/*
* message.c - synchronous message handling
*/
#include <linuxcomp.h>
#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 <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
;
dev_warn
(&urb
->dev
->dev
, "%s timeout on ep%d%s\n",
usb_pipecontrol
(urb
->pipe
) ? "control" : "bulk",
usb_pipeendpoint
(urb
->pipe
),
usb_pipein
(urb
->pipe
) ? "in" : "out");
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 = jiffies26
+ 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
)
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)
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 jiffies26 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 jiffies26 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 pending urbs so they won't rx/tx bad data.
*/
for (i
= 0, found
= 0; i
< io
->entries
; i
++) {
if (!io
->urbs
[i
])
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;
}
}
urb
->dev
= 0;
/* 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_TRANSFER_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
= 0;
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
;
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_irqrestore
(&io
->lock
, flags
);
switch (retval
) {
/* maybe we retrying will recover */
case -ENXIO
: // hc didn't queue this one
case -EAGAIN
:
case -ENOMEM
:
io
->urbs
[i
]->dev
= 0;
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
= 0;
io
->urbs
[i
]->status
= retval
;
dev_dbg
(&io
->dev
->dev
, "%s, submit --> %d\n",
__FUNCTION__
, 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
!= -EINPROGRESS
&& retval
!= -EBUSY
)
dev_warn
(&io
->dev
->dev
, "%s, unlink --> %d\n",
__FUNCTION__
, retval
);
}
}
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
= 0;
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
);
}
/**
* 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_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 marks the
* endpoint as halted and sets its maxpacket size to 0 to prevent
* further submissions.
*/
void usb_disable_endpoint
(struct usb_device
*dev
, unsigned int epaddr
)
{
if (dev
&& dev
->bus
&& dev
->bus
->op
&& dev
->bus
->op
->disable
)
dev
->bus
->op
->disable
(dev
, epaddr
);
else {
unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
if (usb_endpoint_out
(epaddr
)) {
usb_endpoint_halt
(dev
, epnum
, 1);
dev
->epmaxpacketout
[epnum
] = 0;
} else {
usb_endpoint_halt
(dev
, epnum
, 0);
dev
->epmaxpacketin
[epnum
] = 0;
}
}
}
/**
* 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
*hintf
=
&intf
->altsetting
[intf
->act_altsetting
];
int i
;
for (i
= 0; i
< hintf
->desc.
bNumEndpoints; ++i
) {
usb_disable_endpoint
(dev
,
hintf
->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;
dev
->halted
[0] = dev
->halted
[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);
device_del
(&interface
->dev
);
}
dev
->actconfig
= 0;
if (dev
->state
== USB_STATE_CONFIGURED
)
dev
->state
= USB_STATE_ADDRESS
;
}
}
/*
* usb_enable_endpoint - Enable an endpoint for USB communications
* @dev: the device whose interface is being enabled
* @epd: pointer to the endpoint descriptor
*
* Marks the endpoint as running, resets its toggle, and stores
* its maxpacket value. For control endpoints, both the input
* and output sides are handled.
*/
void usb_enable_endpoint
(struct usb_device
*dev
,
struct usb_endpoint_descriptor
*epd
)
{
int maxsize
= epd
->wMaxPacketSize
;
unsigned int epaddr
= epd
->bEndpointAddress
;
unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
int is_control
= ((epd
->bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) ==
USB_ENDPOINT_XFER_CONTROL
);
if (usb_endpoint_out
(epaddr
) || is_control
) {
usb_endpoint_running
(dev
, epnum
, 1);
usb_settoggle
(dev
, epnum
, 1, 0);
dev
->epmaxpacketout
[epnum
] = maxsize
;
}
if (!usb_endpoint_out
(epaddr
) || is_control
) {
usb_endpoint_running
(dev
, epnum
, 0);
usb_settoggle
(dev
, epnum
, 0, 0);
dev
->epmaxpacketin
[epnum
] = maxsize
;
}
}
/*
* 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.
