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linux/drivers/usb/gadget/epautoconf.c
David Brownell a4c39c41bf usb gadget: descriptor copying support 
Define three new descriptor manipulation utilities, for use when
setting up functions that may have multiple instances:

	usb_copy_descriptors() to copy a vector of descriptors
	usb_free_descriptors() to free the copy
	usb_find_endpoint() to find a copied version

These will be used as follows.  Functions will continue to have static
tables of descriptors they update, now used as __initdata templates.

When a function creates a new instance, it patches those tables with
relevant interface and string IDs, plus endpoint assignments.  Then it
copies those morphed descriptors, associates the copies with the new
function instance, and records the endpoint descriptors to use when
activating the endpoints.  When initialization is done, only the copies
remain in memory.  The copies are freed on driver removal.

This ensures that each instance has descriptors which hold the right
instance-specific data.  Two instances in the same configuration will
obviously never share the same interface IDs or use the same endpoints.
Instances in different configurations won't do so either, which means
this is slightly less memory-efficient in some cases.

This also includes a bugfix to the epautoconf code that shows up with
this usage model.  It must replace the previous endpoint number when
updating the template descriptors, not just mask in a few more bits.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 15:16:00 -07:00

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/*
* epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
*
* Copyright (C) 2004 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include "gadget_chips.h"
/* we must assign addresses for configurable endpoints (like net2280) */
static __initdata unsigned epnum;
// #define MANY_ENDPOINTS
#ifdef MANY_ENDPOINTS
/* more than 15 configurable endpoints */
static __initdata unsigned in_epnum;
#endif
/*
* This should work with endpoints from controller drivers sharing the
* same endpoint naming convention. By example:
*
* - ep1, ep2, ... address is fixed, not direction or type
* - ep1in, ep2out, ... address and direction are fixed, not type
* - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
* - ep1in-bulk, ep2out-iso, ... all three are fixed
* - ep-* ... no functionality restrictions
*
* Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
* Less common restrictions are implied by gadget_is_*().
*
* NOTE: each endpoint is unidirectional, as specified by its USB
* descriptor; and isn't specific to a configuration or altsetting.
*/
static int __init
ep_matches (
struct usb_gadget *gadget,
struct usb_ep *ep,
struct usb_endpoint_descriptor *desc
)
{
u8 type;
const char *tmp;
u16 max;
/* endpoint already claimed? */
if (NULL != ep->driver_data)
return 0;
/* only support ep0 for portable CONTROL traffic */
type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
if (USB_ENDPOINT_XFER_CONTROL == type)
return 0;
/* some other naming convention */
if ('e' != ep->name[0])
return 0;
/* type-restriction: "-iso", "-bulk", or "-int".
* direction-restriction: "in", "out".
*/
if ('-' != ep->name[2]) {
tmp = strrchr (ep->name, '-');
if (tmp) {
switch (type) {
case USB_ENDPOINT_XFER_INT:
/* bulk endpoints handle interrupt transfers,
* except the toggle-quirky iso-synch kind
*/
if ('s' == tmp[2]) // == "-iso"
return 0;
/* for now, avoid PXA "interrupt-in";
* it's documented as never using DATA1.
*/
if (gadget_is_pxa (gadget)
&& 'i' == tmp [1])
return 0;
break;
case USB_ENDPOINT_XFER_BULK:
if ('b' != tmp[1]) // != "-bulk"
return 0;
break;
case USB_ENDPOINT_XFER_ISOC:
if ('s' != tmp[2]) // != "-iso"
return 0;
}
} else {
tmp = ep->name + strlen (ep->name);
}
/* direction-restriction: "..in-..", "out-.." */
tmp--;
if (!isdigit (*tmp)) {
if (desc->bEndpointAddress & USB_DIR_IN) {
if ('n' != *tmp)
return 0;
} else {
if ('t' != *tmp)
return 0;
}
}
}
/* endpoint maxpacket size is an input parameter, except for bulk
* where it's an output parameter representing the full speed limit.
* the usb spec fixes high speed bulk maxpacket at 512 bytes.
*/
max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
switch (type) {
case USB_ENDPOINT_XFER_INT:
/* INT: limit 64 bytes full speed, 1024 high speed */
if (!gadget->is_dualspeed && max > 64)
return 0;
/* FALLTHROUGH */
case USB_ENDPOINT_XFER_ISOC:
/* ISO: limit 1023 bytes full speed, 1024 high speed */
if (ep->maxpacket < max)
return 0;
if (!gadget->is_dualspeed && max > 1023)
return 0;
/* BOTH: "high bandwidth" works only at high speed */
if ((desc->wMaxPacketSize & __constant_cpu_to_le16(3<<11))) {
