usb_settings.c File Reference

USB device settings. More...

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ipxe/usb.h>
#include <ipxe/settings.h>
#include <ipxe/init.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static int	usb_settings_applies (struct settings *settings __unused, const struct setting *setting)
	Check applicability of USB device setting. More...
static int	usb_settings_fetch (struct settings *settings __unused, struct setting *setting, void *data, size_t len)
	Fetch value of USB device setting. More...
static void	usb_settings_init (void)
	Initialise USB device settings. More...
struct init_fn usb_settings_init_fn	__init_fn (INIT_NORMAL)
	USB device settings initialiser. More...

Variables
static const struct settings_scope	usb_settings_scope
	USB device settings scope. More...
static struct settings_operations	usb_settings_operations
	USB device settings operations. More...
static struct settings	usb_settings
	USB device settings. More...

Detailed Description

USB device settings.

Definition in file usb_settings.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

usb_settings_applies()

static int usb_settings_applies ( struct settings *settings  __unused, const struct setting *  setting  )

static

Check applicability of USB device setting.

Parameters

settings	Settings block
setting	Setting

Return values

applies

Setting applies within this settings block

Definition at line 49 of file usb_settings.c.

                                                                  {

        return ( setting->scope == &usb_settings_scope );
}

References setting::scope, and usb_settings_scope.

usb_settings_fetch()

static int usb_settings_fetch ( struct settings *settings  __unused, struct setting *  setting, void *  data, size_t  len  )

static

Fetch value of USB device setting.

Parameters

settings	Settings block
setting	Setting to fetch
data	Buffer to fill with setting data
len	Length of buffer

Return values

len	Length of setting data, or negative error

Definition at line 64 of file usb_settings.c.

                                                         {
        uint8_t *dst = data;
        const uint8_t *src;
        const uint8_t *desc;
        struct usb_bus *bus;
        struct usb_device *usb;
        int tag_direction;
        unsigned int tag_busdev;
        unsigned int tag_offset;
        unsigned int tag_len;
        unsigned int index;
        int rc;

        /* Extract parameters from tag */
        tag_direction = ( ( setting->tag & ( 1 << 31 ) ) ? +1 : -1 );
        tag_busdev = ( ( setting->tag >> 16 ) & 0x7fff );
        tag_offset = ( ( setting->tag >> 8 ) & 0xff );
        tag_len = ( ( setting->tag >> 0 ) & 0xff );

        /* Locate USB device */
        bus = find_usb_bus ( USB_BUS ( tag_busdev ) );
        if ( ! bus )
                return -ENODEV;
        usb = find_usb ( bus, USB_DEV ( tag_busdev ) );
        if ( ! usb )
                return -ENODEV;
        desc = ( ( const uint8_t * ) &usb->device );

        /* Following the usage of SMBIOS settings tags, a <length> of
         * zero indicates that the byte at <offset> contains a string
         * index.  An <offset> of zero indicates that the <length>
         * contains a literal string index.
         *
         * Since the byte at offset zero can never contain a string
         * index, and a literal string index can never be zero, the
         * combination of both <length> and <offset> being zero
         * indicates that the entire structure is to be read.
         *
         * By default we reverse the byte direction since USB values
         * are little-endian and iPXE settings are big-endian.  We
         * invert this default when reading the entire structure.
         */
        if ( ( tag_len == 0 ) && ( tag_offset == 0 ) ) {
                tag_len = sizeof ( usb->device );
                tag_direction = -tag_direction;
        } else if ( ( tag_len == 0 ) || ( tag_offset == 0 ) ) {
                index = tag_len;
                if ( ( ! index ) && ( tag_offset < sizeof ( usb->device ) ) )
                        index = desc[tag_offset];
                if ( ( rc = usb_get_string_descriptor ( usb, index, 0, data,
                                                        len ) ) < 0 ) {
                        return rc;
                }
                if ( ! setting->type )
                        setting->type = &setting_type_string;
                return rc;
        }

        /* Limit length */
        if ( tag_offset > sizeof ( usb->device ) ) {
                tag_len = 0;
        } else if ( ( tag_offset + tag_len ) > sizeof ( usb->device ) ) {
                tag_len = ( sizeof ( usb->device ) - tag_offset );
        }

        /* Copy data, reversing endianness if applicable */
        dst = data;
        src = ( desc + tag_offset );
        if ( tag_direction < 0 )
                src += ( tag_len - 1 );
        if ( len > tag_len )
                len = tag_len;
        for ( ; len-- ; src += tag_direction, dst++ )
                *dst = *src;

        /* Set type to ":hexraw" if not already specified */
        if ( ! setting->type )
                setting->type = &setting_type_hexraw;

        return tag_len;
}

References bus, data, desc, usb_device::device, ENODEV, find_usb(), find_usb_bus(), index, len, rc, src, setting::tag, setting::type, USB_BUS, USB_DEV, and usb_get_string_descriptor().

usb_settings_init()

static void usb_settings_init ( void  )

static

Initialise USB device settings.

Definition at line 164 of file usb_settings.c.

                                       {
        int rc;

        if ( ( rc = register_settings ( &usb_settings, NULL, "usb" ) ) != 0 ) {
                DBG ( "USB could not register settings: %s\n",
                      strerror ( rc ) );
                return;
        }
}

References DBG, NULL, rc, register_settings(), strerror(), and usb_settings.

__init_fn()

struct init_fn usb_settings_init_fn __init_fn

(

INIT_NORMAL

)

USB device settings initialiser.

Variable Documentation

usb_settings_scope

const struct settings_scope usb_settings_scope

static

USB device settings scope.

Definition at line 40 of file usb_settings.c.

Referenced by usb_settings_applies().

usb_settings_operations

struct settings_operations usb_settings_operations

static

Initial value:

= {
        .applies = usb_settings_applies,
        .fetch = usb_settings_fetch,
}

USB device settings operations.

Definition at line 149 of file usb_settings.c.

usb_settings

struct settings usb_settings

static

Initial value:

= {
        .refcnt = NULL,
        .siblings = LIST_HEAD_INIT ( usb_settings.siblings ),
        .children = LIST_HEAD_INIT ( usb_settings.children ),
        .op = &usb_settings_operations,
        .default_scope = &usb_settings_scope,
}

USB device settings.

Definition at line 155 of file usb_settings.c.

Referenced by usb_settings_init().