Google Git
Sign in
gem5 / arm / linux-arm64-legacy / ba516de332c0e574457e58fb5aa0293e628b7b10 / . / drivers / usb / core / hcd.c
blob: 95ccfa0b9fc52876f5166b3edea039409adf9a33 [file] [log] [blame]
/*
* (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
* (C) Copyright Randy Dunlap 2000
* (C) Copyright David Brownell 2000-2002
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/utsname.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/mutex.h>
#include <asm/irq.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
#include <linux/usb.h>
#include "usb.h"
#include "hcd.h"
#include "hub.h"
/*-------------------------------------------------------------------------*/
/*
* USB Host Controller Driver framework
*
* Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
* HCD-specific behaviors/bugs.
*
* This does error checks, tracks devices and urbs, and delegates to a
* "hc_driver" only for code (and data) that really needs to know about
* hardware differences. That includes root hub registers, i/o queues,
* and so on ... but as little else as possible.
*
* Shared code includes most of the "root hub" code (these are emulated,
* though each HC's hardware works differently) and PCI glue, plus request
* tracking overhead. The HCD code should only block on spinlocks or on
* hardware handshaking; blocking on software events (such as other kernel
* threads releasing resources, or completing actions) is all generic.
*
* Happens the USB 2.0 spec says this would be invisible inside the "USBD",
* and includes mostly a "HCDI" (HCD Interface) along with some APIs used
* only by the hub driver ... and that neither should be seen or used by
* usb client device drivers.
*
* Contributors of ideas or unattributed patches include: David Brownell,
* Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
*
* HISTORY:
* 2002-02-21 Pull in most of the usb_bus support from usb.c; some
* associated cleanup. "usb_hcd" still != "usb_bus".
* 2001-12-12 Initial patch version for Linux 2.5.1 kernel.
*/
/*-------------------------------------------------------------------------*/
/* Keep track of which host controller drivers are loaded */
unsigned long usb_hcds_loaded;
EXPORT_SYMBOL_GPL(usb_hcds_loaded);
/* host controllers we manage */
LIST_HEAD (usb_bus_list);
EXPORT_SYMBOL_GPL (usb_bus_list);
/* used when allocating bus numbers */
#define USB_MAXBUS 64
struct usb_busmap {
unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
};
static struct usb_busmap busmap;
/* used when updating list of hcds */
DEFINE_MUTEX(usb_bus_list_lock); /* exported only for usbfs */
EXPORT_SYMBOL_GPL (usb_bus_list_lock);
/* used for controlling access to virtual root hubs */
static DEFINE_SPINLOCK(hcd_root_hub_lock);
/* used when updating an endpoint's URB list */
static DEFINE_SPINLOCK(hcd_urb_list_lock);
/* used to protect against unlinking URBs after the device is gone */
static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
/* wait queue for synchronous unlinks */
DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
static inline int is_root_hub(struct usb_device *udev)
{
return (udev->parent == NULL);
}
/*-------------------------------------------------------------------------*/
/*
* Sharable chunks of root hub code.
*/
/*-------------------------------------------------------------------------*/
#define KERNEL_REL ((LINUX_VERSION_CODE >> 16) & 0x0ff)
#define KERNEL_VER ((LINUX_VERSION_CODE >> 8) & 0x0ff)
/* usb 3.0 root hub device descriptor */
static const u8 usb3_rh_dev_descriptor[18] = {
0x12, /* __u8 bLength; */
0x01, /* __u8 bDescriptorType; Device */
0x00, 0x03, /* __le16 bcdUSB; v3.0 */
0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
0x00, /* __u8 bDeviceSubClass; */
0x03, /* __u8 bDeviceProtocol; USB 3.0 hub */
0x09, /* __u8 bMaxPacketSize0; 2^9 = 512 Bytes */
0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
0x02, 0x00, /* __le16 idProduct; device 0x0002 */
KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
0x03, /* __u8 iManufacturer; */
0x02, /* __u8 iProduct; */
0x01, /* __u8 iSerialNumber; */
0x01 /* __u8 bNumConfigurations; */
};
/* usb 2.0 root hub device descriptor */
static const u8 usb2_rh_dev_descriptor [18] = {
0x12, /* __u8 bLength; */
0x01, /* __u8 bDescriptorType; Device */
0x00, 0x02, /* __le16 bcdUSB; v2.0 */
0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
0x00, /* __u8 bDeviceSubClass; */
0x00, /* __u8 bDeviceProtocol; [ usb 2.0 no TT ] */
0x40, /* __u8 bMaxPacketSize0; 64 Bytes */
0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
0x02, 0x00, /* __le16 idProduct; device 0x0002 */
KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
0x03, /* __u8 iManufacturer; */
0x02, /* __u8 iProduct; */
0x01, /* __u8 iSerialNumber; */
0x01 /* __u8 bNumConfigurations; */
};
/* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
/* usb 1.1 root hub device descriptor */
static const u8 usb11_rh_dev_descriptor [18] = {
0x12, /* __u8 bLength; */
0x01, /* __u8 bDescriptorType; Device */
0x10, 0x01, /* __le16 bcdUSB; v1.1 */
0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
0x00, /* __u8 bDeviceSubClass; */
0x00, /* __u8 bDeviceProtocol; [ low/full speeds only ] */
0x40, /* __u8 bMaxPacketSize0; 64 Bytes */
0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
0x01, 0x00, /* __le16 idProduct; device 0x0001 */
KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
0x03, /* __u8 iManufacturer; */
0x02, /* __u8 iProduct; */
0x01, /* __u8 iSerialNumber; */
0x01 /* __u8 bNumConfigurations; */
};
/*-------------------------------------------------------------------------*/
/* Configuration descriptors for our root hubs */
static const u8 fs_rh_config_descriptor [] = {
/* one configuration */
0x09, /* __u8 bLength; */
0x02, /* __u8 bDescriptorType; Configuration */
0x19, 0x00, /* __le16 wTotalLength; */
0x01, /* __u8 bNumInterfaces; (1) */
0x01, /* __u8 bConfigurationValue; */
0x00, /* __u8 iConfiguration; */
0xc0, /* __u8 bmAttributes;
Bit 7: must be set,
6: Self-powered,
5: Remote wakeup,
4..0: resvd */
0x00, /* __u8 MaxPower; */
/* USB 1.1:
* USB 2.0, single TT organization (mandatory):
* one interface, protocol 0
*
* USB 2.0, multiple TT organization (optional):
* two interfaces, protocols 1 (like single TT)
* and 2 (multiple TT mode) ... config is
* sometimes settable
* NOT IMPLEMENTED
*/
/* one interface */
0x09, /* __u8 if_bLength; */
0x04, /* __u8 if_bDescriptorType; Interface */
0x00, /* __u8 if_bInterfaceNumber; */
0x00, /* __u8 if_bAlternateSetting; */
0x01, /* __u8 if_bNumEndpoints; */
0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
0x00, /* __u8 if_bInterfaceSubClass; */
