![Saravana Kannan](/assets/img/avatar_default.png)
When add_links() still has suppliers that it needs to link to in the future, this patch allows it to differentiate between suppliers that are needed for probing vs suppliers that are needed for sync_state() correctness. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20191028220027.251605-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
169 lines
6.5 KiB
C
169 lines
6.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* fwnode.h - Firmware device node object handle type definition.
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*
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* Copyright (C) 2015, Intel Corporation
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* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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*/
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#ifndef _LINUX_FWNODE_H_
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#define _LINUX_FWNODE_H_
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#include <linux/types.h>
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struct fwnode_operations;
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struct device;
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struct fwnode_handle {
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struct fwnode_handle *secondary;
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const struct fwnode_operations *ops;
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struct device *dev;
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};
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/**
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* struct fwnode_endpoint - Fwnode graph endpoint
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* @port: Port number
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* @id: Endpoint id
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* @local_fwnode: reference to the related fwnode
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*/
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struct fwnode_endpoint {
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unsigned int port;
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unsigned int id;
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const struct fwnode_handle *local_fwnode;
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};
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#define NR_FWNODE_REFERENCE_ARGS 8
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/**
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* struct fwnode_reference_args - Fwnode reference with additional arguments
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* @fwnode:- A reference to the base fwnode
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* @nargs: Number of elements in @args array
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* @args: Integer arguments on the fwnode
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*/
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struct fwnode_reference_args {
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struct fwnode_handle *fwnode;
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unsigned int nargs;
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u64 args[NR_FWNODE_REFERENCE_ARGS];
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};
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/**
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* struct fwnode_operations - Operations for fwnode interface
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* @get: Get a reference to an fwnode.
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* @put: Put a reference to an fwnode.
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* @device_get_match_data: Return the device driver match data.
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* @property_present: Return true if a property is present.
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* @property_read_integer_array: Read an array of integer properties. Return
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* zero on success, a negative error code
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* otherwise.
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* @property_read_string_array: Read an array of string properties. Return zero
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* on success, a negative error code otherwise.
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* @get_parent: Return the parent of an fwnode.
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* @get_next_child_node: Return the next child node in an iteration.
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* @get_named_child_node: Return a child node with a given name.
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* @get_reference_args: Return a reference pointed to by a property, with args
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* @graph_get_next_endpoint: Return an endpoint node in an iteration.
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* @graph_get_remote_endpoint: Return the remote endpoint node of a local
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* endpoint node.
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* @graph_get_port_parent: Return the parent node of a port node.
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* @graph_parse_endpoint: Parse endpoint for port and endpoint id.
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* @add_links: Called after the device corresponding to the fwnode is added
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* using device_add(). The function is expected to create device
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* links to all the suppliers of the device that are available at
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* the time this function is called. The function must NOT stop
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* at the first failed device link if other unlinked supplier
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* devices are present in the system. This is necessary for the
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* driver/bus sync_state() callbacks to work correctly.
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*
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* For example, say Device-C depends on suppliers Device-S1 and
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* Device-S2 and the dependency is listed in that order in the
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* firmware. Say, S1 gets populated from the firmware after
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* late_initcall_sync(). Say S2 is populated and probed way
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* before that in device_initcall(). When C is populated, if this
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* add_links() function doesn't continue past a "failed linking to
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* S1" and continue linking C to S2, then S2 will get a
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* sync_state() callback before C is probed. This is because from
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* the perspective of S2, C was never a consumer when its
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* sync_state() evaluation is done. To avoid this, the add_links()
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* function has to go through all available suppliers of the
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* device (that corresponds to this fwnode) and link to them
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* before returning.
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*
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* If some suppliers are not yet available (indicated by an error
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* return value), this function will be called again when other
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* devices are added to allow creating device links to any newly
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* available suppliers.
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*
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* Return 0 if device links have been successfully created to all
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* the suppliers this device needs to create device links to or if
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* the supplier information is not known.
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*
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* Return -ENODEV if and only if the suppliers needed for probing
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* the device are not yet available to create device links to.
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*
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* Return -EAGAIN if there are suppliers that need to be linked to
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* that are not yet available but none of those suppliers are
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* necessary for probing this device.
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*/
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struct fwnode_operations {
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struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
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void (*put)(struct fwnode_handle *fwnode);
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bool (*device_is_available)(const struct fwnode_handle *fwnode);
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const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
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const struct device *dev);
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bool (*property_present)(const struct fwnode_handle *fwnode,
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const char *propname);
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int (*property_read_int_array)(const struct fwnode_handle *fwnode,
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const char *propname,
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unsigned int elem_size, void *val,
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size_t nval);
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int
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(*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
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const char *propname, const char **val,
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size_t nval);
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struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
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struct fwnode_handle *
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(*get_next_child_node)(const struct fwnode_handle *fwnode,
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struct fwnode_handle *child);
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struct fwnode_handle *
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(*get_named_child_node)(const struct fwnode_handle *fwnode,
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const char *name);
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int (*get_reference_args)(const struct fwnode_handle *fwnode,
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const char *prop, const char *nargs_prop,
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unsigned int nargs, unsigned int index,
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struct fwnode_reference_args *args);
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struct fwnode_handle *
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(*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
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struct fwnode_handle *prev);
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struct fwnode_handle *
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(*graph_get_remote_endpoint)(const struct fwnode_handle *fwnode);
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struct fwnode_handle *
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(*graph_get_port_parent)(struct fwnode_handle *fwnode);
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int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
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struct fwnode_endpoint *endpoint);
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int (*add_links)(const struct fwnode_handle *fwnode,
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struct device *dev);
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};
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#define fwnode_has_op(fwnode, op) \
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((fwnode) && (fwnode)->ops && (fwnode)->ops->op)
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#define fwnode_call_int_op(fwnode, op, ...) \
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(fwnode ? (fwnode_has_op(fwnode, op) ? \
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(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \
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-EINVAL)
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#define fwnode_call_bool_op(fwnode, op, ...) \
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(fwnode_has_op(fwnode, op) ? \
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(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : false)
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#define fwnode_call_ptr_op(fwnode, op, ...) \
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(fwnode_has_op(fwnode, op) ? \
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(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : NULL)
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#define fwnode_call_void_op(fwnode, op, ...) \
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do { \
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if (fwnode_has_op(fwnode, op)) \
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(fwnode)->ops->op(fwnode, ## __VA_ARGS__); \
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} while (false)
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#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev)
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#endif
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