linux-stable/include/linux/fwnode.h
Andy Shevchenko 002752af7b device property: Allow error pointer to be passed to fwnode APIs
Some of the fwnode APIs might return an error pointer instead of NULL
or valid fwnode handle. The result of such API call may be considered
optional and hence the test for it is usually done in a form of

	fwnode = fwnode_find_reference(...);
	if (IS_ERR(fwnode))
		...error handling...

Nevertheless the resulting fwnode may have bumped the reference count
and hence caller of the above API is obliged to call fwnode_handle_put().
Since fwnode may be not valid either as NULL or error pointer the check
has to be performed there. This approach uglifies the code and adds
a point of making a mistake, i.e. forgetting about error point case.

To prevent this, allow an error pointer to be passed to the fwnode APIs.

Fixes: 83b34afb6b ("device property: Introduce fwnode_find_reference()")
Reported-by: Nuno Sá <nuno.sa@analog.com>
Tested-by: Nuno Sá <nuno.sa@analog.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-04-13 20:04:02 +02:00

203 lines
7.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* fwnode.h - Firmware device node object handle type definition.
*
* Copyright (C) 2015, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
#ifndef _LINUX_FWNODE_H_
#define _LINUX_FWNODE_H_
#include <linux/types.h>
#include <linux/list.h>
#include <linux/bits.h>
#include <linux/err.h>
struct fwnode_operations;
struct device;
/*
* fwnode link flags
*
* LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
* NOT_DEVICE: The fwnode will never be populated as a struct device.
* INITIALIZED: The hardware corresponding to fwnode has been initialized.
* NEEDS_CHILD_BOUND_ON_ADD: For this fwnode/device to probe successfully, its
* driver needs its child devices to be bound with
* their respective drivers as soon as they are
* added.
*/
#define FWNODE_FLAG_LINKS_ADDED BIT(0)
#define FWNODE_FLAG_NOT_DEVICE BIT(1)
#define FWNODE_FLAG_INITIALIZED BIT(2)
#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD BIT(3)
struct fwnode_handle {
struct fwnode_handle *secondary;
const struct fwnode_operations *ops;
struct device *dev;
struct list_head suppliers;
struct list_head consumers;
u8 flags;
};
struct fwnode_link {
struct fwnode_handle *supplier;
struct list_head s_hook;
struct fwnode_handle *consumer;
struct list_head c_hook;
};
/**
* struct fwnode_endpoint - Fwnode graph endpoint
* @port: Port number
* @id: Endpoint id
* @local_fwnode: reference to the related fwnode
*/
struct fwnode_endpoint {
unsigned int port;
unsigned int id;
const struct fwnode_handle *local_fwnode;
};
/*
* ports and endpoints defined as software_nodes should all follow a common
* naming scheme; use these macros to ensure commonality.
*/
#define SWNODE_GRAPH_PORT_NAME_FMT "port@%u"
#define SWNODE_GRAPH_ENDPOINT_NAME_FMT "endpoint@%u"
#define NR_FWNODE_REFERENCE_ARGS 8
/**
* struct fwnode_reference_args - Fwnode reference with additional arguments
* @fwnode:- A reference to the base fwnode
* @nargs: Number of elements in @args array
* @args: Integer arguments on the fwnode
*/
struct fwnode_reference_args {
struct fwnode_handle *fwnode;
unsigned int nargs;
u64 args[NR_FWNODE_REFERENCE_ARGS];
};
/**
* struct fwnode_operations - Operations for fwnode interface
* @get: Get a reference to an fwnode.
* @put: Put a reference to an fwnode.
* @device_is_available: Return true if the device is available.
* @device_get_match_data: Return the device driver match data.
* @property_present: Return true if a property is present.
* @property_read_int_array: Read an array of integer properties. Return zero on
* success, a negative error code otherwise.
* @property_read_string_array: Read an array of string properties. Return zero
* on success, a negative error code otherwise.
* @get_name: Return the name of an fwnode.
* @get_name_prefix: Get a prefix for a node (for printing purposes).
