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Diffstat (limited to 'drivers/of/property.c')
| -rw-r--r-- | drivers/of/property.c | 806 |
1 files changed, 806 insertions, 0 deletions
diff --git a/drivers/of/property.c b/drivers/of/property.c new file mode 100644 index 000000000000..07c7c36c5ca8 --- /dev/null +++ b/drivers/of/property.c @@ -0,0 +1,806 @@ +/* + * drivers/of/property.c - Procedures for accessing and interpreting + * Devicetree properties and graphs. + * + * Initially created by copying procedures from drivers/of/base.c. This + * file contains the OF property as well as the OF graph interface + * functions. + * + * 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. + */ + +#define pr_fmt(fmt) "OF: " fmt + +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_graph.h> +#include <linux/string.h> + +#include "of_private.h" + +/** + * 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. + * @min: minimum allowed length of property value + * @max: maximum allowed length of property value (0 means unlimited) + * @len: if !=NULL, actual length is written to here + * + * 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 is too small or too large. + * + */ +static void *of_find_property_value_of_size(const struct device_node *np, + const char *propname, u32 min, u32 max, size_t *len) +{ + struct property *prop = of_find_property(np, propname, NULL); + + if (!prop) + return ERR_PTR(-EINVAL); + if (!prop->value) + return ERR_PTR(-ENODATA); + if (prop->length < min) + return ERR_PTR(-EOVERFLOW); + if (max && prop->length > max) + return ERR_PTR(-EOVERFLOW); + + if (len) + *len = prop->length; + + 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)), + 0, + NULL); + + 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_u64_index - Find and read a u64 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 u64 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 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_index(const struct device_node *np, + const char *propname, + u32 index, u64 *out_value) +{ + const u64 *val = of_find_property_value_of_size(np, propname, + ((index + 1) * sizeof(*out_value)), + 0, NULL); + + if (IS_ERR(val)) + return PTR_ERR(val); + + *out_value = be64_to_cpup(((__be64 *)val) + index); + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u64_index); + +/** + * of_property_read_variable_u8_array - Find and read an array of u8 from a + * property, with bounds on the minimum and maximum array size. + * + * @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_min: minimum number of array elements to read + * @sz_max: maximum number of array elements to read, if zero there is no + * upper limit on the number of elements in the dts entry but only + * sz_min will be read. + * + * Search for a property in a device node and read 8-bit value(s) from + * it. Returns number of elements read on success, -EINVAL if the property + * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW + * if the property data is smaller than sz_min or longer than sz_max. + * + * 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_variable_u8_array(const struct device_node *np, + const char *propname, u8 *out_values, + size_t sz_min, size_t sz_max) +{ + size_t sz, count; + const u8 *val = of_find_property_value_of_size(np, propname, + (sz_min * sizeof(*out_values)), + (sz_max * sizeof(*out_values)), + &sz); + + if (IS_ERR(val)) + return PTR_ERR(val); + + if (!sz_max) + sz = sz_min; + else + sz /= sizeof(*out_values); + + count = sz; + while (count--) + *out_values++ = *val++; + + return sz; +} +EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array); + +/** + * of_property_read_variable_u16_array - Find and read an array of u16 from a + * property, with bounds on the minimum and maximum array size. + * + * @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_min: minimum number of array elements to read + * @sz_max: maximum number of array elements to read, if zero there is no + * upper limit on the number of elements in the dts entry but only + * sz_min will be read. + * + * Search for a property in a device node and read 16-bit value(s) from + * it. Returns number of elements read on success, -EINVAL if the property + * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW + * if the property data is smaller than sz_min or longer than sz_max. + * + * 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_variable_u16_array(const struct device_node *np, + const char *propname, u16 *out_values, + size_t sz_min, size_t sz_max) +{ + size_t sz, count; + const __be16 *val = of_find_property_value_of_size(np, propname, + (sz_min * sizeof(*out_values)), + (sz_max * sizeof(*out_values)), + &sz); + + if (IS_ERR(val)) + return PTR_ERR(val); + + if (!sz_max) + sz = sz_min; + else + sz /= sizeof(*out_values); + + count = sz; + while (count--) + *out_values++ = be16_to_cpup(val++); + + return sz; +} +EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array); + +/** + * of_property_read_variable_u32_array - Find and read an array of 32 bit + * integers from a property, with bounds on the minimum and maximum array size. + * + * @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_min: minimum number of array elements to read + * @sz_max: maximum number of array elements to read, if zero there is no + * upper limit on the number of elements in the dts entry but only + * sz_min will be read. + * + * Search for a property in a device node and read 32-bit value(s) from + * it. Returns number of elements read on success, -EINVAL if the property + * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW + * if the property data is smaller than sz_min or longer than sz_max. + * + * The out_values is modified only if a valid u32 value can be decoded. + */ +int of_property_read_variable_u32_array(const struct device_node *np, + const char *propname, u32 *out_values, + size_t sz_min, size_t sz_max) +{ + size_t sz, count; + const __be32 *val = of_find_property_value_of_size(np, propname, + (sz_min * sizeof(*out_values)), + (sz_max * sizeof(*out_values)), + &sz); + + if (IS_ERR(val)) + return PTR_ERR(val); + + if (!sz_max) + sz = sz_min; + else + sz /= sizeof(*out_values); + + count = sz; + while (count--) + *out_values++ = be32_to_cpup(val++); + + return sz; +} +EXPORT_SYMBOL_GPL(of_property_read_variable_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), + 0, + NULL); + + 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_variable_u64_array - Find and read an array of 64 bit + * integers from a property, with bounds on the minimum and maximum array size. + * + * @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_min: minimum number of array elements to read + * @sz_max: maximum number of array elements to read, if zero there is no + * upper limit on the number of elements in the dts entry but only + * sz_min will be read. + * + * Search for a property in a device node and read 64-bit value(s) from + * it. Returns number of elements read on success, -EINVAL if the property + * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW + * if the property data is smaller than sz_min or longer than sz_max. + * + * The out_values is modified only if a valid u64 value can be decoded. + */ +int of_property_read_variable_u64_array(const struct device_node *np, + const char *propname, u64 *out_values, + size_t sz_min, size_t sz_max) +{ + size_t sz, count; + const __be32 *val = of_find_property_value_of_size(np, propname, + (sz_min * sizeof(*out_values)), + (sz_max * sizeof(*out_values)), + &sz); + + if (IS_ERR(val)) + return PTR_ERR(val); + + if (!sz_max) + sz = sz_min; + else + sz /= sizeof(*out_values); + + count = sz; + while (count--) { + *out_values++ = of_read_number(val, 2); + val += 2; + } + + return sz; +} +EXPORT_SYMBOL_GPL(of_property_read_variable_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(const struct device_node *np, const char *propname, + const char **out_string) +{ + const 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(const struct device_node *np, const char *propname, + const char *string) +{ + const 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(const struct device_node *np, + const char *propname, const char **out_strs, + size_t sz, int skip) +{ + const 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); + +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_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("graph: no port node found in %s\n", + 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_endpoint_by_regs() - get endpoint node of specific identifiers + * @parent: pointer to the parent device node + * @port_reg: identifier (value of reg property) of the parent port node + * @reg: identifier (value of reg property) of the endpoint node + * + * Return: An 'endpoint' node pointer which is identified by reg and at the same + * is the child of a port node identified by port_reg. reg and port_reg are + * ignored when they are -1. + */ +struct device_node *of_graph_get_endpoint_by_regs( + const struct device_node *parent, int port_reg, int reg) +{ + struct of_endpoint endpoint; + struct device_node *node = NULL; + + for_each_endpoint_of_node(parent, node) { + of_graph_parse_endpoint(node, &endpoint); + if (((port_reg == -1) || (endpoint.port == port_reg)) && + ((reg == -1) || (endpoint.id == reg))) + return node; + } + + return NULL; +} +EXPORT_SYMBOL(of_graph_get_endpoint_by_regs); + +/** + * of_graph_get_remote_endpoint() - get remote endpoint node + * @node: pointer to a local endpoint device_node + * + * Return: Remote endpoint node associated with remote endpoint node linked + * to @node. Use of_node_put() on it when done. + */ +struct device_node *of_graph_get_remote_endpoint(const struct device_node *node) +{ + /* Get remote endpoint node. */ + return of_parse_phandle(node, "remote-endpoint", 0); +} +EXPORT_SYMBOL(of_graph_get_remote_endpoint); + +/** + * of_graph_get_port_parent() - get port's parent node + * @node: pointer to a local endpoint device_node + * + * Return: device node associated with endpoint node linked + * to @node. Use of_node_put() on it when done. + */ +struct device_node *of_graph_get_port_parent(struct device_node *node) +{ + unsigned int depth; + + /* Walk 3 levels up only if there is 'ports' node. */ + for (depth = 3; depth && node; depth--) { + node = of_get_next_parent(node); + if (depth == 2 && of_node_cmp(node->name, "ports")) + break; + } + return node; +} +EXPORT_SYMBOL(of_graph_get_port_parent); + +/** + * 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; + + /* Get remote endpoint node. */ + np = of_graph_get_remote_endpoint(node); + + return of_graph_get_port_parent(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_graph_get_remote_endpoint(node); + if (!np) + return NULL; + return of_get_next_parent(np); +} +EXPORT_SYMBOL(of_graph_get_remote_port); + +int of_graph_get_endpoint_count(const struct device_node *np) +{ + struct device_node *endpoint; + int num = 0; + + for_each_endpoint_of_node(np, endpoint) + num++; + + return num; +} +EXPORT_SYMBOL(of_graph_get_endpoint_count); + +/** + * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint + * @node: pointer to parent device_node containing graph port/endpoint + * @port: identifier (value of reg property) of the parent port node + * @endpoint: identifier (value of reg property) of the endpoint 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_node(const struct device_node *node, + u32 port, u32 endpoint) +{ + struct device_node *endpoint_node, *remote; + + endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint); + if (!endpoint_node) { + pr_debug("no valid endpoint (%d, %d) for node %s\n", + port, endpoint, node->full_name); + return NULL; + } + + remote = of_graph_get_remote_port_parent(endpoint_node); + of_node_put(endpoint_node); + if (!remote) { + pr_debug("no valid remote node\n"); + return NULL; + } + + if (!of_device_is_available(remote)) { + pr_debug("not available for remote node\n"); + return NULL; + } + + return remote; +} +EXPORT_SYMBOL(of_graph_get_remote_node); |