// SPDX-License-Identifier: GPL-2.0
/*
* drivers/usb/core/usb.c
*
* (C) Copyright Linus Torvalds 1999
* (C) Copyright Johannes Erdfelt 1999-2001
* (C) Copyright Andreas Gal 1999
* (C) Copyright Gregory P. Smith 1999
* (C) Copyright Deti Fliegl 1999 (new USB architecture)
* (C) Copyright Randy Dunlap 2000
* (C) Copyright David Brownell 2000-2004
* (C) Copyright Yggdrasil Computing, Inc. 2000
* (usb_device_id matching changes by Adam J. Richter)
* (C) Copyright Greg Kroah-Hartman 2002-2003
*
* Released under the GPLv2 only.
*
* NOTE! This is not actually a driver at all, rather this is
* just a collection of helper routines that implement the
* generic USB things that the real drivers can use..
*
* Think of this as a "USB library" rather than anything else,
* with no callbacks. Callbacks are evil.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/usb/of.h>
#include <asm/io.h>
#include <linux/scatterlist.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include "hub.h"
const char *usbcore_name = "usbcore";
static bool nousb; /* Disable USB when built into kernel image */
module_param(nousb, bool, 0444);
/*
* for external read access to <nousb>
*/
int usb_disabled(void)
{
return nousb;
}
EXPORT_SYMBOL_GPL(usb_disabled);
#ifdef CONFIG_PM
/* Default delay value, in seconds */
static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
#else
#define usb_autosuspend_delay 0
#endif
static bool match_endpoint(struct usb_endpoint_descriptor *epd,
struct usb_endpoint_descriptor **bulk_in,
struct usb_endpoint_descriptor **bulk_out,
struct usb_endpoint_descriptor **int_in,
struct usb_endpoint_descriptor **int_out)
{
switch (usb_endpoint_type(epd)) {
case USB_ENDPOINT_XFER_BULK:
if (usb_endpoint_dir_in(epd)) {
if (bulk_in && !*bulk_in) {
*bulk_in = epd;
break;
}
} else {
if (bulk_out && !*bulk_out) {
*bulk_out = epd;
break;
}
}
return false;
case USB_ENDPOINT_XFER_INT:
if (usb_endpoint_dir_in(epd)) {
if (int_in && !*int_in) {
*int_in = epd;
break;
}
} else {
if (int_out && !*int_out) {
*int_out = epd;
break;
}
}
return false;
default:
return false;
}
return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
(!int_in || *int_in) && (!int_out || *int_out);
}
/**
* usb_find_common_endpoints() -- look up common endpoint descriptors
* @alt: alternate setting to search
* @bulk_in: pointer to descriptor pointer, or NULL
* @bulk_out: pointer to descriptor pointer, or NULL
* @int_in: pointer to descriptor pointer, or NULL
* @int_out: pointer to descriptor pointer, or NULL
*
* Search the alternate setting's endpoint descriptors for the first bulk-in,
* bulk-out, interrupt-in and interrupt-out endpoints and return them in the
* provided pointers (unless they are NULL).
*
* If a requested endpoint is not found, the corresponding pointer is set to
* NULL.
*
* Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
*/
int usb_find_common_endpoints(struct usb_host_interface *alt,
struct usb_endpoint_descriptor **bulk_in,
struct usb_endpoint_descriptor **bulk_out,
struct usb_endpoint_descriptor **int_in,
struct usb_endpoint_descriptor **int_out)
{
struct usb_endpoint_descriptor *epd;
int i;
if (bulk_in)
*bulk_in = NULL;
if (bulk_out)
*bulk_out = NULL;
if (int_in)
*int_in = NULL;
if (int_out)
*int_out = NULL;
for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
epd = &alt->endpoint[i].desc;
if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
return 0;
}
return -ENXIO;
}
EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
/**
* usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
* @alt: alternate setting to search
* @bulk_in: pointer to descriptor pointer, or NULL
* @bulk_out: pointer to descriptor pointer, or NULL
* @int_in: pointer to descriptor pointer, or NULL
* @int_out: pointer to descriptor pointer, or NULL
*
* Search the alternate setting's endpoint descriptors for the last bulk-in,
* bulk-out, interrupt-in and interrupt-out endpoints and return them in the
* provided pointers (unless they are NULL).
*
* If a requested endpoint is not found, the corresponding pointer is set to
* NULL.
