Driver core: Unified device properties interface for platform firmware
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>
diff --git a/include/linux/of.h b/include/linux/of.h
index 29f0adc..ce9f6a2 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -23,6 +23,7 @@
#include <linux/spinlock.h>
#include <linux/topology.h>
#include <linux/notifier.h>
+#include <linux/property.h>
#include <asm/byteorder.h>
#include <asm/errno.h>
@@ -263,6 +264,10 @@
size_t sz);
extern int of_property_read_u64(const struct device_node *np,
const char *propname, u64 *out_value);
+extern int of_property_read_u64_array(const struct device_node *np,
+ const char *propname,
+ u64 *out_values,
+ size_t sz);
extern int of_property_read_string(struct device_node *np,
const char *propname,
@@ -477,6 +482,13 @@
return -ENOSYS;
}
+static inline int of_property_read_u64_array(const struct device_node *np,
+ const char *propname,
+ u64 *out_values, size_t sz)
+{
+ return -ENOSYS;
+}
+
static inline int of_property_read_string(struct device_node *np,
const char *propname,
const char **out_string)