drivers/usb/musb/musb_gadget_ep0.c

   1 /*
   2  * MUSB OTG peripheral driver ep0 handling
   3  *
   4  * Copyright 2005 Mentor Graphics Corporation
   5  * Copyright (C) 2005-2006 by Texas Instruments
   6  * Copyright (C) 2006-2007 Nokia Corporation
   7  * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * version 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  *
  23  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  24  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  26  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  30  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  */
  35
  36 #include <linux/kernel.h>
  37 #include <linux/list.h>
  38 #include <linux/timer.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/device.h>
  41 #include <linux/interrupt.h>
  42
  43 #include "musb_core.h"
  44
  45 /* ep0 is always musb->endpoints[0].ep_in */
  46 #define next_ep0_request(musb)  next_in_request(&(musb)->endpoints[0])
  47
  48 /*
  49  * locking note:  we use only the controller lock, for simpler correctness.
  50  * It's always held with IRQs blocked.
  51  *
  52  * It protects the ep0 request queue as well as ep0_state, not just the
  53  * controller and indexed registers.  And that lock stays held unless it
  54  * needs to be dropped to allow reentering this driver ... like upcalls to
  55  * the gadget driver, or adjusting endpoint halt status.
  56  */
  57
  58 static char *decode_ep0stage(u8 stage)
  59 {
  60         switch (stage) {
  61         case MUSB_EP0_STAGE_IDLE:       return "idle";
  62         case MUSB_EP0_STAGE_SETUP:      return "setup";
  63         case MUSB_EP0_STAGE_TX:         return "in";
  64         case MUSB_EP0_STAGE_RX:         return "out";
  65         case MUSB_EP0_STAGE_ACKWAIT:    return "wait";
  66         case MUSB_EP0_STAGE_STATUSIN:   return "in/status";
  67         case MUSB_EP0_STAGE_STATUSOUT:  return "out/status";
  68         default:                        return "?";
  69         }
  70 }
  71
  72 /* handle a standard GET_STATUS request
  73  * Context:  caller holds controller lock
  74  */
  75 static int service_tx_status_request(
  76         struct musb *musb,
  77         const struct usb_ctrlrequest *ctrlrequest)
  78 {
  79         void __iomem    *mbase = musb->mregs;
  80         int handled = 1;
  81         u8 result[2], epnum = 0;
  82         const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
  83
  84         result[1] = 0;
  85
  86         switch (recip) {
  87         case USB_RECIP_DEVICE:
  88                 result[0] = musb->g.is_selfpowered << USB_DEVICE_SELF_POWERED;
  89                 result[0] |= musb->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
  90                 if (musb->g.is_otg) {
  91                         result[0] |= musb->g.b_hnp_enable
  92                                 << USB_DEVICE_B_HNP_ENABLE;
  93                         result[0] |= musb->g.a_alt_hnp_support
  94                                 << USB_DEVICE_A_ALT_HNP_SUPPORT;
  95                         result[0] |= musb->g.a_hnp_support
  96                                 << USB_DEVICE_A_HNP_SUPPORT;
  97                 }
  98                 break;
  99
 100         case USB_RECIP_INTERFACE:
 101                 result[0] = 0;
 102                 break;
 103
 104         case USB_RECIP_ENDPOINT: {
 105                 int             is_in;
 106                 struct musb_ep  *ep;
 107                 u16             tmp;
 108                 void __iomem    *regs;
 109
 110                 epnum = (u8) ctrlrequest->wIndex;
 111                 if (!epnum) {
 112                         result[0] = 0;
 113                         break;
 114                 }
 115
 116                 is_in = epnum & USB_DIR_IN;
 117                 if (is_in) {
 118                         epnum &= 0x0f;
 119                         ep = &musb->endpoints[epnum].ep_in;
 120                 } else {
 121                         ep = &musb->endpoints[epnum].ep_out;
 122                 }
 123                 regs = musb->endpoints[epnum].regs;
 124
 125                 if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
 126                         handled = -EINVAL;
 127                         break;
 128                 }
 129
 130                 musb_ep_select(mbase, epnum);
 131                 if (is_in)
 132                         tmp = musb_readw(regs, MUSB_TXCSR)
 133                                                 & MUSB_TXCSR_P_SENDSTALL;
 134                 else
 135                         tmp = musb_readw(regs, MUSB_RXCSR)
 136                                                 & MUSB_RXCSR_P_SENDSTALL;
 137                 musb_ep_select(mbase, 0);
 138
 139                 result[0] = tmp ? 1 : 0;
 140                 } break;
 141
 142         default:
 143                 /* class, vendor, etc ... delegate */
 144                 handled = 0;
 145                 break;
 146         }
 147
 148         /* fill up the fifo; caller updates csr0 */
 149         if (handled > 0) {
 150                 u16     len = le16_to_cpu(ctrlrequest->wLength);
 151
 152                 if (len > 2)
 153                         len = 2;
 154                 musb_write_fifo(&musb->endpoints[0], len, result);
 155         }
 156
 157         return handled;
 158 }
 159
 160 /*
 161  * handle a control-IN request, the end0 buffer contains the current request
 162  * that is supposed to be a standard control request. Assumes the fifo to
 163  * be at least 2 bytes long.