if (!gadget->is_dualspeed)
return 0;
/* configure your hardware with enough buffering!! */
}
break;
}
/* MATCH!! */
/* report address */
desc->bEndpointAddress &= USB_DIR_IN;
if (isdigit (ep->name [2])) {
u8 num = simple_strtol (&ep->name [2], NULL, 10);
desc->bEndpointAddress |= num;
#ifdef MANY_ENDPOINTS
} else if (desc->bEndpointAddress & USB_DIR_IN) {
if (++in_epnum > 15)
return 0;
desc->bEndpointAddress = USB_DIR_IN | in_epnum;
#endif
} else {
if (++epnum > 15)
return 0;
desc->bEndpointAddress |= epnum;
}
/* report (variable) full speed bulk maxpacket */
if (USB_ENDPOINT_XFER_BULK == type) {
int size = ep->maxpacket;
/* min() doesn't work on bitfields with gcc-3.5 */
if (size > 64)
size = 64;
desc->wMaxPacketSize = cpu_to_le16(size);
}
return 1;
}
static struct usb_ep * __init
find_ep (struct usb_gadget *gadget, const char *name)
{
struct usb_ep *ep;
list_for_each_entry (ep, &gadget->ep_list, ep_list) {
if (0 == strcmp (ep->name, name))
return ep;
}
return NULL;
}
/**
* usb_ep_autoconfig - choose an endpoint matching the descriptor
* @gadget: The device to which the endpoint must belong.
* @desc: Endpoint descriptor, with endpoint direction and transfer mode
* initialized. For periodic transfers, the maximum packet
* size must also be initialized. This is modified on success.
*
* By choosing an endpoint to use with the specified descriptor, this
* routine simplifies writing gadget drivers that work with multiple
* USB device controllers. The endpoint would be passed later to
* usb_ep_enable(), along with some descriptor.
*
* That second descriptor won't always be the same as the first one.
* For example, isochronous endpoints can be autoconfigured for high
* bandwidth, and then used in several lower bandwidth altsettings.
* Also, high and full speed descriptors will be different.
*
* Be sure to examine and test the results of autoconfiguration on your
* hardware. This code may not make the best choices about how to use the
* USB controller, and it can't know all the restrictions that may apply.
* Some combinations of driver and hardware won't be able to autoconfigure.
*
* On success, this returns an un-claimed usb_ep, and modifies the endpoint
* descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
* is initialized as if the endpoint were used at full speed. To prevent
* the endpoint from being returned by a later autoconfig call, claim it
* by assigning ep->driver_data to some non-null value.
*
* On failure, this returns a null endpoint descriptor.
*/
struct usb_ep * __init usb_ep_autoconfig (
struct usb_gadget *gadget,
struct usb_endpoint_descriptor *desc
)
{
struct usb_ep *ep;
u8 type;
type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
/* First, apply chip-specific "best usage" knowledge.
* This might make a good usb_gadget_ops hook ...
*/
if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
/* ep-e, ep-f are PIO with only 64 byte fifos */
ep = find_ep (gadget, "ep-e");
if (ep && ep_matches (gadget, ep, desc))
return ep;
ep = find_ep (gadget, "ep-f");
if (ep && ep_matches (gadget, ep, desc))
return ep;
} else if (gadget_is_goku (gadget)) {
if (USB_ENDPOINT_XFER_INT == type) {
/* single buffering is enough */
ep = find_ep (gadget, "ep3-bulk");
if (ep && ep_matches (gadget, ep, desc))
return ep;
} else if (USB_ENDPOINT_XFER_BULK == type
&& (USB_DIR_IN & desc->bEndpointAddress)) {
/* DMA may be available */
ep = find_ep (gadget, "ep2-bulk");
if (ep && ep_matches (gadget, ep, desc))
return ep;
}
} else if (gadget_is_sh (gadget) && USB_ENDPOINT_XFER_INT == type) {
/* single buffering is enough; maybe 8 byte fifo is too */
ep = find_ep (gadget, "ep3in-bulk");
if (ep && ep_matches (gadget, ep, desc))
return ep;
} else if (gadget_is_mq11xx (gadget) && USB_ENDPOINT_XFER_INT == type) {
ep = find_ep (gadget, "ep1-bulk");
if (ep && ep_matches (gadget, ep, desc))
return ep;
}
/* Second, look at endpoints until an unclaimed one looks usable */
list_for_each_entry (ep, &gadget->ep_list, ep_list) {
if (ep_matches (gadget, ep, desc))
return ep;
}
/* Fail */
return NULL;
}
/**
* usb_ep_autoconfig_reset - reset endpoint autoconfig state
* @gadget: device for which autoconfig state will be reset
*
* Use this for devices where one configuration may need to assign
* endpoint resources very differently from the next one. It clears
* state such as ep->driver_data and the record of assigned endpoints
* used by usb_ep_autoconfig().
*/
void __init usb_ep_autoconfig_reset (struct usb_gadget *gadget)
{
struct usb_ep *ep;
list_for_each_entry (ep, &gadget->ep_list, ep_list) {
ep->driver_data = NULL;
}
#ifdef MANY_ENDPOINTS
in_epnum = 0;
#endif
epnum = 0;
}
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