- 根目录:
- drivers
- usb
- core
- message.c
/*
* message.c - synchronous message handling
*/
#include <linux/pci.h> /* for scatterlist macros */
#include <linux/usb.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/timer.h>
#include <linux/ctype.h>
#include <linux/nls.h>
#include <linux/device.h>
#include <linux/scatterlist.h>
#include <linux/usb/quirks.h>
#include <linux/usb/hcd.h> /* for usbcore internals */
#include <asm/byteorder.h>
#include "usb.h"
static void cancel_async_set_config(struct usb_device *udev);
struct api_context {
struct completion done;
int status;
};
static void usb_api_blocking_completion(struct urb *urb)
{
struct api_context *ctx = urb->context;
ctx->status = urb->status;
complete(&ctx->done);
}
/*
* Starts urb and waits for completion or timeout. Note that this call
* is NOT interruptible. Many device driver i/o requests should be
* interruptible and therefore these drivers should implement their
* own interruptible routines.
*/
static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
{
struct api_context ctx;
unsigned long expire;
int retval;
init_completion(&ctx.done);
urb->context = &ctx;
urb->actual_length = 0;
retval = usb_submit_urb(urb, GFP_NOIO);
if (unlikely(retval))
goto out;
expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
if (!wait_for_completion_timeout(&ctx.done, expire)) {
usb_kill_urb(urb);
retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
dev_dbg(&urb->dev->dev,
"%s timed out on ep%d%s len=%u/%u\n",
current->comm,
usb_endpoint_num(&urb->ep->desc),
usb_urb_dir_in(urb) ? "in" : "out",
urb->actual_length,
urb->transfer_buffer_length);
} else
retval = ctx.status;
out:
if (actual_length)
*actual_length = urb->actual_length;
usb_free_urb(urb);
return retval;
}
/*-------------------------------------------------------------------*/
/* returns status (negative) or length (positive) */
static int usb_internal_control_msg(struct usb_device *usb_dev,
unsigned int pipe,
struct usb_ctrlrequest *cmd,
void *data, int len, int timeout)
{
struct urb *urb;
int retv;
int length;
urb = usb_alloc_urb(0, GFP_NOIO);
if (!urb)
return -ENOMEM;
usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
len, usb_api_blocking_completion, NULL);
retv = usb_start_wait_urb(urb, timeout, &length);
if (retv < 0)
return retv;
else
return length;
}
/**
* usb_control_msg - Builds a control urb, sends it off and waits for completion
* @dev: pointer to the usb device to send the message to
* @pipe: endpoint "pipe" to send the message to
* @request: USB message request value
* @requesttype: USB message request type value
* @value: USB message value
* @index: USB message index value
* @data: pointer to the data to send
* @size: length in bytes of the data to send
* @timeout: time in msecs to wait for the message to complete before timing
* out (if 0 the wait is forever)
*
* Context: !in_interrupt ()
*
* This function sends a simple control message to a specified endpoint and
* waits for the message to complete, or timeout.
*
* Don't use this function from within an interrupt context, like a bottom half
* handler. If you need an asynchronous message, or need to send a message
* from within interrupt context, use usb_submit_urb().
* If a thread in your driver uses this call, make sure your disconnect()
* method can wait for it to complete. Since you don't have a handle on the
* URB used, you can't cancel the request.
*
* Return: If successful, the number of bytes transferred. Otherwise, a negative
* error number.
*/
int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
__u8 requesttype, __u16 value, __u16 index, void *data,
__u16 size, int timeout)
{
struct usb_ctrlrequest *dr;
int ret;
dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
if (!dr)
return -ENOMEM;
dr->bRequestType = requesttype;
dr->bRequest = request;
dr->wValue = cpu_to_le16(value);
dr->wIndex = cpu_to_le16(index);
dr->wLength = cpu_to_le16(size);
ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
kfree(dr);
return ret;
}
EXPORT_SYMBOL_GPL(usb_control_msg);
/**
* usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
* @usb_dev: pointer to the usb device to send the message to
* @pipe: endpoint "pipe" to send the message to
* @data: pointer to the data to send
* @len: length in bytes of the data to send
* @actual_length: pointer to a location to put the actual length transferred
* in bytes
* @timeout: time in msecs to wait for the message to complete before
* timing out (if 0 the wait is forever)
*
* Context: !in_interrupt ()
*
* This function sends a simple interrupt message to a specified endpoint and
* waits for the message to complete, or timeout.
*
* Don't use this function from within an interrupt context, like a bottom half
* handler. If you need an asynchronous message, or need to send a message
* from within interrupt context, use usb_submit_urb() If a thread in your
* driver uses this call, make sure your disconnect() method can wait for it to
* complete. Since you don't have a handle on the URB used, you can't cancel
* the request.
*
* Return:
* If successful, 0. Otherwise a negative error number. The number of actual
* bytes transferred will be stored in the @actual_length paramater.
*/
int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
void *data, int len, int *actual_length, int timeout)
{
return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
}
EXPORT_SYMBOL_GPL(usb_interrupt_msg);
/**
* usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
* @usb_dev: pointer to the usb device to send the message to
* @pipe: endpoint "pipe" to send the message to
* @data: pointer to the data to send
* @len: length in bytes of the data to send
* @actual_length: pointer to a location to put the actual length transferred
* in bytes
* @timeout: time in msecs to wait for the message to complete before
* timing out (if 0 the wait is forever)
*
* Context: !in_interrupt ()
*
* This function sends a simple bulk message to a specified endpoint
* and waits for the message to complete, or timeout.
*
* Don't use this function from within an interrupt context, like a bottom half
* handler. If you need an asynchronous message, or need to send a message
* from within interrupt context, use usb_submit_urb() If a thread in your
* driver uses this call, make sure your disconnect() method can wait for it to
* complete. Since you don't have a handle on the URB used, you can't cancel
* the request.
*
* Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
* users are forced to abuse this routine by using it to submit URBs for
* interrupt endpoints. We will take the liberty of creating an interrupt URB
* (with the default interval) if the target is an interrupt endpoint.
*
* Return:
* If successful, 0. Otherwise a negative error number. The number of actual
* bytes transferred will be stored in the @actual_length parameter.
*
*/
int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
void *data, int len, int *actual_length, int timeout)
{
struct urb *urb;
struct usb_host_endpoint *ep;
ep = usb_pipe_endpoint(usb_dev, pipe);
if (!ep || len < 0)
return -EINVAL;
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
return -ENOMEM;
if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
USB_ENDPOINT_XFER_INT) {
pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
usb_fill_int_urb(urb, usb_dev, pipe, data, len,
usb_api_blocking_completion, NULL,
ep->desc.bInterval);
} else
usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
usb_api_blocking_completion, NULL);
return usb_start_wait_urb(urb, timeout, actual_length);
}
EXPORT_SYMBOL_GPL(usb_bulk_msg);
/*-------------------------------------------------------------------*/
static void sg_clean(struct usb_sg_request *io)
{
if (io->urbs) {
while (io->entries--)
usb_free_urb(io->urbs[io->entries]);
kfree(io->urbs);
io->urbs = NULL;
}
io->dev = NULL;
}
static void sg_complete(struct urb *urb)
{
struct usb_sg_request *io = urb->context;
int status = urb->status;
spin_lock(&io->lock);
/* In 2.5 we require hcds' endpoint queues not to progress after fault
* reports, until the completion callback (this!) returns. That lets
* device driver code (like this routine) unlink queued urbs first,
* if it needs to, since the HC won't work on them at all. So it's
* not possible for page N+1 to overwrite page N, and so on.
