Tribblix: manual page: usb_client_dev

USB_CLIENT_DEV_DATA(9S) Data Structures for Drivers USB_CLIENT_DEV_DATA(9S)

NAME

usb_client_dev_data - Device configuration information

SYNOPSIS

#include <sys/usb/usba.h>

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

DESCRIPTION

The usb_client_dev_data_t structure carries all device configuration
information. It is provided to a USB client driver through a call to
usb_get_dev_data(9F). Most USBA functions require information which
comes from this structure.

The usb_client_dev_data_t structure fields are:

usb_pipe_handle_t dev_default_ph; /* deflt ctrl pipe handle */

ddi_iblock_cookie_t dev_iblock_cookie;/* for calls to mutex_init */
/* for mutexes used by intr */
/* context callbacks. */

usb_dev_descr_t *dev_descr; /* parsed* dev. descriptor */

char *dev_mfg; /* manufacturer's ID string */

char *dev_product; /* product ID string */

char *dev_serial; /* serial num. string */

usb_reg_parse_lvl_t dev_parse_level; /* Parse level */
/* reflecting the tree */
/* (if any) returned through */
/* the dev_cfg array. */

usb_cfg_data_t *dev_cfg; /* parsed* descr tree.*/

uint_t dev_n_cfg; /* num cfgs in parsed descr. */
/* tree, dev_cfg array below.*/

usb_cfg_data_t *dev_curr_cfg; /* Pointer to the tree config*/
/* corresponding to the cfg */
/* active at the time of the */
/* usb_get_dev_data() call */

int dev_curr_if; /* First active interface in */
/* tree under driver's control.*/

/* Always zero when driver */
/* controls whole device. */

* A parsed descriptor is in a struct whose fields' have been adjusted
to the host processor. This may include endianness adjustment (the USB
standard defines that devices report in little-endian bit order) or
structure padding as necessary.

dev_parse_level represents the extent of the device represented by
the tree returned by the dev_cfg field and has the following possible
values:

USB_PARSE_LVL_NONE
Build no tree. dev_n_cfg returns 0, dev_cfg and
dev_curr_cfg are returned NULL, the
dev_curr_xxx fields are invalid.

USB_PARSE_LVL_IF
Parse configured interface only, if
configuration# and interface properties are set
(as when different interfaces are viewed by the
OS as different device instances). If an OS
device instance is set up to represent an
entire physical device, this works like
USB_PARSE_LVL_ALL.

USB_PARSE_LVL_CFG
Parse entire configuration of configured
interface only. This is like USB_PARSE_LVL_IF
except entire configuration is returned.

USB_PARSE_LVL_ALL
Parse entire device (all configurations), even
when driver is bound to a single interface of a
single configuration.

The default control pipe handle is used mainly for control commands
and device setup.

The dev_iblock_cookie is used to initialize client driver mutexes
which are used in interrupt-context callback handlers. (All callback
handlers called with USB_CB_INTR_CONTEXT in their usb_cb_flags_t arg
execute in interrupt context.) This cookie is used in lieu of one
returned by ddi_get_iblock_cookie(9F). Mutexes used in other handlers
or under other conditions should initialize per mutex_init(9F).

The parsed standard USB device descriptor is used for device type
identification.

The several ID strings, including the manufacturer's ID, product ID,
and serial number may be used to identify the device in messages or
to compare it to other devices.

The descriptor tree, returned by dev_cfg, makes a device's parsed
standard USB descriptors available to the driver. The tree is
designed to be easily traversed to get any or all standard USB 3.0
descriptors. (See the "Tree Structure" section of this manpage
below.) dev_n_cfg returns the number of configurations in the tree.
Note that this value may differ from the number of configurations
returned in the device descriptor.

A returned parse_level field of USB_PARSE_LVL_ALL indicates that all
configurations are represented in the tree. This results when
USB_PARSE_LVL_ALL is explicitly requested by the caller in the flags
argument to usb_get_dev_data(), or when the whole device is seen by
the system for the current OS device node (as opposed to only a
single configuration for that OS device node). USB_PARSE_LVL_CFG is
returned when one entire configuration is returned in the tree.
USB_PARSE_LVL_IF is returned when one interface of one configuration
is returned in the tree. In the latter two cases, the returned
configuration is at dev_cfg[USB_DEV_DEFAULT_CONFIG_INDEX].
USB_PARSE_LVL_NONE is returned when no tree is returned. Note that
the value of this field can differ from the parse_level requested as
an argument to usb_get_dev_data().