* @get_parent: Return the parent of an fwnode.
* @get_next_child_node: Return the next child node in an iteration.
* @get_named_child_node: Return a child node with a given name.
* @get_reference_args: Return a reference pointed to by a property, with args
* @graph_get_next_endpoint: Return an endpoint node in an iteration.
* @graph_get_remote_endpoint: Return the remote endpoint node of a local
* endpoint node.
* @graph_get_port_parent: Return the parent node of a port node.
* @graph_parse_endpoint: Parse endpoint for port and endpoint id.
* @add_links: Create fwnode links to all the suppliers of the fwnode. Return
* zero on success, a negative error code otherwise.
*/
struct fwnode_operations {
struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
void (*put)(struct fwnode_handle *fwnode);
bool (*device_is_available)(const struct fwnode_handle *fwnode);
const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
const struct device *dev);
bool (*device_dma_supported)(const struct fwnode_handle *fwnode);
enum dev_dma_attr
(*device_get_dma_attr)(const struct fwnode_handle *fwnode);
bool (*property_present)(const struct fwnode_handle *fwnode,
const char *propname);
int (*property_read_int_array)(const struct fwnode_handle *fwnode,
const char *propname,
unsigned int elem_size, void *val,
size_t nval);
int
(*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
const char *propname, const char **val,
size_t nval);
const char *(*get_name)(const struct fwnode_handle *fwnode);
const char *(*get_name_prefix)(const struct fwnode_handle *fwnode);
struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
struct fwnode_handle *
(*get_next_child_node)(const struct fwnode_handle *fwnode,
struct fwnode_handle *child);
struct fwnode_handle *
(*get_named_child_node)(const struct fwnode_handle *fwnode,
const char *name);
int (*get_reference_args)(const struct fwnode_handle *fwnode,
const char *prop, const char *nargs_prop,
unsigned int nargs, unsigned int index,
struct fwnode_reference_args *args);
struct fwnode_handle *
(*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
struct fwnode_handle *prev);
struct fwnode_handle *
(*graph_get_remote_endpoint)(const struct fwnode_handle *fwnode);
struct fwnode_handle *
(*graph_get_port_parent)(struct fwnode_handle *fwnode);
int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
struct fwnode_endpoint *endpoint);
void __iomem *(*iomap)(struct fwnode_handle *fwnode, int index);
int (*irq_get)(const struct fwnode_handle *fwnode, unsigned int index);
int (*add_links)(struct fwnode_handle *fwnode);
};
#define fwnode_has_op(fwnode, op) \
(!IS_ERR_OR_NULL(fwnode) && (fwnode)->ops && (fwnode)->ops->op)
#define fwnode_call_int_op(fwnode, op, ...) \
(fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : (IS_ERR_OR_NULL(fwnode) ? -EINVAL : -ENXIO))
#define fwnode_call_bool_op(fwnode, op, ...) \
(fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : false)
#define fwnode_call_ptr_op(fwnode, op, ...) \
(fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : NULL)
#define fwnode_call_void_op(fwnode, op, ...) \
do { \
if (fwnode_has_op(fwnode, op)) \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__); \
} while (false)
#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev)
static inline void fwnode_init(struct fwnode_handle *fwnode,
const struct fwnode_operations *ops)
{
fwnode->ops = ops;
INIT_LIST_HEAD(&fwnode->consumers);
INIT_LIST_HEAD(&fwnode->suppliers);
}
static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode,
bool initialized)
{
if (IS_ERR_OR_NULL(fwnode))
return;
if (initialized)
fwnode->flags |= FWNODE_FLAG_INITIALIZED;
else
fwnode->flags &= ~FWNODE_FLAG_INITIALIZED;
}
extern u32 fw_devlink_get_flags(void);
extern bool fw_devlink_is_strict(void);
int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
void fwnode_links_purge(struct fwnode_handle *fwnode);
void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
#endif