*
* That's only for "hard" faults; "soft" faults (unlinks) sometimes
* complete before the HCD can get requests away from hardware,
* though never during cleanup after a hard fault.
*/
if (io->status
&& (io->status != -ECONNRESET
|| status != -ECONNRESET)
&& urb->actual_length) {
dev_err(io->dev->bus->controller,
"dev %s ep%d%s scatterlist error %d/%d\n",
io->dev->devpath,
usb_endpoint_num(&urb->ep->desc),
usb_urb_dir_in(urb) ? "in" : "out",
status, io->status);
/* BUG (); */
}
if (io->status == 0 && status && status != -ECONNRESET) {
int i, found, retval;
io->status = status;
/* the previous urbs, and this one, completed already.
* unlink pending urbs so they won't rx/tx bad data.
* careful: unlink can sometimes be synchronous...
*/
spin_unlock(&io->lock);
for (i = 0, found = 0; i < io->entries; i++) {
if (!io->urbs[i] || !io->urbs[i]->dev)
continue;
if (found) {
retval = usb_unlink_urb(io->urbs[i]);
if (retval != -EINPROGRESS &&
retval != -ENODEV &&
retval != -EBUSY &&
retval != -EIDRM)
dev_err(&io->dev->dev,
"%s, unlink --> %d\n",
__func__, retval);
} else if (urb == io->urbs[i])
found = 1;
}
spin_lock(&io->lock);
}
/* on the last completion, signal usb_sg_wait() */
io->bytes += urb->actual_length;
io->count--;
if (!io->count)
complete(&io->complete);
spin_unlock(&io->lock);
}
/**
* usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
* @io: request block being initialized. until usb_sg_wait() returns,
* treat this as a pointer to an opaque block of memory,
* @dev: the usb device that will send or receive the data
* @pipe: endpoint "pipe" used to transfer the data
* @period: polling rate for interrupt endpoints, in frames or
* (for high speed endpoints) microframes; ignored for bulk
* @sg: scatterlist entries
* @nents: how many entries in the scatterlist
* @length: how many bytes to send from the scatterlist, or zero to
* send every byte identified in the list.
* @mem_flags: SLAB_* flags affecting memory allocations in this call
*
* This initializes a scatter/gather request, allocating resources such as
* I/O mappings and urb memory (except maybe memory used by USB controller
* drivers).
*
* The request must be issued using usb_sg_wait(), which waits for the I/O to
* complete (or to be canceled) and then cleans up all resources allocated by
* usb_sg_init().
*
* The request may be canceled with usb_sg_cancel(), either before or after
* usb_sg_wait() is called.
*
* Return: Zero for success, else a negative errno value.
*/
int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
unsigned pipe, unsigned period, struct scatterlist *sg,
int nents, size_t length, gfp_t mem_flags)
{
int i;
int urb_flags;
int use_sg;
if (!io || !dev || !sg
|| usb_pipecontrol(pipe)
|| usb_pipeisoc(pipe)
|| nents <= 0)
return -EINVAL;
spin_lock_init(&io->lock);
io->dev = dev;
io->pipe = pipe;
if (dev->bus->sg_tablesize > 0) {
use_sg = true;
io->entries = 1;
} else {
use_sg = false;
io->entries = nents;
}
/* initialize all the urbs we'll use */
io->urbs = kmalloc(io->entries * sizeof(*io->urbs), mem_flags);
if (!io->urbs)
goto nomem;
urb_flags = URB_NO_INTERRUPT;
if (usb_pipein(pipe))
urb_flags |= URB_SHORT_NOT_OK;
for_each_sg(sg, sg, io->entries, i) {
struct urb *urb;
unsigned len;
urb = usb_alloc_urb(0, mem_flags);
if (!urb) {
io->entries = i;
goto nomem;
}
io->urbs[i] = urb;
urb->dev = NULL;
urb->pipe = pipe;
urb->interval = period;
urb->transfer_flags = urb_flags;
urb->complete = sg_complete;
urb->context = io;
urb->sg = sg;
if (use_sg) {
/* There is no single transfer buffer */
urb->transfer_buffer = NULL;
urb->num_sgs = nents;
/* A length of zero means transfer the whole sg list */
len = length;
if (len == 0) {
struct scatterlist *sg2;
int j;
for_each_sg(sg, sg2, nents, j)
len += sg2->length;
}
} else {
/*
* Some systems can't use DMA; they use PIO instead.
* For their sakes, transfer_buffer is set whenever
* possible.
*/
if (!PageHighMem(sg_page(sg)))
urb->transfer_buffer = sg_virt(sg);
else
urb->transfer_buffer = NULL;
len = sg->length;
if (length) {
len = min_t(size_t, len, length);
length -= len;
if (length == 0)
io->entries = i + 1;
}
}
urb->transfer_buffer_length = len;
}
io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
/* transaction state */
io->count = io->entries;
io->status = 0;
io->bytes = 0;
init_completion(&io->complete);
return 0;
nomem:
sg_clean(io);
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(usb_sg_init);
/**
* usb_sg_wait - synchronously execute scatter/gather request
* @io: request block handle, as initialized with usb_sg_init().
* some fields become accessible when this call returns.
* Context: !in_interrupt ()
*
* This function blocks until the specified I/O operation completes. It
* leverages the grouping of the related I/O requests to get good transfer
* rates, by queueing the requests. At higher speeds, such queuing can
* significantly improve USB throughput.
*
* There are three kinds of completion for this function.
* (1) success, where io->status is zero. The number of io->bytes
* transferred is as requested.
* (2) error, where io->status is a negative errno value. The number
* of io->bytes transferred before the error is usually less
* than requested, and can be nonzero.
* (3) cancellation, a type of error with status -ECONNRESET that
* is initiated by usb_sg_cancel().
*
* When this function returns, all memory allocated through usb_sg_init() or
* this call will have been freed. The request block parameter may still be
* passed to usb_sg_cancel(), or it may be freed. It could also be
* reinitialized and then reused.
*
* Data Transfer Rates:
*
* Bulk transfers are valid for full or high speed endpoints.
* The best full speed data rate is 19 packets of 64 bytes each
* per frame, or 1216 bytes per millisecond.
* The best high speed data rate is 13 packets of 512 bytes each
* per microframe, or 52 KBytes per millisecond.
*
* The reason to use interrupt transfers through this API would most likely
* be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
* could be transferred. That capability is less useful for low or full
* speed interrupt endpoints, which allow at most one packet per millisecond,
* of at most 8 or 64 bytes (respectively).
*
* It is not necessary to call this function to reserve bandwidth for devices
* under an xHCI host controller, as the bandwidth is reserved when the
* configuration or interface alt setting is selected.
