kernel-ark/drivers/uwb/umc-bus.c
Greg Kroah-Hartman 8e9394ce24 Driver core: create lock/unlock functions for struct device
In the future, we are going to be changing the lock type for struct
device (once we get the lockdep infrastructure properly worked out)  To
make that changeover easier, and to possibly burry the lock in a
different part of struct device, let's create some functions to lock and
unlock a device so that no out-of-core code needs to be changed in the
future.

This patch creates the device_lock/unlock/trylock() functions, and
converts all in-tree users to them.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Magnus Damm <damm@igel.co.jp>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Alex Chiang <achiang@hp.com>
Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Yu Zhao <yu.zhao@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: CHENG Renquan <rqcheng@smu.edu.sg>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Frans Pop <elendil@planet.nl>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:52 -08:00

243 lines
5.4 KiB
C

/*
* Bus for UWB Multi-interface Controller capabilities.
*
* Copyright (C) 2007 Cambridge Silicon Radio Ltd.
*
* This file is released under the GNU GPL v2.
*/
#include <linux/kernel.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include <linux/uwb/umc.h>
#include <linux/pci.h>
static int umc_bus_pre_reset_helper(struct device *dev, void *data)
{
int ret = 0;
if (dev->driver) {
struct umc_dev *umc = to_umc_dev(dev);
struct umc_driver *umc_drv = to_umc_driver(dev->driver);
if (umc_drv->pre_reset)
ret = umc_drv->pre_reset(umc);
else
device_release_driver(dev);
}
return ret;
}
static int umc_bus_post_reset_helper(struct device *dev, void *data)
{
int ret = 0;
if (dev->driver) {
struct umc_dev *umc = to_umc_dev(dev);
struct umc_driver *umc_drv = to_umc_driver(dev->driver);
if (umc_drv->post_reset)
ret = umc_drv->post_reset(umc);
} else
ret = device_attach(dev);
return ret;
}
/**
* umc_controller_reset - reset the whole UMC controller
* @umc: the UMC device for the radio controller.
*
* Drivers or all capabilities of the controller will have their
* pre_reset methods called or be unbound from their device. Then all
* post_reset methods will be called or the drivers will be rebound.
*
* Radio controllers must provide pre_reset and post_reset methods and
* reset the hardware in their start method.
*
* If this is called while a probe() or remove() is in progress it
* will return -EAGAIN and not perform the reset.
*/
int umc_controller_reset(struct umc_dev *umc)
{
struct device *parent = umc->dev.parent;
int ret = 0;
if (device_trylock(parent))
return -EAGAIN;
ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper);
if (ret >= 0)
ret = device_for_each_child(parent, parent, umc_bus_post_reset_helper);
device_unlock(parent);
return ret;
}
EXPORT_SYMBOL_GPL(umc_controller_reset);
/**
* umc_match_pci_id - match a UMC driver to a UMC device's parent PCI device.
* @umc_drv: umc driver with match_data pointing to a zero-terminated
* table of pci_device_id's.
* @umc: umc device whose parent is to be matched.
*/
int umc_match_pci_id(struct umc_driver *umc_drv, struct umc_dev *umc)
{
const struct pci_device_id *id_table = umc_drv->match_data;
struct pci_dev *pci;
if (umc->dev.parent->bus != &pci_bus_type)
return 0;
pci = to_pci_dev(umc->dev.parent);
return pci_match_id(id_table, pci) != NULL;
}
EXPORT_SYMBOL_GPL(umc_match_pci_id);
static int umc_bus_rescan_helper(struct device *dev, void *data)
{
int ret = 0;
if (!dev->driver)
ret = device_attach(dev);
return ret;
}
static void umc_bus_rescan(struct device *parent)
{
int err;
/*
* We can't use bus_rescan_devices() here as it deadlocks when
* it tries to retake the dev->parent semaphore.
*/
err = device_for_each_child(parent, NULL, umc_bus_rescan_helper);
if (err < 0)
printk(KERN_WARNING "%s: rescan of bus failed: %d\n",
KBUILD_MODNAME, err);
}
static int umc_bus_match(struct device *dev, struct device_driver *drv)
{
struct umc_dev *umc = to_umc_dev(dev);
struct umc_driver *umc_driver = to_umc_driver(drv);
if (umc->cap_id == umc_driver->cap_id) {
if (umc_driver->match)
return umc_driver->match(umc_driver, umc);
else
return 1;
}
return 0;
}
static int umc_device_probe(struct device *dev)
{
struct umc_dev *umc;
struct umc_driver *umc_driver;
int err;
umc_driver = to_umc_driver(dev->driver);
umc = to_umc_dev(dev);
get_device(dev);
err = umc_driver->probe(umc);
if (err)
put_device(dev);
else
umc_bus_rescan(dev->parent);
return err;
}
static int umc_device_remove(struct device *dev)
{
struct umc_dev *umc;
struct umc_driver *umc_driver;
umc_driver = to_umc_driver(dev->driver);
umc = to_umc_dev(dev);
umc_driver->remove(umc);
put_device(dev);
return 0;
}
static int umc_device_suspend(struct device *dev, pm_message_t state)
{
struct umc_dev *umc;
struct umc_driver *umc_driver;
int err = 0;
umc = to_umc_dev(dev);
if (dev->driver) {
umc_driver = to_umc_driver(dev->driver);
if (umc_driver->suspend)
err = umc_driver->suspend(umc, state);
}
return err;
}
static int umc_device_resume(struct device *dev)
{
struct umc_dev *umc;
struct umc_driver *umc_driver;
int err = 0;
umc = to_umc_dev(dev);
if (dev->driver) {
umc_driver = to_umc_driver(dev->driver);
if (umc_driver->resume)
err = umc_driver->resume(umc);
}
return err;
}
static ssize_t capability_id_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct umc_dev *umc = to_umc_dev(dev);
return sprintf(buf, "0x%02x\n", umc->cap_id);
}
static ssize_t version_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct umc_dev *umc = to_umc_dev(dev);
return sprintf(buf, "0x%04x\n", umc->version);
}
static struct device_attribute umc_dev_attrs[] = {
__ATTR_RO(capability_id),
__ATTR_RO(version),
__ATTR_NULL,
};
struct bus_type umc_bus_type = {
.name = "umc",
.match = umc_bus_match,
.probe = umc_device_probe,
.remove = umc_device_remove,
.suspend = umc_device_suspend,
.resume = umc_device_resume,
.dev_attrs = umc_dev_attrs,
};
EXPORT_SYMBOL_GPL(umc_bus_type);
static int __init umc_bus_init(void)
{
return bus_register(&umc_bus_type);
}
module_init(umc_bus_init);
static void __exit umc_bus_exit(void)
{
bus_unregister(&umc_bus_type);
}
module_exit(umc_bus_exit);
MODULE_DESCRIPTION("UWB Multi-interface Controller capability bus");
MODULE_AUTHOR("Cambridge Silicon Radio Ltd.");
MODULE_LICENSE("GPL");