/* * message.c - synchronous message handling */ #include /* for scatterlist macros */ #include #include #include #include #include #include #include "hcd.h" /* for usbcore internals */ struct usb_api_data { wait_queue_head_t wqh; int done; }; static void usb_api_blocking_completion(struct urb *urb, struct pt_regs *regs) { struct usb_api_data *awd = (struct usb_api_data *)urb->context; awd->done = 1; wmb(); wake_up(&awd->wqh); } // Starts urb and waits for completion or timeout static int usb_start_wait_urb(struct urb *urb, int timeout, int* actual_length) { DECLARE_WAITQUEUE(wait, current); struct usb_api_data awd; int status; init_waitqueue_head(&awd.wqh); awd.done = 0; set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&awd.wqh, &wait); urb->context = &awd; status = usb_submit_urb(urb, GFP_ATOMIC); if (status) { // something went wrong usb_free_urb(urb); set_current_state(TASK_RUNNING); remove_wait_queue(&awd.wqh, &wait); return status; } while (timeout && !awd.done) { timeout = schedule_timeout(timeout); set_current_state(TASK_UNINTERRUPTIBLE); rmb(); } set_current_state(TASK_RUNNING); remove_wait_queue(&awd.wqh, &wait); if (!timeout && !awd.done) { if (urb->status != -EINPROGRESS) { /* No callback?!! */ printk(KERN_ERR "usb: raced timeout, " "pipe 0x%x status %d time left %d\n", urb->pipe, urb->status, timeout); status = urb->status; } else { warn("usb_control/bulk_msg: timeout"); usb_unlink_urb(urb); // remove urb safely status = -ETIMEDOUT; } } else status = urb->status; if (actual_length) *actual_length = urb->actual_length; usb_free_urb(urb); return status; } /*-------------------------------------------------------------------*/ // returns status (negative) or length (positive) 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, 0); 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 jiffies 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. * * If successful, it returns the number of bytes transferred, otherwise a negative error number. * * 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. */ 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 = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO); int ret; if (!dr) return -ENOMEM; dr->bRequestType= requesttype; dr->bRequest = request; dr->wValue = cpu_to_le16p(&value); dr->wIndex = cpu_to_le16p(&index); dr->wLength = cpu_to_le16p(&size); //dbg("usb_control_msg"); ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout); kfree(dr); return ret; } /** * 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 jiffies 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. * * If successful, it returns 0, otherwise a negative error number. * The number of actual bytes transferred will be stored in the * actual_length paramater. * * 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. */ int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, void *data, int len, int *actual_length, int timeout) { struct urb *urb; if (len < 0) return -EINVAL; urb=usb_alloc_urb(0, GFP_KERNEL); if (!urb) return -ENOMEM; usb_fill_bulk_urb(urb, usb_dev, pipe, data, len, usb_api_blocking_completion, 0); return usb_start_wait_urb(urb,timeout,actual_length); } /*-------------------------------------------------------------------*/ 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 = 0; } if (io->dev->dev.dma_mask != 0) usb_buffer_unmap_sg (io->dev, io->pipe, io->sg, io->nents); io->dev = 0; } static void sg_complete (struct urb *urb, struct pt_regs *regs) { struct usb_sg_request *io = (struct usb_sg_request *) urb->context; unsigned long flags; spin_lock_irqsave (&io->lock, flags); /* 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 || urb->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_pipeendpoint (urb->pipe), usb_pipein (urb->pipe) ? "in" : "out", urb->status, io->status); // BUG (); } if (urb->status && urb->status != -ECONNRESET) { int i, found, status; io->status = urb->status; /* the previous urbs, and this one, completed already. * unlink the later ones so they won't rx/tx bad data, * * FIXME don't bother unlinking urbs that haven't yet been * submitted; those non-error cases shouldn't be syslogged */ for (i = 0, found = 0; i < io->entries; i++) { if (found) { status = usb_unlink_urb (io->urbs [i]); if (status && status != -EINPROGRESS) err ("sg_complete, unlink --> %d", status); } else if (urb == io->urbs [i]) found = 1; } } /* on the last completion, signal usb_sg_wait() */ io->bytes += urb->actual_length; io->count--; if (!io->count) complete (&io->complete); spin_unlock_irqrestore (&io->lock, flags); } /** * 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 * * Returns zero for success, else a negative errno value. 