*/
void usb_sg_wait(struct usb_sg_request *io)
{
int i;
int entries = io->entries;
/* queue the urbs. */
spin_lock_irq(&io->lock);
i = 0;
while (i < entries && !io->status) {
int retval;
io->urbs[i]->dev = io->dev;
retval = usb_submit_urb(io->urbs[i], GFP_ATOMIC);
/* after we submit, let completions or cancellations fire;
* we handshake using io->status.
*/
spin_unlock_irq(&io->lock);
switch (retval) {
/* maybe we retrying will recover */
case -ENXIO: /* hc didn't queue this one */
case -EAGAIN:
case -ENOMEM:
retval = 0;
yield();
break;
/* no error? continue immediately.
*
* NOTE: to work better with UHCI (4K I/O buffer may
* need 3K of TDs) it may be good to limit how many
* URBs are queued at once; N milliseconds?
*/
case 0:
++i;
cpu_relax();
break;
/* fail any uncompleted urbs */
default:
io->urbs[i]->status = retval;
dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
__func__, retval);
usb_sg_cancel(io);
}
spin_lock_irq(&io->lock);
if (retval && (io->status == 0 || io->status == -ECONNRESET))
io->status = retval;
}
io->count -= entries - i;
if (io->count == 0)
complete(&io->complete);
spin_unlock_irq(&io->lock);
/* OK, yes, this could be packaged as non-blocking.
* So could the submit loop above ... but it's easier to
* solve neither problem than to solve both!
*/
wait_for_completion(&io->complete);
sg_clean(io);
}
EXPORT_SYMBOL_GPL(usb_sg_wait);
/**
* usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
* @io: request block, initialized with usb_sg_init()
*
* This stops a request after it has been started by usb_sg_wait().
* It can also prevents one initialized by usb_sg_init() from starting,
* so that call just frees resources allocated to the request.
*/
void usb_sg_cancel(struct usb_sg_request *io)
{
unsigned long flags;
spin_lock_irqsave(&io->lock, flags);
/* shut everything down, if it didn't already */
if (!io->status) {
int i;
io->status = -ECONNRESET;
spin_unlock(&io->lock);
for (i = 0; i < io->entries; i++) {
int retval;
if (!io->urbs[i]->dev)
continue;
retval = usb_unlink_urb(io->urbs[i]);
if (retval != -EINPROGRESS
&& retval != -ENODEV
&& retval != -EBUSY
&& retval != -EIDRM)
dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
__func__, retval);
}
spin_lock(&io->lock);
}
spin_unlock_irqrestore(&io->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_sg_cancel);
/*-------------------------------------------------------------------*/
/**
* usb_get_descriptor - issues a generic GET_DESCRIPTOR request
* @dev: the device whose descriptor is being retrieved
* @type: the descriptor type (USB_DT_*)
* @index: the number of the descriptor
* @buf: where to put the descriptor
* @size: how big is "buf"?
* Context: !in_interrupt ()
*
* Gets a USB descriptor. Convenience functions exist to simplify
* getting some types of descriptors. Use
* usb_get_string() or usb_string() for USB_DT_STRING.
* Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
* are part of the device structure.
* In addition to a number of USB-standard descriptors, some
* devices also use class-specific or vendor-specific descriptors.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Return: The number of bytes received on success, or else the status code
* returned by the underlying usb_control_msg() call.
*/
int usb_get_descriptor(struct usb_device *dev, unsigned char type,
unsigned char index, void *buf, int size)
{
int i;
int result;
memset(buf, 0, size); /* Make sure we parse really received data */
for (i = 0; i < 3; ++i) {
/* retry on length 0 or error; some devices are flakey */
result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
(type << 8) + index, 0, buf, size,
USB_CTRL_GET_TIMEOUT);
if (result <= 0 && result != -ETIMEDOUT)
continue;
if (result > 1 && ((u8 *)buf)[1] != type) {
result = -ENODATA;
continue;
}
break;
}
return result;
}
EXPORT_SYMBOL_GPL(usb_get_descriptor);
/**
* usb_get_string - gets a string descriptor
* @dev: the device whose string descriptor is being retrieved
* @langid: code for language chosen (from string descriptor zero)
* @index: the number of the descriptor
* @buf: where to put the string
* @size: how big is "buf"?
* Context: !in_interrupt ()
*
* Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
* in little-endian byte order).
* The usb_string() function will often be a convenient way to turn
* these strings into kernel-printable form.
*
* Strings may be referenced in device, configuration, interface, or other
* descriptors, and could also be used in vendor-specific ways.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Return: The number of bytes received on success, or else the status code
* returned by the underlying usb_control_msg() call.
*/
static int usb_get_string(struct usb_device *dev, unsigned short langid,
unsigned char index, void *buf, int size)
{
int i;
int result;
for (i = 0; i < 3; ++i) {
/* retry on length 0 or stall; some devices are flakey */
result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
(USB_DT_STRING << 8) + index, langid, buf, size,
USB_CTRL_GET_TIMEOUT);
if (result == 0 || result == -EPIPE)
continue;
if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
result = -ENODATA;
continue;
}
break;
}
return result;
}
static void usb_try_string_workarounds(unsigned char *buf, int *length)
{
int newlength, oldlength = *length;
for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
if (!isprint(buf[newlength]) || buf[newlength + 1])
break;
if (newlength > 2) {
buf[0] = newlength;
*length = newlength;
}
}
static int usb_string_sub(struct usb_device *dev, unsigned int langid,
unsigned int index, unsigned char *buf)
{
int rc;
/* Try to read the string descriptor by asking for the maximum
* possible number of bytes */
if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
rc = -EIO;
else
rc = usb_get_string(dev, langid, index, buf, 255);
/* If that failed try to read the descriptor length, then
* ask for just that many bytes */
if (rc < 2) {
rc = usb_get_string(dev, langid, index, buf, 2);
if (rc == 2)
rc = usb_get_string(dev, langid, index, buf, buf[0]);
}
if (rc >= 2) {
if (!buf[0] && !buf[1])
usb_try_string_workarounds(buf, &rc);
/* There might be extra junk at the end of the descriptor */
if (buf[0] < rc)
rc = buf[0];
rc = rc - (rc & 1); /* force a multiple of two */
}
if (rc < 2)
rc = (rc < 0 ? rc : -EINVAL);
return rc;
}
static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
{
int err;
if (dev->have_langid)
return 0;
if (dev->string_langid < 0)
return -EPIPE;
err = usb_string_sub(dev, 0, 0, tbuf);
/* If the string was reported but is malformed, default to english
* (0x0409) */
if (err == -ENODATA || (err > 0 && err < 4)) {
dev->string_langid = 0x0409;
dev->have_langid = 1;
dev_err(&dev->dev,
"string descriptor 0 malformed (err = %d), "
"defaulting to 0x%04x\n",
err, dev->string_langid);
return 0;
}
/* In case of all other errors, we assume the device is not able to
* deal with strings at all. Set string_langid to -1 in order to
* prevent any string to be retrieved from the device */
if (err < 0) {
dev_err(&dev->dev, "string descriptor 0 read error: %d\n",
err);
dev->string_langid = -1;
return -EPIPE;
}
/* always use the first langid listed */
dev->string_langid = tbuf[2] | (tbuf[3] << 8);
dev->have_langid = 1;
dev_dbg(&dev->dev, "default language 0x%04x\n",
dev->string_langid);
return 0;
}
/**
* usb_string - returns UTF-8 version of a string descriptor
* @dev: the device whose string descriptor is being retrieved
* @index: the number of the descriptor
* @buf: where to put the string
* @size: how big is "buf"?