 164  *
 165  * @return 0 if the request was NOT HANDLED,
 166  * < 0 when error
 167  * > 0 when the request is processed
 168  *
 169  * Context:  caller holds controller lock
 170  */
 171 static int
 172 service_in_request(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
 173 {
 174         int handled = 0;        /* not handled */
 175
 176         if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
 177                         == USB_TYPE_STANDARD) {
 178                 switch (ctrlrequest->bRequest) {
 179                 case USB_REQ_GET_STATUS:
 180                         handled = service_tx_status_request(musb,
 181                                         ctrlrequest);
 182                         break;
 183
 184                 /* case USB_REQ_SYNC_FRAME: */
 185
 186                 default:
 187                         break;
 188                 }
 189         }
 190         return handled;
 191 }
 192
 193 /*
 194  * Context:  caller holds controller lock
 195  */
 196 static void musb_g_ep0_giveback(struct musb *musb, struct usb_request *req)
 197 {
 198         musb_g_giveback(&musb->endpoints[0].ep_in, req, 0);
 199 }
 200
 201 /*
 202  * Tries to start B-device HNP negotiation if enabled via sysfs
 203  */
 204 static inline void musb_try_b_hnp_enable(struct musb *musb)
 205 {
 206         void __iomem    *mbase = musb->mregs;
 207         u8              devctl;
 208
 209         dev_dbg(musb->controller, "HNP: Setting HR\n");
 210         devctl = musb_readb(mbase, MUSB_DEVCTL);
 211         musb_writeb(mbase, MUSB_DEVCTL, devctl | MUSB_DEVCTL_HR);
 212 }
 213
 214 /*
 215  * Handle all control requests with no DATA stage, including standard
 216  * requests such as:
 217  * USB_REQ_SET_CONFIGURATION, USB_REQ_SET_INTERFACE, unrecognized
 218  *      always delegated to the gadget driver
 219  * USB_REQ_SET_ADDRESS, USB_REQ_CLEAR_FEATURE, USB_REQ_SET_FEATURE
 220  *      always handled here, except for class/vendor/... features
 221  *
 222  * Context:  caller holds controller lock
 223  */
 224 static int
 225 service_zero_data_request(struct musb *musb,
 226                 struct usb_ctrlrequest *ctrlrequest)
 227 __releases(musb->lock)
 228 __acquires(musb->lock)
 229 {
 230         int handled = -EINVAL;
 231         void __iomem *mbase = musb->mregs;
 232         const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
 233
 234         /* the gadget driver handles everything except what we MUST handle */
 235         if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
 236                         == USB_TYPE_STANDARD) {
 237                 switch (ctrlrequest->bRequest) {
 238                 case USB_REQ_SET_ADDRESS:
 239                         /* change it after the status stage */
 240                         musb->set_address = true;
 241                         musb->address = (u8) (ctrlrequest->wValue & 0x7f);
 242                         handled = 1;
 243                         break;
 244
 245                 case USB_REQ_CLEAR_FEATURE:
 246                         switch (recip) {
 247                         case USB_RECIP_DEVICE:
 248                                 if (ctrlrequest->wValue
 249                                                 != USB_DEVICE_REMOTE_WAKEUP)
 250                                         break;
 251                                 musb->may_wakeup = 0;
 252                                 handled = 1;
 253                                 break;
 254                         case USB_RECIP_INTERFACE:
 255                                 break;
 256                         case USB_RECIP_ENDPOINT:{
 257                                 const u8                epnum =
 258                                         ctrlrequest->wIndex & 0x0f;
 259                                 struct musb_ep          *musb_ep;
 260                                 struct musb_hw_ep       *ep;
 261                                 struct musb_request     *request;
 262                                 void __iomem            *regs;
 263                                 int                     is_in;
 264                                 u16                     csr;
 265
 266                                 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
 267                                     ctrlrequest->wValue != USB_ENDPOINT_HALT)
 268                                         break;
 269
 270                                 ep = musb->endpoints + epnum;
 271                                 regs = ep->regs;
 272                                 is_in = ctrlrequest->wIndex & USB_DIR_IN;
 273                                 if (is_in)
 274                                         musb_ep = &ep->ep_in;
 275                                 else
 276                                         musb_ep = &ep->ep_out;
 277                                 if (!musb_ep->desc)
 278                                         break;
 279
 280                                 handled = 1;
 281                                 /* Ignore request if endpoint is wedged */
 282                                 if (musb_ep->wedged)
 283                                         break;
 284