0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */
0x00, /* __u8 if_iInterface; */
/* one endpoint (status change endpoint) */
0x07, /* __u8 ep_bLength; */
0x05, /* __u8 ep_bDescriptorType; Endpoint */
0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
0x03, /* __u8 ep_bmAttributes; Interrupt */
0x02, 0x00, /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
0xff /* __u8 ep_bInterval; (255ms -- usb 2.0 spec) */
};
static const u8 hs_rh_config_descriptor [] = {
/* one configuration */
0x09, /* __u8 bLength; */
0x02, /* __u8 bDescriptorType; Configuration */
0x19, 0x00, /* __le16 wTotalLength; */
0x01, /* __u8 bNumInterfaces; (1) */
0x01, /* __u8 bConfigurationValue; */
0x00, /* __u8 iConfiguration; */
0xc0, /* __u8 bmAttributes;
Bit 7: must be set,
6: Self-powered,
5: Remote wakeup,
4..0: resvd */
0x00, /* __u8 MaxPower; */
/* USB 1.1:
* USB 2.0, single TT organization (mandatory):
* one interface, protocol 0
*
* USB 2.0, multiple TT organization (optional):
* two interfaces, protocols 1 (like single TT)
* and 2 (multiple TT mode) ... config is
* sometimes settable
* NOT IMPLEMENTED
*/
/* one interface */
0x09, /* __u8 if_bLength; */
0x04, /* __u8 if_bDescriptorType; Interface */
0x00, /* __u8 if_bInterfaceNumber; */
0x00, /* __u8 if_bAlternateSetting; */
0x01, /* __u8 if_bNumEndpoints; */
0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
0x00, /* __u8 if_bInterfaceSubClass; */
0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */
0x00, /* __u8 if_iInterface; */
/* one endpoint (status change endpoint) */
0x07, /* __u8 ep_bLength; */
0x05, /* __u8 ep_bDescriptorType; Endpoint */
0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
0x03, /* __u8 ep_bmAttributes; Interrupt */
/* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
* see hub.c:hub_configure() for details. */
(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
0x0c /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */
};
static const u8 ss_rh_config_descriptor[] = {
/* one configuration */
0x09, /* __u8 bLength; */
0x02, /* __u8 bDescriptorType; Configuration */
0x19, 0x00, /* __le16 wTotalLength; FIXME */
0x01, /* __u8 bNumInterfaces; (1) */
0x01, /* __u8 bConfigurationValue; */
0x00, /* __u8 iConfiguration; */
0xc0, /* __u8 bmAttributes;
Bit 7: must be set,
6: Self-powered,
5: Remote wakeup,
4..0: resvd */
0x00, /* __u8 MaxPower; */
/* one interface */
0x09, /* __u8 if_bLength; */
0x04, /* __u8 if_bDescriptorType; Interface */
0x00, /* __u8 if_bInterfaceNumber; */
0x00, /* __u8 if_bAlternateSetting; */
0x01, /* __u8 if_bNumEndpoints; */
0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
0x00, /* __u8 if_bInterfaceSubClass; */
0x00, /* __u8 if_bInterfaceProtocol; */
0x00, /* __u8 if_iInterface; */
/* one endpoint (status change endpoint) */
0x07, /* __u8 ep_bLength; */
0x05, /* __u8 ep_bDescriptorType; Endpoint */
0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
0x03, /* __u8 ep_bmAttributes; Interrupt */
/* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
* see hub.c:hub_configure() for details. */
(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
0x0c /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */
/*
* All 3.0 hubs should have an endpoint companion descriptor,
* but we're ignoring that for now. FIXME?
*/
};
/*-------------------------------------------------------------------------*/
/*
* helper routine for returning string descriptors in UTF-16LE
* input can actually be ISO-8859-1; ASCII is its 7-bit subset
*/
static unsigned ascii2utf(char *s, u8 *utf, int utfmax)
{
unsigned retval;
for (retval = 0; *s && utfmax > 1; utfmax -= 2, retval += 2) {
*utf++ = *s++;
*utf++ = 0;
}
if (utfmax > 0) {
*utf = *s;
++retval;
}
return retval;
}
/*
* rh_string - provides manufacturer, product and serial strings for root hub
* @id: the string ID number (1: serial number, 2: product, 3: vendor)
* @hcd: the host controller for this root hub
* @data: return packet in UTF-16 LE
* @len: length of the return packet
*
* Produces either a manufacturer, product or serial number string for the
* virtual root hub device.
*/
static unsigned rh_string(int id, struct usb_hcd *hcd, u8 *data, unsigned len)
{
char buf [100];
// language ids
if (id == 0) {
buf[0] = 4; buf[1] = 3; /* 4 bytes string data */
buf[2] = 0x09; buf[3] = 0x04; /* MSFT-speak for "en-us" */
len = min_t(unsigned, len, 4);
memcpy (data, buf, len);
return len;
// serial number
} else if (id == 1) {
strlcpy (buf, hcd->self.bus_name, sizeof buf);
// product description
} else if (id == 2) {
strlcpy (buf, hcd->product_desc, sizeof buf);
// id 3 == vendor description
} else if (id == 3) {
snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
init_utsname()->release, hcd->driver->description);
}
switch (len) { /* All cases fall through */
default:
len = 2 + ascii2utf (buf, data + 2, len - 2);
case 2:
data [1] = 3; /* type == string */
case 1:
data [0] = 2 * (strlen (buf) + 1);
case 0:
; /* Compiler wants a statement here */
}
return len;
}
/* Root hub control transfers execute synchronously */
static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
{
struct usb_ctrlrequest *cmd;
u16 typeReq, wValue, wIndex, wLength;
u8 *ubuf = urb->transfer_buffer;
u8 tbuf [sizeof (struct usb_hub_descriptor)]
__attribute__((aligned(4)));
const u8 *bufp = tbuf;
unsigned len = 0;
int status;
u8 patch_wakeup = 0;
u8 patch_protocol = 0;
might_sleep();
spin_lock_irq(&hcd_root_hub_lock);
status = usb_hcd_link_urb_to_ep(hcd, urb);
spin_unlock_irq(&hcd_root_hub_lock);
if (status)
return status;
urb->hcpriv = hcd; /* Indicate it's queued */
cmd = (struct usb_ctrlrequest *) urb->setup_packet;
typeReq = (cmd->bRequestType << 8) | cmd->bRequest;
wValue = le16_to_cpu (cmd->wValue);
wIndex = le16_to_cpu (cmd->wIndex);
wLength = le16_to_cpu (cmd->wLength);
if (wLength > urb->transfer_buffer_length)
goto error;
urb->actual_length = 0;
switch (typeReq) {
/* DEVICE REQUESTS */
/* The root hub's remote wakeup enable bit is implemented using
* driver model wakeup flags. If this system supports wakeup
* through USB, userspace may change the default "allow wakeup"
* policy through sysfs or these calls.
*
* Most root hubs support wakeup from downstream devices, for
* runtime power management (disabling USB clocks and reducing
* VBUS power usage). However, not all of them do so; silicon,
* board, and BIOS bugs here are not uncommon, so these can't
* be treated quite like external hubs.
*
* Likewise, not all root hubs will pass wakeup events upstream,
* to wake up the whole system. So don't assume root hub and
* controller capabilities are identical.