* Context: !in_interrupt ()
*
* This converts the UTF-16LE encoded strings returned by devices, from
* usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
* that are more usable in most kernel contexts. Note that this function
* chooses strings in the first language supported by the device.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Return: length of the string (>= 0) or usb_control_msg status (< 0).
*/
int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
{
unsigned char *tbuf;
int err;
if (dev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
if (size <= 0 || !buf || !index)
return -EINVAL;
buf[0] = 0;
tbuf = kmalloc(256, GFP_NOIO);
if (!tbuf)
return -ENOMEM;
err = usb_get_langid(dev, tbuf);
if (err < 0)
goto errout;
err = usb_string_sub(dev, dev->string_langid, index, tbuf);
if (err < 0)
goto errout;
size--; /* leave room for trailing NULL char in output buffer */
err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
UTF16_LITTLE_ENDIAN, buf, size);
buf[err] = 0;
if (tbuf[1] != USB_DT_STRING)
dev_dbg(&dev->dev,
"wrong descriptor type %02x for string %d (\"%s\")\n",
tbuf[1], index, buf);
errout:
kfree(tbuf);
return err;
}
EXPORT_SYMBOL_GPL(usb_string);
/* one UTF-8-encoded 16-bit character has at most three bytes */
#define MAX_USB_STRING_SIZE (127 * 3 + 1)
/**
* usb_cache_string - read a string descriptor and cache it for later use
* @udev: the device whose string descriptor is being read
* @index: the descriptor index
*
* Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
* or %NULL if the index is 0 or the string could not be read.
*/
char *usb_cache_string(struct usb_device *udev, int index)
{
char *buf;
char *smallbuf = NULL;
int len;
if (index <= 0)
return NULL;
buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
if (buf) {
len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
if (len > 0) {
smallbuf = kmalloc(++len, GFP_NOIO);
if (!smallbuf)
return buf;
memcpy(smallbuf, buf, len);
}
kfree(buf);
}
return smallbuf;
}
/*
* usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
* @dev: the device whose device descriptor is being updated
* @size: how much of the descriptor to read
* Context: !in_interrupt ()
*
* Updates the copy of the device descriptor stored in the device structure,
* which dedicates space for this purpose.
*
* Not exported, only for use by the core. If drivers really want to read
* the device descriptor directly, they can call usb_get_descriptor() with
* type = USB_DT_DEVICE and index = 0.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Return: The number of bytes received on success, or else the status code
* returned by the underlying usb_control_msg() call.
*/
int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
{
struct usb_device_descriptor *desc;
int ret;
if (size > sizeof(*desc))
return -EINVAL;
desc = kmalloc(sizeof(*desc), GFP_NOIO);
if (!desc)
return -ENOMEM;
ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
if (ret >= 0)
memcpy(&dev->descriptor, desc, size);
kfree(desc);
return ret;
}
/**
* usb_get_status - issues a GET_STATUS call
* @dev: the device whose status is being checked
* @type: USB_RECIP_*; for device, interface, or endpoint
* @target: zero (for device), else interface or endpoint number
* @data: pointer to two bytes of bitmap data
* Context: !in_interrupt ()
*
* Returns device, interface, or endpoint status. Normally only of
* interest to see if the device is self powered, or has enabled the
* remote wakeup facility; or whether a bulk or interrupt endpoint
* is halted ("stalled").
*
* Bits in these status bitmaps are set using the SET_FEATURE request,
* and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
* function should be used to clear halt ("stall") status.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Returns 0 and the status value in *@data (in host byte order) on success,
* or else the status code from the underlying usb_control_msg() call.
*/
int usb_get_status(struct usb_device *dev, int type, int target, void *data)
{
int ret;
__le16 *status = kmalloc(sizeof(*status), GFP_KERNEL);
if (!status)
return -ENOMEM;
ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, status,
sizeof(*status), USB_CTRL_GET_TIMEOUT);
if (ret == 2) {
*(u16 *) data = le16_to_cpu(*status);
ret = 0;
} else if (ret >= 0) {
ret = -EIO;
}
kfree(status);
return ret;
}
EXPORT_SYMBOL_GPL(usb_get_status);
/**
* usb_clear_halt - tells device to clear endpoint halt/stall condition
* @dev: device whose endpoint is halted
* @pipe: endpoint "pipe" being cleared
* Context: !in_interrupt ()
*
* This is used to clear halt conditions for bulk and interrupt endpoints,
* as reported by URB completion status. Endpoints that are halted are
* sometimes referred to as being "stalled". Such endpoints are unable
* to transmit or receive data until the halt status is cleared. Any URBs
* queued for such an endpoint should normally be unlinked by the driver
* before clearing the halt condition, as described in sections 5.7.5
* and 5.8.5 of the USB 2.0 spec.
*
* Note that control and isochronous endpoints don't halt, although control
* endpoints report "protocol stall" (for unsupported requests) using the
* same status code used to report a true stall.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Return: Zero on success, or else the status code returned by the
* underlying usb_control_msg() call.
*/
int usb_clear_halt(struct usb_device *dev, int pipe)
{
int result;
int endp = usb_pipeendpoint(pipe);
if (usb_pipein(pipe))
endp |= USB_DIR_IN;
/* we don't care if it wasn't halted first. in fact some devices
* (like some ibmcam model 1 units) seem to expect hosts to make
* this request for iso endpoints, which can't halt!
*/
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
USB_ENDPOINT_HALT, endp, NULL, 0,
USB_CTRL_SET_TIMEOUT);
/* don't un-halt or force to DATA0 except on success */
if (result < 0)
return result;
/* NOTE: seems like Microsoft and Apple don't bother verifying
* the clear "took", so some devices could lock up if you check...
* such as the Hagiwara FlashGate DUAL. So we won't bother.
*
* NOTE: make sure the logic here doesn't diverge much from
* the copy in usb-storage, for as long as we need two copies.
*/
usb_reset_endpoint(dev, endp);
return 0;
}
EXPORT_SYMBOL_GPL(usb_clear_halt);
static int create_intf_ep_devs(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *alt = intf->cur_altsetting;
int i;
if (intf->ep_devs_created || intf->unregistering)
return 0;
for (i = 0; i < alt->desc.bNumEndpoints; ++i)
(void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
intf->ep_devs_created = 1;
return 0;
}
static void remove_intf_ep_devs(struct usb_interface *intf)
{
struct usb_host_interface *alt = intf->cur_altsetting;
int i;
if (!intf->ep_devs_created)
return;
for (i = 0; i < alt->desc.bNumEndpoints; ++i)
usb_remove_ep_devs(&alt->endpoint[i]);
intf->ep_devs_created = 0;
}
/**
* usb_disable_endpoint -- Disable an endpoint by address
* @dev: the device whose endpoint is being disabled
* @epaddr: the endpoint's address. Endpoint number for output,
* endpoint number + USB_DIR_IN for input
* @reset_hardware: flag to erase any endpoint state stored in the
* controller hardware
*
* Disables the endpoint for URB submission and nukes all pending URBs.
