------------------------------------------------------- */ +/* fwnode operations */ + +static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + + kobject_get(&swnode->kobj); + + return &swnode->fwnode; +} + +static void software_node_put(struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + + kobject_put(&swnode->kobj); +} + +static bool software_node_property_present(const struct fwnode_handle *fwnode, + const char *propname) +{ + struct swnode *swnode = to_swnode(fwnode); + + return !!property_entry_get(swnode->node->properties, propname); +} + +static int software_node_read_int_array(const struct fwnode_handle *fwnode, + const char *propname, + unsigned int elem_size, void *val, + size_t nval) +{ + struct swnode *swnode = to_swnode(fwnode); + + return property_entry_read_int_array(swnode->node->properties, propname, + elem_size, val, nval); +} + +static int software_node_read_string_array(const struct fwnode_handle *fwnode, + const char *propname, + const char **val, size_t nval) +{ + struct swnode *swnode = to_swnode(fwnode); + + return property_entry_read_string_array(swnode->node->properties, + propname, val, nval); +} + +static const char * +software_node_get_name(const struct fwnode_handle *fwnode) +{ + const struct swnode *swnode = to_swnode(fwnode); + + return kobject_name(&swnode->kobj); +} + +static const char * +software_node_get_name_prefix(const struct fwnode_handle *fwnode) +{ + struct fwnode_handle *parent; + const char *prefix; + + parent = fwnode_get_parent(fwnode); + if (!parent) + return ""; + + /* Figure out the prefix from the parents. */ + while (is_software_node(parent)) + parent = fwnode_get_next_parent(parent); + + prefix = fwnode_get_name_prefix(parent); + fwnode_handle_put(parent); + + /* Guess something if prefix was NULL. */ + return prefix ?: "/"; +} + +static struct fwnode_handle * +software_node_get_parent(const struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + + if (!swnode || !swnode->parent) + return NULL; + + return fwnode_handle_get(&swnode->parent->fwnode); +} + +static struct fwnode_handle * +software_node_get_next_child(const struct fwnode_handle *fwnode, + struct fwnode_handle *child) +{ + struct swnode *p = to_swnode(fwnode); + struct swnode *c = to_swnode(child); + + if (!p || list_empty(&p->children) || + (c && list_is_last(&c->entry, &p->children))) { + fwnode_handle_put(child); + return NULL; + } + + if (c) + c = list_next_entry(c, entry); + else + c = list_first_entry(&p->children, struct swnode, entry); + + fwnode_handle_put(child); + return fwnode_handle_get(&c->fwnode); +} + +static struct fwnode_handle * +software_node_get_named_child_node(const struct fwnode_handle *fwnode, + const char *childname) +{ + struct swnode *swnode = to_swnode(fwnode); + struct swnode *child; + + if (!swnode || list_empty(&swnode->children)) + return NULL; + + list_for_each_entry(child, &swnode->children, entry) { + if (!strcmp(childname, kobject_name(&child->kobj))) { + kobject_get(&child->kobj); + return &child->fwnode; + } + } + return NULL; +} + +static int +software_node_get_reference_args(const struct fwnode_handle *fwnode, + const char *propname, const char *nargs_prop, + unsigned int nargs, unsigned int index, + struct fwnode_reference_args *args) +{ + struct swnode *swnode = to_swnode(fwnode); + const struct software_node_ref_args *ref_array; + const struct software_node_ref_args *ref; + const struct property_entry *prop; + struct fwnode_handle *refnode; + u32 nargs_prop_val; + int error; + int i; + + prop = property_entry_get(swnode->node->properties, propname); + if (!prop) + return -ENOENT; + + if (prop->type != DEV_PROP_REF) + return -EINVAL; + + /* + * We expect that references are never stored inline, even + * single ones, as they are too big. + */ + if (prop->is_inline) + return -EINVAL; + + if (index * sizeof(*ref) >= prop->length) + return -ENOENT; + + ref_array = prop->pointer; + ref = &ref_array[index]; + + refnode = software_node_fwnode(ref->node); + if (!refnode) + return -ENOENT; + + if (nargs_prop) { + error = property_entry_read_int_array(ref->node->properties, + nargs_prop, sizeof(u32), + &nargs_prop_val, 1); + if (error) + return error; + + nargs = nargs_prop_val; + } + + if (nargs > NR_FWNODE_REFERENCE_ARGS) + return -EINVAL; + + if (!args) + return 0; + + args->fwnode = software_node_get(refnode); + args->nargs = nargs; + + for (i = 0; i < nargs; i++) + args->args[i] = ref->args[i]; + + return 0; +} + +static struct fwnode_handle * +swnode_graph_find_next_port(const struct fwnode_handle *parent, + struct fwnode_handle *port) +{ + struct fwnode_handle *old = port; + + while ((port = software_node_get_next_child(parent, old))) { + /* + * fwnode ports have naming style "port@", so we search for any + * children that follow that convention. + */ + if (!strncmp(to_swnode(port)->node->name, "port@", + strlen("port@"))) + return port; + old = port; + } + + return NULL; +} + +static struct fwnode_handle * +software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode, + struct fwnode_handle *endpoint) +{ + struct swnode *swnode = to_swnode(fwnode); + struct fwnode_handle *parent; + struct fwnode_handle *port; + + if (!swnode) + return NULL; + + if (endpoint) { + port = software_node_get_parent(endpoint); + parent = software_node_get_parent(port); + } else { + parent = software_node_get_named_child_node(fwnode, "ports"); + if (!parent) + parent = software_node_get(&swnode->fwnode); + + port = swnode_graph_find_next_port(parent, NULL); + } + + for (; port; port = swnode_graph_find_next_port(parent, port)) { + endpoint = software_node_get_next_child(port, endpoint); + if (endpoint) { + fwnode_handle_put(port); + break; + } + } + + fwnode_handle_put(parent); + + return endpoint; +} + +static struct fwnode_handle * +software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + const struct software_node_ref_args *ref; + const struct property_entry *prop; + + if (!swnode) + return NULL; + + prop = property_entry_get(swnode->node->properties, "remote-endpoint"); + if (!prop || prop->type != DEV_PROP_REF || prop->is_inline) + return NULL; + + ref = prop->pointer; + + return software_node_get(software_node_fwnode(ref[0].node)); +} + +static struct fwnode_handle * +software_node_graph_get_port_parent(struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + + swnode = swnode->parent; + if (swnode && !strcmp(swnode->node->name, "ports")) + swnode = swnode->parent; + + return swnode ? software_node_get(&swnode->fwnode) : NULL; +} + +static int +software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode, + struct fwnode_endpoint *endpoint) +{ + struct swnode *swnode = to_swnode(fwnode); + const char *parent_name = swnode->parent->node->name; + int ret; + + if (strlen("port@") >= strlen(parent_name) || + strncmp(parent_name, "port@", strlen("port@"))) + return -EINVAL; + + /* Ports have naming style "port@n", we need to select the n */ + ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port); + if (ret) + return ret; + + endpoint->id = swnode->id; + endpoint->local_fwnode = fwnode; + + return 0; +} + +static const struct fwnode_operations software_node_ops = { + .get = software_node_get, + .put = software_node_put, + .property_present = software_node_property_present, + .property_read_int_array = software_node_read_int_array, + .property_read_string_array = software_node_read_string_array, + .get_name = software_node_get_name, + .get_name_prefix = software_node_get_name_prefix, + .get_parent = software_node_get_parent, + .get_next_child_node = software_node_get_next_child, + .get_named_child_node = software_node_get_named_child_node, + .get_reference_args = software_node_get_reference_args, + .graph_get_next_endpoint = software_node_graph_get_next_endpoint, + .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint, + .graph_get_port_parent = software_node_graph_get_port_parent, + .graph_parse_endpoint = software_node_graph_parse_endpoint, +}; + +/* -------------------------------------------------------------------------- */ + +/** + * software_node_find_by_name - Find software node by name + * @parent: Parent of the software node + * @name: Name of the software node + * + * The function will find a node that is child of @parent and that is named + * @name. If no node is found, the function returns NULL. + * + * NOTE: you will need to drop the reference with fwnode_handle_put() after use. + */ +const struct software_node * +software_node_find_by_name(const struct software_node *parent, const char *name) +{ + struct swnode *swnode = NULL; + struct kobject *k; + + if (!name) + return NULL; + + spin_lock(&swnode_kset->list_lock); + + list_for_each_entry(k, &swnode_kset->list, entry) { + swnode = kobj_to_swnode(k); + if (parent == swnode->node->parent && swnode->node->name && + !strcmp(name, swnode->node->name)) { + kobject_get(&swnode->kobj); + break; + } + swnode = NULL; + } + + spin_unlock(&swnode_kset->list_lock); + + return swnode ? swnode->node : NULL; +} +EXPORT_SYMBOL_GPL(software_node_find_by_name); + +static struct software_node *software_node_alloc(const struct property_entry *properties) +{ + struct property_entry *props; + struct software_node *node; + + props = property_entries_dup(properties); + if (IS_ERR(props)) + return ERR_CAST(props); + + node = kzalloc(sizeof(*node), GFP_KERNEL); + if (!node) { + property_entries_free(props); + return ERR_PTR(-ENOMEM); + } + + node->properties = props; + + return node; +} + +static void software_node_free(const struct software_node *node) +{ + property_entries_free(node->properties); + kfree(node); +} + +static