*/
void usb_enable_interface
(struct usb_device
*dev
,
struct usb_interface
*intf
)
{
struct usb_host_interface
*hintf
=
&intf
->altsetting
[intf
->act_altsetting
];
int i
;
for (i
= 0; i
< hintf
->desc.
bNumEndpoints; ++i
)
usb_enable_endpoint
(dev
, &hintf
->endpoint
[i
].
desc);
}
/**
* 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
;
int ret
;
int manual
= 0;
iface
= usb_ifnum_to_if
(dev
, interface
);
if (!iface
) {
warn
("selecting invalid interface %d", interface
);
return -EINVAL
;
}
if (alternate
< 0 || alternate
>= iface
->num_altsetting
)
return -EINVAL
;
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);
/* 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) {
dbg
("manual set_interface for dev %d, iface %d, alt %d",
dev
->devnum
, 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
);
iface
->act_altsetting
= alternate
;
/* 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
) {
struct usb_host_interface
*iface_as
=
&iface
->altsetting
[alternate
];
int i
;
for (i
= 0; i
< iface_as
->desc.
bNumEndpoints; i
++) {
unsigned int epaddr
=
iface_as
->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.
*
* 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
;
/* caller must own dev->serialize (config won't change)
* and the usb bus readlock (so driver bindings are stable);
* so 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, HZ
* USB_CTRL_SET_TIMEOUT
);
if (retval
< 0) {
dev
->state
= USB_STATE_ADDRESS
;
return retval
;
}
dev
->toggle
[0] = dev
->toggle
[1] = 0;
dev
->halted
[0] = dev
->halted
[1] = 0;
/* re-init hc/hcd interface/endpoint state */
for (i
= 0; i
< config
->desc.
bNumInterfaces; i
++) {
struct usb_interface
*intf
= config
->interface
[i
];
intf
->act_altsetting
= 0;
usb_enable_interface
(dev
, intf
);
}
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
* 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,
* and must not hold the driver model lock for USB; usb device driver
* probe() methods may not 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
;
/* dev->serialize guards all config changes */
down
(&dev
->serialize
);
for (i
=0; i
<dev
->descriptor.
bNumConfigurations; i
++) {
if (dev
->config
[i
].
desc.
bConfigurationValue == configuration
) {
cp
= &dev
->config
[i
];
break;
}
}
if ((!cp
&& configuration
!= 0)) {
ret
= -EINVAL
;
goto out
;
}
if (cp
&& configuration
== 0)
dev_warn
(&dev
->dev
, "config 0 descriptor??\n");
/* 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, HZ
* USB_CTRL_SET_TIMEOUT
)) < 0)
goto out
;
dev
->actconfig
= cp
;
//** if (!configuration) 2.6.1
if (!cp
)
dev
->state
= USB_STATE_ADDRESS
;
else {
dev
->state
= USB_STATE_CONFIGURED
;
/* re-initialize hc/hcd/usbcore interface/endpoint state.
* this triggers binding of drivers to interfaces; and
* maybe probe() calls will choose different altsettings.
*/
for (i
= 0; i
< cp
->desc.
bNumInterfaces; ++i
) {
struct usb_interface
*intf
= cp
->interface
[i
];
struct usb_interface_descriptor
*desc
;
intf
->act_altsetting
= 0;
desc
= &intf
->altsetting
[0].
desc;
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;
sprintf26
(&intf
->dev.
bus_id[0], "%d-%s:%d.%d",
dev
->bus
->busnum
, dev
->devpath
,
configuration
,
desc
->bInterfaceNumber
);
dev_dbg
(&dev
->dev
,
"registering %s (config #%d, interface %d)\n",
intf
->dev.
bus_id, configuration
,
desc
->bInterfaceNumber
);
device_add
(&intf
->dev
);
usb_create_driverfs_intf_files
(intf
);
}
}
out
:
up
(&dev
->serialize
);
return ret
;
}
/**
* 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 (err
< 4 || 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
);
// synchronous calls that also maintain usbcore state
EXPORT_SYMBOL
(usb_clear_halt
);
EXPORT_SYMBOL
(usb_reset_configuration
);
EXPORT_SYMBOL
(usb_set_configuration
);
EXPORT_SYMBOL
(usb_set_interface
);