*
* Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
*/
int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
struct usb_endpoint_descriptor **bulk_in,
struct usb_endpoint_descriptor **bulk_out,
struct usb_endpoint_descriptor **int_in,
struct usb_endpoint_descriptor **int_out)
{
struct usb_endpoint_descriptor *epd;
int i;
if (bulk_in)
*bulk_in = NULL;
if (bulk_out)
*bulk_out = NULL;
if (int_in)
*int_in = NULL;
if (int_out)
*int_out = NULL;
for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
epd = &alt->endpoint[i].desc;
if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
return 0;
}
return -ENXIO;
}
EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
/**
* usb_find_endpoint() - Given an endpoint address, search for the endpoint's
* usb_host_endpoint structure in an interface's current altsetting.
* @intf: the interface whose current altsetting should be searched
* @ep_addr: the endpoint address (number and direction) to find
*
* Search the altsetting's list of endpoints for one with the specified address.
*
* Return: Pointer to the usb_host_endpoint if found, %NULL otherwise.
*/
static const struct usb_host_endpoint *usb_find_endpoint(
const struct usb_interface *intf, unsigned int ep_addr)
{
int n;
const struct usb_host_endpoint *ep;
n = intf->cur_altsetting->desc.bNumEndpoints;
ep = intf->cur_altsetting->endpoint;
for (; n > 0; (--n, ++ep)) {
if (ep->desc.bEndpointAddress == ep_addr)
return ep;
}
return NULL;
}
/**
* usb_check_bulk_endpoints - Check whether an interface's current altsetting
* contains a set of bulk endpoints with the given addresses.
* @intf: the interface whose current altsetting should be searched
* @ep_addrs: 0-terminated array of the endpoint addresses (number and
* direction) to look for
*
* Search for endpoints with the specified addresses and check their types.
*
* Return: %true if all the endpoints are found and are bulk, %false otherwise.
*/
bool usb_check_bulk_endpoints(
const struct usb_interface *intf, const u8 *ep_addrs)
{
const struct usb_host_endpoint *ep;
for (; *ep_addrs; ++ep_addrs) {
ep = usb_find_endpoint(intf, *ep_addrs);
if (!ep || !usb_endpoint_xfer_bulk(&ep->desc))
return false;
}
return true;
}
EXPORT_SYMBOL_GPL(usb_check_bulk_endpoints);
/**
* usb_check_int_endpoints - Check whether an interface's current altsetting
* contains a set of interrupt endpoints with the given addresses.
* @intf: the interface whose current altsetting should be searched
* @ep_addrs: 0-terminated array of the endpoint addresses (number and
* direction) to look for
*
* Search for endpoints with the specified addresses and check their types.
*
* Return: %true if all the endpoints are found and are interrupt,
* %false otherwise.
*/
bool usb_check_int_endpoints(
const struct usb_interface *intf, const u8 *ep_addrs)
{
const struct usb_host_endpoint *ep;
for (; *ep_addrs; ++ep_addrs) {
ep = usb_find_endpoint(intf, *ep_addrs);
if (!ep || !usb_endpoint_xfer_int(&ep->desc))
return false;
}
return true;
}
EXPORT_SYMBOL_GPL(usb_check_int_endpoints);
/**
* usb_find_alt_setting() - Given a configuration, find the alternate setting
* for the given interface.
* @config: the configuration to search (not necessarily the current config).
* @iface_num: interface number to search in
* @alt_num: alternate interface setting number to search for.
*
* Search the configuration's interface cache for the given alt setting.
*
* Return: The alternate setting, if found. %NULL otherwise.
*/
struct usb_host_interface *usb_find_alt_setting(
struct usb_host_config *config,
unsigned int iface_num,
unsigned int alt_num)
{
struct usb_interface_cache *intf_cache = NULL;
int i;
if (!config)
return NULL;
for (i = 0; i < config->desc.bNumInterfaces; i++) {
if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
== iface_num) {
intf_cache = config->intf_cache[i];
break;
}
}
if (!intf_cache)
return NULL;
for (i = 0; i < intf_cache->num_altsetting; i++)
if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
return &intf_cache->altsetting[i];
printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
"config %u\n", alt_num, iface_num,
config->desc.bConfigurationValue);
return NULL;
}
EXPORT_SYMBOL_GPL(usb_find_alt_setting);
/**
* usb_ifnum_to_if - get the interface object with a given interface number
* @dev: the device whose current configuration is considered
* @ifnum: the desired interface
*
* This walks the device descriptor for the currently active configuration
* to find the interface object with the particular interface number.