*/
case DeviceRequest | USB_REQ_GET_STATUS:
tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
<< USB_DEVICE_REMOTE_WAKEUP)
| (1 << USB_DEVICE_SELF_POWERED);
tbuf [1] = 0;
len = 2;
break;
case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
if (wValue == USB_DEVICE_REMOTE_WAKEUP)
device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
else
goto error;
break;
case DeviceOutRequest | USB_REQ_SET_FEATURE:
if (device_can_wakeup(&hcd->self.root_hub->dev)
&& wValue == USB_DEVICE_REMOTE_WAKEUP)
device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
else
goto error;
break;
case DeviceRequest | USB_REQ_GET_CONFIGURATION:
tbuf [0] = 1;
len = 1;
/* FALLTHROUGH */
case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
break;
case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
switch (wValue & 0xff00) {
case USB_DT_DEVICE << 8:
switch (hcd->driver->flags & HCD_MASK) {
case HCD_USB3:
bufp = usb3_rh_dev_descriptor;
break;
case HCD_USB2:
bufp = usb2_rh_dev_descriptor;
break;
case HCD_USB11:
bufp = usb11_rh_dev_descriptor;
break;
default:
goto error;
}
len = 18;
if (hcd->has_tt)
patch_protocol = 1;
break;
case USB_DT_CONFIG << 8:
switch (hcd->driver->flags & HCD_MASK) {
case HCD_USB3:
bufp = ss_rh_config_descriptor;
len = sizeof ss_rh_config_descriptor;
break;
case HCD_USB2:
bufp = hs_rh_config_descriptor;
len = sizeof hs_rh_config_descriptor;
break;
case HCD_USB11:
bufp = fs_rh_config_descriptor;
len = sizeof fs_rh_config_descriptor;
break;
default:
goto error;
}
if (device_can_wakeup(&hcd->self.root_hub->dev))
patch_wakeup = 1;
break;
case USB_DT_STRING << 8:
if ((wValue & 0xff) < 4)
urb->actual_length = rh_string(wValue & 0xff,
hcd, ubuf, wLength);
else /* unsupported IDs --> "protocol stall" */
goto error;
break;
default:
goto error;
}
break;
case DeviceRequest | USB_REQ_GET_INTERFACE:
tbuf [0] = 0;
len = 1;
/* FALLTHROUGH */
case DeviceOutRequest | USB_REQ_SET_INTERFACE:
break;
case DeviceOutRequest | USB_REQ_SET_ADDRESS:
// wValue == urb->dev->devaddr
dev_dbg (hcd->self.controller, "root hub device address %d\n",
wValue);
break;
/* INTERFACE REQUESTS (no defined feature/status flags) */
/* ENDPOINT REQUESTS */
case EndpointRequest | USB_REQ_GET_STATUS:
// ENDPOINT_HALT flag
tbuf [0] = 0;
tbuf [1] = 0;
len = 2;
/* FALLTHROUGH */
case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
case EndpointOutRequest | USB_REQ_SET_FEATURE:
dev_dbg (hcd->self.controller, "no endpoint features yet\n");
break;
/* CLASS REQUESTS (and errors) */
default:
/* non-generic request */
switch (typeReq) {
case GetHubStatus:
case GetPortStatus:
len = 4;
break;
case GetHubDescriptor:
len = sizeof (struct usb_hub_descriptor);
break;
}
status = hcd->driver->hub_control (hcd,
typeReq, wValue, wIndex,
tbuf, wLength);
break;
error:
/* "protocol stall" on error */
status = -EPIPE;
}
if (status) {
len = 0;
if (status != -EPIPE) {
dev_dbg (hcd->self.controller,
"CTRL: TypeReq=0x%x val=0x%x "
"idx=0x%x len=%d ==> %d\n",
typeReq, wValue, wIndex,
wLength, status);
}
}
if (len) {
if (urb->transfer_buffer_length < len)
len = urb->transfer_buffer_length;
urb->actual_length = len;
// always USB_DIR_IN, toward host
memcpy (ubuf, bufp, len);
/* report whether RH hardware supports remote wakeup */
if (patch_wakeup &&
len > offsetof (struct usb_config_descriptor,
bmAttributes))
((struct usb_config_descriptor *)ubuf)->bmAttributes
|= USB_CONFIG_ATT_WAKEUP;
/* report whether RH hardware has an integrated TT */
if (patch_protocol &&
len > offsetof(struct usb_device_descriptor,
bDeviceProtocol))
((struct usb_device_descriptor *) ubuf)->
bDeviceProtocol = 1;
}
/* any errors get returned through the urb completion */
spin_lock_irq(&hcd_root_hub_lock);
usb_hcd_unlink_urb_from_ep(hcd, urb);
/* This peculiar use of spinlocks echoes what real HC drivers do.
* Avoiding calls to local_irq_disable/enable makes the code
* RT-friendly.
*/
spin_unlock(&hcd_root_hub_lock);
usb_hcd_giveback_urb(hcd, urb, status);
spin_lock(&hcd_root_hub_lock);
spin_unlock_irq(&hcd_root_hub_lock);
return 0;
}
/*-------------------------------------------------------------------------*/
/*
* Root Hub interrupt transfers are polled using a timer if the
* driver requests it; otherwise the driver is responsible for
* calling usb_hcd_poll_rh_status() when an event occurs.
*
* Completions are called in_interrupt(), but they may or may not
* be in_irq().
*/
void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
{
struct urb *urb;
int length;
unsigned long flags;
char buffer[6]; /* Any root hubs with > 31 ports? */
if (unlikely(!hcd->rh_registered))
return;
if (!hcd->uses_new_polling && !hcd->status_urb)
return;
length = hcd->driver->hub_status_data(hcd, buffer);
if (length > 0) {
/* try to complete the status urb */
spin_lock_irqsave(&hcd_root_hub_lock, flags);
urb = hcd->status_urb;
if (urb) {
hcd->poll_pending = 0;
hcd->status_urb = NULL;
urb->actual_length = length;
memcpy(urb->transfer_buffer, buffer, length);
usb_hcd_unlink_urb_from_ep(hcd, urb);
spin_unlock(&hcd_root_hub_lock);
usb_hcd_giveback_urb(hcd, urb, 0);
spin_lock(&hcd_root_hub_lock);
} else {
length = 0;
hcd->poll_pending = 1;
}
spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
}
/* The USB 2.0 spec says 256 ms. This is close enough and won't
* exceed that limit if HZ is 100. The math is more clunky than
* maybe expected, this is to make sure that all timers for USB devices
* fire at the same time to give the CPU a break inbetween */
if (hcd->uses_new_polling ? hcd->poll_rh :
(length == 0 && hcd->status_urb != NULL))
mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
}
EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
/* timer callback */
static void rh_timer_func (unsigned long _hcd)
{
usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
}
/*-------------------------------------------------------------------------*/
static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
{
int retval;
unsigned long flags;
unsigned len = 1 + (urb->dev->maxchild / 8);
spin_lock_irqsave (&hcd_root_hub_lock, flags);
if (hcd->status_urb || urb->transfer_buffer_length < len) {
dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
retval = -EINVAL;
goto done;
}
retval = usb_hcd_link_urb_to_ep(hcd, urb);
if (retval)
goto done;
hcd->status_urb = urb;
urb->hcpriv = hcd; /* indicate it's queued */
if (!hcd->uses_new_polling)
mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
/* If a status change has already occurred, report it ASAP */
else if (hcd->poll_pending)
mod_timer(&hcd->rh_timer, jiffies);
retval = 0;
done:
spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
return retval;
}
static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
{
if (usb_endpoint_xfer_int(&urb->ep->desc))
return rh_queue_status (hcd, urb);
if (usb_endpoint_xfer_control(&urb->ep->desc))
return rh_call_control (hcd, urb);
return -EINVAL;
}
/*-------------------------------------------------------------------------*/
/* Unlinks of root-hub control URBs are legal, but they don't do anything
* since these URBs always execute synchronously.
*/
static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
unsigned long flags;
int rc;
spin_lock_irqsave(&hcd_root_hub_lock, flags);
rc = usb_hcd_check_unlink_urb(hcd, urb, status);
if (rc)
goto done;
if (usb_endpoint_num(&urb->ep->desc) == 0) { /* Control URB */
; /* Do nothing */
} else { /* Status URB */
if (!hcd->uses_new_polling)
del_timer (&hcd->rh_timer);
if (urb == hcd->status_urb) {
hcd->status_urb = NULL;
usb_hcd_unlink_urb_from_ep(hcd, urb);
spin_unlock(&hcd_root_hub_lock);
usb_hcd_giveback_urb(hcd, urb, status);
spin_lock(&hcd_root_hub_lock);
}
}
done:
spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
return rc;
}
/*
* Show & store the current value of authorized_default
*/
static ssize_t usb_host_authorized_default_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct usb_device *rh_usb_dev = to_usb_device(dev);
struct usb_bus *usb_bus = rh_usb_dev->bus;
struct usb_hcd *usb_hcd;
if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
return -ENODEV;
usb_hcd = bus_to_hcd(usb_bus);
return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
}
static ssize_t usb_host_authorized_default_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
ssize_t result;
unsigned val;
struct usb_device *rh_usb_dev = to_usb_device(dev);
struct usb_bus *usb_bus = rh_usb_dev->bus;
struct usb_hcd *usb_hcd;
if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
return -ENODEV;
usb_hcd = bus_to_hcd(usb_bus);
result = sscanf(buf, "%u\n", &val);
if (result == 1) {
usb_hcd->authorized_default = val? 1 : 0;
result = size;
}
else
result = -EINVAL;
return result;
}
static DEVICE_ATTR(authorized_default, 0644,
usb_host_authorized_default_show,
usb_host_authorized_default_store);
/* Group all the USB bus attributes */
static struct attribute *usb_bus_attrs[] = {
&dev_attr_authorized_default.attr,
NULL,
};
static struct attribute_group usb_bus_attr_group = {
.name = NULL, /* we want them in the same directory */
.attrs = usb_bus_attrs,
};
/*-------------------------------------------------------------------------*/
/**
* usb_bus_init - shared initialization code
* @bus: the bus structure being initialized
*
* This code is used to initialize a usb_bus structure, memory for which is
* separately managed.
