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Commit 16ba08d5 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 97badf87

drivers/base/property.c

+93 −5
Original line number Diff line number Diff line
@@ -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 @@ bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname) 
	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 @@ EXPORT_SYMBOL_GPL(device_property_read_string); 
		_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 @@ int fwnode_property_read_string_array(struct fwnode_handle *fwnode, 
		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);

include/linux/fwnode.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ enum fwnode_type { 
	FWNODE_INVALID = 0,

	FWNODE_OF,

	FWNODE_ACPI,

	FWNODE_PDATA,

};



struct fwnode_handle {

include/linux/property.h

+33 −0
Original line number Diff line number Diff line
@@ -131,4 +131,37 @@ static inline int fwnode_property_read_u64(struct fwnode_handle *fwnode, 
	return fwnode_property_read_u64_array(fwnode, propname, val, 1);

}



/**

 * struct property_entry - "Built-in" device property representation.

 * @name: Name of the property.

 * @type: Type of the property.

 * @nval: Number of items of type @type making up the value.

 * @value: Value of the property (an array of @nval items of type @type).

 */

struct property_entry {

	const char *name;

	enum dev_prop_type type;

	size_t nval;

	union {

		void *raw_data;

		u8 *u8_data;

		u16 *u16_data;

		u32 *u32_data;

		u64 *u64_data;

		const char **str;

	} value;

};



/**

 * struct property_set - Collection of "built-in" device properties.

 * @fwnode: Handle to be pointed to by the fwnode field of struct device.

 * @properties: Array of properties terminated with a null entry.

 */

struct property_set {

	struct fwnode_handle fwnode;

	struct property_entry *properties;

};



void device_add_property_set(struct device *dev, struct property_set *pset);



#endif /* _LINUX_PROPERTY_H_ */