illumos: manual page: usb_pipe_ctrl

USB_PIPE_CTRL_XFER(9F) Kernel Functions for Drivers USB_PIPE_CTRL_XFER(9F)

NAME

usb_pipe_ctrl_xfer, usb_pipe_ctrl_xfer_wait - USB control pipe transfer
functions

SYNOPSIS

#include <sys/usb/usba.h>

int usb_pipe_ctrl_xfer(usb_pipe_handle_t pipe_handle,
usb_ctrl_req_t *request, usb_flags_t flags);

int usb_pipe_ctrl_xfer_wait(usb_pipe_handle_t pipe_handle,
usb_ctrl_setup_t *setup, mblk_t **data,
usb_cr_t * completion_reason, usb_cb_flags_t *cb_flags,
usb_flags_t flags);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

For usb_pipe_ctrl_xfer():

pipe_handle
Control pipe handle on which request is made.

request
Pointer to control transfer request.

flags
USB_FLAGS_SLEEP is the only flag recognized. Wait for all
pending request callbacks to complete.

For usb_pipe_ctrl_xfer_wait():

pipe_handle
Control pipe handle on which request is made.

setup
Pointer to setup parameters. (See below.)

data
Pointer to mblk containing data bytes to transfer
with command. Ignored if NULL.

completion_reason
Returns overall completion status. Ignored if NULL.
Please see usb_callback_flags(9S) for more
information.

callback_flags
Returns flags set either during autoclearing or some
other callback, which indicate recovery handling
done in callback. Ignored if NULL.

flags
No flags are recognized. Reserved for future
expansion.

DESCRIPTION

The usb_pipe_ctrl_xfer() function requests the USBA framework to perform
a transfer through a USB control pipe. The request is passed to the host
controller driver (HCD), which performs the necessary transactions to
complete the request. Requests are synchronous when USB_FLAGS_SLEEP is
specified in flags; calls for synchronous requests do not return until
their transaction is completed. Asynchronous requests (made without
specifying the USB_FLAGS_SLEEP flag) notifies the caller of their
completion via a callback function.

The usb_pipe_ctrl_xfer_wait() function is a wrapper around
usb_pipe_ctrl_xfer() that performs allocation and deallocation of all
required data structures, and a synchronous control-pipe transfer. It
takes a usb_ctrl_setup_t containing most usb setup parameters as an
argument:

uchar_t bmRequestType /* characteristics of request. */
/* (See USB 2.0 spec, section 9.3). */
/* Combine one direction of: */
/* USB_DEV_REQ_HOST_TO_DEV */
/* USB_DEV_REQ_DEV_TO_HOST */
/* with one request type of: */
/* USB_DEV_REQ_TYPE_STANDARD */
/* USB_DEV_REQ_TYPE_CLASS */
/* USB_DEV_REQ_TYPE_VENDOR */
/* with one recipient type of: */
/* USB_DEV_REQ_RCPT_DEV */
/* USB_DEV_REQ_RCPT_IF */
/* USB_DEV_REQ_RCPT_EP */
/* USB_DEV_REQ_RCPT_OTHER. */

uchar_t bRequest /* request or command. */
/* (See USB 2.0 spec, section */
/* 9.3 for standard commands.) */

uint16_t wValue /* value which varies according to */
/* the command (bRequest). */

uint16_t wIndex /* value which varies according to */
/* the command, typically used to */
/* pass an index or offset. */

uint16_t wLength /* number of data bytes to transfer */
/* with command, if any. Same as */
/* size of mblk "data" below. */

usb_req_attrs_t attrs; /* required request attributes */

Please see usb_request_attributes(9S), or refer to Section 5.5 of the USB
2.0 specification for more information on these parameters. (The USB 2.0
specification is available at www.usb.org.)

Mblks for data are allocated optionally when a request is allocated via
usb_alloc_ctrl_req(9F) by passing a positive value for the len argument.
Control requests passing or receiving no supplemental data need not
allocate an mblk.

RETURN VALUES

For usb_pipe_ctrl_xfer():

USB_SUCCESS
Transfer was successful.

USB_INVALID_ARGS
Request is NULL.

USB_INVALID_CONTEXT
Called from interrupt context with the
USB_FLAGS_SLEEP flag set.

USB_INVALID_REQUEST
The request has been freed or otherwise
invalidated.

A set of conflicting attributes were specified.
See usb_request_attributes(9S).

The normal and/or exception callback is NULL and
USB_FLAGS_SLEEP is not set.

Data space not provided to a control request
while ctrl_wLength is nonzero.

USB_INVALID_PIPE
Pipe handle is NULL or invalid.

Pipe is closing or closed.

USB_NO_RESOURCES
Memory, descriptors or other resources
unavailable.

USB_HC_HARDWARE_ERROR
Host controller is in error state.

USB_FAILURE
An asynchronous transfer failed or an internal
error occurred.

The pipe is in an unsuitable state (error, busy,
not ready).

Additional status information may be available in the
ctrl_completion_reason and ctrl_cb_flags fields of the request. Please
see usb_callback_flags(9S) and usb_completion_reason(9S) for more
information.