 285                                 musb_ep_select(mbase, epnum);
 286                                 if (is_in) {
 287                                         csr  = musb_readw(regs, MUSB_TXCSR);
 288                                         csr |= MUSB_TXCSR_CLRDATATOG |
 289                                                MUSB_TXCSR_P_WZC_BITS;
 290                                         csr &= ~(MUSB_TXCSR_P_SENDSTALL |
 291                                                  MUSB_TXCSR_P_SENTSTALL |
 292                                                  MUSB_TXCSR_TXPKTRDY);
 293                                         musb_writew(regs, MUSB_TXCSR, csr);
 294                                 } else {
 295                                         csr  = musb_readw(regs, MUSB_RXCSR);
 296                                         csr |= MUSB_RXCSR_CLRDATATOG |
 297                                                MUSB_RXCSR_P_WZC_BITS;
 298                                         csr &= ~(MUSB_RXCSR_P_SENDSTALL |
 299                                                  MUSB_RXCSR_P_SENTSTALL);
 300                                         musb_writew(regs, MUSB_RXCSR, csr);
 301                                 }
 302
 303                                 /* Maybe start the first request in the queue */
 304                                 request = next_request(musb_ep);
 305                                 if (!musb_ep->busy && request) {
 306                                         dev_dbg(musb->controller, "restarting the request\n");
 307                                         musb_ep_restart(musb, request);
 308                                 }
 309
 310                                 /* select ep0 again */
 311                                 musb_ep_select(mbase, 0);
 312                                 } break;
 313                         default:
 314                                 /* class, vendor, etc ... delegate */
 315                                 handled = 0;
 316                                 break;
 317                         }
 318                         break;
 319
 320                 case USB_REQ_SET_FEATURE:
 321                         switch (recip) {
 322                         case USB_RECIP_DEVICE:
 323                                 handled = 1;
 324                                 switch (ctrlrequest->wValue) {
 325                                 case USB_DEVICE_REMOTE_WAKEUP:
 326                                         musb->may_wakeup = 1;
 327                                         break;
 328                                 case USB_DEVICE_TEST_MODE:
 329                                         if (musb->g.speed != USB_SPEED_HIGH)
 330                                                 goto stall;
 331                                         if (ctrlrequest->wIndex & 0xff)
 332                                                 goto stall;
 333
 334                                         switch (ctrlrequest->wIndex >> 8) {
 335                                         case 1:
 336                                                 pr_debug("TEST_J\n");
 337                                                 /* TEST_J */
 338                                                 musb->test_mode_nr =
 339                                                         MUSB_TEST_J;
 340                                                 break;
 341                                         case 2:
 342                                                 /* TEST_K */
 343                                                 pr_debug("TEST_K\n");
 344                                                 musb->test_mode_nr =
 345                                                         MUSB_TEST_K;
 346                                                 break;
 347                                         case 3:
 348                                                 /* TEST_SE0_NAK */
 349                                                 pr_debug("TEST_SE0_NAK\n");
 350                                                 musb->test_mode_nr =
 351                                                         MUSB_TEST_SE0_NAK;
 352                                                 break;
 353                                         case 4:
 354                                                 /* TEST_PACKET */
 355                                                 pr_debug("TEST_PACKET\n");
 356                                                 musb->test_mode_nr =
 357                                                         MUSB_TEST_PACKET;
 358                                                 break;
 359
 360                                         case 0xc0:
 361                                                 /* TEST_FORCE_HS */
 362                                                 pr_debug("TEST_FORCE_HS\n");
 363                                                 musb->test_mode_nr =
 364                                                         MUSB_TEST_FORCE_HS;
 365                                                 break;
 366                                         case 0xc1:
 367                                                 /* TEST_FORCE_FS */
 368                                                 pr_debug("TEST_FORCE_FS\n");