*
* Note that configuration descriptors are not required to assign interface
* numbers sequentially, so that it would be incorrect to assume that
* the first interface in that descriptor corresponds to interface zero.
* This routine helps device drivers avoid such mistakes.
* However, you should make sure that you do the right thing with any
* alternate settings available for this interfaces.
*
* Don't call this function unless you are bound to one of the interfaces
* on this device or you have locked the device!
*
* Return: A pointer to the interface that has @ifnum as interface number,
* if found. %NULL otherwise.
*/
struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
unsigned ifnum)
{
struct usb_host_config *config = dev->actconfig;
int i;
if (!config)
return NULL;
for (i = 0; i < config->desc.bNumInterfaces; i++)
if (config->interface[i]->altsetting[0]
.desc.bInterfaceNumber == ifnum)
return config->interface[i];
return NULL;
}
EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
/**
* usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
* @intf: the interface containing the altsetting in question
* @altnum: the desired alternate setting number
*
* This searches the altsetting array of the specified interface for
* an entry with the correct bAlternateSetting value.
*
* Note that altsettings need not be stored sequentially by number, so
* it would be incorrect to assume that the first altsetting entry in
* the array corresponds to altsetting zero. This routine helps device
* drivers avoid such mistakes.
*
* Don't call this function unless you are bound to the intf interface
* or you have locked the device!
*
* Return: A pointer to the entry of the altsetting array of @intf that
* has @altnum as the alternate setting number. %NULL if not found.
*/
struct usb_host_interface *usb_altnum_to_altsetting(
const struct usb_interface *intf,
unsigned int altnum)
{
int i;
for (i = 0; i < intf->num_altsetting; i++) {
if (intf->altsetting[i].desc.bAlternateSetting == altnum)
return &intf->altsetting[i];
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
struct find_interface_arg {
int minor;
struct device_driver *drv;
};
static int __find_interface(struct device *dev, const void *data)
{
const struct find_interface_arg *arg = data;
struct usb_interface *intf;
if (!is_usb_interface(dev))
return 0;
if (dev->driver != arg->drv)
return 0;
intf = to_usb_interface(dev);
return intf->minor == arg->minor;
}
/**
* usb_find_interface - find usb_interface pointer for driver and device
* @drv: the driver whose current configuration is considered
* @minor: the minor number of the desired device
*
* This walks the bus device list and returns a pointer to the interface
* with the matching minor and driver. Note, this only works for devices
* that share the USB major number.
*
* Return: A pointer to the interface with the matching major and @minor.
*/
struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
{
struct find_interface_arg argb;
struct device *dev;
argb.minor = minor;
argb.drv = &drv->driver;
dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
/* Drop reference count from bus_find_device */
put_device(dev);
return dev ? to_usb_interface(dev) : NULL;
}
EXPORT_SYMBOL_GPL(usb_find_interface);
struct each_dev_arg {
void *data;
int (*fn)(struct usb_device *, void *);
};
static int __each_dev(struct device *dev, void *data)
{
struct each_dev_arg *arg = (struct each_dev_arg *)data;
/* There are struct usb_interface on the same bus, filter them out */
if (!is_usb_device(dev))
return 0;
return arg->fn(to_usb_device(dev), arg->data);
}
/**
* usb_for_each_dev - iterate over all USB devices in the system
* @data: data pointer that will be handed to the callback function
* @fn: callback function to be called for each USB device
*
* Iterate over all USB devices and call @fn for each, passing it @data. If it
* returns anything other than 0, we break the iteration prematurely and return
* that value.
*/
int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
{
struct each_dev_arg arg = {data, fn};
return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
}
EXPORT_SYMBOL_GPL(usb_for_each_dev);
/**
* usb_release_dev - free a usb device structure when all users of it are finished.
* @dev: device that's been disconnected
*
* Will be called only by the device core when all users of this usb device are
* done.
*/
static void usb_release_dev(struct device *dev)
{
struct usb_device *udev;
struct usb_hcd *hcd;
udev = to_usb_device(dev);
hcd = bus_to_hcd(udev->bus);
usb_destroy_configuration(udev);
usb_release_bos_descriptor(udev);
of_node_put(dev->of_node);
usb_put_hcd(hcd);
kfree(udev->product);
kfree(udev->manufacturer);
kfree(udev->serial);
kfree(udev);
}
static int usb_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
const struct usb_device *usb_dev;
usb_dev = to_usb_device(dev);
if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
return -ENOMEM;
if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
return -ENOMEM;
return 0;
}
#ifdef CONFIG_PM
/* USB device Power-Management thunks.
