drivers/usb/gadget/epautoconf.c

   1 /*
   2  * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
   3  *
   4  * Copyright (C) 2004 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
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/device.h>
  16
  17 #include <linux/ctype.h>
  18 #include <linux/string.h>
  19
  20 #include <linux/usb/ch9.h>
  21 #include <linux/usb/gadget.h>
  22
  23 #include "gadget_chips.h"
  24
  25
  26 /* we must assign addresses for configurable endpoints (like net2280) */
  27 static unsigned epnum;
  28
  29 // #define MANY_ENDPOINTS
  30 #ifdef MANY_ENDPOINTS
  31 /* more than 15 configurable endpoints */
  32 static unsigned in_epnum;
  33 #endif
  34
  35
  36 /*
  37  * This should work with endpoints from controller drivers sharing the
  38  * same endpoint naming convention.  By example:
  39  *
  40  *      - ep1, ep2, ... address is fixed, not direction or type
  41  *      - ep1in, ep2out, ... address and direction are fixed, not type
  42  *      - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
  43  *      - ep1in-bulk, ep2out-iso, ... all three are fixed
  44  *      - ep-* ... no functionality restrictions
  45  *
  46  * Type suffixes are "-bulk", "-iso", or "-int".  Numbers are decimal.
  47  * Less common restrictions are implied by gadget_is_*().
  48  *
  49  * NOTE:  each endpoint is unidirectional, as specified by its USB
  50  * descriptor; and isn't specific to a configuration or altsetting.
  51  */
  52 static int
  53 ep_matches (
  54         struct usb_gadget               *gadget,
  55         struct usb_ep                   *ep,
  56         struct usb_endpoint_descriptor  *desc,
  57         struct usb_ss_ep_comp_descriptor *ep_comp
  58 )
  59 {
  60         u8              type;
  61         const char      *tmp;
  62         u16             max;
  63
  64         int             num_req_streams = 0;
  65
  66         /* endpoint already claimed? */
  67         if (NULL != ep->driver_data)
  68                 return 0;
  69
  70         /* only support ep0 for portable CONTROL traffic */
  71         type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
  72         if (USB_ENDPOINT_XFER_CONTROL == type)
  73                 return 0;
  74
  75         /* some other naming convention */
  76         if ('e' != ep->name[0])
  77                 return 0;
  78
  79         /* type-restriction:  "-iso", "-bulk", or "-int".
  80          * direction-restriction:  "in", "out".
  81          */
  82         if ('-' != ep->name[2]) {
  83                 tmp = strrchr (ep->name, '-');
  84                 if (tmp) {
  85                         switch (type) {
  86                         case USB_ENDPOINT_XFER_INT:
  87                                 /* bulk endpoints handle interrupt transfers,
  88                                  * except the toggle-quirky iso-synch kind
  89                                  */
  90                                 if ('s' == tmp[2])      // == "-iso"
  91                                         return 0;
  92                                 /* for now, avoid PXA "interrupt-in";
  93                                  * it's documented as never using DATA1.
  94                                  */
  95                                 if (gadget_is_pxa (gadget)
  96                                                 && 'i' == tmp [1])
  97                                         return 0;
  98                                 break;
  99                         case USB_ENDPOINT_XFER_BULK:
 100                                 if ('b' != tmp[1])      // != "-bulk"
 101                                         return 0;
 102                                 break;
 103                         case USB_ENDPOINT_XFER_ISOC:
 104                                 if ('s' != tmp[2])      // != "-iso"
 105                                         return 0;
 106                         }
 107                 } else {
 108                         tmp = ep->name + strlen (ep->name);
 109                 }
 110
 111                 /* direction-restriction:  "..in-..", "out-.." */
 112                 tmp--;
 113                 if (!isdigit (*tmp)) {
 114                         if (desc->bEndpointAddress & USB_DIR_IN) {
 115                                 if ('n' != *tmp)
 116                                         return 0;
 117                         } else {
 118                                 if ('t' != *tmp)
 119                                         return 0;
 120                         }
 121                 }
 122         }
 123
 124         /*
 125          * Get the number of required streams from the EP companion
 126          * descriptor and see if the EP matches it
 127          */
 128         if (usb_endpoint_xfer_bulk(desc)) {
 129                 if (ep_comp && gadget->max_speed >= USB_SPEED_SUPER) {
 130                         num_req_streams = ep_comp->bmAttributes & 0x1f;
 131                         if (num_req_streams > ep->max_streams)
 132                                 return 0;
 133                 }
 134
 135         }
 136
 137         /*
 138          * If the protocol driver hasn't yet decided on wMaxPacketSize
 139          * and wants to know the maximum possible, provide the info.
 140          */
 141         if (desc->wMaxPacketSize == 0)
 142                 desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket);
 143
 144         /* endpoint maxpacket size is an input parameter, except for bulk
 145          * where it's an output parameter representing the full speed limit.
 146          * the usb spec fixes high speed bulk maxpacket at 512 bytes.