 369                                                 musb->test_mode_nr =
 370                                                         MUSB_TEST_FORCE_FS;
 371                                                 break;
 372                                         case 0xc2:
 373                                                 /* TEST_FIFO_ACCESS */
 374                                                 pr_debug("TEST_FIFO_ACCESS\n");
 375                                                 musb->test_mode_nr =
 376                                                         MUSB_TEST_FIFO_ACCESS;
 377                                                 break;
 378                                         case 0xc3:
 379                                                 /* TEST_FORCE_HOST */
 380                                                 pr_debug("TEST_FORCE_HOST\n");
 381                                                 musb->test_mode_nr =
 382                                                         MUSB_TEST_FORCE_HOST;
 383                                                 break;
 384                                         default:
 385                                                 goto stall;
 386                                         }
 387
 388                                         /* enter test mode after irq */
 389                                         if (handled > 0)
 390                                                 musb->test_mode = true;
 391                                         break;
 392                                 case USB_DEVICE_B_HNP_ENABLE:
 393                                         if (!musb->g.is_otg)
 394                                                 goto stall;
 395                                         musb->g.b_hnp_enable = 1;
 396                                         musb_try_b_hnp_enable(musb);
 397                                         break;
 398                                 case USB_DEVICE_A_HNP_SUPPORT:
 399                                         if (!musb->g.is_otg)
 400                                                 goto stall;
 401                                         musb->g.a_hnp_support = 1;
 402                                         break;
 403                                 case USB_DEVICE_A_ALT_HNP_SUPPORT:
 404                                         if (!musb->g.is_otg)
 405                                                 goto stall;
 406                                         musb->g.a_alt_hnp_support = 1;
 407                                         break;
 408                                 case USB_DEVICE_DEBUG_MODE:
 409                                         handled = 0;
 410                                         break;
 411 stall:
 412                                 default:
 413                                         handled = -EINVAL;
 414                                         break;
 415                                 }
 416                                 break;
 417
 418                         case USB_RECIP_INTERFACE:
 419                                 break;
 420
 421                         case USB_RECIP_ENDPOINT:{
 422                                 const u8                epnum =
 423                                         ctrlrequest->wIndex & 0x0f;
 424                                 struct musb_ep          *musb_ep;
 425                                 struct musb_hw_ep       *ep;
 426                                 void __iomem            *regs;
 427                                 int                     is_in;
 428                                 u16                     csr;
 429
 430                                 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
 431                                     ctrlrequest->wValue != USB_ENDPOINT_HALT)
 432                                         break;
 433
 434                                 ep = musb->endpoints + epnum;
 435                                 regs = ep->regs;
 436                                 is_in = ctrlrequest->wIndex & USB_DIR_IN;
 437                                 if (is_in)
 438                                         musb_ep = &ep->ep_in;
 439                                 else
 440                                         musb_ep = &ep->ep_out;
 441                                 if (!musb_ep->desc)
 442                                         break;
 443
 444                                 musb_ep_select(mbase, epnum);
 445                                 if (is_in) {
 446                                         csr = musb_readw(regs, MUSB_TXCSR);
 447                                         if (csr & MUSB_TXCSR_FIFONOTEMPTY)
 448                                                 csr |= MUSB_TXCSR_FLUSHFIFO;
 449                                         csr |= MUSB_TXCSR_P_SENDSTALL
 450                                                 | MUSB_TXCSR_CLRDATATOG
 451                                                 | MUSB_TXCSR_P_WZC_BITS;
 452                                         musb_writew(regs, MUSB_TXCSR, csr);
 453                                 } else {
 454                                         csr = musb_readw(regs, MUSB_RXCSR);