* If @reset_hardware is set then also deallocates hcd/hardware state
* for the endpoint.
*/
void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
bool reset_hardware)
{
unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
struct usb_host_endpoint *ep;
if (!dev)
return;
if (usb_endpoint_out(epaddr)) {
ep = dev->ep_out[epnum];
if (reset_hardware)
dev->ep_out[epnum] = NULL;
} else {
ep = dev->ep_in[epnum];
if (reset_hardware)
dev->ep_in[epnum] = NULL;
}
if (ep) {
ep->enabled = 0;
usb_hcd_flush_endpoint(dev, ep);
if (reset_hardware)
usb_hcd_disable_endpoint(dev, ep);
}
}
/**
* usb_reset_endpoint - Reset an endpoint's state.
* @dev: the device whose endpoint is to be reset
* @epaddr: the endpoint's address. Endpoint number for output,
* endpoint number + USB_DIR_IN for input
*
* Resets any host-side endpoint state such as the toggle bit,
* sequence number or current window.
*/
void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
{
unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
struct usb_host_endpoint *ep;
if (usb_endpoint_out(epaddr))
ep = dev->ep_out[epnum];
else
ep = dev->ep_in[epnum];
if (ep)
usb_hcd_reset_endpoint(dev, ep);
}
EXPORT_SYMBOL_GPL(usb_reset_endpoint);
/**
* usb_disable_interface -- Disable all endpoints for an interface
* @dev: the device whose interface is being disabled
* @intf: pointer to the interface descriptor
* @reset_hardware: flag to erase any endpoint state stored in the
* controller hardware
*
* Disables all the endpoints for the interface's current altsetting.
*/
void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
bool reset_hardware)
{
struct usb_host_interface *alt = intf->cur_altsetting;
int i;
for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
usb_disable_endpoint(dev,
alt->endpoint[i].desc.bEndpointAddress,
reset_hardware);
}
}
/**
* usb_disable_device - Disable all the endpoints for a USB device
* @dev: the device whose endpoints are being disabled
* @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
*
* Disables all the device's endpoints, potentially including endpoint 0.
* Deallocates hcd/hardware state for the endpoints (nuking all or most
* pending urbs) and usbcore state for the interfaces, so that usbcore
* must usb_set_configuration() before any interfaces could be used.
*/
void usb_disable_device(struct usb_device *dev, int skip_ep0)
{
int i;
struct usb_hcd *hcd = bus_to_hcd(dev->bus);
/* getting rid of interfaces will disconnect
* any drivers bound to them (a key side effect)
*/
if (dev->actconfig) {
/*
* FIXME: In order to avoid self-deadlock involving the
* bandwidth_mutex, we have to mark all the interfaces
* before unregistering any of them.
*/
for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
dev->actconfig->interface[i]->unregistering = 1;
for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
struct usb_interface *interface;
/* remove this interface if it has been registered */
interface = dev->actconfig->interface[i];
if (!device_is_registered(&interface->dev))
continue;
dev_dbg(&dev->dev, "unregistering interface %s\n",
dev_name(&interface->dev));
remove_intf_ep_devs(interface);
device_del(&interface->dev);
}
/* Now that the interfaces are unbound, nobody should
* try to access them.
*/
for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
put_device(&dev->actconfig->interface[i]->dev);
dev->actconfig->interface[i] = NULL;
}
if (dev->usb2_hw_lpm_enabled == 1)
usb_set_usb2_hardware_lpm(dev, 0);
usb_unlocked_disable_lpm(dev);
usb_disable_ltm(dev);
dev->actconfig = NULL;
if (dev->state == USB_STATE_CONFIGURED)
usb_set_device_state(dev, USB_STATE_ADDRESS);
}
dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
skip_ep0 ? "non-ep0" : "all");
if (hcd->driver->check_bandwidth) {
/* First pass: Cancel URBs, leave endpoint pointers intact. */
for (i = skip_ep0; i < 16; ++i) {
usb_disable_endpoint(dev, i, false);
usb_disable_endpoint(dev, i + USB_DIR_IN, false);
}
/* Remove endpoints from the host controller internal state */
mutex_lock(hcd->bandwidth_mutex);
usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
mutex_unlock(hcd->bandwidth_mutex);
/* Second pass: remove endpoint pointers */
}
for (i = skip_ep0; i < 16; ++i) {
usb_disable_endpoint(dev, i, true);
usb_disable_endpoint(dev, i + USB_DIR_IN, true);
}
}
/**
* usb_enable_endpoint - Enable an endpoint for USB communications
* @dev: the device whose interface is being enabled
* @ep: the endpoint
* @reset_ep: flag to reset the endpoint state
*
* Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
* For control endpoints, both the input and output sides are handled.
*/
void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
bool reset_ep)
{
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);
if (reset_ep)
usb_hcd_reset_endpoint(dev, ep);
if (is_out || is_control)
dev->ep_out[epnum] = ep;
if (!is_out || is_control)
dev->ep_in[epnum] = ep;
ep->enabled = 1;
}
/**
* usb_enable_interface - Enable all the endpoints for an interface
* @dev: the device whose interface is being enabled
* @intf: pointer to the interface descriptor
* @reset_eps: flag to reset the endpoints' state
*
* Enables all the endpoints for the interface's current altsetting.
*/
void usb_enable_interface(struct usb_device *dev,
struct usb_interface *intf, bool reset_eps)
{
struct usb_host_interface *alt = intf->cur_altsetting;
int i;
for (i = 0; i < alt->desc.bNumEndpoints; ++i)
usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
}
/**
* usb_set_interface - Makes a particular alternate setting be current
* @dev: the device whose interface is being updated
* @interface: the interface being updated
* @alternate: the setting being chosen.
* Context: !in_interrupt ()
*
* This is used to enable data transfers on interfaces that may not
* be enabled by default. Not all devices support such configurability.
* Only the driver bound to an interface may change its setting.
*
* Within any given configuration, each interface may have several
* alternative settings. These are often used to control levels of
* bandwidth consumption. For example, the default setting for a high
* speed interrupt endpoint may not send more than 64 bytes per microframe,
* while interrupt transfers of up to 3KBytes per microframe are legal.
* Also, isochronous endpoints may never be part of an
* interface's default setting. To access such bandwidth, alternate
* interface settings must be made current.
*
* Note that in the Linux USB subsystem, bandwidth associated with
* an endpoint in a given alternate setting is not reserved until an URB
* is submitted that needs that bandwidth. Some other operating systems
* allocate bandwidth early, when a configuration is chosen.
*
* This call is synchronous, and may not be used in an interrupt context.
* Also, drivers must not change altsettings while urbs are scheduled for
* endpoints in that interface; all such urbs must first be completed
* (perhaps forced by unlinking).
*
* Return: Zero on success, or else the status code returned by the
* underlying usb_control_msg() call.