*/
static void usb_bus_init (struct usb_bus *bus)
{
memset (&bus->devmap, 0, sizeof(struct usb_devmap));
bus->devnum_next = 1;
bus->root_hub = NULL;
bus->busnum = -1;
bus->bandwidth_allocated = 0;
bus->bandwidth_int_reqs = 0;
bus->bandwidth_isoc_reqs = 0;
INIT_LIST_HEAD (&bus->bus_list);
}
/*-------------------------------------------------------------------------*/
/**
* usb_register_bus - registers the USB host controller with the usb core
* @bus: pointer to the bus to register
* Context: !in_interrupt()
*
* Assigns a bus number, and links the controller into usbcore data
* structures so that it can be seen by scanning the bus list.
*/
static int usb_register_bus(struct usb_bus *bus)
{
int result = -E2BIG;
int busnum;
mutex_lock(&usb_bus_list_lock);
busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
if (busnum >= USB_MAXBUS) {
printk (KERN_ERR "%s: too many buses\n", usbcore_name);
goto error_find_busnum;
}
set_bit (busnum, busmap.busmap);
bus->busnum = busnum;
/* Add it to the local list of buses */
list_add (&bus->bus_list, &usb_bus_list);
mutex_unlock(&usb_bus_list_lock);
usb_notify_add_bus(bus);
dev_info (bus->controller, "new USB bus registered, assigned bus "
"number %d\n", bus->busnum);
return 0;
error_find_busnum:
mutex_unlock(&usb_bus_list_lock);
return result;
}
/**
* usb_deregister_bus - deregisters the USB host controller
* @bus: pointer to the bus to deregister
* Context: !in_interrupt()
*
* Recycles the bus number, and unlinks the controller from usbcore data
* structures so that it won't be seen by scanning the bus list.
*/
static void usb_deregister_bus (struct usb_bus *bus)
{
dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
/*
* NOTE: make sure that all the devices are removed by the
* controller code, as well as having it call this when cleaning
* itself up
*/
mutex_lock(&usb_bus_list_lock);
list_del (&bus->bus_list);
mutex_unlock(&usb_bus_list_lock);
usb_notify_remove_bus(bus);
clear_bit (bus->busnum, busmap.busmap);
}
/**
* register_root_hub - called by usb_add_hcd() to register a root hub
* @hcd: host controller for this root hub
*
* This function registers the root hub with the USB subsystem. It sets up
* the device properly in the device tree and then calls usb_new_device()
* to register the usb device. It also assigns the root hub's USB address
* (always 1).
*/
static int register_root_hub(struct usb_hcd *hcd)
{
struct device *parent_dev = hcd->self.controller;
struct usb_device *usb_dev = hcd->self.root_hub;
const int devnum = 1;
int retval;
usb_dev->devnum = devnum;
usb_dev->bus->devnum_next = devnum + 1;
memset (&usb_dev->bus->devmap.devicemap, 0,
sizeof usb_dev->bus->devmap.devicemap);
set_bit (devnum, usb_dev->bus->devmap.devicemap);
usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
mutex_lock(&usb_bus_list_lock);
usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
if (retval != sizeof usb_dev->descriptor) {
mutex_unlock(&usb_bus_list_lock);
dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
dev_name(&usb_dev->dev), retval);
return (retval < 0) ? retval : -EMSGSIZE;
}
retval = usb_new_device (usb_dev);
if (retval) {
dev_err (parent_dev, "can't register root hub for %s, %d\n",
dev_name(&usb_dev->dev), retval);
}
mutex_unlock(&usb_bus_list_lock);
if (retval == 0) {
spin_lock_irq (&hcd_root_hub_lock);
hcd->rh_registered = 1;
spin_unlock_irq (&hcd_root_hub_lock);
/* Did the HC die before the root hub was registered? */
if (hcd->state == HC_STATE_HALT)
usb_hc_died (hcd); /* This time clean up */
}
return retval;
}
/*-------------------------------------------------------------------------*/
/**
* usb_calc_bus_time - approximate periodic transaction time in nanoseconds
* @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
* @is_input: true iff the transaction sends data to the host
* @isoc: true for isochronous transactions, false for interrupt ones
* @bytecount: how many bytes in the transaction.
*
* Returns approximate bus time in nanoseconds for a periodic transaction.
* See USB 2.0 spec section 5.11.3; only periodic transfers need to be
* scheduled in software, this function is only used for such scheduling.
*/
long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
{
unsigned long tmp;
switch (speed) {
case USB_SPEED_LOW: /* INTR only */
if (is_input) {
tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
} else {
tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
}
case USB_SPEED_FULL: /* ISOC or INTR */
if (isoc) {
tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
} else {
tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
return (9107L + BW_HOST_DELAY + tmp);
}
case USB_SPEED_HIGH: /* ISOC or INTR */
// FIXME adjust for input vs output
if (isoc)
tmp = HS_NSECS_ISO (bytecount);
else
tmp = HS_NSECS (bytecount);
return tmp;
default:
pr_debug ("%s: bogus device speed!\n", usbcore_name);
return -1;
}
}
EXPORT_SYMBOL_GPL(usb_calc_bus_time);
/*-------------------------------------------------------------------------*/
/*
* Generic HC operations.
*/
/*-------------------------------------------------------------------------*/
/**
* usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
* @hcd: host controller to which @urb was submitted
* @urb: URB being submitted
*
* Host controller drivers should call this routine in their enqueue()
* method. The HCD's private spinlock must be held and interrupts must
* be disabled. The actions carried out here are required for URB
* submission, as well as for endpoint shutdown and for usb_kill_urb.
*
* Returns 0 for no error, otherwise a negative error code (in which case
* the enqueue() method must fail). If no error occurs but enqueue() fails
* anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
* the private spinlock and returning.
*/
int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
{
int rc = 0;
spin_lock(&hcd_urb_list_lock);
/* Check that the URB isn't being killed */
if (unlikely(atomic_read(&urb->reject))) {
rc = -EPERM;
goto done;
}
if (unlikely(!urb->ep->enabled)) {
rc = -ENOENT;
goto done;
}
if (unlikely(!urb->dev->can_submit)) {
rc = -EHOSTUNREACH;
goto done;
}
/*
* Check the host controller's state and add the URB to the
* endpoint's queue.
*/
switch (hcd->state) {
case HC_STATE_RUNNING:
case HC_STATE_RESUMING:
urb->unlinked = 0;
list_add_tail(&urb->urb_list, &urb->ep->urb_list);
break;
default:
rc = -ESHUTDOWN;
goto done;
}
done:
spin_unlock(&hcd_urb_list_lock);
return rc;
}
EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
/**
* usb_hcd_check_unlink_urb - check whether an URB may be unlinked
* @hcd: host controller to which @urb was submitted
* @urb: URB being checked for unlinkability
* @status: error code to store in @urb if the unlink succeeds
*
* Host controller drivers should call this routine in their dequeue()
* method. The HCD's private spinlock must be held and interrupts must
* be disabled. The actions carried out here are required for making
* sure than an unlink is valid.
*
* Returns 0 for no error, otherwise a negative error code (in which case
* the dequeue() method must fail). The possible error codes are:
*
* -EIDRM: @urb was not submitted or has already completed.
* The completion function may not have been called yet.
*
* -EBUSY: @urb has already been unlinked.