* There's no need to distinguish here between quiescing a USB device
* and powering it down; the generic_suspend() routine takes care of
* it by skipping the usb_port_suspend() call for a quiesce. And for
* USB interfaces there's no difference at all.
*/
static int usb_dev_prepare(struct device *dev)
{
return 0; /* Implement eventually? */
}
static void usb_dev_complete(struct device *dev)
{
/* Currently used only for rebinding interfaces */
usb_resume_complete(dev);
}
static int usb_dev_suspend(struct device *dev)
{
return usb_suspend(dev, PMSG_SUSPEND);
}
static int usb_dev_resume(struct device *dev)
{
return usb_resume(dev, PMSG_RESUME);
}
static int usb_dev_freeze(struct device *dev)
{
return usb_suspend(dev, PMSG_FREEZE);
}
static int usb_dev_thaw(struct device *dev)
{
return usb_resume(dev, PMSG_THAW);
}
static int usb_dev_poweroff(struct device *dev)
{
return usb_suspend(dev, PMSG_HIBERNATE);
}
static int usb_dev_restore(struct device *dev)
{
return usb_resume(dev, PMSG_RESTORE);
}
static const struct dev_pm_ops usb_device_pm_ops = {
.prepare = usb_dev_prepare,
.complete = usb_dev_complete,
.suspend = usb_dev_suspend,
.resume = usb_dev_resume,
.freeze = usb_dev_freeze,
.thaw = usb_dev_thaw,
.poweroff = usb_dev_poweroff,
.restore = usb_dev_restore,
.runtime_suspend = usb_runtime_suspend,
.runtime_resume = usb_runtime_resume,
.runtime_idle = usb_runtime_idle,
};
#endif /* CONFIG_PM */
static char *usb_devnode(const struct device *dev,
umode_t *mode, kuid_t *uid, kgid_t *gid)
{
const struct usb_device *usb_dev;
usb_dev = to_usb_device(dev);
return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
usb_dev->bus->busnum, usb_dev->devnum);
}
const struct device_type usb_device_type = {
.name = "usb_device",
.release = usb_release_dev,
.uevent = usb_dev_uevent,
.devnode = usb_devnode,
#ifdef CONFIG_PM
.pm = &usb_device_pm_ops,
#endif
};
static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
{
struct usb_hub *hub;
if (!dev->parent)
return true; /* Root hub always ok [and always wired] */
switch (hcd->dev_policy) {
case USB_DEVICE_AUTHORIZE_NONE:
default:
return false;
case USB_DEVICE_AUTHORIZE_ALL:
return true;
case USB_DEVICE_AUTHORIZE_INTERNAL:
hub = usb_hub_to_struct_hub(dev->parent);
return hub->ports[dev->portnum - 1]->connect_type ==
USB_PORT_CONNECT_TYPE_HARD_WIRED;
}
}
/**
* usb_alloc_dev - usb device constructor (usbcore-internal)
* @parent: hub to which device is connected; null to allocate a root hub
* @bus: bus used to access the device
* @port1: one-based index of port; ignored for root hubs
*
* Context: task context, might sleep.
*
* Only hub drivers (including virtual root hub drivers for host
* controllers) should ever call this.
*
* This call may not be used in a non-sleeping context.
*
* Return: On success, a pointer to the allocated usb device. %NULL on
* failure.
*/
struct usb_device *usb_alloc_dev(struct usb_device *parent,
struct usb_bus *bus, unsigned port1)
{
struct usb_device *dev;
struct usb_hcd *usb_hcd = bus_to_hcd(bus);
unsigned raw_port = port1;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
if (!usb_get_hcd(usb_hcd)) {
kfree(dev);
return NULL;
}
/* Root hubs aren't true devices, so don't allocate HCD resources */
if (usb_hcd->driver->alloc_dev && parent &&
!usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
usb_put_hcd(bus_to_hcd(bus));
kfree(dev);
return NULL;
}
device_initialize(&dev->dev);
dev->dev.bus = &usb_bus_type;
dev->dev.type = &usb_device_type;
dev->dev.groups = usb_device_groups;
set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
dev->state = USB_STATE_ATTACHED;
dev->lpm_disable_count = 1;
atomic_set(&dev->urbnum, 0);
INIT_LIST_HEAD(&dev->ep0.urb_list);
dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
/* ep0 maxpacket comes later, from device descriptor */
usb_enable_endpoint(dev, &dev->ep0, false);
dev->can_submit = 1;
/* Save readable and stable topology id, distinguishing devices
* by location for diagnostics, tools, driver model, etc. The
* string is a path along hub ports, from the root. Each device's
* dev->devpath will be stable until USB is re-cabled, and hubs
* are often labeled with these port numbers. The name isn't
* as stable: bus->busnum changes easily from modprobe order,
* cardbus or pci hotplugging, and so on.
