linux/drivers/base/devcon.c
Linus Torvalds f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00

219 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/**
* Device connections
*
* Copyright (C) 2018 Intel Corporation
* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
*/
#include <linux/device.h>
#include <linux/property.h>
static DEFINE_MUTEX(devcon_lock);
static LIST_HEAD(devcon_list);
typedef void *(*devcon_match_fn_t)(struct device_connection *con, int ep,
void *data);
static void *
fwnode_graph_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
void *data, devcon_match_fn_t match)
{
struct device_connection con = { .id = con_id };
struct fwnode_handle *ep;
void *ret;
fwnode_graph_for_each_endpoint(fwnode, ep) {
con.fwnode = fwnode_graph_get_remote_port_parent(ep);
if (!fwnode_device_is_available(con.fwnode))
continue;
ret = match(&con, -1, data);
fwnode_handle_put(con.fwnode);
if (ret) {
fwnode_handle_put(ep);
return ret;
}
}
return NULL;
}
static void *
fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
void *data, devcon_match_fn_t match)
{
struct device_connection con = { };
void *ret;
int i;
for (i = 0; ; i++) {
con.fwnode = fwnode_find_reference(fwnode, con_id, i);
if (IS_ERR(con.fwnode))
break;
ret = match(&con, -1, data);
fwnode_handle_put(con.fwnode);
if (ret)
return ret;
}
return NULL;
}
/**
* device_connection_find_match - Find physical connection to a device
* @dev: Device with the connection
* @con_id: Identifier for the connection
* @data: Data for the match function
* @match: Function to check and convert the connection description
*
* Find a connection with unique identifier @con_id between @dev and another
* device. @match will be used to convert the connection description to data the
* caller is expecting to be returned.
*/
void *device_connection_find_match(struct device *dev, const char *con_id,
void *data, devcon_match_fn_t match)
{
struct fwnode_handle *fwnode = dev_fwnode(dev);
const char *devname = dev_name(dev);
struct device_connection *con;
void *ret = NULL;
int ep;
if (!match)
return NULL;
if (fwnode) {
ret = fwnode_graph_devcon_match(fwnode, con_id, data, match);
if (ret)
return ret;
ret = fwnode_devcon_match(fwnode, con_id, data, match);
if (ret)
return ret;
}
mutex_lock(&devcon_lock);
list_for_each_entry(con, &devcon_list, list) {
ep = match_string(con->endpoint, 2, devname);
if (ep < 0)
continue;
if (con_id && strcmp(con->id, con_id))
continue;
ret = match(con, !ep, data);
if (ret)
break;
}
mutex_unlock(&devcon_lock);
return ret;
}
EXPORT_SYMBOL_GPL(device_connection_find_match);
extern struct bus_type platform_bus_type;
extern struct bus_type pci_bus_type;
extern struct bus_type i2c_bus_type;
extern struct bus_type spi_bus_type;
static struct bus_type *generic_match_buses[] = {
&platform_bus_type,
#ifdef CONFIG_PCI
&pci_bus_type,
#endif
#ifdef CONFIG_I2C
&i2c_bus_type,
#endif
#ifdef CONFIG_SPI_MASTER
&spi_bus_type,
#endif
NULL,
};
static int device_fwnode_match(struct device *dev, const void *fwnode)
{
return dev_fwnode(dev) == fwnode;
}
static void *device_connection_fwnode_match(struct device_connection *con)
{
struct bus_type *bus;
struct device *dev;
for (bus = generic_match_buses[0]; bus; bus++) {
dev = bus_find_device(bus, NULL, (void *)con->fwnode,
device_fwnode_match);
if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
return dev;
put_device(dev);
}
return NULL;
}
/* This tries to find the device from the most common bus types by name. */
static void *generic_match(struct device_connection *con, int ep, void *data)
{
struct bus_type *bus;
struct device *dev;
if (con->fwnode)
return device_connection_fwnode_match(con);
for (bus = generic_match_buses[0]; bus; bus++) {
dev = bus_find_device_by_name(bus, NULL, con->endpoint[ep]);
if (dev)
return dev;
}
/*
* We only get called if a connection was found, tell the caller to
* wait for the other device to show up.
*/
return ERR_PTR(-EPROBE_DEFER);
}
/**
* device_connection_find - Find two devices connected together
* @dev: Device with the connection
* @con_id: Identifier for the connection
*
* Find a connection with unique identifier @con_id between @dev and
* another device. On success returns handle to the device that is connected
* to @dev, with the reference count for the found device incremented. Returns
* NULL if no matching connection was found, or ERR_PTR(-EPROBE_DEFER) when a
* connection was found but the other device has not been enumerated yet.
*/
struct device *device_connection_find(struct device *dev, const char *con_id)
{
return device_connection_find_match(dev, con_id, NULL, generic_match);
}
EXPORT_SYMBOL_GPL(device_connection_find);
/**
* device_connection_add - Register a connection description
* @con: The connection description to be registered
*/
void device_connection_add(struct device_connection *con)
{
mutex_lock(&devcon_lock);
list_add_tail(&con->list, &devcon_list);
mutex_unlock(&devcon_lock);
}
EXPORT_SYMBOL_GPL(device_connection_add);
/**
* device_connections_remove - Unregister connection description
* @con: The connection description to be unregistered
*/
void device_connection_remove(struct device_connection *con)
{
mutex_lock(&devcon_lock);
list_del(&con->list);
mutex_unlock(&devcon_lock);
}
EXPORT_SYMBOL_GPL(device_connection_remove);