*/
int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
int status)
{
struct list_head *tmp;
/* insist the urb is still queued */
list_for_each(tmp, &urb->ep->urb_list) {
if (tmp == &urb->urb_list)
break;
}
if (tmp != &urb->urb_list)
return -EIDRM;
/* Any status except -EINPROGRESS means something already started to
* unlink this URB from the hardware. So there's no more work to do.
*/
if (urb->unlinked)
return -EBUSY;
urb->unlinked = status;
/* IRQ setup can easily be broken so that USB controllers
* never get completion IRQs ... maybe even the ones we need to
* finish unlinking the initial failed usb_set_address()
* or device descriptor fetch.
*/
if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags) &&
!is_root_hub(urb->dev)) {
dev_warn(hcd->self.controller, "Unlink after no-IRQ? "
"Controller is probably using the wrong IRQ.\n");
set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
}
return 0;
}
EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
/**
* usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
* @hcd: host controller to which @urb was submitted
* @urb: URB being unlinked
*
* Host controller drivers should call this routine before calling
* usb_hcd_giveback_urb(). The HCD's private spinlock must be held and
* interrupts must be disabled. The actions carried out here are required
* for URB completion.
*/
void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
{
/* clear all state linking urb to this dev (and hcd) */
spin_lock(&hcd_urb_list_lock);
list_del_init(&urb->urb_list);
spin_unlock(&hcd_urb_list_lock);
}
EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
/*
* Some usb host controllers can only perform dma using a small SRAM area.
* The usb core itself is however optimized for host controllers that can dma
* using regular system memory - like pci devices doing bus mastering.
*
* To support host controllers with limited dma capabilites we provide dma
* bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
* For this to work properly the host controller code must first use the
* function dma_declare_coherent_memory() to point out which memory area
* that should be used for dma allocations.
*
* The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
* dma using dma_alloc_coherent() which in turn allocates from the memory
* area pointed out with dma_declare_coherent_memory().
*
* So, to summarize...
*
* - We need "local" memory, canonical example being
* a small SRAM on a discrete controller being the
* only memory that the controller can read ...
* (a) "normal" kernel memory is no good, and
* (b) there's not enough to share
*
* - The only *portable* hook for such stuff in the
* DMA framework is dma_declare_coherent_memory()
*
* - So we use that, even though the primary requirement
* is that the memory be "local" (hence addressible
* by that device), not "coherent".
*
*/
static int hcd_alloc_coherent(struct usb_bus *bus,
gfp_t mem_flags, dma_addr_t *dma_handle,
void **vaddr_handle, size_t size,
enum dma_data_direction dir)
{
unsigned char *vaddr;
vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
mem_flags, dma_handle);
if (!vaddr)
return -ENOMEM;
/*
* Store the virtual address of the buffer at the end
* of the allocated dma buffer. The size of the buffer
* may be uneven so use unaligned functions instead
* of just rounding up. It makes sense to optimize for
* memory footprint over access speed since the amount
* of memory available for dma may be limited.
*/
put_unaligned((unsigned long)*vaddr_handle,
(unsigned long *)(vaddr + size));
if (dir == DMA_TO_DEVICE)
memcpy(vaddr, *vaddr_handle, size);
*vaddr_handle = vaddr;
return 0;
}
static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
void **vaddr_handle, size_t size,
enum dma_data_direction dir)
{
unsigned char *vaddr = *vaddr_handle;
vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
if (dir == DMA_FROM_DEVICE)
memcpy(vaddr, *vaddr_handle, size);
hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
*vaddr_handle = vaddr;
*dma_handle = 0;
}
static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
gfp_t mem_flags)
{
enum dma_data_direction dir;
int ret = 0;
/* Map the URB's buffers for DMA access.
* Lower level HCD code should use *_dma exclusively,
* unless it uses pio or talks to another transport,
* or uses the provided scatter gather list for bulk.
*/
if (is_root_hub(urb->dev))
return 0;
if (usb_endpoint_xfer_control(&urb->ep->desc)
&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
if (hcd->self.uses_dma)
urb->setup_dma = dma_map_single(
hcd->self.controller,
urb->setup_packet,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
else if (hcd->driver->flags & HCD_LOCAL_MEM)
ret = hcd_alloc_coherent(
urb->dev->bus, mem_flags,
&urb->setup_dma,
(void **)&urb->setup_packet,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
}
dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
if (ret == 0 && urb->transfer_buffer_length != 0
&& !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
if (hcd->self.uses_dma)
urb->transfer_dma = dma_map_single (
hcd->self.controller,
urb->transfer_buffer,
urb->transfer_buffer_length,
dir);
else if (hcd->driver->flags & HCD_LOCAL_MEM) {
ret = hcd_alloc_coherent(
urb->dev->bus, mem_flags,
&urb->transfer_dma,
&urb->transfer_buffer,
urb->transfer_buffer_length,
dir);
if (ret && usb_endpoint_xfer_control(&urb->ep->desc)
&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
hcd_free_coherent(urb->dev->bus,
&urb->setup_dma,
(void **)&urb->setup_packet,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
}
}
return ret;
}
static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
enum dma_data_direction dir;
if (is_root_hub(urb->dev))
return;
if (usb_endpoint_xfer_control(&urb->ep->desc)
&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
if (hcd->self.uses_dma)
dma_unmap_single(hcd->self.controller, urb->setup_dma,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
else if (hcd->driver->flags & HCD_LOCAL_MEM)
hcd_free_coherent(urb->dev->bus, &urb->setup_dma,
(void **)&urb->setup_packet,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
}
dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
if (urb->transfer_buffer_length != 0
&& !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
if (hcd->self.uses_dma)
dma_unmap_single(hcd->self.controller,
urb->transfer_dma,
urb->transfer_buffer_length,
dir);
else if (hcd->driver->flags & HCD_LOCAL_MEM)
hcd_free_coherent(urb->dev->bus, &urb->transfer_dma,
&urb->transfer_buffer,
urb->transfer_buffer_length,
dir);
}
}
/*-------------------------------------------------------------------------*/
/* may be called in any context with a valid urb->dev usecount
* caller surrenders "ownership" of urb
* expects usb_submit_urb() to have sanity checked and conditioned all
* inputs in the urb
*/
int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
{
int status;
struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
/* increment urb's reference count as part of giving it to the HCD
* (which will control it). HCD guarantees that it either returns
* an error or calls giveback(), but not both.
*/
usb_get_urb(urb);
atomic_inc(&urb->use_count);
atomic_inc(&urb->dev->urbnum);
usbmon_urb_submit(&hcd->self, urb);
/* NOTE requirements on root-hub callers (usbfs and the hub
* driver, for now): URBs' urb->transfer_buffer must be
* valid and usb_buffer_{sync,unmap}() not be needed, since
* they could clobber root hub response data. Also, control
* URBs must be submitted in process context with interrupts
* enabled.
*/
status = map_urb_for_dma(hcd, urb, mem_flags);
if (unlikely(status)) {
usbmon_urb_submit_error(&hcd->self, urb, status);
goto error;
}
if (is_root_hub(urb->dev))
status = rh_urb_enqueue(hcd, urb);
else
status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
if (unlikely(status)) {
usbmon_urb_submit_error(&hcd->self, urb, status);
unmap_urb_for_dma(hcd, urb);
error:
urb->hcpriv = NULL;
INIT_LIST_HEAD(&urb->urb_list);
atomic_dec(&urb->use_count);
atomic_dec(&urb->dev->urbnum);
if (atomic_read(&urb->reject))
wake_up(&usb_kill_urb_queue);
usb_put_urb(urb);
}
return status;
}
/*-------------------------------------------------------------------------*/
/* this makes the hcd giveback() the urb more quickly, by kicking it
* off hardware queues (which may take a while) and returning it as
* soon as practical. we've already set up the urb's return status,
* but we can't know if the callback completed already.