*/
if (unlikely(!parent)) {
dev->devpath[0] = '0';
dev->route = 0;
dev->dev.parent = bus->controller;
device_set_of_node_from_dev(&dev->dev, bus->sysdev);
dev_set_name(&dev->dev, "usb%d", bus->busnum);
} else {
/* match any labeling on the hubs; it's one-based */
if (parent->devpath[0] == '0') {
snprintf(dev->devpath, sizeof dev->devpath,
"%d", port1);
/* Root ports are not counted in route string */
dev->route = 0;
} else {
snprintf(dev->devpath, sizeof dev->devpath,
"%s.%d", parent->devpath, port1);
/* Route string assumes hubs have less than 16 ports */
if (port1 < 15)
dev->route = parent->route +
(port1 << ((parent->level - 1)*4));
else
dev->route = parent->route +
(15 << ((parent->level - 1)*4));
}
dev->dev.parent = &parent->dev;
dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
if (!parent->parent) {
/* device under root hub's port */
raw_port = usb_hcd_find_raw_port_number(usb_hcd,
port1);
}
dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
/* hub driver sets up TT records */
}
dev->portnum = port1;
dev->bus = bus;
dev->parent = parent;
INIT_LIST_HEAD(&dev->filelist);
#ifdef CONFIG_PM
pm_runtime_set_autosuspend_delay(&dev->dev,
usb_autosuspend_delay * 1000);
dev->connect_time = jiffies;
dev->active_duration = -jiffies;
#endif
dev->authorized = usb_dev_authorized(dev, usb_hcd);
return dev;
}
EXPORT_SYMBOL_GPL(usb_alloc_dev);
/**
* usb_get_dev - increments the reference count of the usb device structure
* @dev: the device being referenced
*
* Each live reference to a device should be refcounted.
*
* Drivers for USB interfaces should normally record such references in
* their probe() methods, when they bind to an interface, and release
* them by calling usb_put_dev(), in their disconnect() methods.
* However, if a driver does not access the usb_device structure after
* its disconnect() method returns then refcounting is not necessary,
* because the USB core guarantees that a usb_device will not be
* deallocated until after all of its interface drivers have been unbound.
*
* Return: A pointer to the device with the incremented reference counter.
*/
struct usb_device *usb_get_dev(struct usb_device *dev)
{
if (dev)
get_device(&dev->dev);
return dev;
}
EXPORT_SYMBOL_GPL(usb_get_dev);
/**
* usb_put_dev - release a use of the usb device structure
* @dev: device that's been disconnected
*
* Must be called when a user of a device is finished with it. When the last
* user of the device calls this function, the memory of the device is freed.
*/
void usb_put_dev(struct usb_device *dev)
{
if (dev)
put_device(&dev->dev);
}
EXPORT_SYMBOL_GPL(usb_put_dev);
/**
* usb_get_intf - increments the reference count of the usb interface structure
* @intf: the interface being referenced
*
* Each live reference to a interface must be refcounted.
*
* Drivers for USB interfaces should normally record such references in
* their probe() methods, when they bind to an interface, and release
* them by calling usb_put_intf(), in their disconnect() methods.
* However, if a driver does not access the usb_interface structure after
* its disconnect() method returns then refcounting is not necessary,
* because the USB core guarantees that a usb_interface will not be
* deallocated until after its driver has been unbound.
*
* Return: A pointer to the interface with the incremented reference counter.
*/
struct usb_interface *usb_get_intf(struct usb_interface *intf)
{
if (intf)
get_device(&intf->dev);
return intf;
}
EXPORT_SYMBOL_GPL(usb_get_intf);
/**
* usb_put_intf - release a use of the usb interface structure
* @intf: interface that's been decremented
*
* Must be called when a user of an interface is finished with it. When the
* last user of the interface calls this function, the memory of the interface
* is freed.
