LXR uboot/drivers/usb/gadget/config.c

   1/*
   2 * usb/gadget/config.c -- simplify building config descriptors
   3 *
   4 * Copyright (C) 2003 David Brownell
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 *
  20 * Ported to U-boot by: Thomas Smits <ts.smits@gmail.com> and
  21 *                      Remy Bohmer <linux@bohmer.net>
  22 */
  23
  24#include <common.h>
  25#include <asm/errno.h>
  26#include <linux/list.h>
  27#include <linux/string.h>
  28
  29#include <linux/usb/ch9.h>
  30#include <linux/usb/gadget.h>
  31
  32
  33/**
  34 * usb_descriptor_fillbuf - fill buffer with descriptors
  35 * @buf: Buffer to be filled
  36 * @buflen: Size of buf
  37 * @src: Array of descriptor pointers, terminated by null pointer.
  38 *
  39 * Copies descriptors into the buffer, returning the length or a
  40 * negative error code if they can't all be copied.  Useful when
  41 * assembling descriptors for an associated set of interfaces used
  42 * as part of configuring a composite device; or in other cases where
  43 * sets of descriptors need to be marshaled.
  44 */
  45int
  46usb_descriptor_fillbuf(void *buf, unsigned buflen,
  47                const struct usb_descriptor_header **src)
  48{
  49        u8      *dest = buf;
  50
  51        if (!src)
  52                return -EINVAL;
  53
  54        /* fill buffer from src[] until null descriptor ptr */
  55        for (; NULL != *src; src++) {
  56                unsigned                len = (*src)->bLength;
  57
  58                if (len > buflen)
  59                        return -EINVAL;
  60                memcpy(dest, *src, len);
  61                buflen -= len;
  62                dest += len;
  63        }
  64        return dest - (u8 *)buf;
  65}
  66
  67
  68/**
  69 * usb_gadget_config_buf - builts a complete configuration descriptor
  70 * @config: Header for the descriptor, including characteristics such
  71 *      as power requirements and number of interfaces.
  72 * @desc: Null-terminated vector of pointers to the descriptors (interface,
  73 *      endpoint, etc) defining all functions in this device configuration.
  74 * @buf: Buffer for the resulting configuration descriptor.
  75 * @length: Length of buffer.  If this is not big enough to hold the
  76 *      entire configuration descriptor, an error code will be returned.
  77 *
  78 * This copies descriptors into the response buffer, building a descriptor
  79 * for that configuration.  It returns the buffer length or a negative
  80 * status code.  The config.wTotalLength field is set to match the length
  81 * of the result, but other descriptor fields (including power usage and
  82 * interface count) must be set by the caller.
  83 *
  84 * Gadget drivers could use this when constructing a config descriptor
  85 * in response to USB_REQ_GET_DESCRIPTOR.  They will need to patch the
  86 * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
  87 */
  88int usb_gadget_config_buf(
  89        const struct usb_config_descriptor      *config,
  90        void                                    *buf,
  91        unsigned                                length,
  92        const struct usb_descriptor_header      **desc
  93)
  94{
  95        struct usb_config_descriptor            *cp = buf;
  96        int                                     len;
  97
  98        /* config descriptor first */
  99        if (length < USB_DT_CONFIG_SIZE || !desc)
 100                return -EINVAL;
 101        *cp = *config;
 102
 103        /* then interface/endpoint/class/vendor/... */
 104        len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8 *)buf,
 105                        length - USB_DT_CONFIG_SIZE, desc);
 106        if (len < 0)
 107                return len;
 108        len += USB_DT_CONFIG_SIZE;
 109        if (len > 0xffff)
 110                return -EINVAL;
 111
 112        /* patch up the config descriptor */
 113        cp->bLength = USB_DT_CONFIG_SIZE;
 114        cp->bDescriptorType = USB_DT_CONFIG;
 115        cp->wTotalLength = cpu_to_le16(len);
 116        cp->bmAttributes |= USB_CONFIG_ATT_ONE;
 117        return len;
 118}
 119