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. */ 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, int mem_flags ) { int i; int urb_flags; int dma; 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; io->sg = sg; io->nents = nents; /* not all host controllers use DMA (like the mainstream pci ones); * they can use PIO (sl811) or be software over another transport. */ dma = (dev->dev.dma_mask != 0); if (dma) io->entries = usb_buffer_map_sg (dev, pipe, sg, nents); else io->entries = nents; /* initialize all the urbs we'll use */ if (io->entries <= 0) return io->entries; io->count = 0; io->urbs = kmalloc (io->entries * sizeof *io->urbs, mem_flags); if (!io->urbs) goto nomem; urb_flags = URB_ASYNC_UNLINK | URB_NO_DMA_MAP | URB_NO_INTERRUPT; if (usb_pipein (pipe)) urb_flags |= URB_SHORT_NOT_OK; for (i = 0; i < io->entries; i++, io->count = i) { unsigned len; io->urbs [i] = usb_alloc_urb (0, mem_flags); if (!io->urbs [i]) { io->entries = i; goto nomem; } io->urbs [i]->dev = dev; io->urbs [i]->pipe = pipe; io->urbs [i]->interval = period; io->urbs [i]->transfer_flags = urb_flags; io->urbs [i]->complete = sg_complete; io->urbs [i]->context = io; io->urbs [i]->status = -EINPROGRESS; io->urbs [i]->actual_length = 0; if (dma) { /* hc may use _only_ transfer_dma */ io->urbs [i]->transfer_dma = sg_dma_address (sg + i); len = sg_dma_len (sg + i); } else { /* hc may use _only_ transfer_buffer */ io->urbs [i]->transfer_buffer = page_address (sg [i].page) + sg [i].offset; len = sg [i].length; } if (length) { len = min_t (unsigned, len, length); length -= len; if (length == 0) io->entries = i + 1; } io->urbs [i]->transfer_buffer_length = len; } io->urbs [--i]->transfer_flags &= ~URB_NO_INTERRUPT; /* transaction state */ io->status = 0; io->bytes = 0; init_completion (&io->complete); return 0; nomem: sg_clean (io); return -ENOMEM; } /** * 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) cancelation, 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). */ void usb_sg_wait (struct usb_sg_request *io) { int i; unsigned long flags; /* queue the urbs. */ spin_lock_irqsave (&io->lock, flags); for (i = 0; i < io->entries && !io->status; i++) { int retval; retval = usb_submit_urb (io->urbs [i], SLAB_ATOMIC); /* after we submit, let completions or cancelations fire; * we handshake using io->status. */ spin_unlock_irqrestore (&io->lock, flags); switch (retval) { /* maybe we retrying will recover */ case -ENXIO: // hc didn't queue this one case -EAGAIN: case -ENOMEM: retval = 0; i--; // FIXME: should it usb_sg_cancel() on INTERRUPT? 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: cpu_relax (); break; /* fail any uncompleted urbs */ default: io->urbs [i]->status = retval; dbg ("usb_sg_msg, submit --> %d", retval); usb_sg_cancel (io); } spin_lock_irqsave (&io->lock, flags); if (retval && io->status == -ECONNRESET) io->status = retval; } spin_unlock_irqrestore (&io->lock, flags); /* 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); } /** * 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; for (i = 0; i < io->entries; i++) { int retval; if (!io->urbs [i]->dev) continue; retval = usb_unlink_urb (io->urbs [i]); if (retval && retval != -EINPROGRESS) warn ("usb_sg_cancel, unlink --> %d", retval); // FIXME don't warn on "not yet submitted" error } } spin_unlock_irqrestore (&io->lock, flags); } /*-------------------------------------------------------------------*/ /** * 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_device_descriptor() for USB_DT_DEVICE, * and usb_get_string() or usb_string() for USB_DT_STRING. * Configuration descriptors (USB_DT_CONFIG) are part of the device * structure, at least for the current configuration. * 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. * * Returns 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 = 5; int result; memset(buf,0,size); // Make sure we parse really received data while (i--) { /* retries if the returned length was 0; flakey device */ if ((result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, (type << 8) + index, 0, buf, size, HZ * USB_CTRL_GET_TIMEOUT)) > 0 || result == -EPIPE) break; } return result; } /** * 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. * * Returns the number of bytes received on success, or else the status code * returned by the underlying usb_control_msg() call. */ int usb_get_string(struct usb_device *dev, unsigned