*/
int usb_set_interface(struct usb_device *dev, int interface, int alternate)
{
struct usb_interface *iface;
struct usb_host_interface *alt;
struct usb_hcd *hcd = bus_to_hcd(dev->bus);
int ret;
int manual = 0;
unsigned int epaddr;
unsigned int pipe;
if (dev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
iface = usb_ifnum_to_if(dev, interface);
if (!iface) {
dev_dbg(&dev->dev, "selecting invalid interface %d\n",
interface);
return -EINVAL;
}
if (iface->unregistering)
return -ENODEV;
alt = usb_altnum_to_altsetting(iface, alternate);
if (!alt) {
dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
alternate);
return -EINVAL;
}
/* Make sure we have enough bandwidth for this alternate interface.
* Remove the current alt setting and add the new alt setting.
*/
mutex_lock(hcd->bandwidth_mutex);
/* Disable LPM, and re-enable it once the new alt setting is installed,
* so that the xHCI driver can recalculate the U1/U2 timeouts.
*/
if (usb_disable_lpm(dev)) {
dev_err(&iface->dev, "%s Failed to disable LPM\n.", __func__);
mutex_unlock(hcd->bandwidth_mutex);
return -ENOMEM;
}
ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
if (ret < 0) {
dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
alternate);
usb_enable_lpm(dev);
mutex_unlock(hcd->bandwidth_mutex);
return ret;
}
if (dev->quirks & USB_QUIRK_NO_SET_INTF)
ret = -EPIPE;
else
ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
alternate, interface, NULL, 0, 5000);
/* 9.4.10 says devices don't need this and are free to STALL the
* request if the interface only has one alternate setting.
*/
if (ret == -EPIPE && iface->num_altsetting == 1) {
dev_dbg(&dev->dev,
"manual set_interface for iface %d, alt %d\n",
interface, alternate);
manual = 1;
} else if (ret < 0) {
/* Re-instate the old alt setting */
usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
usb_enable_lpm(dev);
mutex_unlock(hcd->bandwidth_mutex);
return ret;
}
mutex_unlock(hcd->bandwidth_mutex);
/* FIXME drivers shouldn't need to replicate/bugfix the logic here
* when they implement async or easily-killable versions of this or
* other "should-be-internal" functions (like clear_halt).
* should hcd+usbcore postprocess control requests?
*/
/* prevent submissions using previous endpoint settings */
if (iface->cur_altsetting != alt) {
remove_intf_ep_devs(iface);
usb_remove_sysfs_intf_files(iface);
}
usb_disable_interface(dev, iface, true);
iface->cur_altsetting = alt;
/* Now that the interface is installed, re-enable LPM. */
usb_unlocked_enable_lpm(dev);
/* If the interface only has one altsetting and the device didn't
* accept the request, we attempt to carry out the equivalent action
* by manually clearing the HALT feature for each endpoint in the
* new altsetting.
*/
if (manual) {
int i;
for (i = 0; i < alt->desc.bNumEndpoints; i++) {
epaddr = alt->endpoint[i].desc.bEndpointAddress;
pipe = __create_pipe(dev,
USB_ENDPOINT_NUMBER_MASK & epaddr) |
(usb_endpoint_out(epaddr) ?
USB_DIR_OUT : USB_DIR_IN);
usb_clear_halt(dev, pipe);
}
}
/* 9.1.1.5: reset toggles for all endpoints in the new altsetting
*
* Note:
* Despite EP0 is always present in all interfaces/AS, the list of
* endpoints from the descriptor does not contain EP0. Due to its
* omnipresence one might expect EP0 being considered "affected" by
* any SetInterface request and hence assume toggles need to be reset.
* However, EP0 toggles are re-synced for every individual transfer
* during the SETUP stage - hence EP0 toggles are "don't care" here.
* (Likewise, EP0 never "halts" on well designed devices.)
*/
usb_enable_interface(dev, iface, true);
if (device_is_registered(&iface->dev)) {
usb_create_sysfs_intf_files(iface);
create_intf_ep_devs(iface);
}
return 0;
}
EXPORT_SYMBOL_GPL(usb_set_interface);
/**
* usb_reset_configuration - lightweight device reset
* @dev: the device whose configuration is being reset
*
* This issues a standard SET_CONFIGURATION request to the device using
* the current configuration. The effect is to reset most USB-related
* state in the device, including interface altsettings (reset to zero),
* endpoint halts (cleared), and endpoint state (only for bulk and interrupt
* endpoints). Other usbcore state is unchanged, including bindings of
* usb device drivers to interfaces.
*
* Because this affects multiple interfaces, avoid using this with composite
* (multi-interface) devices. Instead, the driver for each interface may
* use usb_set_interface() on the interfaces it claims. Be careful though;
* some devices don't support the SET_INTERFACE request, and others won't
* reset all the interface state (notably endpoint state). Resetting the whole
* configuration would affect other drivers' interfaces.
*
* The caller must own the device lock.
*
* Return: Zero on success, else a negative error code.
*/
int usb_reset_configuration(struct usb_device *dev)
{
int i, retval;
struct usb_host_config *config;
struct usb_hcd *hcd = bus_to_hcd(dev->bus);
if (dev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
/* caller must have locked the device and must own
* the usb bus readlock (so driver bindings are stable);
* calls during probe() are fine
*/
for (i = 1; i < 16; ++i) {
usb_disable_endpoint(dev, i, true);
usb_disable_endpoint(dev, i + USB_DIR_IN, true);
}
config = dev->actconfig;
retval = 0;
mutex_lock(hcd->bandwidth_mutex);
/* Disable LPM, and re-enable it once the configuration is reset, so
* that the xHCI driver can recalculate the U1/U2 timeouts.
*/
if (usb_disable_lpm(dev)) {
dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
mutex_unlock(hcd->bandwidth_mutex);
return -ENOMEM;
}
/* Make sure we have enough bandwidth for each alternate setting 0 */
for (i = 0; i < config->desc.bNumInterfaces; i++) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;
alt = usb_altnum_to_altsetting(intf, 0);
if (!alt)
alt = &intf->altsetting[0];
if (alt != intf->cur_altsetting)
retval = usb_hcd_alloc_bandwidth(dev, NULL,
intf->cur_altsetting, alt);
if (retval < 0)
break;
}
/* If not, reinstate the old alternate settings */
if (retval < 0) {
reset_old_alts:
for (i--; i >= 0; i--) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;
alt = usb_altnum_to_altsetting(intf, 0);
if (!alt)
alt = &intf->altsetting[0];
if (alt != intf->cur_altsetting)
usb_hcd_alloc_bandwidth(dev, NULL,
alt, intf->cur_altsetting);
}
usb_enable_lpm(dev);
mutex_unlock(hcd->bandwidth_mutex);
return retval;
}
retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
USB_REQ_SET_CONFIGURATION, 0,
config->desc.bConfigurationValue, 0,
NULL, 0, USB_CTRL_SET_TIMEOUT);
if (retval < 0)
goto reset_old_alts;
mutex_unlock(hcd->bandwidth_mutex);
/* re-init hc/hcd interface/endpoint state */
for (i = 0; i < config->desc.bNumInterfaces; i++) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;
alt = usb_altnum_to_altsetting(intf, 0);
/* No altsetting 0? We'll assume the first altsetting.
* We could use a GetInterface call, but if a device is
* so non-compliant that it doesn't have altsetting 0
* then I wouldn't trust its reply anyway.
