X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fof%2Fbase.c;h=ad8ac1a8af28689acc7198b22fe95a888d62e6a6;hb=9e3ee1c39c0cc71222f9980ccbf87fe072897eef;hp=723d80d704e063575d667b031c5251a14f6054e1;hpb=97e873e5c8ad8711ce4cca080cff4eb5d21b3aeb;p=linux-2.6 diff --git a/drivers/of/base.c b/drivers/of/base.c index 723d80d704..ad8ac1a8af 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -18,6 +18,14 @@ */ #include #include +#include + +struct device_node *allnodes; + +/* use when traversing tree through the allnext, child, sibling, + * or parent members of struct device_node. + */ +DEFINE_RWLOCK(devtree_lock); int of_n_addr_cells(struct device_node *np) { @@ -51,6 +59,29 @@ int of_n_size_cells(struct device_node *np) } EXPORT_SYMBOL(of_n_size_cells); +struct property *of_find_property(const struct device_node *np, + const char *name, + int *lenp) +{ + struct property *pp; + + if (!np) + return NULL; + + read_lock(&devtree_lock); + for (pp = np->properties; pp != 0; pp = pp->next) { + if (of_prop_cmp(pp->name, name) == 0) { + if (lenp != 0) + *lenp = pp->length; + break; + } + } + read_unlock(&devtree_lock); + + return pp; +} +EXPORT_SYMBOL(of_find_property); + /* * Find a property with a given name for a given node * and return the value. @@ -63,3 +94,382 @@ const void *of_get_property(const struct device_node *np, const char *name, return pp ? pp->value : NULL; } EXPORT_SYMBOL(of_get_property); + +/** 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) +{ + const char* cp; + int cplen, l; + + cp = of_get_property(device, "compatible", &cplen); + if (cp == NULL) + return 0; + while (cplen > 0) { + if (of_compat_cmp(cp, compat, strlen(compat)) == 0) + return 1; + l = strlen(cp) + 1; + cp += l; + cplen -= l; + } + + return 0; +} +EXPORT_SYMBOL(of_device_is_compatible); + +/** + * of_device_is_available - check if a device is available for use + * + * @device: Node to check for availability + * + * Returns 1 if the status property is absent or set to "okay" or "ok", + * 0 otherwise + */ +int of_device_is_available(const struct device_node *device) +{ + const char *status; + int statlen; + + status = of_get_property(device, "status", &statlen); + if (status == NULL) + return 1; + + if (statlen > 0) { + if (!strcmp(status, "okay") || !strcmp(status, "ok")) + return 1; + } + + return 0; +} +EXPORT_SYMBOL(of_device_is_available); + +/** + * of_get_parent - Get a node's parent if any + * @node: Node to get parent + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_parent(const struct device_node *node) +{ + struct device_node *np; + + if (!node) + return NULL; + + read_lock(&devtree_lock); + np = of_node_get(node->parent); + read_unlock(&devtree_lock); + 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; + + if (!node) + return NULL; + + read_lock(&devtree_lock); + parent = of_node_get(node->parent); + of_node_put(node); + read_unlock(&devtree_lock); + return parent; +} + +/** + * of_get_next_child - Iterate a node childs + * @node: parent node + * @prev: previous child of the parent node, or NULL to get first + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_next_child(const struct device_node *node, + struct device_node *prev) +{ + struct device_node *next; + + read_lock(&devtree_lock); + next = prev ? prev->sibling : node->child; + for (; next; next = next->sibling) + if (of_node_get(next)) + break; + of_node_put(prev); + read_unlock(&devtree_lock); + return next; +} +EXPORT_SYMBOL(of_get_next_child); + +/** + * of_find_node_by_path - Find a node matching a full OF path + * @path: The full path to match + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_path(const char *path) +{ + struct device_node *np = allnodes; + + read_lock(&devtree_lock); + for (; np; np = np->allnext) { + if (np->full_name && (of_node_cmp(np->full_name, path) == 0) + && of_node_get(np)) + break; + } + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_by_path); + +/** + * of_find_node_by_name - Find a node by its "name" property + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @name: The name string to match against + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_by_name(struct device_node *from, + const char *name) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) + if (np->name && (of_node_cmp(np->name, name) == 0) + && of_node_get(np)) + break; + of_node_put(from); + read_unlock(&devtree_lock); + 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; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) + if (np->type && (of_node_cmp(np->type, type) == 0) + && of_node_get(np)) + break; + of_node_put(from); + read_unlock(&devtree_lock); + 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; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + if (type + && !