*/
static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
{
int value;
if (is_root_hub(urb->dev))
value = usb_rh_urb_dequeue(hcd, urb, status);
else {
/* The only reason an HCD might fail this call is if
* it has not yet fully queued the urb to begin with.
* Such failures should be harmless. */
value = hcd->driver->urb_dequeue(hcd, urb, status);
}
return value;
}
/*
* called in any context
*
* caller guarantees urb won't be recycled till both unlink()
* and the urb's completion function return
*/
int usb_hcd_unlink_urb (struct urb *urb, int status)
{
struct usb_hcd *hcd;
int retval = -EIDRM;
unsigned long flags;
/* Prevent the device and bus from going away while
* the unlink is carried out. If they are already gone
* then urb->use_count must be 0, since disconnected
* devices can't have any active URBs.
*/
spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
if (atomic_read(&urb->use_count) > 0) {
retval = 0;
usb_get_dev(urb->dev);
}
spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
if (retval == 0) {
hcd = bus_to_hcd(urb->dev->bus);
retval = unlink1(hcd, urb, status);
usb_put_dev(urb->dev);
}
if (retval == 0)
retval = -EINPROGRESS;
else if (retval != -EIDRM && retval != -EBUSY)
dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
urb, retval);
return retval;
}
/*-------------------------------------------------------------------------*/
/**
* usb_hcd_giveback_urb - return URB from HCD to device driver
* @hcd: host controller returning the URB
* @urb: urb being returned to the USB device driver.
* @status: completion status code for the URB.
* Context: in_interrupt()
*
* This hands the URB from HCD to its USB device driver, using its
* completion function. The HCD has freed all per-urb resources
* (and is done using urb->hcpriv). It also released all HCD locks;
* the device driver won't cause problems if it frees, modifies,
* or resubmits this URB.
*
* If @urb was unlinked, the value of @status will be overridden by
* @urb->unlinked. Erroneous short transfers are detected in case
* the HCD hasn't checked for them.
*/
void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
{
urb->hcpriv = NULL;
if (unlikely(urb->unlinked))
status = urb->unlinked;
else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
urb->actual_length < urb->transfer_buffer_length &&
!status))
status = -EREMOTEIO;
unmap_urb_for_dma(hcd, urb);
usbmon_urb_complete(&hcd->self, urb, status);
usb_unanchor_urb(urb);
/* pass ownership to the completion handler */
urb->status = status;
urb->complete (urb);
atomic_dec (&urb->use_count);
if (unlikely(atomic_read(&urb->reject)))
wake_up (&usb_kill_urb_queue);
usb_put_urb (urb);
}
EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
/*-------------------------------------------------------------------------*/
/* Cancel all URBs pending on this endpoint and wait for the endpoint's
* queue to drain completely. The caller must first insure that no more
* URBs can be submitted for this endpoint.
*/
void usb_hcd_flush_endpoint(struct usb_device *udev,
struct usb_host_endpoint *ep)
{
struct usb_hcd *hcd;
struct urb *urb;
if (!ep)
return;
might_sleep();
hcd = bus_to_hcd(udev->bus);
/* No more submits can occur */
spin_lock_irq(&hcd_urb_list_lock);
rescan:
list_for_each_entry (urb, &ep->urb_list, urb_list) {
int is_in;
if (urb->unlinked)
continue;
usb_get_urb (urb);
is_in = usb_urb_dir_in(urb);
spin_unlock(&hcd_urb_list_lock);
/* kick hcd */
unlink1(hcd, urb, -ESHUTDOWN);
dev_dbg (hcd->self.controller,
"shutdown urb %p ep%d%s%s\n",
urb, usb_endpoint_num(&ep->desc),
is_in ? "in" : "out",
({ char *s;
switch (usb_endpoint_type(&ep->desc)) {
case USB_ENDPOINT_XFER_CONTROL:
s = ""; break;
case USB_ENDPOINT_XFER_BULK:
s = "-bulk"; break;
case USB_ENDPOINT_XFER_INT:
s = "-intr"; break;
default:
s = "-iso"; break;
};
s;
}));
usb_put_urb (urb);
/* list contents may have changed */
spin_lock(&hcd_urb_list_lock);
goto rescan;
}
spin_unlock_irq(&hcd_urb_list_lock);
/* Wait until the endpoint queue is completely empty */
while (!list_empty (&ep->urb_list)) {
spin_lock_irq(&hcd_urb_list_lock);
/* The list may have changed while we acquired the spinlock */
urb = NULL;
if (!list_empty (&ep->urb_list)) {
urb = list_entry (ep->urb_list.prev, struct urb,
urb_list);
usb_get_urb (urb);
}
spin_unlock_irq(&hcd_urb_list_lock);
if (urb) {
usb_kill_urb (urb);
usb_put_urb (urb);
}
}
}
/* Check whether a new configuration or alt setting for an interface
* will exceed the bandwidth for the bus (or the host controller resources).
* Only pass in a non-NULL config or interface, not both!
* Passing NULL for both new_config and new_intf means the device will be
* de-configured by issuing a set configuration 0 command.
*/
int usb_hcd_check_bandwidth(struct usb_device *udev,
struct usb_host_config *new_config,
struct usb_interface *new_intf)
{
int num_intfs, i, j;
struct usb_interface_cache *intf_cache;
struct usb_host_interface *alt = 0;
int ret = 0;
struct usb_hcd *hcd;
struct usb_host_endpoint *ep;
hcd = bus_to_hcd(udev->bus);
if (!hcd->driver->check_bandwidth)
return 0;
/* Configuration is being removed - set configuration 0 */
if (!new_config && !new_intf) {
for (i = 1; i < 16; ++i) {
ep = udev->ep_out[i];
if (ep)
hcd->driver->drop_endpoint(hcd, udev, ep);
ep = udev->ep_in[i];
if (ep)
hcd->driver->drop_endpoint(hcd, udev, ep);
}
hcd->driver->check_bandwidth(hcd, udev);
return 0;
}
/* Check if the HCD says there's enough bandwidth. Enable all endpoints
* each interface's alt setting 0 and ask the HCD to check the bandwidth
* of the bus. There will always be bandwidth for endpoint 0, so it's
* ok to exclude it.
*/
if (new_config) {
num_intfs = new_config->desc.bNumInterfaces;
/* Remove endpoints (except endpoint 0, which is always on the
* schedule) from the old config from the schedule
*/
for (i = 1; i < 16; ++i) {
ep = udev->ep_out[i];
if (ep) {
ret = hcd->driver->drop_endpoint(hcd, udev, ep);
if (ret < 0)
goto reset;
}
ep = udev->ep_in[i];
if (ep) {
ret = hcd->driver->drop_endpoint(hcd, udev, ep);
if (ret < 0)
goto reset;
}
}
for (i = 0; i < num_intfs; ++i) {
/* Dig the endpoints for alt setting 0 out of the
* interface cache for this interface
*/
intf_cache = new_config->intf_cache[i];
for (j = 0; j < intf_cache->num_altsetting; j++) {
if (intf_cache->altsetting[j].desc.bAlternateSetting == 0)
alt = &intf_cache->altsetting[j];
}
if (!alt) {
printk(KERN_DEBUG "Did not find alt setting 0 for intf %d\n", i);
continue;
}
for (j = 0; j < alt->desc.bNumEndpoints; j++) {
ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
if (ret < 0)
goto reset;
}
}
}
ret = hcd->driver->check_bandwidth(hcd, udev);
reset:
if (ret < 0)
hcd->driver->reset_bandwidth(hcd, udev);
return ret;
}
/* Disables the endpoint: synchronizes with the hcd to make sure all
* endpoint state is gone from hardware. usb_hcd_flush_endpoint() must
* have been called previously. Use for set_configuration, set_interface,
* driver removal, physical disconnect.
*
* example: a qh stored in ep->hcpriv, holding state related to endpoint
* type, maxpacket size, toggle, halt status, and scheduling.
