device property: Introduce firmware node type for platform data
Introduce data structures and code allowing "built-in" properties
to be associated with devices in such a way that they will be used
by the device_property_* API if no proper firmware node (neither DT
nor ACPI) is present for the given device.
Each property is to be represented by a property_entry structure.
An array of property_entry structures (terminated with a null
entry) can be pointed to by the properties field of struct
property_set that can be added as a firmware node to a struct
device using device_add_property_set(). That will cause the
device_property_* API to use that property_set as the source
of properties if the given device does not have a DT node or
an ACPI companion device object associated with it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 62787bc..6a3f7d8 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -10,10 +10,96 @@
* published by the Free Software Foundation.
*/
-#include <linux/property.h>
-#include <linux/export.h>
#include <linux/acpi.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
#include <linux/of.h>
+#include <linux/property.h>
+
+/**
+ * device_add_property_set - Add a collection of properties to a device object.
+ * @dev: Device to add properties to.
+ * @pset: Collection of properties to add.
+ *
+ * Associate a collection of device properties represented by @pset with @dev
+ * as its secondary firmware node.
+ */
+void device_add_property_set(struct device *dev, struct property_set *pset)
+{
+ if (pset)
+ pset->fwnode.type = FWNODE_PDATA;
+
+ set_secondary_fwnode(dev, &pset->fwnode);
+}
+EXPORT_SYMBOL_GPL(device_add_property_set);
+
+static inline bool is_pset(struct fwnode_handle *fwnode)
+{
+ return fwnode && fwnode->type == FWNODE_PDATA;
+}
+
+static inline struct property_set *to_pset(struct fwnode_handle *fwnode)
+{
+ return is_pset(fwnode) ?
+ container_of(fwnode, struct property_set, fwnode) : NULL;
+}
+
+static struct property_entry *pset_prop_get(struct property_set *pset,
+ const char *name)
+{
+ struct property_entry *prop;
+
+ if (!pset || !pset->properties)
+ return NULL;
+
+ for (prop = pset->properties; prop->name; prop++)
+ if (!strcmp(name, prop->name))
+ return prop;
+
+ return NULL;
+}
+
+static int pset_prop_read_array(struct property_set *pset, const char *name,
+ enum dev_prop_type type, void *val, size_t nval)
+{
+ struct property_entry *prop;
+ unsigned int item_size;
+
+ prop = pset_prop_get(pset, name);
+ if (!prop)
+ return -ENODATA;
+
+ if (prop->type != type)
+ return -EPROTO;
+
+ if (!val)
+ return prop->nval;
+
+ if (prop->nval < nval)
+ return -EOVERFLOW;
+
+ switch (type) {
+ case DEV_PROP_U8:
+ item_size = sizeof(u8);
+ break;
+ case DEV_PROP_U16:
+ item_size = sizeof(u16);
+ break;
+ case DEV_PROP_U32:
+ item_size = sizeof(u32);
+ break;
+ case DEV_PROP_U64:
+ item_size = sizeof(u64);
+ break;
+ case DEV_PROP_STRING:
+ item_size = sizeof(const char *);
+ break;
+ default:
+ return -EINVAL;
+ }
+ memcpy(val, prop->value.raw_data, nval * item_size);
+ return 0;
+}
static inline struct fwnode_handle *dev_fwnode(struct device *dev)
{
@@ -46,7 +132,7 @@
else if (is_acpi_node(fwnode))
return !acpi_dev_prop_get(acpi_node(fwnode), propname, NULL);
- return false;
+ return !!pset_prop_get(to_pset(fwnode), propname);
}
EXPORT_SYMBOL_GPL(fwnode_property_present);
@@ -205,7 +291,8 @@
_ret_ = acpi_dev_prop_read(acpi_node(_fwnode_), _propname_, \
_proptype_, _val_, _nval_); \
else \
- _ret_ = -ENXIO; \
+ _ret_ = pset_prop_read_array(to_pset(_fwnode_), _propname_, \
+ _proptype_, _val_, _nval_); \
_ret_; \
})
@@ -344,7 +431,8 @@
return acpi_dev_prop_read(acpi_node(fwnode), propname,
DEV_PROP_STRING, val, nval);
- return -ENXIO;
+ return pset_prop_read_array(to_pset(fwnode), propname,
+ DEV_PROP_STRING, val, nval);
}
EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);