Add new generic routines are provided for retrieving properties from
device description objects in the platform firmware in case there are
no struct device objects for them (either those objects have not been
created yet or they do not exist at all).
The following functions are provided:
fwnode_property_present()
fwnode_property_read_u8()
fwnode_property_read_u16()
fwnode_property_read_u32()
fwnode_property_read_u64()
fwnode_property_read_string()
fwnode_property_read_u8_array()
fwnode_property_read_u16_array()
fwnode_property_read_u32_array()
fwnode_property_read_u64_array()
fwnode_property_read_string_array()
in analogy with the corresponding functions for struct device added
previously. For all of them, the first argument is a pointer to struct
fwnode_handle (new type) that allows a device description object
(depending on what platform firmware interface is in use) to be
obtained.
Add a new macro device_for_each_child_node() for iterating over the
children of the device description object associated with a given
device and a new function device_get_child_node_count() returning the
number of a given device's child nodes.
The interface covers both ACPI and Device Trees.
Suggested-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a uniform interface by which device drivers can request device
properties from the platform firmware by providing a property name
and the corresponding data type. The purpose of it is to help to
write portable code that won't depend on any particular platform
firmware interface.
The following general helper functions are added:
device_property_present()
device_property_read_u8()
device_property_read_u16()
device_property_read_u32()
device_property_read_u64()
device_property_read_string()
device_property_read_u8_array()
device_property_read_u16_array()
device_property_read_u32_array()
device_property_read_u64_array()
device_property_read_string_array()
The first one allows the caller to check if the given property is
present. The next 5 of them allow single-valued properties of
various types to be retrieved in a uniform way. The remaining 5 are
for reading properties with multiple values (arrays of either numbers
or strings).
The interface covers both ACPI and Device Trees.
This change set includes material from Mika Westerberg and Aaron Lu.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
