diff options
Diffstat (limited to 'drivers/usb/core/message.c')
| -rw-r--r-- | drivers/usb/core/message.c | 1480 |
1 files changed, 1480 insertions, 0 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c new file mode 100644 index 000000000000..40bdb38e7bcb --- /dev/null +++ b/drivers/usb/core/message.c @@ -0,0 +1,1480 @@ +/* + * message.c - synchronous message handling + */ + +#include <linux/config.h> + +#ifdef CONFIG_USB_DEBUG + #define DEBUG +#else + #undef DEBUG +#endif + +#include <linux/pci.h> /* for scatterlist macros */ +#include <linux/usb.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/timer.h> +#include <linux/ctype.h> +#include <linux/device.h> +#include <asm/byteorder.h> + +#include "hcd.h" /* for usbcore internals */ +#include "usb.h" + +static void usb_api_blocking_completion(struct urb *urb, struct pt_regs *regs) +{ + complete((struct completion *)urb->context); +} + + +static void timeout_kill(unsigned long data) +{ + struct urb *urb = (struct urb *) data; + + usb_unlink_urb(urb); +} + +// Starts urb and waits for completion or timeout +// note that this call is NOT interruptible, while +// many device driver i/o requests should be interruptible +static int usb_start_wait_urb(struct urb *urb, int timeout, int* actual_length) +{ + struct completion done; + struct timer_list timer; + int status; + + init_completion(&done); + urb->context = &done; + urb->transfer_flags |= URB_ASYNC_UNLINK; + urb->actual_length = 0; + status = usb_submit_urb(urb, GFP_NOIO); + + if (status == 0) { + if (timeout > 0) { + init_timer(&timer); + timer.expires = jiffies + msecs_to_jiffies(timeout); + timer.data = (unsigned long)urb; + timer.function = timeout_kill; + /* grr. timeout _should_ include submit delays. */ + add_timer(&timer); + } + wait_for_completion(&done); + status = urb->status; + /* note: HCDs return ETIMEDOUT for other reasons too */ + if (status == -ECONNRESET) { + dev_dbg(&urb->dev->dev, + "%s timed out on ep%d%s len=%d/%d\n", + current->comm, + usb_pipeendpoint(urb->pipe), + usb_pipein(urb->pipe) ? "in" : "out", + urb->actual_length, + urb->transfer_buffer_length + ); + if (urb->actual_length > 0) + status = 0; + else + status = -ETIMEDOUT; + } + if (timeout > 0) + del_timer_sync(&timer); + } + + if (actual_length) + *actual_length = urb->actual_length; + usb_free_urb(urb); + return status; +} + +/*-------------------------------------------------------------------*/ +// 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. + * + * 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 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. + * + * 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, NULL); + + 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 = NULL; + } + if (io->dev->dev.dma_mask != NULL) + usb_buffer_unmap_sg (io->dev, io->pipe, io->sg, io->nents); + io->dev = NULL; +} + +static void sg_complete (struct urb *urb, struct pt_regs *regs) +{ + struct usb_sg_request *io = (struct usb_sg_request *) urb->context; + + 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 + || 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 (io->status == 0 && urb->status && urb->status != -ECONNRESET) { + int i, found, status; + + io->status = urb->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) { + status = usb_unlink_urb (io->urbs [i]); + if (status != -EINPROGRESS && status != -EBUSY) + dev_err (&io->dev->dev, + "%s, unlink --> %d\n", + __FUNCTION__, status); + } else if (urb == io->urbs [i]) + found = 1; + } + spin_lock (&io->lock); + } + urb->dev = NULL; + + /* 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 + * + * 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 != NULL); + 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 = io->entries; + io->urbs = kmalloc (io->entries * sizeof *io->urbs, mem_flags); + if (!io->urbs) + goto nomem; + + urb_flags = URB_ASYNC_UNLINK | URB_NO_TRANSFER_DMA_MAP + | URB_NO_INTERRUPT; + if (usb_pipein (pipe)) + urb_flags |= URB_SHORT_NOT_OK; + + for (i = 0; i < io->entries; 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 = NULL; + 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, entries = io->entries; + + /* queue the urbs. */ + spin_lock_irq (&io->lock); + for (i = 0; i < entries && !io->status; i++) { + int retval; + + io->urbs [i]->dev = io->dev; + retval = usb_submit_urb (io->urbs [i], SLAB_ATOMIC); + + /* after we submit, let completions or cancelations 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: + io->urbs[i]->dev = NULL; + retval = 0; + i--; + 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]->dev = NULL; + io->urbs [i]->status = retval; + dev_dbg (&io->dev->dev, "%s, submit --> %d\n", + __FUNCTION__, 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); +} + +/** + * 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 != -EBUSY) + dev_warn (&io->dev->dev, "%s, unlink --> %d\n", + __FUNCTION__, retval); + } + spin_lock (&io->lock); + } + 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_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. + * + * 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; + int result; + + memset(buf,0,size); // Make sure we parse really received data + + 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, + (type << 8) + index, 0, buf, size, + USB_CTRL_GET_TIMEOUT); + if (result == 0 || result == -EPIPE) + continue; + if (result > 1 && ((u8 *)buf)[1] != type) { + result = -EPROTO; + continue; + } + 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) +{ + 