*/
if (!alt)
alt = &intf->altsetting[0];
if (alt != intf->cur_altsetting) {
remove_intf_ep_devs(intf);
usb_remove_sysfs_intf_files(intf);
}
intf->cur_altsetting = alt;
usb_enable_interface(dev, intf, true);
if (device_is_registered(&intf->dev)) {
usb_create_sysfs_intf_files(intf);
create_intf_ep_devs(intf);
}
}
/* Now that the interfaces are installed, re-enable LPM. */
usb_unlocked_enable_lpm(dev);
return 0;
}
EXPORT_SYMBOL_GPL(usb_reset_configuration);
static void usb_release_interface(struct device *dev)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usb_interface_cache *intfc =
altsetting_to_usb_interface_cache(intf->altsetting);
kref_put(&intfc->ref, usb_release_interface_cache);
kfree(intf);
}
static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct usb_device *usb_dev;
struct usb_interface *intf;
struct usb_host_interface *alt;
intf = to_usb_interface(dev);
usb_dev = interface_to_usbdev(intf);
alt = intf->cur_altsetting;
if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol))
return -ENOMEM;
if (add_uevent_var(env,
"MODALIAS=usb:"
"v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
le16_to_cpu(usb_dev->descriptor.idVendor),
le16_to_cpu(usb_dev->descriptor.idProduct),
le16_to_cpu(usb_dev->descriptor.bcdDevice),
usb_dev->descriptor.bDeviceClass,
usb_dev->descriptor.bDeviceSubClass,
usb_dev->descriptor.bDeviceProtocol,
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol,
alt->desc.bInterfaceNumber))
return -ENOMEM;
return 0;
}
struct device_type usb_if_device_type = {
.name = "usb_interface",
.release = usb_release_interface,
.uevent = usb_if_uevent,
};
static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
struct usb_host_config *config,
u8 inum)
{
struct usb_interface_assoc_descriptor *retval = NULL;
struct usb_interface_assoc_descriptor *intf_assoc;
int first_intf;
int last_intf;
int i;
for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
intf_assoc = config->intf_assoc[i];
if (intf_assoc->bInterfaceCount == 0)
continue;
first_intf = intf_assoc->bFirstInterface;
last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
if (inum >= first_intf && inum <= last_intf) {
if (!retval)
retval = intf_assoc;
else
dev_err(&dev->dev, "Interface #%d referenced"
" by multiple IADs\n", inum);
}
}
return retval;
}
/*
* Internal function to queue a device reset
*
* This is initialized into the workstruct in 'struct
* usb_device->reset_ws' that is launched by
* message.c:usb_set_configuration() when initializing each 'struct
* usb_interface'.
*
* It is safe to get the USB device without reference counts because
* the life cycle of @iface is bound to the life cycle of @udev. Then,
* this function will be ran only if @iface is alive (and before
* freeing it any scheduled instances of it will have been cancelled).
*
* We need to set a flag (usb_dev->reset_running) because when we call
* the reset, the interfaces might be unbound. The current interface
* cannot try to remove the queued work as it would cause a deadlock
* (you cannot remove your work from within your executing
* workqueue). This flag lets it know, so that
* usb_cancel_queued_reset() doesn't try to do it.
*
* See usb_queue_reset_device() for more details
*/
static void __usb_queue_reset_device(struct work_struct *ws)
{
int rc;
struct usb_interface *iface =
container_of(ws, struct usb_interface, reset_ws);
struct usb_device *udev = interface_to_usbdev(iface);
rc = usb_lock_device_for_reset(udev, iface);
if (rc >= 0) {
iface->reset_running = 1;
usb_reset_device(udev);
iface->reset_running = 0;
usb_unlock_device(udev);
}
}
/*
* usb_set_configuration - Makes a particular device setting be current
* @dev: the device whose configuration is being updated
* @configuration: the configuration being chosen.
* Context: !in_interrupt(), caller owns the device lock
*
* This is used to enable non-default device modes. Not all devices
* use this kind of configurability; many devices only have one
* configuration.
*
* @configuration is the value of the configuration to be installed.
* According to the USB spec (e.g. section 9.1.1.5), configuration values
* must be non-zero; a value of zero indicates that the device in
* unconfigured. However some devices erroneously use 0 as one of their
* configuration values. To help manage such devices, this routine will
* accept @configuration = -1 as indicating the device should be put in
* an unconfigured state.
*
* USB device configurations may affect Linux interoperability,
* power consumption and the functionality available. For example,
* the default configuration is limited to using 100mA of bus power,
* so that when certain device functionality requires more power,
* and the device is bus powered, that functionality should be in some
* non-default device configuration. Other device modes may also be
* reflected as configuration options, such as whether two ISDN
* channels are available independently; and choosing between open
* standard device protocols (like CDC) or proprietary ones.
*
* Note that a non-authorized device (dev->authorized == 0) will only
* be put in unconfigured mode.
*
* Note that USB has an additional level of device configurability,
* associated with interfaces. That configurability is accessed using
* usb_set_interface().
*
* This call is synchronous. The calling context must be able to sleep,
* must own the device lock, and must not hold the driver model's USB
* bus mutex; usb interface driver probe() methods cannot use this routine.
*
* Returns zero on success, or else the status code returned by the
* underlying call that failed. On successful completion, each interface
* in the original device configuration has been destroyed, and each one
* in the new configuration has been probed by all relevant usb device
* drivers currently known to the kernel.
*/
int usb_set_configuration(struct usb_device *dev, int configuration)
{
int i, ret;
struct usb_host_config *cp = NULL;
struct usb_interface **new_interfaces = NULL;
struct usb_hcd *hcd = bus_to_hcd(dev->bus);
int n, nintf;
if (dev->authorized == 0 || configuration == -1)
configuration = 0;
else {
for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
if (dev->config[i].desc.bConfigurationValue ==
configuration) {
cp = &dev->config[i];
break;
}
}
}
if ((!cp && configuration != 0))
return -EINVAL;
/* The USB spec says configuration 0 means unconfigured.
* But if a device includes a configuration numbered 0,
* we will accept it as a correctly configured state.
* Use -1 if you really want to unconfigure the device.
*/
if (cp && configuration == 0)
dev_warn(&dev->dev, "config 0 descriptor??\n");
/* Allocate memory for new interfaces before doing anything else,
* so that if we run out then nothing will have changed. */
n = nintf = 0;
if (cp) {
nintf = cp->desc.bNumInterfaces;
new_interfaces = kmalloc(nintf * sizeof(*new_interfaces),
GFP_NOIO);
if (!new_interfaces) {
dev_err(&dev->dev, "Out of memory\n");
return -ENOMEM;
}
for (; n < nintf; ++n) {
new_interfaces[n] = kzalloc(
sizeof(struct usb_interface),
GFP_NOIO);
if (!new_interfaces[n]) {
dev_err(&dev->dev, "Out of memory\n");
ret = -ENOMEM;
free_interfaces:
while (--n >= 0)
kfree(new_interfaces[n]);
kfree(new_interfaces);
return ret;
}
}
i = dev->bus_mA - usb_get_max_power(dev, cp);
if (i < 0)
dev_warn(&dev->dev, "new config #%d exceeds power "
"limit by %dmA\n",
configuration, -i);
}
/* Wake up the device so we can send it the Set-Config request */
ret = usb_autoresume_device(dev);
if (ret)
goto free_interfaces;
/* if it's already configured, clear out old state first.
