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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/usb/core/usb.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/usb/core/usb.c')
-rw-r--r--drivers/usb/core/usb.c1159
1 files changed, 1159 insertions, 0 deletions
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
new file mode 100644
index 000000000..3500e3c94
--- /dev/null
+++ b/drivers/usb/core/usb.c
@@ -0,0 +1,1159 @@
+// 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/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->drvwrap.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(struct device *dev, struct kobj_uevent_env *env)
+{
+ 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(struct device *dev,
+ umode_t *mode, kuid_t *uid, kgid_t *gid)
+{
+ 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);
+}
+
+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
+};
+
+
+/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
+static unsigned usb_bus_is_wusb(struct usb_bus *bus)
+{
+ struct usb_hcd *hcd = bus_to_hcd(bus);
+ return hcd->wireless;
+}
+
+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 root_hub = 0;
+ 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);
+ root_hub = 1;
+ } 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);
+ if (!root_hub)
+ dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
+
+ 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 = 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:
+ 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();
+ 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_LICENSE("GPL");