Sometimes it is useful to be able to extract an index of certain string value from an array of strings. A typical use case is to give a name to a DMA channel, PWM, clock and so on.
Provide an implementation using unified device property accessors that follows of_property_match_string() but works for all supported fwnodes. Signed-off-by: Mika Westerberg <[email protected]> --- drivers/base/property.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/property.h | 4 +++ 2 files changed, 72 insertions(+) diff --git a/drivers/base/property.c b/drivers/base/property.c index 2d75366c61e0..a128db413f01 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -287,6 +287,28 @@ int device_property_read_string(struct device *dev, const char *propname, } EXPORT_SYMBOL_GPL(device_property_read_string); +/** + * device_property_match_string - find a string in an array and return index + * @dev: Device to get the property of + * @propname: Name of the property holding the array + * @string: String to look for + * + * Find a given string in a string array and if it is found return the + * index back. + * + * Return: %0 if the property was found (success), + * %-EINVAL if given arguments are not valid, + * %-ENODATA if the property does not have a value, + * %-EPROTO if the property is not an array of strings, + * %-ENXIO if no suitable firmware interface is present. + */ +int device_property_match_string(struct device *dev, const char *propname, + const char *string) +{ + return fwnode_property_match_string(dev_fwnode(dev), propname, string); +} +EXPORT_SYMBOL_GPL(device_property_match_string); + #define OF_DEV_PROP_READ_ARRAY(node, propname, type, val, nval) \ (val) ? of_property_read_##type##_array((node), (propname), (val), (nval)) \ : of_property_count_elems_of_size((node), (propname), sizeof(type)) @@ -479,6 +501,52 @@ int fwnode_property_read_string(struct fwnode_handle *fwnode, EXPORT_SYMBOL_GPL(fwnode_property_read_string); /** + * fwnode_property_match_string - find a string in an array and return index + * @fwnode: Firmware node to get the property of + * @propname: Name of the property holding the array + * @string: String to look for + * + * Find a given string in a string array and if it is found return the + * index back. + * + * Return: %0 if the property was found (success), + * %-EINVAL if given arguments are not valid, + * %-ENODATA if the property does not have a value, + * %-EPROTO if the property is not an array of strings, + * %-ENXIO if no suitable firmware interface is present. + */ +int fwnode_property_match_string(struct fwnode_handle *fwnode, + const char *propname, const char *string) +{ + const char **values; + int nval, ret, i; + + nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0); + if (nval < 0) + return nval; + + values = kcalloc(nval, sizeof(*values), GFP_KERNEL); + if (!values) + return -ENOMEM; + + ret = fwnode_property_read_string_array(fwnode, propname, values, nval); + if (ret < 0) + goto out; + + ret = -ENODATA; + for (i = 0; i < nval; i++) { + if (!strcmp(values[i], string)) { + ret = i; + break; + } + } +out: + kfree(values); + return ret; +} +EXPORT_SYMBOL_GPL(fwnode_property_match_string); + +/** * device_get_next_child_node - Return the next child node handle for a device * @dev: Device to find the next child node for. * @child: Handle to one of the device's child nodes or a null handle. diff --git a/include/linux/property.h b/include/linux/property.h index a59c6ee566c2..463de52fe891 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -40,6 +40,8 @@ int device_property_read_string_array(struct device *dev, const char *propname, const char **val, size_t nval); int device_property_read_string(struct device *dev, const char *propname, const char **val); +int device_property_match_string(struct device *dev, + const char *propname, const char *string); bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname); int fwnode_property_read_u8_array(struct fwnode_handle *fwnode, @@ -59,6 +61,8 @@ int fwnode_property_read_string_array(struct fwnode_handle *fwnode, size_t nval); int fwnode_property_read_string(struct fwnode_handle *fwnode, const char *propname, const char **val); +int fwnode_property_match_string(struct fwnode_handle *fwnode, + const char *propname, const char *string); struct fwnode_handle *device_get_next_child_node(struct device *dev, struct fwnode_handle *child); -- 2.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