void software_node_release(struct kobject *kobj) +{ + struct swnode *swnode = kobj_to_swnode(kobj); + + if (swnode->parent) { + ida_simple_remove(&swnode->parent->child_ids, swnode->id); + list_del(&swnode->entry); + } else { + ida_simple_remove(&swnode_root_ids, swnode->id); + } + + if (swnode->allocated) + software_node_free(swnode->node); + + ida_destroy(&swnode->child_ids); + kfree(swnode); +} + +static const struct kobj_type software_node_type = { + .release = software_node_release, + .sysfs_ops = &kobj_sysfs_ops, +}; + +static struct fwnode_handle * +swnode_register(const struct software_node *node, struct swnode *parent, + unsigned int allocated) +{ + struct swnode *swnode; + int ret; + + swnode = kzalloc(sizeof(*swnode), GFP_KERNEL); + if (!swnode) + return ERR_PTR(-ENOMEM); + + ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids, + 0, 0, GFP_KERNEL); + if (ret < 0) { + kfree(swnode); + return ERR_PTR(ret); + } + + swnode->id = ret; + swnode->node = node; + swnode->parent = parent; + swnode->kobj.kset = swnode_kset; + fwnode_init(&swnode->fwnode, &software_node_ops); + + ida_init(&swnode->child_ids); + INIT_LIST_HEAD(&swnode->entry); + INIT_LIST_HEAD(&swnode->children); + + if (node->name) + ret = kobject_init_and_add(&swnode->kobj, &software_node_type, + parent ? &parent->kobj : NULL, + "%s", node->name); + else + ret = kobject_init_and_add(&swnode->kobj, &software_node_type, + parent ? &parent->kobj : NULL, + "node%d", swnode->id); + if (ret) { + kobject_put(&swnode->kobj); + return ERR_PTR(ret); + } + + /* + * Assign the flag only in the successful case, so + * the above kobject_put() won't mess up with properties. + */ + swnode->allocated = allocated; + + if (parent) + list_add_tail(&swnode->entry, &parent->children); + + kobject_uevent(&swnode->kobj, KOBJ_ADD); + return &swnode->fwnode; +} + +/** + * software_node_register_node_group - Register a group of software nodes + * @node_group: NULL terminated array of software node pointers to be registered + * + * Register multiple software nodes at once. If any node in the array + * has its .parent pointer set (which can only be to another software_node), + * then its parent **must** have been registered before it is; either outside + * of this function or by ordering the array such that parent comes before + * child. + */ +int software_node_register_node_group(const struct software_node **node_group) +{ + unsigned int i; + int ret; + + if (!node_group) + return 0; + + for (i = 0; node_group[i]; i++) { + ret = software_node_register(node_group[i]); + if (ret) { + software_node_unregister_node_group(node_group); + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(software_node_register_node_group); + +/** + * software_node_unregister_node_group - Unregister a group of software nodes + * @node_group: NULL terminated array of software node pointers to be unregistered + * + * Unregister multiple software nodes at once. If parent pointers are set up + * in any of the software nodes then the array **must** be ordered such that + * parents come before their children. + * + * NOTE: If you are uncertain whether the array is ordered such that + * parents will be unregistered before their children, it is wiser to + * remove the nodes individually, in the correct order (child before + * parent). + */ +void software_node_unregister_node_group( + const struct software_node **node_group) +{ + unsigned int i = 0; + + if (!node_group) + return; + + while (node_group[i]) + i++; + + while (i--) + software_node_unregister(node_group[i]); +} +EXPORT_SYMBOL_GPL(software_node_unregister_node_group); + +/** + * software_node_register - Register static software node + * @node: The software node to be registered + */ +int software_node_register(const struct software_node *node) +{ + struct swnode *parent = software_node_to_swnode(node->parent); + + if (software_node_to_swnode(node)) + return -EEXIST; + + if (node->parent && !parent) + return -EINVAL; + + return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0)); +} +EXPORT_SYMBOL_GPL(software_node_register); + +/** + * software_node_unregister - Unregister static software node + * @node: The software node to be unregistered + */ +void software_node_unregister(const struct software_node *node) +{ + struct swnode *swnode; + + swnode = software_node_to_swnode(node); + if (swnode) + fwnode_remove_software_node(&swnode->fwnode); +} +EXPORT_SYMBOL_GPL(software_node_unregister); + +struct fwnode_handle * +fwnode_create_software_node(const struct property_entry *properties, + const struct fwnode_handle *parent) +{ + struct fwnode_handle *fwnode; + struct software_node *node; + struct swnode *p; + + if (IS_ERR(parent)) + return ERR_CAST(parent); + + p = to_swnode(parent); + if (parent && !p) + return ERR_PTR(-EINVAL); + + node = software_node_alloc(properties); + if (IS_ERR(node)) + return ERR_CAST(node); + + node->parent = p ? p->node : NULL; + + fwnode = swnode_register(node, p, 1); + if (IS_ERR(fwnode)) + software_node_free(node); + + return fwnode; +} +EXPORT_SYMBOL_GPL(fwnode_create_software_node); + +void fwnode_remove_software_node(struct fwnode_handle *fwnode) +{ + struct swnode *swnode = to_swnode(fwnode); + + if (!swnode) + return; + + kobject_put(&swnode->kobj); +} +EXPORT_SYMBOL_GPL(fwnode_remove_software_node); + +/** + * device_add_software_node - Assign software node to a device + * @dev: The device the software node is meant for. + * @node: The software node. + * + * This function will make @node the secondary firmware node pointer of @dev. If + * @dev has no primary node, then @node will become the primary node. The + * function will register @node automatically if it wasn't already registered. + */ +int device_add_software_node(struct device *dev, const struct software_node *node) +{ + struct swnode *swnode; + int ret; + + /* Only one software node per device. */ + if (dev_to_swnode(dev)) + return -EBUSY; + + swnode = software_node_to_swnode(node); + if (swnode) { + kobject_get(&swnode->kobj); + } else { + ret = software_node_register(node); + if (ret) + return ret; + + swnode = software_node_to_swnode(node); + } + + set_secondary_fwnode(dev, &swnode->fwnode); + + /* + * If the device has been fully registered by the time this function is + * called, software_node_notify() must be called separately so that the + * symlinks get created and the reference count of the node is kept in + * balance. + */ + if (device_is_registered(dev)) + software_node_notify(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(device_add_software_node); + +/** + * device_remove_software_node - Remove device's software node + * @dev: The device with the software node. + * + * This function will unregister the software node of @dev. + */ +void device_remove_software_node(struct device *dev) +{ + struct swnode *swnode; + + swnode = dev_to_swnode(dev); + if (!swnode) + return; + + if (device_is_registered(dev)) + software_node_notify_remove(dev); + + set_secondary_fwnode(dev, NULL); + kobject_put(&swnode->kobj); +} +EXPORT_SYMBOL_GPL(device_remove_software_node); + +/** + * device_create_managed_software_node - Create a software node for a device + * @dev: The device the software node is assigned to. + * @properties: Device properties for the software node. + * @parent: Parent of the software node. + * + * Creates a software node as a managed resource for @dev, which means the + * lifetime of the newly created software node is tied to the lifetime of @dev. + * Software nodes created with this function should not be reused or shared + * because of that. The function takes a deep copy of @properties for the + * software node. + * + * Since the new software node is assigned directly to @dev, and since it should + * not be shared, it is not returned to the caller. The function returns 0 on + * success, and errno in case of an error. + */ +int device_create_managed_software_node(struct device *dev, + const struct property_entry *properties, + const struct software_node *parent) +{ + struct fwnode_handle *p = software_node_fwnode(parent); + struct fwnode_handle *fwnode; + + if (parent && !p) + return -EINVAL; + + fwnode = fwnode_create_software_node(properties, p); + if (IS_ERR(fwnode)) + return PTR_ERR(fwnode); + + to_swnode(fwnode)->managed = true; + set_secondary_fwnode(dev, fwnode); + + if (device_is_registered(dev)) + software_node_notify(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(device_create_managed_software_node); + +void software_node_notify(struct device *dev) +{ + struct swnode *swnode; + int ret; + + swnode = dev_to_swnode(dev); + if (!swnode) + return; + + ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node"); + if (ret) + return; + + ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev)); + if (ret) { + sysfs_remove_link(&dev->kobj, "software_node"); + return; + } + + kobject_get(&swnode->kobj); +} + +void software_node_notify_remove(struct device *dev) +{ + struct swnode *swnode; + + swnode = dev_to_swnode(dev); + if (!swnode) + return; + + sysfs_remove_link(&swnode->kobj, dev_name(dev)); + sysfs_remove_link(&dev->kobj, "software_node"); + kobject_put(&swnode->kobj); + + if (swnode->managed) { + set_secondary_fwnode(dev, NULL); + kobject_put(&swnode->kobj); + } +} + +static int __init software_node_init(void) +{ + swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj); + if (!swnode_kset) + return -ENOMEM; + return 0; +} +postcore_initcall(software_node_init); + +static void __exit software_node_exit(void) +{ + ida_destroy(&swnode_root_ids); + kset_unregister(swnode_kset); +} +__exitcall(software_node_exit); |