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)) + 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 */ + 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; +} + +/** + * 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; + unsigned int u, idx; + + if (dev->state == USB_STATE_SUSPENDED) + return -EHOSTUNREACH; + 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_string_sub(dev, 0, 0, tbuf); + if (err < 0) { + dev_err (&dev->dev, + "string descriptor 0 read error: %d\n", + err); + goto errout; + } else if (err < 4) { + dev_err (&dev->dev, "string descriptor 0 too short\n"); + err = -EINVAL; + goto errout; + } else { + dev->have_langid = -1; + dev->string_langid = tbuf[2] | (tbuf[3]<< 8); + /* always use the first langid listed */ + dev_dbg (&dev->dev, "default language 0x%04x\n", + dev->string_langid); + } + } + + 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 */ + 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; + + 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; +} + +/* + * 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. 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. + * + * 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. + * + * 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, 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 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) +{ + int ret; + u16 *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); + + *(u16 *)data = *status; + kfree(status); + return ret; +} + +/** + * 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, + 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. + */ + + /* toggle was reset by the clear */ + usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0); + + return 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 + * + * Deallocates hcd/hardware state for this endpoint ... and nukes all + * pending urbs. + * + * If the HCD hasn't registered a disable() function, this sets the + * endpoint's maxpacket size to 0 to prevent further submissions. + */ +void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr) +{ + 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]; + dev->ep_out[epnum] = NULL; + } else { + ep = dev->ep_in[epnum]; + dev->ep_in[epnum] = NULL; + } + if (ep && dev->bus && dev->bus->op && dev->bus->op->disable) + dev->bus->op->disable(dev, ep); +} + +/** + * usb_disable_interface -- Disable all endpoints for an interface + * @dev: the device whose interface is being disabled + * @intf: pointer to the interface descriptor + * + * Disables all the endpoints for the interface's current altsetting. + */ +void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf) +{ + 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); + } +} + +/* + * 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; + + dev_dbg(&dev->dev, "%s nuking %s URBs\n", __FUNCTION__, + skip_ep0 ? "non-ep0" : "all"); + for (i = skip_ep0; i < 16; ++i) { + usb_disable_endpoint(dev, i); + usb_disable_endpoint(dev, i + USB_DIR_IN); + } + dev->toggle[0] = dev->toggle[1] = 0; + + /* getting rid of interfaces will disconnect + * any drivers bound to them (a key side effect) + */ + if (dev->actconfig) { + for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) { + struct usb_interface *interface; + + /* remove this interface */ + interface = dev->actconfig->interface[i]; + dev_dbg (&dev->dev, "unregistering interface %s\n", + interface->dev.bus_id); + usb_remove_sysfs_intf_files(interface); + kfree(interface->cur_altsetting->string); + interface->cur_altsetting->string = NULL; + 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; + } + dev->actconfig = NULL; + if (dev->state == USB_STATE_CONFIGURED) + usb_set_device_state(dev, USB_STATE_ADDRESS); + } +} + + +/* + * usb_enable_endpoint - Enable an endpoint for USB communications + * @dev: the device whose interface is being enabled + * @ep: the endpoint + * + * Resets the endpoint toggle, and sets dev->ep_{in,out} pointers. + * For control endpoints, both the input and output sides are handled. + */ +static void +usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep) +{ + unsigned int epaddr = ep->desc.bEndpointAddress; + unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK; + int is_control; + + is_control = ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) + == USB_ENDPOINT_XFER_CONTROL); + if (usb_endpoint_out(epaddr) || is_control) { + usb_settoggle(dev, epnum, 1, 0); + dev->ep_out[epnum] = ep; + } + if (!usb_endpoint_out(epaddr) || is_control) { + usb_settoggle(dev, epnum, 0, 0); + dev->ep_in[epnum] = ep; + } +} + +/* + * usb_enable_interface - Enable all the endpoints for an interface + * @dev: the device whose interface is being enabled + * @intf: pointer to the interface descriptor + * + * Enables all the endpoints for the interface's current altsetting. + */ +static void usb_enable_interface(struct usb_device *dev, + struct usb_interface *intf) +{ + 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]); +} + +/** + * 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 *alt; + int ret; + int manual = 0; + + 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; + } + + alt = usb_altnum_to_altsetting(iface, alternate); + if (!alt) { + warn("selecting invalid altsetting %d", alternate); + return -EINVAL; + } + + 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) + 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 */ + usb_disable_interface(dev, iface); + + /* 9.1.1.5 says: + * + * Configuring a device or changing an alternate setting + * causes all