TREE STRUCTURE

The root of the tree is dev_cfg, an array of usb_cfg_data_t
configuration nodes, each representing one device configuration. The
array index does not correspond to a configuration's value; use the
bConfigurationValue field of the configuration descriptor within to
find out the proper number for a given configuration.

The size of the array is returned in dev_n_cfg. The array itself is
not NULL terminated.

When USB_PARSE_LVL_ALL is returned in dev_parse_level, index 0
pertains to the first valid configuration. This pertains to device
configuration 1 as USB configuration 0 is not defined. When
dev_parse_level returns USB_PARSE_LVL_CFG or USB_PARSE_LVL_IF, index
0 pertains to the device's one configuration recognized by the
system. (Note that the configuration level is the only descriptor
level in the tree where the index value does not correspond to the
descriptor's value.)

Each usb_cfg_data_t configuration node contains a parsed usb
configuration descriptor (usb_cfg_descr_t cfg_descr) a pointer to its
string description (char *cfg_str) and string size (cfg_strsize), a
pointer to an array of interface nodes (usb_if_data_t *cfg_if), and a
pointer to an array of class/vendor (cv) descriptor nodes
(usb_cvs_data_t *cfg_cvs). The interface node array size is kept in
cfg_n_if, and the cv node array size is kept in cfg_n_cvs; neither
array is NULL terminated. When USB_PARSE_LVL_IF is returned in
dev_parse_level, the only interface (or alternate group) included in
the tree is that which is recognized by the system for the current OS
device node.

Each interface can present itself potentially in one of several
alternate ways. An alternate tree node (usb_alt_if_data_t)
represents an alternate representation. Each usb_if_data_t interface
node points to an array of alternate nodes (usb_alt_if_data_t
*if_alt) and contains the size of the array (if_n_alt).

Each interface alternate node holds an interface descriptor
(usb_if_descr_t altif_descr), a pointer to its string description
(char *altif_str), and has its own set of endpoints and bound cv
descriptors. The pointer to the array of endpoints is usb_ep_data_t
*altif_ep); the endpoint array size is altif_n_ep. The pointer to
the array of cv descriptors is usb_cvs_data_t *altif_cvs; the cv
descriptor array size is altif_n_cvs.

Each endpoint node holds an endpoint descriptor (usb_ep_descr_t
ep_descr), a pointer to an array of cv descriptors for that endpoint
(usb_cvs_data_t *ep_cvs), and the size of that array (ep_n_cvs). An
endpoint descriptor may be passed to usb_pipe_open(9F) to establish a
logical connection for data transfer.

Class and vendor descriptors (cv descriptors) are grouped with the
configuration, interface or endpoint descriptors they immediately
follow in the raw data returned by the device. Tree nodes
representing such descriptors (usb_cvs_data_t) contain a pointer to
the raw data (uchar_t *cvs_buf) and the size of the data (uint_t
cvs_buf_len).

Configuration and interface alternate nodes return string
descriptions. Note that all string descriptions returned have a
maximum length of USB_MAXSTRINGLEN bytes and are in English ASCII.

EXAMPLES

In the following example, a device's configuration data, including
the following descriptor tree, is retrieved by usb_get_dev_data(9F)
into usb_client_dev_data_t *reg_data:

config 1
iface 0
alt 0
endpt 0
config 2
iface 0
iface 1
alt 0
endpt 0
cv 0
alt 1
endpt 0
endpt 1
cv 0
endpt 2
alt 2
endpt 0
cv 0

and suppose that the C/V data is of the following format:

typedef struct cv_data {
char char1;
short short1;
char char2;
} cv_data_t;

Parse the data of C/V descriptor 0, second configuration
(index 1), iface 1, alt 2, endpt 0.

usb_client_dev_data_t reg_data;
usb_cvs_data_t *cv_node;
cv_data_t parsed_data;

cv_node =
®_data->dev_cfg[1].cfg_if[1].if_alt[2].altif_ep[0].ep_cvs[0];
(void)usb_parse_data("csc",
(void *)(&cv_node->cvs_buf), cv_node->cvs_buf_len,
&parsed_data, sizeof(cv_data_t));

ATTRIBUTES