*/
void usb_hcd_disable_endpoint(struct usb_device *udev,
struct usb_host_endpoint *ep)
{
struct usb_hcd *hcd;
might_sleep();
hcd = bus_to_hcd(udev->bus);
if (hcd->driver->endpoint_disable)
hcd->driver->endpoint_disable(hcd, ep);
}
/**
* usb_hcd_reset_endpoint - reset host endpoint state
* @udev: USB device.
* @ep: the endpoint to reset.
*
* Resets any host endpoint state such as the toggle bit, sequence
* number and current window.
*/
void usb_hcd_reset_endpoint(struct usb_device *udev,
struct usb_host_endpoint *ep)
{
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
if (hcd->driver->endpoint_reset)
hcd->driver->endpoint_reset(hcd, ep);
else {
int epnum = usb_endpoint_num(&ep->desc);
int is_out = usb_endpoint_dir_out(&ep->desc);
int is_control = usb_endpoint_xfer_control(&ep->desc);
usb_settoggle(udev, epnum, is_out, 0);
if (is_control)
usb_settoggle(udev, epnum, !is_out, 0);
}
}
/* Protect against drivers that try to unlink URBs after the device
* is gone, by waiting until all unlinks for @udev are finished.
* Since we don't currently track URBs by device, simply wait until
* nothing is running in the locked region of usb_hcd_unlink_urb().
*/
void usb_hcd_synchronize_unlinks(struct usb_device *udev)
{
spin_lock_irq(&hcd_urb_unlink_lock);
spin_unlock_irq(&hcd_urb_unlink_lock);
}
/*-------------------------------------------------------------------------*/
/* called in any context */
int usb_hcd_get_frame_number (struct usb_device *udev)
{
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
if (!HC_IS_RUNNING (hcd->state))
return -ESHUTDOWN;
return hcd->driver->get_frame_number (hcd);
}
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_PM
int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
{
struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
int status;
int old_state = hcd->state;
dev_dbg(&rhdev->dev, "bus %s%s\n",
(msg.event & PM_EVENT_AUTO ? "auto-" : ""), "suspend");
if (!hcd->driver->bus_suspend) {
status = -ENOENT;
} else {
hcd->state = HC_STATE_QUIESCING;
status = hcd->driver->bus_suspend(hcd);
}
if (status == 0) {
usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
hcd->state = HC_STATE_SUSPENDED;
} else {
hcd->state = old_state;
dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
"suspend", status);
}
return status;
}
int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
{
struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
int status;
int old_state = hcd->state;
dev_dbg(&rhdev->dev, "usb %s%s\n",
(msg.event & PM_EVENT_AUTO ? "auto-" : ""), "resume");
if (!hcd->driver->bus_resume)
return -ENOENT;
if (hcd->state == HC_STATE_RUNNING)
return 0;
hcd->state = HC_STATE_RESUMING;
status = hcd->driver->bus_resume(hcd);
if (status == 0) {
/* TRSMRCY = 10 msec */
msleep(10);
usb_set_device_state(rhdev, rhdev->actconfig
? USB_STATE_CONFIGURED
: USB_STATE_ADDRESS);
hcd->state = HC_STATE_RUNNING;
} else {
hcd->state = old_state;
dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
"resume", status);
if (status != -ESHUTDOWN)
usb_hc_died(hcd);
}
return status;
}
/* Workqueue routine for root-hub remote wakeup */
static void hcd_resume_work(struct work_struct *work)
{
struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
struct usb_device *udev = hcd->self.root_hub;
usb_lock_device(udev);
usb_mark_last_busy(udev);
usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
usb_unlock_device(udev);
}
/**
* usb_hcd_resume_root_hub - called by HCD to resume its root hub
* @hcd: host controller for this root hub
*
* The USB host controller calls this function when its root hub is
* suspended (with the remote wakeup feature enabled) and a remote
* wakeup request is received. The routine submits a workqueue request
* to resume the root hub (that is, manage its downstream ports again).
*/
void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
{
unsigned long flags;
spin_lock_irqsave (&hcd_root_hub_lock, flags);
if (hcd->rh_registered)
queue_work(ksuspend_usb_wq, &hcd->wakeup_work);
spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
}
EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
#endif
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_USB_OTG
/**
* usb_bus_start_enum - start immediate enumeration (for OTG)
* @bus: the bus (must use hcd framework)
* @port_num: 1-based number of port; usually bus->otg_port
* Context: in_interrupt()
*
* Starts enumeration, with an immediate reset followed later by
* khubd identifying and possibly configuring the device.
* This is needed by OTG controller drivers, where it helps meet
* HNP protocol timing requirements for starting a port reset.
*/
int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
{
struct usb_hcd *hcd;
int status = -EOPNOTSUPP;
/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
* boards with root hubs hooked up to internal devices (instead of
* just the OTG port) may need more attention to resetting...
*/
hcd = container_of (bus, struct usb_hcd, self);
if (port_num && hcd->driver->start_port_reset)
status = hcd->driver->start_port_reset(hcd, port_num);
/* run khubd shortly after (first) root port reset finishes;
* it may issue others, until at least 50 msecs have passed.
*/
if (status == 0)
mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
return status;
}
EXPORT_SYMBOL_GPL(usb_bus_start_enum);
#endif
/*-------------------------------------------------------------------------*/
/**
* usb_hcd_irq - hook IRQs to HCD framework (bus glue)
* @irq: the IRQ being raised
* @__hcd: pointer to the HCD whose IRQ is being signaled
*
* If the controller isn't HALTed, calls the driver's irq handler.
* Checks whether the controller is now dead.
*/
irqreturn_t usb_hcd_irq (int irq, void *__hcd)
{
struct usb_hcd *hcd = __hcd;
unsigned long flags;
irqreturn_t rc;
/* IRQF_DISABLED doesn't work correctly with shared IRQs
* when the first handler doesn't use it. So let's just
* assume it's never used.
*/
local_irq_save(flags);
if (unlikely(hcd->state == HC_STATE_HALT ||
!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
rc = IRQ_NONE;
} else if (hcd->driver->irq(hcd) == IRQ_NONE) {
rc = IRQ_NONE;
} else {
set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
if (unlikely(hcd->state == HC_STATE_HALT))
usb_hc_died(hcd);
rc = IRQ_HANDLED;
}
local_irq_restore(flags);
return rc;
}
/*-------------------------------------------------------------------------*/
/**
* usb_hc_died - report abnormal shutdown of a host controller (bus glue)
* @hcd: pointer to the HCD representing the controller
*
* This is called by bus glue to report a USB host controller that died
* while operations may still have been pending. It's called automatically
* by the PCI glue, so only glue for non-PCI busses should need to call it.
*/
void usb_hc_died (struct usb_hcd *hcd)
{
unsigned long flags;
dev_err (hcd->self.controller, "HC died; cleaning up\n");
spin_lock_irqsave (&hcd_root_hub_lock, flags);
if (hcd->rh_registered) {
hcd->poll_rh = 0;
/* make khubd clean up old urbs and devices */
usb_set_device_state (hcd->self.root_hub,
USB_STATE_NOTATTACHED);
usb_kick_khubd (hcd->self.root_hub);
}
spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
}
EXPORT_SYMBOL_GPL (usb_hc_died);
/*-------------------------------------------------------------------------*/
/**
* usb_create_hcd - create and initialize an HCD structure
* @driver: HC driver that will use this hcd
* @dev: device for this HC, stored in hcd->self.controller
* @bus_name: value to store in hcd->self.bus_name
* Context: !in_interrupt()
*
* Allocate a struct usb_hcd, with extra space at the end for the
* HC driver's private data. Initialize the generic members of the
* hcd structure.
*
* If memory is unavailable, returns NULL.