(np->type && (of_node_cmp(np->type, type) == 0))) + continue; + if (of_device_is_compatible(np, compatible) && of_node_get(np)) + break; + } + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_compatible_node); + +/** + * of_match_node - Tell if an device_node has a matching of_match structure + * @matches: array of of device match structures to search in + * @node: the of device structure to match against + * + * Low level utility function used by device matching. + */ +const struct of_device_id *of_match_node(const struct of_device_id *matches, + const struct device_node *node) +{ + while (matches->name[0] || matches->type[0] || matches->compatible[0]) { + int match = 1; + if (matches->name[0]) + match &= node->name + && !strcmp(matches->name, node->name); + if (matches->type[0]) + match &= node->type + && !strcmp(matches->type, node->type); + if (matches->compatible[0]) + match &= of_device_is_compatible(node, + matches->compatible); + if (match) + return matches; + matches++; + } + return NULL; +} +EXPORT_SYMBOL(of_match_node); + +/** + * of_find_matching_node - 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 + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_matching_node(struct device_node *from, + const struct of_device_id *matches) +{ + struct device_node *np; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + if (of_match_node(matches, np) && of_node_get(np)) + break; + } + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_matching_node); + +/** + * of_modalias_table: Table of explicit compatible ==> modalias mappings + * + * This table allows particulare compatible property values to be mapped + * to modalias strings. This is useful for busses which do not directly + * understand the OF device tree but are populated based on data contained + * within the device tree. SPI and I2C are the two current users of this + * table. + * + * In most cases, devices do not need to be listed in this table because + * the modalias value can be derived directly from the compatible table. + * However, if for any reason a value cannot be derived, then this table + * provides a method to override the implicit derivation. + * + * At the moment, a single table is used for all bus types because it is + * assumed that the data size is small and that the compatible values + * should already be distinct enough to differentiate between SPI, I2C + * and other devices. + */ +struct of_modalias_table { + char *of_device; + char *modalias; +}; +static struct of_modalias_table of_modalias_table[] = { + /* Empty for now; add entries as needed */ +}; + +/** + * 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 determine + * an appropriate modalias value for a particular device tree node. Three + * separate methods are used to derive a modalias value. + * + * First method is to lookup the compatible value in of_modalias_table. + * Second is to look for a "linux," entry in the compatible list + * and used that for modalias. Third is to strip off the manufacturer + * prefix from the first compatible entry and use the remainder as modalias + * + * This routine returns 0 on success + */ +int of_modalias_node(struct device_node *node, char *modalias, int len) +{ + int i, cplen; + const char *compatible; + const char *p; + + /* 1. search for exception list entry */ + for (i = 0; i < ARRAY_SIZE(of_modalias_table); i++) { + compatible = of_modalias_table[i].of_device; + if (!of_device_is_compatible(node, compatible)) + continue; + strlcpy(modalias, of_modalias_table[i].modalias, len); + return 0; + } + + compatible = of_get_property(node, "compatible", &cplen); + if (!compatible) + return -ENODEV; + + /* 2. search for linux, entry */ + p = compatible; + while (cplen > 0) { + if (!strncmp(p, "linux,", 6)) { + p += 6; + strlcpy(modalias, p, len); + return 0; + } + + i = strlen(p) + 1; + p += i; + cplen -= i; + } + + /* 3. take first compatible entry and strip manufacturer */ + p = strchr(compatible, ','); + if (!p) + return -ENODEV; + p++; + strlcpy(modalias, p, len); + return 0; +} +EXPORT_SYMBOL_GPL(of_modalias_node); +