 455                                         csr |= MUSB_RXCSR_P_SENDSTALL
 456                                                 | MUSB_RXCSR_FLUSHFIFO
 457                                                 | MUSB_RXCSR_CLRDATATOG
 458                                                 | MUSB_RXCSR_P_WZC_BITS;
 459                                         musb_writew(regs, MUSB_RXCSR, csr);
 460                                 }
 461
 462                                 /* select ep0 again */
 463                                 musb_ep_select(mbase, 0);
 464                                 handled = 1;
 465                                 } break;
 466
 467                         default:
 468                                 /* class, vendor, etc ... delegate */
 469                                 handled = 0;
 470                                 break;
 471                         }
 472                         break;
 473                 default:
 474                         /* delegate SET_CONFIGURATION, etc */
 475                         handled = 0;
 476                 }
 477         } else
 478                 handled = 0;
 479         return handled;
 480 }
 481
 482 /* we have an ep0out data packet
 483  * Context:  caller holds controller lock
 484  */
 485 static void ep0_rxstate(struct musb *musb)
 486 {
 487         void __iomem            *regs = musb->control_ep->regs;
 488         struct musb_request     *request;
 489         struct usb_request      *req;
 490         u16                     count, csr;
 491
 492         request = next_ep0_request(musb);
 493         req = &request->request;
 494
 495         /* read packet and ack; or stall because of gadget driver bug:
 496          * should have provided the rx buffer before setup() returned.
 497          */
 498         if (req) {
 499                 void            *buf = req->buf + req->actual;
 500                 unsigned        len = req->length - req->actual;
 501
 502                 /* read the buffer */
 503                 count = musb_readb(regs, MUSB_COUNT0);
 504                 if (count > len) {
 505                         req->status = -EOVERFLOW;
 506                         count = len;
 507                 }
 508                 if (count > 0) {
 509                         musb_read_fifo(&musb->endpoints[0], count, buf);
 510                         req->actual += count;
 511                 }
 512                 csr = MUSB_CSR0_P_SVDRXPKTRDY;
 513                 if (count < 64 || req->actual == req->length) {
 514                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 515                         csr |= MUSB_CSR0_P_DATAEND;
 516                 } else
 517                         req = NULL;
 518         } else
 519                 csr = MUSB_CSR0_P_SVDRXPKTRDY | MUSB_CSR0_P_SENDSTALL;
 520
 521
 522         /* Completion handler may choose to stall, e.g. because the
 523          * message just received holds invalid data.
 524          */
 525         if (req) {
 526                 musb->ackpend = csr;
 527                 musb_g_ep0_giveback(musb, req);
 528                 if (!musb->ackpend)
 529                         return;
 530                 musb->ackpend = 0;
 531         }
 532         musb_ep_select(musb->mregs, 0);
 533         musb_writew(regs, MUSB_CSR0, csr);
 534 }
 535
 536 /*
 537  * transmitting to the host (IN), this code might be called from IRQ
 538  * and from kernel thread.
 539  *
 540  * Context:  caller holds controller lock
 541  */
 542 static void ep0_txstate(struct musb *musb)
 543 {
 544         void __iomem            *regs = musb->control_ep->regs;
 545         struct musb_request     *req = next_ep0_request(musb);
 546         struct usb_request      *request;
 547         u16                     csr = MUSB_CSR0_TXPKTRDY;
 548         u8                      *fifo_src;
 549         u8                      fifo_count;
 550
 551         if (!req) {
 552                 /* WARN_ON(1); */
 553                 dev_dbg(musb->controller, "odd; csr0 %04x\n", musb_readw(regs, MUSB_CSR0));
 554                 return;
 555         }
 556
 557         request = &req->request;
 558
 559         /* load the data */
 560         fifo_src = (u8 *) request->buf + request->actual;
 561         fifo_count = min((unsigned) MUSB_EP0_FIFOSIZE,
 562                 request->length - request->actual);
 563         musb_write_fifo(&musb->endpoints[0], fifo_count, fifo_src);
 564         request->actual += fifo_count;
 565
 566         /* update the flags */
 567         if (fifo_count < MUSB_MAX_END0_PACKET
 568                         || (request->actual == request->length
 569                                 && !request->zero)) {
 570                 musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
 571                 csr |= MUSB_CSR0_P_DATAEND;
 572         } else
 573                 request = NULL;
 574
 575         /* report completions as soon as the fifo's loaded; there's no
 576          * win in waiting till this last packet gets acked.  (other than
 577          * very precise fault reporting, needed by USB TMC; possible with
 578          * this hardware, but not usable from portable gadget drivers.)
 579          */
 580         if (request) {
 581                 musb->ackpend = csr;
 582                 musb_g_ep0_giveback(musb, request);
 583                 if (!musb->ackpend)
 584                         return;
 585                 musb->ackpend = 0;
 586         }
 587
 588         /* send it out, triggering a "txpktrdy cleared" irq */
 589         musb_ep_select(musb->mregs, 0);
 590         musb_writew(regs, MUSB_CSR0, csr);
 591 }
 592
 593 /*
 594  * Read a SETUP packet (struct usb_ctrlrequest) from the hardware.
 595  * Fields are left in USB byte-order.
 596  *
 597  * Context:  caller holds controller lock.
 598  */
 599 static void
 600 musb_read_setup(struct musb *musb, struct usb_ctrlrequest *req)
 601 {
 602         struct musb_request     *r;
 603         void __iomem            *regs = musb->control_ep->regs;
 604
 605         musb_read_fifo(&musb->endpoints[0], sizeof *req, (u8 *)req);
 606
 607         /* NOTE:  earlier 2.6 versions changed setup packets to host
 608          * order, but now USB packets always stay in USB byte order.
 609          */
 610         dev_dbg(musb->controller, "SETUP req%02x.%02x v%04x i%04x l%d\n",
 611                 req->bRequestType,
 612                 req->bRequest,
 613                 le16_to_cpu(req->wValue),
 614                 le16_to_cpu(req->wIndex),
 615                 le16_to_cpu(req->wLength));
 616
 617         /* clean up any leftover transfers */
 618         r = next_ep0_request(musb);
 619         if (r)
 620                 musb_g_ep0_giveback(musb, &r->request);
 621
 622         /* For zero-data requests we want to delay the STATUS stage to
 623          * avoid SETUPEND errors.  If we read data (OUT), delay accepting
 624          * packets until there's a buffer to store them in.
 625          *
 626          * If we write data, the controller acts happier if we enable
 627          * the TX FIFO right away, and give the controller a moment
 628          * to switch modes...
 629          */
 630         musb->set_address = false;
 631         musb->ackpend = MUSB_CSR0_P_SVDRXPKTRDY;
 632         if (req->wLength == 0) {
 633                 if (req->bRequestType & USB_DIR_IN)
 634                         musb->ackpend |= MUSB_CSR0_TXPKTRDY;
 635                 musb->ep0_state = MUSB_EP0_STAGE_ACKWAIT;
 636         } else if (req->bRequestType & USB_DIR_IN) {
 637                 musb->ep0_state = MUSB_EP0_STAGE_TX;
 638                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDRXPKTRDY);
 639                 while ((musb_readw(regs, MUSB_CSR0)
 640                                 & MUSB_CSR0_RXPKTRDY) != 0)
 641                         cpu_relax();
 642                 musb->ackpend = 0;
 643         } else
 644                 musb->ep0_state = MUSB_EP0_STAGE_RX;
 645 }
 646
 647 static int
 648 forward_to_driver(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
 649 __releases(musb->lock)
 650 __acquires(musb->lock)
 651 {
 652         int retval;
 653         if (!musb->gadget_driver)
 654                 return -EOPNOTSUPP;
 655         spin_unlock(&musb->lock);
 656         retval = musb->gadget_driver->setup(&musb->g, ctrlrequest);
 657         spin_lock(&musb->lock);
 658         return retval;
 659 }
 660
 661 /*
 662  * Handle peripheral ep0 interrupt
 663  *
 664  * Context: irq handler; we won't re-enter the driver that way.