*/
struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
struct device *dev, const char *bus_name)
{
struct usb_hcd *hcd;
hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
if (!hcd) {
dev_dbg (dev, "hcd alloc failed\n");
return NULL;
}
dev_set_drvdata(dev, hcd);
kref_init(&hcd->kref);
usb_bus_init(&hcd->self);
hcd->self.controller = dev;
hcd->self.bus_name = bus_name;
hcd->self.uses_dma = (dev->dma_mask != NULL);
init_timer(&hcd->rh_timer);
hcd->rh_timer.function = rh_timer_func;
hcd->rh_timer.data = (unsigned long) hcd;
#ifdef CONFIG_PM
INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
#endif
hcd->driver = driver;
hcd->product_desc = (driver->product_desc) ? driver->product_desc :
"USB Host Controller";
return hcd;
}
EXPORT_SYMBOL_GPL(usb_create_hcd);
static void hcd_release (struct kref *kref)
{
struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
kfree(hcd);
}
struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
{
if (hcd)
kref_get (&hcd->kref);
return hcd;
}
EXPORT_SYMBOL_GPL(usb_get_hcd);
void usb_put_hcd (struct usb_hcd *hcd)
{
if (hcd)
kref_put (&hcd->kref, hcd_release);
}
EXPORT_SYMBOL_GPL(usb_put_hcd);
/**
* usb_add_hcd - finish generic HCD structure initialization and register
* @hcd: the usb_hcd structure to initialize
* @irqnum: Interrupt line to allocate
* @irqflags: Interrupt type flags
*
* Finish the remaining parts of generic HCD initialization: allocate the
* buffers of consistent memory, register the bus, request the IRQ line,
* and call the driver's reset() and start() routines.
*/
int usb_add_hcd(struct usb_hcd *hcd,
unsigned int irqnum, unsigned long irqflags)
{
int retval;
struct usb_device *rhdev;
dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
hcd->authorized_default = hcd->wireless? 0 : 1;
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
/* HC is in reset state, but accessible. Now do the one-time init,
* bottom up so that hcds can customize the root hubs before khubd
* starts talking to them. (Note, bus id is assigned early too.)
*/
if ((retval = hcd_buffer_create(hcd)) != 0) {
dev_dbg(hcd->self.controller, "pool alloc failed\n");
return retval;
}
if ((retval = usb_register_bus(&hcd->self)) < 0)
goto err_register_bus;
if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
dev_err(hcd->self.controller, "unable to allocate root hub\n");
retval = -ENOMEM;
goto err_allocate_root_hub;
}
switch (hcd->driver->flags & HCD_MASK) {
case HCD_USB11:
rhdev->speed = USB_SPEED_FULL;
break;
case HCD_USB2:
rhdev->speed = USB_SPEED_HIGH;
break;
case HCD_USB3:
rhdev->speed = USB_SPEED_SUPER;
break;
default:
goto err_allocate_root_hub;
}
hcd->self.root_hub = rhdev;
/* wakeup flag init defaults to "everything works" for root hubs,
* but drivers can override it in reset() if needed, along with
* recording the overall controller's system wakeup capability.
*/
device_init_wakeup(&rhdev->dev, 1);
/* "reset" is misnamed; its role is now one-time init. the controller
* should already have been reset (and boot firmware kicked off etc).
*/
if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
dev_err(hcd->self.controller, "can't setup\n");
goto err_hcd_driver_setup;
}
/* NOTE: root hub and controller capabilities may not be the same */
if (device_can_wakeup(hcd->self.controller)
&& device_can_wakeup(&hcd->self.root_hub->dev))
dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
/* enable irqs just before we start the controller */
if (hcd->driver->irq) {
/* IRQF_DISABLED doesn't work as advertised when used together
* with IRQF_SHARED. As usb_hcd_irq() will always disable
* interrupts we can remove it here.
*/
if (irqflags & IRQF_SHARED)
irqflags &= ~IRQF_DISABLED;
snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
hcd->driver->description, hcd->self.busnum);
if ((retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
hcd->irq_descr, hcd)) != 0) {
dev_err(hcd->self.controller,
"request interrupt %d failed\n", irqnum);
goto err_request_irq;
}
hcd->irq = irqnum;
dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
(hcd->driver->flags & HCD_MEMORY) ?
"io mem" : "io base",
(unsigned long long)hcd->rsrc_start);
} else {
hcd->irq = -1;
if (hcd->rsrc_start)
dev_info(hcd->self.controller, "%s 0x%08llx\n",
(hcd->driver->flags & HCD_MEMORY) ?
"io mem" : "io base",
(unsigned long long)hcd->rsrc_start);
}
if ((retval = hcd->driver->start(hcd)) < 0) {
dev_err(hcd->self.controller, "startup error %d\n", retval);
goto err_hcd_driver_start;
}
/* starting here, usbcore will pay attention to this root hub */
rhdev->bus_mA = min(500u, hcd->power_budget);
if ((retval = register_root_hub(hcd)) != 0)
goto err_register_root_hub;
retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
if (retval < 0) {
printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
retval);
goto error_create_attr_group;
}
if (hcd->uses_new_polling && hcd->poll_rh)
usb_hcd_poll_rh_status(hcd);
return retval;
error_create_attr_group:
mutex_lock(&usb_bus_list_lock);
usb_disconnect(&hcd->self.root_hub);
mutex_unlock(&usb_bus_list_lock);
err_register_root_hub:
hcd->driver->stop(hcd);
err_hcd_driver_start:
if (hcd->irq >= 0)
free_irq(irqnum, hcd);
err_request_irq:
err_hcd_driver_setup:
hcd->self.root_hub = NULL;
usb_put_dev(rhdev);
err_allocate_root_hub:
usb_deregister_bus(&hcd->self);
err_register_bus:
hcd_buffer_destroy(hcd);
return retval;
}
EXPORT_SYMBOL_GPL(usb_add_hcd);
/**
* usb_remove_hcd - shutdown processing for generic HCDs
* @hcd: the usb_hcd structure to remove
* Context: !in_interrupt()
*
* Disconnects the root hub, then reverses the effects of usb_add_hcd(),
* invoking the HCD's stop() method.
*/
void usb_remove_hcd(struct usb_hcd *hcd)
{
dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
if (HC_IS_RUNNING (hcd->state))
hcd->state = HC_STATE_QUIESCING;
dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
spin_lock_irq (&hcd_root_hub_lock);
hcd->rh_registered = 0;
spin_unlock_irq (&hcd_root_hub_lock);
#ifdef CONFIG_PM
cancel_work_sync(&hcd->wakeup_work);
#endif
sysfs_remove_group(&hcd->self.root_hub->dev.kobj, &usb_bus_attr_group);
mutex_lock(&usb_bus_list_lock);
usb_disconnect(&hcd->self.root_hub);
mutex_unlock(&usb_bus_list_lock);
hcd->driver->stop(hcd);
hcd->state = HC_STATE_HALT;
hcd->poll_rh = 0;
del_timer_sync(&hcd->rh_timer);
if (hcd->irq >= 0)
free_irq(hcd->irq, hcd);
usb_deregister_bus(&hcd->self);
hcd_buffer_destroy(hcd);
}
EXPORT_SYMBOL_GPL(usb_remove_hcd);
void
usb_hcd_platform_shutdown(struct platform_device* dev)
{
struct usb_hcd *hcd = platform_get_drvdata(dev);
if (hcd->driver->shutdown)
hcd->driver->shutdown(hcd);
}
EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
/*-------------------------------------------------------------------------*/
#if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
struct usb_mon_operations *mon_ops;
/*
* The registration is unlocked.
* We do it this way because we do not want to lock in hot paths.
*
* Notice that the code is minimally error-proof. Because usbmon needs
* symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
*/
int usb_mon_register (struct usb_mon_operations *ops)
{
if (mon_ops)
return -EBUSY;
mon_ops = ops;
mb();
return 0;
}
EXPORT_SYMBOL_GPL (usb_mon_register);
void usb_mon_deregister (void)
{
if (mon_ops == NULL) {
printk(KERN_ERR "USB: monitor was not registered\n");
return;
}
mon_ops = NULL;
mb();
}
EXPORT_SYMBOL_GPL (usb_mon_deregister);
#endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */