/*
* 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 unsigned epnum;
// #define MANY_ENDPOINTS
#ifdef MANY_ENDPOINTS
/* more than 15 configurable endpoints */
static 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
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 & 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_strtoul (&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 *
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 *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;
}
#ifdef CONFIG_BLACKFIN
} else if (gadget_is_musbhdrc(gadget)) {
if ((USB_ENDPOINT_XFER_BULK == type) ||
(USB_ENDPOINT_XFER_ISOC == type)) {
if (USB_DIR_IN & desc->bEndpointAddress)
ep = find_ep (gadget, "ep5in");
else
ep = find_ep (gadget, "ep6out");
} else if (USB_ENDPOINT_XFER_INT == type) {
if (USB_DIR_IN & desc->bEndpointAddress)
ep = find_ep(gadget, "ep1in");
else
ep = find_ep(gadget, "ep2out");
} else
ep = NULL;
if (ep && ep_matches (gadget, ep, desc))
return ep;
#endif
}
/* 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 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;
}