of the status and configuration values + * associated with endpoints in the affected interfaces to + * be set to their default values. This includes setting + * the data toggle of any endpoint using data toggles to + * the value DATA0. + * + * Some devices take this too literally and don't reset the data + * toggles if the new altsetting is the same as the old one (the + * command isn't "changing" an alternate setting). We will manually + * reset the toggles when the new and old altsettings are the same. + * Most devices won't need this, but fortunately it doesn't happen + * often. + */ + if (iface->cur_altsetting == alt) + manual = 1; + iface->cur_altsetting = alt; + + /* If the interface only has one altsetting and the device didn't + * accept the request (or whenever the old altsetting is the same + * as the new one), 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++) { + unsigned int epaddr = + alt->endpoint[i].desc.bEndpointAddress; + unsigned int 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); + + return 0; +} + +/** + * 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 data toggle (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. Resetting the whole + * configuration would affect other drivers' interfaces. + * + * The caller must own the device lock. + * + * Returns zero on success, else a negative error code. + */ +int usb_reset_configuration(struct usb_device *dev) +{ + int i, retval; + struct usb_host_config *config; + + 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); + usb_disable_endpoint(dev, i + USB_DIR_IN); + } + + config = dev->actconfig; + 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) { + usb_set_device_state(dev, USB_STATE_ADDRESS); + return retval; + } + + dev->toggle[0] = dev->toggle[1] = 0; + + /* 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]; + + intf->cur_altsetting = alt; + usb_enable_interface(dev, intf); + } + return 0; +} + +static void release_interface(struct device *dev) +{ + struct usb_interface *intf = to_usb_interface(dev); + struct usb_interface_cache *intfc = + altsetting_to_usb_interface_cache(intf->altsetting); + + kref_put(&intfc->ref, usb_release_interface_cache); + kfree(intf); +} + +/* + * 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. + * + * 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 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 rwsem; usb device driver probe() methods cannot use this routine. + * + * Returns zero on success, or else the status code returned by the + * underlying call that failed. On succesful 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; + int n, nintf; + + 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. + */ + if (cp && configuration == 0) + dev_warn(&dev->dev, "config 0 descriptor??\n"); + + if (dev->state == USB_STATE_SUSPENDED) + return -EHOSTUNREACH; + + /* 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_KERNEL); + if (!new_interfaces) { + dev_err(&dev->dev, "Out of memory"); + return -ENOMEM; + } + + for (; n < nintf; ++n) { + new_interfaces[n] = kmalloc( + sizeof(struct usb_interface), + GFP_KERNEL); + if (!new_interfaces[n]) { + dev_err(&dev->dev, "Out of memory"); + ret = -ENOMEM; +free_interfaces: + while (--n >= 0) + kfree(new_interfaces[n]); + kfree(new_interfaces); + return ret; + } + } + } + + /* 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 + + if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), + USB_REQ_SET_CONFIGURATION, 0, configuration, 0, + NULL, 0, USB_CTRL_SET_TIMEOUT)) < 0) + goto free_interfaces; + + dev->actconfig = cp; + if (!cp) + usb_set_device_state(dev, USB_STATE_ADDRESS); + else { + usb_set_device_state(dev, USB_STATE_CONFIGURED); + + /* 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]; + memset(intf, 0, sizeof(*intf)); + 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->cur_altsetting = alt; + usb_enable_interface(dev, intf); + intf->dev.parent = &dev->dev; + intf->dev.driver = NULL; + intf->dev.bus = &usb_bus_type; + intf->dev.dma_mask = dev->dev.dma_mask; + intf->dev.release = release_interface; + device_initialize (&intf->dev); + sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d", + dev->bus->busnum, dev->devpath, + configuration, + alt->desc.bInterfaceNumber); + } + kfree(new_interfaces); + + if ((cp->desc.iConfiguration) && + (cp->string == NULL)) { + cp->string = kmalloc(256, GFP_KERNEL); + if (cp->string) + usb_string(dev, cp->desc.iConfiguration, cp->string, 256); + } + + /* 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]; + struct usb_interface_descriptor *desc; + + desc = &intf->altsetting [0].desc; + dev_dbg (&dev->dev, + "adding %s (config #%d, interface %d)\n", + intf->dev.bus_id, configuration, + desc->bInterfaceNumber); + ret = device_add (&intf->dev); + if (ret != 0) { + dev_err(&dev->dev, + "device_add(%s) --> %d\n", + intf->dev.bus_id, + ret); + continue; + } + if ((intf->cur_altsetting->desc.iInterface) && + (intf->cur_altsetting->string == NULL)) { + intf->cur_altsetting->string = kmalloc(256, GFP_KERNEL); + if (intf->cur_altsetting->string) + usb_string(dev, intf->cur_altsetting->desc.iInterface, + intf->cur_altsetting->string, 256); + } + usb_create_sysfs_intf_files (intf); + } + } + + return ret; +} + +// 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_status); +EXPORT_SYMBOL(usb_get_string); +EXPORT_SYMBOL(usb_string); + +// synchronous calls that also maintain usbcore state +EXPORT_SYMBOL(usb_clear_halt); +EXPORT_SYMBOL(usb_reset_configuration); +EXPORT_SYMBOL(usb_set_interface); + |