linux/drivers/usb/gadget/config.c
Sebastian Andrzej Siewior 10287baec7 usb: gadget: always update HS/SS descriptors and create a copy of them
HS and SS descriptors are staticaly created. They are updated during the
bind process with the endpoint address, string id or interface numbers.

After that, the descriptor chain is linked to struct usb_function which
is used by composite in order to serve the GET_DESCRIPTOR requests,
number of available configs and so on.

There is no need to assign the HS descriptor only if the UDC supports
HS speed because composite won't report those to the host if HS support
has not been reached. The same reasoning is valid for SS.

This patch makes sure each function updates HS/SS descriptors
unconditionally and uses the newly introduced helper function to create a
copy the descriptors for the speed which is supported by the UDC.

While at that, also rename f->descriptors to f->fs_descriptors in order
to make it more explicit what that means.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2012-10-31 15:09:44 +02:00

198 lines
5.6 KiB
C

/*
* usb/gadget/config.c -- simplify building config descriptors
*
* Copyright (C) 2003 David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/composite.h>
/**
* usb_descriptor_fillbuf - fill buffer with descriptors
* @buf: Buffer to be filled
* @buflen: Size of buf
* @src: Array of descriptor pointers, terminated by null pointer.
*
* Copies descriptors into the buffer, returning the length or a
* negative error code if they can't all be copied. Useful when
* assembling descriptors for an associated set of interfaces used
* as part of configuring a composite device; or in other cases where
* sets of descriptors need to be marshaled.
*/
int
usb_descriptor_fillbuf(void *buf, unsigned buflen,
const struct usb_descriptor_header **src)
{
u8 *dest = buf;
if (!src)
return -EINVAL;
/* fill buffer from src[] until null descriptor ptr */
for (; NULL != *src; src++) {
unsigned len = (*src)->bLength;
if (len > buflen)
return -EINVAL;
memcpy(dest, *src, len);
buflen -= len;
dest += len;
}
return dest - (u8 *)buf;
}
EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
/**
* usb_gadget_config_buf - builts a complete configuration descriptor
* @config: Header for the descriptor, including characteristics such
* as power requirements and number of interfaces.
* @desc: Null-terminated vector of pointers to the descriptors (interface,
* endpoint, etc) defining all functions in this device configuration.
* @buf: Buffer for the resulting configuration descriptor.
* @length: Length of buffer. If this is not big enough to hold the
* entire configuration descriptor, an error code will be returned.
*
* This copies descriptors into the response buffer, building a descriptor
* for that configuration. It returns the buffer length or a negative
* status code. The config.wTotalLength field is set to match the length
* of the result, but other descriptor fields (including power usage and
* interface count) must be set by the caller.
*
* Gadget drivers could use this when constructing a config descriptor
* in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the
* resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
*/
int usb_gadget_config_buf(
const struct usb_config_descriptor *config,
void *buf,
unsigned length,
const struct usb_descriptor_header **desc
)
{
struct usb_config_descriptor *cp = buf;
int len;
/* config descriptor first */
if (length < USB_DT_CONFIG_SIZE || !desc)
return -EINVAL;
*cp = *config;
/* then interface/endpoint/class/vendor/... */
len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf,
length - USB_DT_CONFIG_SIZE, desc);
if (len < 0)
return len;
len += USB_DT_CONFIG_SIZE;
if (len > 0xffff)
return -EINVAL;
/* patch up the config descriptor */
cp->bLength = USB_DT_CONFIG_SIZE;
cp->bDescriptorType = USB_DT_CONFIG;
cp->wTotalLength = cpu_to_le16(len);
cp->bmAttributes |= USB_CONFIG_ATT_ONE;
return len;
}
EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
/**
* usb_copy_descriptors - copy a vector of USB descriptors
* @src: null-terminated vector to copy
* Context: initialization code, which may sleep
*
* This makes a copy of a vector of USB descriptors. Its primary use
* is to support usb_function objects which can have multiple copies,
* each needing different descriptors. Functions may have static
* tables of descriptors, which are used as templates and customized
* with identifiers (for interfaces, strings, endpoints, and more)
* as needed by a given function instance.
*/
struct usb_descriptor_header **
usb_copy_descriptors(struct usb_descriptor_header **src)
{
struct usb_descriptor_header **tmp;
unsigned bytes;
unsigned n_desc;
void *mem;
struct usb_descriptor_header **ret;
/* count descriptors and their sizes; then add vector size */
for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
bytes += (*tmp)->bLength;
bytes += (n_desc + 1) * sizeof(*tmp);
mem = kmalloc(bytes, GFP_KERNEL);
if (!mem)
return NULL;
/* fill in pointers starting at "tmp",
* to descriptors copied starting at "mem";
* and return "ret"
*/
tmp = mem;
ret = mem;
mem += (n_desc + 1) * sizeof(*tmp);
while (*src) {
memcpy(mem, *src, (*src)->bLength);
*tmp = mem;
tmp++;
mem += (*src)->bLength;
src++;
}
*tmp = NULL;
return ret;
}
EXPORT_SYMBOL_GPL(usb_copy_descriptors);
int usb_assign_descriptors(struct usb_function *f,
struct usb_descriptor_header **fs,
struct usb_descriptor_header **hs,
struct usb_descriptor_header **ss)
{
struct usb_gadget *g = f->config->cdev->gadget;
if (fs) {
f->fs_descriptors = usb_copy_descriptors(fs);
if (!f->fs_descriptors)
goto err;
}
if (hs && gadget_is_dualspeed(g)) {
f->hs_descriptors = usb_copy_descriptors(hs);
if (!f->hs_descriptors)
goto err;
}
if (ss && gadget_is_superspeed(g)) {
f->ss_descriptors = usb_copy_descriptors(ss);
if (!f->ss_descriptors)
goto err;
}
return 0;
err:
usb_free_all_descriptors(f);
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(usb_assign_descriptors);
void usb_free_all_descriptors(struct usb_function *f)
{
usb_free_descriptors(f->fs_descriptors);
usb_free_descriptors(f->hs_descriptors);
usb_free_descriptors(f->ss_descriptors);
}
EXPORT_SYMBOL_GPL(usb_free_all_descriptors);