diff options
| -rw-r--r-- | drivers/of/base.c | 33 | ||||
| -rw-r--r-- | include/linux/of.h | 9 |
2 files changed, 42 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 321d3ef0500..f6c89ed38db 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -746,6 +746,39 @@ struct device_node *of_find_node_by_phandle(phandle handle) EXPORT_SYMBOL(of_find_node_by_phandle); /** + * 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) +{ + struct property *prop = of_find_property(np, propname, NULL); + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (((index + 1) * sizeof(*out_value)) > prop->length) + return -EOVERFLOW; + + *out_value = be32_to_cpup(((__be32 *)prop->value) + index); + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u32_index); + +/** * of_property_read_u8_array - Find and read an array of u8 from a property. * * @np: device node from which the property value is to be read. diff --git a/include/linux/of.h b/include/linux/of.h index a0f12928494..c0747a44eaf 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -235,6 +235,9 @@ extern struct device_node *of_find_node_with_property( extern struct property *of_find_property(const struct device_node *np, const char *name, int *lenp); +extern int of_property_read_u32_index(const struct device_node *np, + const char *propname, + u32 index, u32 *out_value); extern int of_property_read_u8_array(const struct device_node *np, const char *propname, u8 *out_values, size_t sz); extern int of_property_read_u16_array(const struct device_node *np, @@ -394,6 +397,12 @@ static inline struct device_node *of_find_compatible_node( return NULL; } +static inline int of_property_read_u32_index(const struct device_node *np, + const char *propname, u32 index, u32 *out_value) +{ + return -ENOSYS; +} + static inline int of_property_read_u8_array(const struct device_node *np, const char *propname, u8 *out_values, size_t sz) { |