 147          */
 148         max = 0x7ff & usb_endpoint_maxp(desc);
 149         switch (type) {
 150         case USB_ENDPOINT_XFER_INT:
 151                 /* INT:  limit 64 bytes full speed, 1024 high/super speed */
 152                 if (!gadget_is_dualspeed(gadget) && max > 64)
 153                         return 0;
 154                 /* FALLTHROUGH */
 155
 156         case USB_ENDPOINT_XFER_ISOC:
 157                 /* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
 158                 if (ep->maxpacket < max)
 159                         return 0;
 160                 if (!gadget_is_dualspeed(gadget) && max > 1023)
 161                         return 0;
 162
 163                 /* BOTH:  "high bandwidth" works only at high speed */
 164                 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) {
 165                         if (!gadget_is_dualspeed(gadget))
 166                                 return 0;
 167                         /* configure your hardware with enough buffering!! */
 168                 }
 169                 break;
 170         }
 171
 172         /* MATCH!! */
 173
 174         /* report address */
 175         desc->bEndpointAddress &= USB_DIR_IN;
 176         if (isdigit (ep->name [2])) {
 177                 u8      num = simple_strtoul (&ep->name [2], NULL, 10);
 178                 desc->bEndpointAddress |= num;
 179 #ifdef  MANY_ENDPOINTS
 180         } else if (desc->bEndpointAddress & USB_DIR_IN) {
 181                 if (++in_epnum > 15)
 182                         return 0;
 183                 desc->bEndpointAddress = USB_DIR_IN | in_epnum;
 184 #endif
 185         } else {
 186                 if (++epnum > 15)
 187                         return 0;
 188                 desc->bEndpointAddress |= epnum;
 189         }
 190
 191         /* report (variable) full speed bulk maxpacket */
 192         if ((USB_ENDPOINT_XFER_BULK == type) && !ep_comp) {
 193                 int size = ep->maxpacket;
 194
 195                 /* min() doesn't work on bitfields with gcc-3.5 */
 196                 if (size > 64)
 197                         size = 64;
 198                 desc->wMaxPacketSize = cpu_to_le16(size);
 199         }
 200         ep->address = desc->bEndpointAddress;
 201         return 1;
 202 }
 203
 204 static struct usb_ep *
 205 find_ep (struct usb_gadget *gadget, const char *name)
 206 {
 207         struct usb_ep   *ep;
 208
 209         list_for_each_entry (ep, &gadget->ep_list, ep_list) {
 210                 if (0 == strcmp (ep->name, name))
 211                         return ep;
 212         }
 213         return NULL;
 214 }
 215
 216 /**
 217  * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
 218  * descriptor and ep companion descriptor
 219  * @gadget: The device to which the endpoint must belong.
 220  * @desc: Endpoint descriptor, with endpoint direction and transfer mode
 221  *    initialized.  For periodic transfers, the maximum packet
 222  *    size must also be initialized.  This is modified on
 223  *    success.
 224  * @ep_comp: Endpoint companion descriptor, with the required
 225  *    number of streams. Will be modified when the chosen EP
 226  *    supports a different number of streams.
 227  *
 228  * This routine replaces the usb_ep_autoconfig when needed
 229  * superspeed enhancments. If such enhancemnets are required,
 230  * the FD should call usb_ep_autoconfig_ss directly and provide
 231  * the additional ep_comp parameter.
 232  *
 233  * By choosing an endpoint to use with the specified descriptor,
 234  * this routine simplifies writing gadget drivers that work with
 235  * multiple USB device controllers.  The endpoint would be
 236  * passed later to usb_ep_enable(), along with some descriptor.
 237  *
 238  * That second descriptor won't always be the same as the first one.
 239  * For example, isochronous endpoints can be autoconfigured for high
 240  * bandwidth, and then used in several lower bandwidth altsettings.
 241  * Also, high and full speed descriptors will be different.
 242  *
 243  * Be sure to examine and test the results of autoconfiguration
 244  * on your hardware.  This code may not make the best choices
 245  * about how to use the USB controller, and it can't know all
 246  * the restrictions that may apply. Some combinations of driver
 247  * and hardware won't be able to autoconfigure.
 248  *
 249  * On success, this returns an un-claimed usb_ep, and modifies the endpoint
 250  * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
 251  * is initialized as if the endpoint were used at full speed and
 252  * the bmAttribute field in the ep companion descriptor is
 253  * updated with the assigned number of streams if it is
 254  * different from the original value. To prevent the endpoint
 255  * from being returned by a later autoconfig call, claim it by
 256  * assigning ep->driver_data to some non-null value.
 257  *
 258  * On failure, this returns a null endpoint descriptor.
 259  */
 260 struct usb_ep *usb_ep_autoconfig_ss(
 261         struct usb_gadget               *gadget,
 262         struct usb_endpoint_descriptor  *desc,
 263         struct usb_ss_ep_comp_descriptor *ep_comp
 264 )
 265 {
 266         struct usb_ep   *ep;
 267         u8              type;
 268
 269         type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
 270
 271         /* First, apply chip-specific "best usage" knowledge.