short langid, unsigned char index, void *buf, int size) { return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, (USB_DT_STRING << 8) + index, langid, buf, size, HZ * USB_CTRL_GET_TIMEOUT); } /** * usb_get_device_descriptor - (re)reads the device descriptor * @dev: the device whose device descriptor is being updated * Context: !in_interrupt () * * Updates the copy of the device descriptor stored in the device structure, * which dedicates space for this purpose. Note that several fields are * converted to the host CPU's byte order: the USB version (bcdUSB), and * vendors product and version fields (idVendor, idProduct, and bcdDevice). * That lets device drivers compare against non-byteswapped constants. * * There's normally no need to use this call, although some devices * will change their descriptors after events like updating firmware. * * This call is synchronous, and may not be used in an interrupt context. * * Returns 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) { int ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, sizeof(dev->descriptor)); if (ret >= 0) { le16_to_cpus(&dev->descriptor.bcdUSB); le16_to_cpus(&dev->descriptor.idVendor); le16_to_cpus(&dev->descriptor.idProduct); le16_to_cpus(&dev->descriptor.bcdDevice); } 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 the number of bytes received on success, or else the status code * returned by the underlying usb_control_msg() call. */ int usb_get_status(struct usb_device *dev, int type, int target, void *data) { return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, data, 2, HZ * USB_CTRL_GET_TIMEOUT); } // hub-only!! ... and only exported for reset/reinit path. // otherwise used internally, when setting up a config void usb_set_maxpacket(struct usb_device *dev) { int i, b; for (i=0; iactconfig->desc.bNumInterfaces; i++) { struct usb_interface *ifp = dev->actconfig->interface + i; struct usb_host_interface *as = ifp->altsetting + ifp->act_altsetting; struct usb_host_endpoint *ep = as->endpoint; int e; for (e=0; edesc.bNumEndpoints; e++) { struct usb_endpoint_descriptor *d; d = &ep [e].desc; b = d->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK; if ((d->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_CONTROL) { /* Control => bidirectional */ dev->epmaxpacketout[b] = d->wMaxPacketSize; dev->epmaxpacketin [b] = d->wMaxPacketSize; } else if (usb_endpoint_out(d->bEndpointAddress)) { if (d->wMaxPacketSize > dev->epmaxpacketout[b]) dev->epmaxpacketout[b] = d->wMaxPacketSize; } else { if (d->wMaxPacketSize > dev->epmaxpacketin [b]) dev->epmaxpacketin [b] = d->wMaxPacketSize; } } } } /** * 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. * * Returns 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, 0, endp, NULL, 0, HZ * 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. */ /* toggle was reset by the clear, then ep was reactivated */ usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0); usb_endpoint_running(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe)); return 0; } /** * 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). * * Returns 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 *iface_as; int i, ret; iface = usb_ifnum_to_if(dev, interface); if (!iface) { warn("selecting invalid interface %d", interface); return -EINVAL; } /* 9.4.10 says devices don't need this, if the interface only has one alternate setting */ if (iface->num_altsetting == 1) { dbg("ignoring set_interface for dev %d, iface %d, alt %d", dev->devnum, interface, alternate); return 0; } if (alternate < 0 || alternate >= iface->num_altsetting) return -EINVAL; if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE, iface->altsetting[alternate] .desc.bAlternateSetting, interface, NULL, 0, HZ * 5)) < 0) return ret; /* 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 */ iface_as = iface->altsetting + iface->act_altsetting; for (i = 0; i < iface_as->desc.bNumEndpoints; i++) { u8 ep = iface_as->endpoint [i].desc.bEndpointAddress; int out = !(ep & USB_DIR_IN); ep &= USB_ENDPOINT_NUMBER_MASK; (out ? dev->epmaxpacketout : dev->epmaxpacketin ) [ep] = 0; // FIXME want hcd hook here, "no such endpoint" } iface->act_altsetting = alternate; /* 9.1.1.5: reset toggles for all endpoints affected by this iface-as * * 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.) */ iface_as = &iface->altsetting[alternate]; for (i = 0; i < iface_as->desc.bNumEndpoints; i++) { u8 ep = iface_as->endpoint[i].desc.bEndpointAddress; int out = !