diff options
| -rw-r--r-- | drivers/of/base.c | 84 | ||||
| -rw-r--r-- | include/linux/of.h | 18 |
2 files changed, 102 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 3ff22e3..f7239b3 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -662,6 +662,90 @@ int of_property_read_string(struct device_node *np, const char *propname, EXPORT_SYMBOL_GPL(of_property_read_string); /** + * of_property_read_string_index - Find and read a string from a multiple + * strings 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 string in the list of strings + * @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) in the list of strings + * contained in that property. + * 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_index(struct device_node *np, const char *propname, + int index, const char **output) +{ + struct property *prop = of_find_property(np, propname, NULL); + int i = 0; + size_t l = 0, total = 0; + const char *p; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) >= prop->length) + return -EILSEQ; + + p = prop->value; + + for (i = 0; total < prop->length; total += l, p += l) { + l = strlen(p) + 1; + if ((*p != 0) && (i++ == index)) { + *output = p; + return 0; + } + } + return -ENODATA; +} +EXPORT_SYMBOL_GPL(of_property_read_string_index); + + +/** + * of_property_count_strings - Find and return the number of strings from a + * multiple strings property. + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device tree node and retrieve the number of null + * terminated string contain in it. Returns the number of strings 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. + */ +int of_property_count_strings(struct device_node *np, const char *propname) +{ + struct property *prop = of_find_property(np, propname, NULL); + int i = 0; + size_t l = 0, total = 0; + const char *p; + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) >= prop->length) + return -EILSEQ; + + p = prop->value; + + for (i = 0; total < prop->length; total += l, p += l) { + l = strlen(p) + 1; + if (*p != 0) + i++; + } + return i; +} +EXPORT_SYMBOL_GPL(of_property_count_strings); + +/** * of_parse_phandle - Resolve a phandle property to a device_node pointer * @np: Pointer to device node holding phandle property * @phandle_name: Name of property holding a phandle value diff --git a/include/linux/of.h b/include/linux/of.h index 9180dc5..5dfe2d5 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -203,6 +203,11 @@ extern int of_property_read_u32_array(const struct device_node *np, extern int of_property_read_string(struct device_node *np, const char *propname, const char **out_string); +extern int of_property_read_string_index(struct device_node *np, + const char *propname, + int index, const char **output); +extern int of_property_count_strings(struct device_node *np, + const char *propname); extern int of_device_is_compatible(const struct device_node *device, const char *); extern int of_device_is_available(const struct device_node *device); @@ -256,6 +261,19 @@ static inline int of_property_read_string(struct device_node *np, return -ENOSYS; } +static inline int of_property_read_string_index(struct device_node *np, + const char *propname, int index, + const char **out_string) +{ + return -ENOSYS; +} + +static inline int of_property_count_strings(struct device_node *np, + const char *propname) +{ + return -ENOSYS; +} + static inline const void *of_get_property(const struct device_node *node, const char *name, int *lenp) |