X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fusb%2Fcore%2Fmessage.c;fp=kernel%2Fdrivers%2Fusb%2Fcore%2Fmessage.c;h=f368d2053da534ca975804dfad2bd8ddc77d5fba;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/usb/core/message.c b/kernel/drivers/usb/core/message.c new file mode 100644 index 000000000..f368d2053 --- /dev/null +++ b/kernel/drivers/usb/core/message.c @@ -0,0 +1,1992 @@ +/* + * message.c - synchronous message handling + */ + +#include /* for scatterlist macros */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* for usbcore internals */ +#include + +#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 parameter. + */ +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, + "language id specifier not provided by device, defaulting to English\n"); + 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 i, ret, 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; + } + /* Changing alt-setting also frees any allocated streams */ + for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++) + iface->cur_altsetting->endpoint[i].streams = 0; + + 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); + usb_put_dev(interface_to_usbdev(intf)); + 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 + * 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) { + usb_reset_device(udev); + usb_unlock_device(udev); + } + usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */ +} + + +/* + * 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); + usb_get_dev(dev); + } + 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; +} +EXPORT_SYMBOL_GPL(usb_set_configuration); + +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);