linux-stable/include/linux/fwnode.h

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/* 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>
struct fwnode_operations;
struct device;
/*
* fwnode link flags
*
* LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
driver core: fw_devlink: Detect supplier devices that will never be added During the initial parsing of firmware by fw_devlink, fw_devlink might infer that some supplier firmware nodes would get populated as devices. But the inference is not always correct. This patch tries to logically detect and fix such mistakes as boot progresses or more devices probe. fw_devlink makes a fundamental assumption that once a device binds to a driver, it will populate (i.e: add as struct devices) all the child firmware nodes that could be populated as devices (if they aren't populated already). So, whenever a device probes, we check all its child firmware nodes. If a child firmware node has a corresponding device populated, we don't modify the child node or its descendants. However, if a child firmware node has not been populated as a device, we delete all the fwnode links where the child node or its descendants are suppliers. This ensures that no other device is blocked on a firmware node that will never be populated as a device. We also mark such fwnodes as NOT_DEVICE, so that no new fwnode links are created with these nodes as suppliers. Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210205222644.2357303-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-05 22:26:37 +00:00
* NOT_DEVICE: The fwnode will never be populated as a struct device.
*/
#define FWNODE_FLAG_LINKS_ADDED BIT(0)
driver core: fw_devlink: Detect supplier devices that will never be added During the initial parsing of firmware by fw_devlink, fw_devlink might infer that some supplier firmware nodes would get populated as devices. But the inference is not always correct. This patch tries to logically detect and fix such mistakes as boot progresses or more devices probe. fw_devlink makes a fundamental assumption that once a device binds to a driver, it will populate (i.e: add as struct devices) all the child firmware nodes that could be populated as devices (if they aren't populated already). So, whenever a device probes, we check all its child firmware nodes. If a child firmware node has a corresponding device populated, we don't modify the child node or its descendants. However, if a child firmware node has not been populated as a device, we delete all the fwnode links where the child node or its descendants are suppliers. This ensures that no other device is blocked on a firmware node that will never be populated as a device. We also mark such fwnodes as NOT_DEVICE, so that no new fwnode links are created with these nodes as suppliers. Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default") Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210205222644.2357303-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-05 22:26:37 +00:00
#define FWNODE_FLAG_NOT_DEVICE BIT(1)
struct fwnode_handle {
2015-04-03 21:23:37 +00:00
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;
};
#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 (*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);
int (*add_links)(struct fwnode_handle *fwnode);
};
#define fwnode_has_op(fwnode, op) \
((fwnode) && (fwnode)->ops && (fwnode)->ops->op)
#define fwnode_call_int_op(fwnode, op, ...) \
(fwnode ? (fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \
-EINVAL)
#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);
}
extern u32 fw_devlink_get_flags(void);
int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
void fwnode_links_purge(struct fwnode_handle *fwnode);
#endif