*/
void usb_put_intf(struct usb_interface *intf)
{
if (intf)
put_device(&intf->dev);
}
EXPORT_SYMBOL_GPL(usb_put_intf);
/**
* usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
* @intf: the usb interface
*
* While a USB device cannot perform DMA operations by itself, many USB
* controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
* for the given USB interface, if any. The returned device structure must be
* released with put_device().
*
* See also usb_get_dma_device().
*
* Returns: A reference to the usb interface's DMA endpoint; or NULL if none
* exists.
*/
struct device *usb_intf_get_dma_device(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct device *dmadev;
if (!udev->bus)
return NULL;
dmadev = get_device(udev->bus->sysdev);
if (!dmadev || !dmadev->dma_mask) {
put_device(dmadev);
return NULL;
}
return dmadev;
}
EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
/* USB device locking
*
* USB devices and interfaces are locked using the semaphore in their
* embedded struct device. The hub driver guarantees that whenever a
* device is connected or disconnected, drivers are called with the
* USB device locked as well as their particular interface.
*
* Complications arise when several devices are to be locked at the same
* time. Only hub-aware drivers that are part of usbcore ever have to
* do this; nobody else needs to worry about it. The rule for locking
* is simple:
*
* When locking both a device and its parent, always lock the
* parent first.
*/
/**
* usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
* @udev: device that's being locked
* @iface: interface bound to the driver making the request (optional)
*
* Attempts to acquire the device lock, but fails if the device is
* NOTATTACHED or SUSPENDED, or if iface is specified and the interface
* is neither BINDING nor BOUND. Rather than sleeping to wait for the
* lock, the routine polls repeatedly. This is to prevent deadlock with
* disconnect; in some drivers (such as usb-storage) the disconnect()
* or suspend() method will block waiting for a device reset to complete.
*
* Return: A negative error code for failure, otherwise 0.
*/
int usb_lock_device_for_reset(struct usb_device *udev,
const struct usb_interface *iface)
{
unsigned long jiffies_expire = jiffies + HZ;
if (udev->state == USB_STATE_NOTATTACHED)
return -ENODEV;
if (udev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
iface->condition == USB_INTERFACE_UNBOUND))
return -EINTR;
while (!usb_trylock_device(udev)) {
/* If we can't acquire the lock after waiting one second,
* we're probably deadlocked */
if (time_after(jiffies, jiffies_expire))
return -EBUSY;
msleep(15);
if (udev->state == USB_STATE_NOTATTACHED)
return -ENODEV;
if (udev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
iface->condition == USB_INTERFACE_UNBOUND))
return -EINTR;
}
return 0;
}
EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
/**
* usb_get_current_frame_number - return current bus frame number
* @dev: the device whose bus is being queried
*
* Return: The current frame number for the USB host controller used
* with the given USB device. This can be used when scheduling
* isochronous requests.
*
* Note: Different kinds of host controller have different "scheduling
* horizons". While one type might support scheduling only 32 frames
* into the future, others could support scheduling up to 1024 frames
* into the future.
*
*/
int usb_get_current_frame_number(struct usb_device *dev)
{
return usb_hcd_get_frame_number(dev);
}
EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
/*-------------------------------------------------------------------*/
/*
* __usb_get_extra_descriptor() finds a descriptor of specific type in the
* extra field of the interface and endpoint descriptor structs.
*/
int __usb_get_extra_descriptor(char *buffer, unsigned size,
unsigned char type, void **ptr, size_t minsize)
{
struct usb_descriptor_header *header;
while (size >= sizeof(struct usb_descriptor_header)) {
header = (struct usb_descriptor_header *)buffer;
if (header->bLength < 2 || header->bLength > size) {
printk(KERN_ERR
"%s: bogus descriptor, type %d length %d\n",
usbcore_name,
header->bDescriptorType,
header->bLength);
return -1;
}
if (header->bDescriptorType == type && header->bLength >= minsize) {
*ptr = header;
return 0;
}
buffer += header->bLength;
size -= header->bLength;
}
return -1;
}
EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
/**
* usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
* @dev: device the buffer will be used with
* @size: requested buffer size
* @mem_flags: affect whether allocation may block
* @dma: used to return DMA address of buffer
*
* Return: Either null (indicating no buffer could be allocated), or the
* cpu-space pointer to a buffer that may be used to perform DMA to the
* specified device. Such cpu-space buffers are returned along with the DMA
* address (through the pointer provided).