For usb_pipe_ctrl_xfer_wait():

USB_SUCCESS
Request was successful.

USB_INVALID_CONTEXT
Called from interrupt context.

USB_INVALID_ARGS
dip is NULL.

Any error code returned by usb_pipe_ctrl_xfer().

Additional status information may be available in the
ctrl_completion_reason and ctrl_cb_flags fields of the request. Please
see usb_callback_flags(9S) and usb_completion_reason(9S) for more
information.

CONTEXT

The usb_pipe_ctrl_xfer() function may be called from kernel or user
context without regard to arguments and from the interrupt context only
when the USB_FLAGS_SLEEP flag is clear.

The usb_pipe_ctrl_xfer_wait() function may be called from kernel or user
context.

EXAMPLES

/* Allocate, initialize and issue a synchronous control request. */

usb_ctrl_req_t ctrl_req;
void control_pipe_exception_callback(
usb_pipe_handle_t, usb_ctrl_req_t*);

ctrl_req = usb_alloc_ctrl_req(dip, 0, USB_FLAGS_SLEEP);

ctrl_req->ctrl_bmRequestType = USB_DEV_REQ_HOST_TO_DEV |
USB_DEV_REQ_TYPE_CLASS | USB_DEV_REQ_RCPT_OTHER;

ctrl_req->ctrl_bRequest = (uint8_t)USB_PRINTER_SOFT_RESET;
ctrl_req->ctrl_exc_cb = control_pipe_exception_callback;
...
...
if ((rval = usb_pipe_ctrl_xfer(pipe, ctrl_req, USB_FLAGS_SLEEP))
!= USB_SUCCESS) {
cmn_err (CE_WARN, "%s%d: Error issuing USB cmd.",
ddi_driver_name(dip), ddi_get_instance(dip));
}

-------

/*
* Allocate, initialize and issue an asynchronous control request to
* read a configuration descriptor.
*/

usb_ctrl_req_t *ctrl_req;
void control_pipe_normal_callback(
usb_pipe_handle_t, usb_ctrl_req_t*);
void control_pipe_exception_callback(
usb_pipe_handle_t, usb_ctrl_req_t*);
struct buf *bp = ...;

ctrl_req =
usb_alloc_ctrl_req(dip, sizeof(usb_cfg_descr_t), USB_FLAGS_SLEEP);

ctrl_req->ctrl_bmRequestType = USB_DEV_REQ_DEV_TO_HOST |
USB_DEV_REQ_TYPE_STANDARD | USB_DEV_REQ_RCPT_DEV;

ctrl_req->ctrl_wLength = sizeof(usb_cfg_descr_t);
ctrl_req->ctrl_wValue = USB_DESCR_TYPE_SETUP_CFG | 0;
ctrl_req->ctrl_bRequest = (uint8_t)USB_REQ_GET_DESCR;
ctrl_req->ctrl_cb = control_pipe_normal_callback;
ctrl_req->ctrl_exc_cb = control_pipe_exception_callback;

/* Make buf struct available to callback handler. */
ctrl_req->ctrl_client_private = (usb_opaque_t)bp;
...
...
if ((rval = usb_pipe_ctrl_xfer(pipe, ctrl_req, USB_FLAGS_NOSLEEP))
!= USB_SUCCESS) {
cmn_err (CE_WARN, "%s%d: Error issuing USB cmd.",
ddi_driver_name(dip), ddi_get_instance(dip));
}

-------

/* Call usb_pipe_ctrl_xfer_wait() to get device status. */

mblk_t *data;
usb_cr_t completion_reason;
usb_cb_flags_t callback_flags;
usb_ctrl_setup_t setup_params = {
USB_DEV_REQ_DEV_TO_HOST | /* bmRequestType */
USB_DEV_REQ_TYPE_STANDARD | USB_DEV_REQ_RCPT_DEV,
USB_REQ_GET_STATUS, /* bRequest */
0, /* wValue */
0, /* wIndex */
USB_GET_STATUS_LEN, /* wLength */
0 /* attributes. */
};

if (usb_pipe_ctrl_xfer_wait(
pipe,
&setup_params,
&data,
&compleetion_reason,
&callback_flags,
0) != USB_SUCCESS) {
cmn_err (CE_WARN,
"%s%d: USB get status command failed: "
"reason=%d callback_flags=0x%x",
ddi_driver_name(dip), ddi_get_instance(dip),
completion_reason, callback_flags);
return (EIO);
}

/* Check data length. Should be USB_GET_STATUS_LEN (2 bytes). */
length_returned = data->b_wptr - data->b_rptr;
if (length_returned != USB_GET_STATUS_LEN) {
cmn_err (CE_WARN,
"%s%d: USB get status command returned %d bytes of data.",
ddi_driver_name(dip), ddi_get_instance(dip), length_returned);
return (EIO);
}

/* Retrieve data in endian neutral way. */
status = (*(data->b_rptr + 1) << 8) | *(data->b_rptr);

ATTRIBUTES