 272          * This might make a good usb_gadget_ops hook ...
 273          */
 274         if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
 275                 /* ep-e, ep-f are PIO with only 64 byte fifos */
 276                 ep = find_ep (gadget, "ep-e");
 277                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
 278                         goto found_ep;
 279                 ep = find_ep (gadget, "ep-f");
 280                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
 281                         goto found_ep;
 282
 283         } else if (gadget_is_goku (gadget)) {
 284                 if (USB_ENDPOINT_XFER_INT == type) {
 285                         /* single buffering is enough */
 286                         ep = find_ep(gadget, "ep3-bulk");
 287                         if (ep && ep_matches(gadget, ep, desc, ep_comp))
 288                                 goto found_ep;
 289                 } else if (USB_ENDPOINT_XFER_BULK == type
 290                                 && (USB_DIR_IN & desc->bEndpointAddress)) {
 291                         /* DMA may be available */
 292                         ep = find_ep(gadget, "ep2-bulk");
 293                         if (ep && ep_matches(gadget, ep, desc,
 294                                               ep_comp))
 295                                 goto found_ep;
 296                 }
 297
 298 #ifdef CONFIG_BLACKFIN
 299         } else if (gadget_is_musbhdrc(gadget)) {
 300                 if ((USB_ENDPOINT_XFER_BULK == type) ||
 301                     (USB_ENDPOINT_XFER_ISOC == type)) {
 302                         if (USB_DIR_IN & desc->bEndpointAddress)
 303                                 ep = find_ep (gadget, "ep5in");
 304                         else
 305                                 ep = find_ep (gadget, "ep6out");
 306                 } else if (USB_ENDPOINT_XFER_INT == type) {
 307                         if (USB_DIR_IN & desc->bEndpointAddress)
 308                                 ep = find_ep(gadget, "ep1in");
 309                         else
 310                                 ep = find_ep(gadget, "ep2out");
 311                 } else
 312                         ep = NULL;
 313                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
 314                         goto found_ep;
 315 #endif
 316         }
 317
 318         /* Second, look at endpoints until an unclaimed one looks usable */
 319         list_for_each_entry (ep, &gadget->ep_list, ep_list) {
 320                 if (ep_matches(gadget, ep, desc, ep_comp))
 321                         goto found_ep;
 322         }
 323
 324         /* Fail */
 325         return NULL;
 326 found_ep:
 327         ep->desc = NULL;
 328         ep->comp_desc = NULL;
 329         return ep;
 330 }
 331
 332 /**
 333  * usb_ep_autoconfig() - choose an endpoint matching the
 334  * descriptor
 335  * @gadget: The device to which the endpoint must belong.
 336  * @desc: Endpoint descriptor, with endpoint direction and transfer mode
 337  *      initialized.  For periodic transfers, the maximum packet
 338  *      size must also be initialized.  This is modified on success.
 339  *
 340  * By choosing an endpoint to use with the specified descriptor, this
 341  * routine simplifies writing gadget drivers that work with multiple
 342  * USB device controllers.  The endpoint would be passed later to
 343  * usb_ep_enable(), along with some descriptor.
 344  *
 345  * That second descriptor won't always be the same as the first one.
 346  * For example, isochronous endpoints can be autoconfigured for high
 347  * bandwidth, and then used in several lower bandwidth altsettings.
 348  * Also, high and full speed descriptors will be different.
 349  *
 350  * Be sure to examine and test the results of autoconfiguration on your
 351  * hardware.  This code may not make the best choices about how to use the
 352  * USB controller, and it can't know all the restrictions that may apply.
 353  * Some combinations of driver and hardware won't be able to autoconfigure.
 354  *
 355  * On success, this returns an un-claimed usb_ep, and modifies the endpoint
 356  * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
 357  * is initialized as if the endpoint were used at full speed.  To prevent
 358  * the endpoint from being returned by a later autoconfig call, claim it
 359  * by assigning ep->driver_data to some non-null value.
 360  *
 361  * On failure, this returns a null endpoint descriptor.
 362  */
 363 struct usb_ep *usb_ep_autoconfig(
 364         struct usb_gadget               *gadget,
 365         struct usb_endpoint_descriptor  *desc
 366 )
 367 {
 368         return usb_ep_autoconfig_ss(gadget, desc, NULL);
 369 }
 370
 371
 372 /**
 373  * usb_ep_autoconfig_reset - reset endpoint autoconfig state
 374  * @gadget: device for which autoconfig state will be reset
 375  *
 376  * Use this for devices where one configuration may need to assign
 377  * endpoint resources very differently from the next one.  It clears
 378  * state such as ep->driver_data and the record of assigned endpoints
 379  * used by usb_ep_autoconfig().
 380  */
 381 void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
 382 {
 383         struct usb_ep   *ep;
 384
 385         list_for_each_entry (ep, &gadget->ep_list, ep_list) {
 386                 ep->driver_data = NULL;
 387         }
 388 #ifdef  MANY_ENDPOINTS
 389         in_epnum = 0;
 390 #endif
 391         epnum = 0;
 392 }
 393