text: /*
   * 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 & 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 * __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;
  		}
  
  #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 __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;
  }
  
  