diff options
| -rw-r--r-- | drivers/of/base.c | 121 | ||||
| -rw-r--r-- | drivers/of/fdt.c | 6 | ||||
| -rw-r--r-- | drivers/of/pdt.c | 8 | ||||
| -rw-r--r-- | include/linux/of.h | 7 |
4 files changed, 138 insertions, 4 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 3ff22e32b602..8abde58cbe82 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -17,14 +17,39 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ +#include <linux/ctype.h> #include <linux/module.h> #include <linux/of.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/proc_fs.h> +/** + * struct alias_prop - Alias property in 'aliases' node + * @link: List node to link the structure in aliases_lookup list + * @alias: Alias property name + * @np: Pointer to device_node that the alias stands for + * @id: Index value from end of alias name + * @stem: Alias string without the index + * + * The structure represents one alias property of 'aliases' node as + * an entry in aliases_lookup list. + */ +struct alias_prop { + struct list_head link; + const char *alias; + struct device_node *np; + int id; + char stem[0]; +}; + +static LIST_HEAD(aliases_lookup); + struct device_node *allnodes; struct device_node *of_chosen; +struct device_node *of_aliases; + +static DEFINE_MUTEX(of_aliases_mutex); /* use when traversing tree through the allnext, child, sibling, * or parent members of struct device_node. @@ -988,3 +1013,99 @@ out_unlock: } #endif /* defined(CONFIG_OF_DYNAMIC) */ +static void of_alias_add(struct alias_prop *ap, struct device_node *np, + int id, const char *stem, int stem_len) +{ + ap->np = np; + ap->id = id; + strncpy(ap->stem, stem, stem_len); + ap->stem[stem_len] = 0; + list_add_tail(&ap->link, &aliases_lookup); + pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n", + ap->alias, ap->stem, ap->id, np ? np->full_name : NULL); +} + +/** + * of_alias_scan - Scan all properties of 'aliases' node + * + * The function scans all the properties of 'aliases' node and populate + * the the global lookup table with the properties. It returns the + * number of alias_prop found, or error code in error case. + * + * @dt_alloc: An allocator that provides a virtual address to memory + * for the resulting tree + */ +void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) +{ + struct property *pp; + + of_chosen = of_find_node_by_path("/chosen"); + if (of_chosen == NULL) + of_chosen = of_find_node_by_path("/chosen@0"); + of_aliases = of_find_node_by_path("/aliases"); + if (!of_aliases) + return; + + for_each_property(pp, of_aliases->properties) { + const char *start = pp->name; + const char *end = start + strlen(start); + struct device_node *np; + struct alias_prop *ap; + int id, len; + + /* Skip those we do not want to proceed */ + if (!strcmp(pp->name, "name") || + !strcmp(pp->name, "phandle") || + !strcmp(pp->name, "linux,phandle")) + continue; + + np = of_find_node_by_path(pp->value); + if (!np) + continue; + + /* walk the alias backwards to extract the id and work out + * the 'stem' string */ + while (isdigit(*(end-1)) && end > start) + end--; + len = end - start; + + if (kstrtoint(end, 10, &id) < 0) + continue; + + /* Allocate an alias_prop with enough space for the stem */ + ap = dt_alloc(sizeof(*ap) + len + 1, 4); + if (!ap) + continue; + ap->alias = start; + of_alias_add(ap, np, id, start, len); + } +} + +/** + * of_alias_get_id - Get alias id for the given device_node + * @np: Pointer to the given device_node + * @stem: Alias stem of the given device_node + * + * The function travels the lookup table to get alias id for the given + * device_node and alias stem. It returns the alias id if find it. + */ +int of_alias_get_id(struct device_node *np, const char *stem) +{ + struct alias_prop *app; + int id = -ENODEV; + + mutex_lock(&of_aliases_mutex); + list_for_each_entry(app, &aliases_lookup, link) { + if (strcmp(app->stem, stem) != 0) + continue; + + if (np == app->np) { + id = app->id; + break; + } + } + mutex_unlock(&of_aliases_mutex); + + return id; +} +EXPORT_SYMBOL_GPL(of_alias_get_id); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 65200af29c52..aeec35bc3789 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -707,10 +707,8 @@ void __init unflatten_device_tree(void) __unflatten_device_tree(initial_boot_params, &allnodes, early_init_dt_alloc_memory_arch); - /* Get pointer to OF "/chosen" node for use everywhere */ - of_chosen = of_find_node_by_path("/chosen"); - if (of_chosen == NULL) - of_chosen = of_find_node_by_path("/chosen@0"); + /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */ + of_alias_scan(early_init_dt_alloc_memory_arch); } #endif /* CONFIG_OF_EARLY_FLATTREE */ diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c index 4d87b5dc9284..bc5b3990f6ed 100644 --- a/drivers/of/pdt.c +++ b/drivers/of/pdt.c @@ -229,6 +229,11 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent, return ret; } +static void *kernel_tree_alloc(u64 size, u64 align) +{ + return prom_early_alloc(size); +} + void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) { struct device_node **nextp; @@ -245,4 +250,7 @@ void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) nextp = &allnodes->allnext; allnodes->child = of_pdt_build_tree(allnodes, of_pdt_prom_ops->getchild(allnodes->phandle), &nextp); + + /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */ + of_alias_scan(kernel_tree_alloc); } diff --git a/include/linux/of.h b/include/linux/of.h index 9180dc5cb00b..8b6383d876ca 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -68,6 +68,7 @@ struct device_node { /* Pointer for first entry in chain of all nodes. */ extern struct device_node *allnodes; extern struct device_node *of_chosen; +extern struct device_node *of_aliases; extern rwlock_t devtree_lock; static inline bool of_have_populated_dt(void) @@ -209,6 +210,9 @@ extern int of_device_is_available(const struct device_node *device); extern const void *of_get_property(const struct device_node *node, const char *name, int *lenp); +#define for_each_property(pp, properties) \ + for (pp = properties; pp != NULL; pp = pp->next) + extern int of_n_addr_cells(struct device_node *np); extern int of_n_size_cells(struct device_node *np); extern const struct of_device_id *of_match_node( @@ -221,6 +225,9 @@ extern int of_parse_phandles_with_args(struct device_node *np, const char *list_name, const char *cells_name, int index, struct device_node **out_node, const void **out_args); +extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); +extern int of_alias_get_id(struct device_node *np, const char *stem); + extern int of_machine_is_compatible(const char *compat); extern int prom_add_property(struct device_node* np, struct property* prop); |