(ep & USB_DIR_IN); ep &= USB_ENDPOINT_NUMBER_MASK; usb_settoggle (dev, ep, out, 0); (out ? dev->epmaxpacketout : dev->epmaxpacketin) [ep] = iface_as->endpoint [i].desc.wMaxPacketSize; } return 0; } /** * 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 () * * This is used to enable non-default device modes. Not all devices * support this kind of configurability. By default, configuration * zero is selected after enumeration; many devices only have a single * configuration. * * USB devices may support one or more configurations, which affect * 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 will be in some * non-default device configuration. Other device modes may also be * reflected as configuration options, such as whether two ISDN * channels are presented as independent 64Kb/s interfaces or as one * bonded 128Kb/s interface. * * 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, and may not be used in an interrupt context. * * Returns zero on success, or else the status code returned by the * underlying usb_control_msg() call. */ int usb_set_configuration(struct usb_device *dev, int configuration) { int i, ret; struct usb_host_config *cp = NULL; for (i=0; idescriptor.bNumConfigurations; i++) { if (dev->config[i].desc.bConfigurationValue == configuration) { cp = &dev->config[i]; break; } } if ((!cp && configuration != 0) || (cp && configuration == 0)) { warn("selecting invalid configuration %d", configuration); return -EINVAL; } /* if it's already configured, clear out old state first. */ if (dev->state != USB_STATE_ADDRESS) { /* FIXME unbind drivers from all "old" interfaces. * handshake with hcd to reset cached hc endpoint state. */ } if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION, 0, configuration, 0, NULL, 0, HZ * USB_CTRL_SET_TIMEOUT)) < 0) return ret; if (configuration) dev->state = USB_STATE_CONFIGURED; else dev->state = USB_STATE_ADDRESS; dev->actconfig = cp; /* reset more hc/hcd endpoint state */ dev->toggle[0] = 0; dev->toggle[1] = 0; dev->halted[0] = 0; dev->halted[1] = 0; usb_set_maxpacket(dev); return 0; } /** * usb_string - returns ISO 8859-1 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 ISO-8859-1 encoded ones * that are more usable in most kernel contexts. Note that all characters * in the chosen descriptor that can't be encoded using ISO-8859-1 * are converted to the question mark ("?") character, and this function * chooses strings in the first language supported by the device. * * The ASCII (or, redundantly, "US-ASCII") character set is the seven-bit * subset of ISO 8859-1. ISO-8859-1 is the eight-bit subset of Unicode, * and is appropriate for use many uses of English and several other * Western European languages. (But it doesn't include the "Euro" symbol.) * * This call is synchronous, and may not be used in an interrupt context. * * Returns 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, len; unsigned int u, idx; if (size <= 0 || !buf || !index) return -EINVAL; buf[0] = 0; tbuf = kmalloc(256, GFP_KERNEL); if (!tbuf) return -ENOMEM; /* get langid for strings if it's not yet known */ if (!dev->have_langid) { err = usb_get_string(dev, 0, 0, tbuf, 4); if (err < 0) { err("error getting string descriptor 0 (error=%d)", err); goto errout; } else if (tbuf[0] < 4) { err("string descriptor 0 too short"); err = -EINVAL; goto errout; } else { dev->have_langid = -1; dev->string_langid = tbuf[2] | (tbuf[3]<< 8); /* always use the first langid listed */ dbg("USB device number %d default language ID 0x%x", dev->devnum, dev->string_langid); } } /* * ask for the length of the string */ err = usb_get_string(dev, dev->string_langid, index, tbuf, 2); if(err<2) goto errout; len=tbuf[0]; err = usb_get_string(dev, dev->string_langid, index, tbuf, len); if (err < 0) goto errout; size--; /* leave room for trailing NULL char in output buffer */ for (idx = 0, u = 2; u < err; u += 2) { if (idx >= size) break; if (tbuf[u+1]) /* high byte */ buf[idx++] = '?'; /* non ISO-8859-1 character */ else buf[idx++] = tbuf[u]; } buf[idx] = 0; err = idx; errout: kfree(tbuf); return err; } // synchronous request completion model EXPORT_SYMBOL(usb_control_msg); EXPORT_SYMBOL(usb_bulk_msg); EXPORT_SYMBOL(usb_sg_init); EXPORT_SYMBOL(usb_sg_cancel); EXPORT_SYMBOL(usb_sg_wait); // synchronous control message convenience routines EXPORT_SYMBOL(usb_get_descriptor); EXPORT_SYMBOL(usb_get_device_descriptor); EXPORT_SYMBOL(usb_get_status); EXPORT_SYMBOL(usb_get_string); EXPORT_SYMBOL(usb_string); EXPORT_SYMBOL(usb_clear_halt); EXPORT_SYMBOL(usb_set_configuration); EXPORT_SYMBOL(usb_set_interface);