* getting rid of old interfaces means unbinding their drivers.
*/
if (dev->state != USB_STATE_ADDRESS)
usb_disable_device(dev, 1); /* Skip ep0 */
/* Get rid of pending async Set-Config requests for this device */
cancel_async_set_config(dev);
/* Make sure we have bandwidth (and available HCD resources) for this
* configuration. Remove endpoints from the schedule if we're dropping
* this configuration to set configuration 0. After this point, the
* host controller will not allow submissions to dropped endpoints. If
* this call fails, the device state is unchanged.
*/
mutex_lock(hcd->bandwidth_mutex);
/* Disable LPM, and re-enable it once the new configuration is
* installed, so that the xHCI driver can recalculate the U1/U2
* timeouts.
*/
if (dev->actconfig && usb_disable_lpm(dev)) {
dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
mutex_unlock(hcd->bandwidth_mutex);
ret = -ENOMEM;
goto free_interfaces;
}
ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
if (ret < 0) {
if (dev->actconfig)
usb_enable_lpm(dev);
mutex_unlock(hcd->bandwidth_mutex);
usb_autosuspend_device(dev);
goto free_interfaces;
}
/*
* Initialize the new interface structures and the
* hc/hcd/usbcore interface/endpoint state.
*/
for (i = 0; i < nintf; ++i) {
struct usb_interface_cache *intfc;
struct usb_interface *intf;
struct usb_host_interface *alt;
cp->interface[i] = intf = new_interfaces[i];
intfc = cp->intf_cache[i];
intf->altsetting = intfc->altsetting;
intf->num_altsetting = intfc->num_altsetting;
kref_get(&intfc->ref);
alt = usb_altnum_to_altsetting(intf, 0);
/* No altsetting 0? We'll assume the first altsetting.
* We could use a GetInterface call, but if a device is
* so non-compliant that it doesn't have altsetting 0
* then I wouldn't trust its reply anyway.
*/
if (!alt)
alt = &intf->altsetting[0];
intf->intf_assoc =
find_iad(dev, cp, alt->desc.bInterfaceNumber);
intf->cur_altsetting = alt;
usb_enable_interface(dev, intf, true);
intf->dev.parent = &dev->dev;
intf->dev.driver = NULL;
intf->dev.bus = &usb_bus_type;
intf->dev.type = &usb_if_device_type;
intf->dev.groups = usb_interface_groups;
intf->dev.dma_mask = dev->dev.dma_mask;
INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
intf->minor = -1;
device_initialize(&intf->dev);
pm_runtime_no_callbacks(&intf->dev);
dev_set_name(&intf->dev, "%d-%s:%d.%d",
dev->bus->busnum, dev->devpath,
configuration, alt->desc.bInterfaceNumber);
}
kfree(new_interfaces);
ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
USB_REQ_SET_CONFIGURATION, 0, configuration, 0,
NULL, 0, USB_CTRL_SET_TIMEOUT);
if (ret < 0 && cp) {
/*
* All the old state is gone, so what else can we do?
* The device is probably useless now anyway.
*/
usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
for (i = 0; i < nintf; ++i) {
usb_disable_interface(dev, cp->interface[i], true);
put_device(&cp->interface[i]->dev);
cp->interface[i] = NULL;
}
cp = NULL;
}
dev->actconfig = cp;
mutex_unlock(hcd->bandwidth_mutex);
if (!cp) {
usb_set_device_state(dev, USB_STATE_ADDRESS);
/* Leave LPM disabled while the device is unconfigured. */
usb_autosuspend_device(dev);
return ret;
}
usb_set_device_state(dev, USB_STATE_CONFIGURED);
if (cp->string == NULL &&
!(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
/* Now that the interfaces are installed, re-enable LPM. */
usb_unlocked_enable_lpm(dev);
/* Enable LTM if it was turned off by usb_disable_device. */
usb_enable_ltm(dev);
/* Now that all the interfaces are set up, register them
* to trigger binding of drivers to interfaces. probe()
* routines may install different altsettings and may
* claim() any interfaces not yet bound. Many class drivers
* need that: CDC, audio, video, etc.
*/
for (i = 0; i < nintf; ++i) {
struct usb_interface *intf = cp->interface[i];
dev_dbg(&dev->dev,
"adding %s (config #%d, interface %d)\n",
dev_name(&intf->dev), configuration,
intf->cur_altsetting->desc.bInterfaceNumber);
device_enable_async_suspend(&intf->dev);
ret = device_add(&intf->dev);
if (ret != 0) {
dev_err(&dev->dev, "device_add(%s) --> %d\n",
dev_name(&intf->dev), ret);
continue;
}
create_intf_ep_devs(intf);
}
usb_autosuspend_device(dev);
return 0;
}
static LIST_HEAD(set_config_list);
static DEFINE_SPINLOCK(set_config_lock);
struct set_config_request {
struct usb_device *udev;
int config;
struct work_struct work;
struct list_head node;
};
/* Worker routine for usb_driver_set_configuration() */
static void driver_set_config_work(struct work_struct *work)
{
struct set_config_request *req =
container_of(work, struct set_config_request, work);
struct usb_device *udev = req->udev;
usb_lock_device(udev);
spin_lock(&set_config_lock);
list_del(&req->node);
spin_unlock(&set_config_lock);
if (req->config >= -1) /* Is req still valid? */
usb_set_configuration(udev, req->config);
usb_unlock_device(udev);
usb_put_dev(udev);
kfree(req);
}
/* Cancel pending Set-Config requests for a device whose configuration
* was just changed
*/
static void cancel_async_set_config(struct usb_device *udev)
{
struct set_config_request *req;
spin_lock(&set_config_lock);
list_for_each_entry(req, &set_config_list, node) {
if (req->udev == udev)
req->config = -999; /* Mark as cancelled */
}
spin_unlock(&set_config_lock);
}
/**
* usb_driver_set_configuration - Provide a way for drivers to change device configurations
* @udev: the device whose configuration is being updated
* @config: the configuration being chosen.
* Context: In process context, must be able to sleep
*
* Device interface drivers are not allowed to change device configurations.
* This is because changing configurations will destroy the interface the
* driver is bound to and create new ones; it would be like a floppy-disk
* driver telling the computer to replace the floppy-disk drive with a
* tape drive!
*
* Still, in certain specialized circumstances the need may arise. This
* routine gets around the normal restrictions by using a work thread to
* submit the change-config request.
*
* Return: 0 if the request was successfully queued, error code otherwise.
* The caller has no way to know whether the queued request will eventually
* succeed.
*/
int usb_driver_set_configuration(struct usb_device *udev, int config)
{
struct set_config_request *req;
req = kmalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->udev = udev;
req->config = config;
INIT_WORK(&req->work, driver_set_config_work);
spin_lock(&set_config_lock);
list_add(&req->node, &set_config_list);
spin_unlock(&set_config_lock);
usb_get_dev(udev);
schedule_work(&req->work);
return 0;
}
EXPORT_SYMBOL_GPL(usb_driver_set_configuration);