*
* Note:
* These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
* to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
* hardware during URB completion/resubmit. The implementation varies between
* platforms, depending on details of how DMA will work to this device.
* Using these buffers also eliminates cacheline sharing problems on
* architectures where CPU caches are not DMA-coherent. On systems without
* bus-snooping caches, these buffers are uncached.
*
* When the buffer is no longer used, free it with usb_free_coherent().
*/
void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
dma_addr_t *dma)
{
if (!dev || !dev->bus)
return NULL;
return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
}
EXPORT_SYMBOL_GPL(usb_alloc_coherent);
/**
* usb_free_coherent - free memory allocated with usb_alloc_coherent()
* @dev: device the buffer was used with
* @size: requested buffer size
* @addr: CPU address of buffer
* @dma: DMA address of buffer
*
* This reclaims an I/O buffer, letting it be reused. The memory must have
* been allocated using usb_alloc_coherent(), and the parameters must match
* those provided in that allocation request.
*/
void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
dma_addr_t dma)
{
if (!dev || !dev->bus)
return;
if (!addr)
return;
hcd_buffer_free(dev->bus, size, addr, dma);
}
EXPORT_SYMBOL_GPL(usb_free_coherent);
/*
* Notifications of device and interface registration
*/
static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
void *data)
{
struct device *dev = data;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
if (dev->type == &usb_device_type)
(void) usb_create_sysfs_dev_files(to_usb_device(dev));
else if (dev->type == &usb_if_device_type)
usb_create_sysfs_intf_files(to_usb_interface(dev));
break;
case BUS_NOTIFY_DEL_DEVICE:
if (dev->type == &usb_device_type)
usb_remove_sysfs_dev_files(to_usb_device(dev));
else if (dev->type == &usb_if_device_type)
usb_remove_sysfs_intf_files(to_usb_interface(dev));
break;
}
return 0;
}
static struct notifier_block usb_bus_nb = {
.notifier_call = usb_bus_notify,
};
static void usb_debugfs_init(void)
{
debugfs_create_file("devices", 0444, usb_debug_root, NULL,
&usbfs_devices_fops);
}
static void usb_debugfs_cleanup(void)
{
debugfs_lookup_and_remove("devices", usb_debug_root);
}
/*
* Init
*/
static int __init usb_init(void)
{
int retval;
if (usb_disabled()) {
pr_info("%s: USB support disabled\n", usbcore_name);
return 0;
}
usb_init_pool_max();
usb_debugfs_init();
usb_acpi_register();
retval = bus_register(&usb_bus_type);
if (retval)
goto bus_register_failed;
retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
if (retval)
goto bus_notifier_failed;
retval = usb_major_init();
if (retval)
goto major_init_failed;
retval = class_register(&usbmisc_class);
if (retval)
goto class_register_failed;
retval = usb_register(&usbfs_driver);
if (retval)
goto driver_register_failed;
retval = usb_devio_init();
if (retval)
goto usb_devio_init_failed;
retval = usb_hub_init();
if (retval)
goto hub_init_failed;
retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
if (!retval)
goto out;
usb_hub_cleanup();
hub_init_failed:
usb_devio_cleanup();
usb_devio_init_failed:
usb_deregister(&usbfs_driver);
driver_register_failed:
class_unregister(&usbmisc_class);
class_register_failed:
usb_major_cleanup();
major_init_failed:
bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
bus_notifier_failed:
bus_unregister(&usb_bus_type);
bus_register_failed:
usb_acpi_unregister();
usb_debugfs_cleanup();
out:
return retval;
}
/*
* Cleanup
*/
static void __exit usb_exit(void)
{
/* This will matter if shutdown/reboot does exitcalls. */
if (usb_disabled())
return;
usb_release_quirk_list();
usb_deregister_device_driver(&usb_generic_driver);
usb_major_cleanup();
usb_deregister(&usbfs_driver);
usb_devio_cleanup();
usb_hub_cleanup();
class_unregister(&usbmisc_class);
bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
bus_unregister(&usb_bus_type);
usb_acpi_unregister();
usb_debugfs_cleanup();
idr_destroy(&usb_bus_idr);
}
subsys_initcall(usb_init);
module_exit(usb_exit);
MODULE_DESCRIPTION("USB core host-side support");
MODULE_LICENSE("GPL");
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