 665  */
 666 irqreturn_t musb_g_ep0_irq(struct musb *musb)
 667 {
 668         u16             csr;
 669         u16             len;
 670         void __iomem    *mbase = musb->mregs;
 671         void __iomem    *regs = musb->endpoints[0].regs;
 672         irqreturn_t     retval = IRQ_NONE;
 673
 674         musb_ep_select(mbase, 0);       /* select ep0 */
 675         csr = musb_readw(regs, MUSB_CSR0);
 676         len = musb_readb(regs, MUSB_COUNT0);
 677
 678         dev_dbg(musb->controller, "csr %04x, count %d, ep0stage %s\n",
 679                         csr, len, decode_ep0stage(musb->ep0_state));
 680
 681         if (csr & MUSB_CSR0_P_DATAEND) {
 682                 /*
 683                  * If DATAEND is set we should not call the callback,
 684                  * hence the status stage is not complete.
 685                  */
 686                 return IRQ_HANDLED;
 687         }
 688
 689         /* I sent a stall.. need to acknowledge it now.. */
 690         if (csr & MUSB_CSR0_P_SENTSTALL) {
 691                 musb_writew(regs, MUSB_CSR0,
 692                                 csr & ~MUSB_CSR0_P_SENTSTALL);
 693                 retval = IRQ_HANDLED;
 694                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 695                 csr = musb_readw(regs, MUSB_CSR0);
 696         }
 697
 698         /* request ended "early" */
 699         if (csr & MUSB_CSR0_P_SETUPEND) {
 700                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);
 701                 retval = IRQ_HANDLED;
 702                 /* Transition into the early status phase */
 703                 switch (musb->ep0_state) {
 704                 case MUSB_EP0_STAGE_TX:
 705                         musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
 706                         break;
 707                 case MUSB_EP0_STAGE_RX:
 708                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 709                         break;
 710                 default:
 711                         ERR("SetupEnd came in a wrong ep0stage %s\n",
 712                             decode_ep0stage(musb->ep0_state));
 713                 }
 714                 csr = musb_readw(regs, MUSB_CSR0);
 715                 /* NOTE:  request may need completion */
 716         }
 717
 718         /* docs from Mentor only describe tx, rx, and idle/setup states.
 719          * we need to handle nuances around status stages, and also the
 720          * case where status and setup stages come back-to-back ...
 721          */
 722         switch (musb->ep0_state) {
 723
 724         case MUSB_EP0_STAGE_TX:
 725                 /* irq on clearing txpktrdy */
 726                 if ((csr & MUSB_CSR0_TXPKTRDY) == 0) {
 727                         ep0_txstate(musb);
 728                         retval = IRQ_HANDLED;
 729                 }
 730                 break;
 731
 732         case MUSB_EP0_STAGE_RX:
 733                 /* irq on set rxpktrdy */
 734                 if (csr & MUSB_CSR0_RXPKTRDY) {
 735                         ep0_rxstate(musb);
 736                         retval = IRQ_HANDLED;
 737                 }
 738                 break;
 739
 740         case MUSB_EP0_STAGE_STATUSIN:
 741                 /* end of sequence #2 (OUT/RX state) or #3 (no data) */
 742
 743                 /* update address (if needed) only @ the end of the
 744                  * status phase per usb spec, which also guarantees
 745                  * we get 10 msec to receive this irq... until this
 746                  * is done we won't see the next packet.
 747                  */
 748                 if (musb->set_address) {
 749                         musb->set_address = false;
 750                         musb_writeb(mbase, MUSB_FADDR, musb->address);
 751                 }
 752
 753                 /* enter test mode if needed (exit by reset) */
 754                 else if (musb->test_mode) {
 755                         dev_dbg(musb->controller, "entering TESTMODE\n");
 756
 757                         if (MUSB_TEST_PACKET == musb->test_mode_nr)
 758                                 musb_load_testpacket(musb);
 759
 760                         musb_writeb(mbase, MUSB_TESTMODE,
 761                                         musb->test_mode_nr);
 762                 }
 763                 /* FALLTHROUGH */
 764
 765         case MUSB_EP0_STAGE_STATUSOUT:
 766                 /* end of sequence #1: write to host (TX state) */
 767                 {
 768                         struct musb_request     *req;
 769
 770                         req = next_ep0_request(musb);
 771                         if (req)
 772                                 musb_g_ep0_giveback(musb, &req->request);
 773                 }
 774
 775                 /*
 776                  * In case when several interrupts can get coalesced,
 777                  * check to see if we've already received a SETUP packet...
 778                  */
 779                 if (csr & MUSB_CSR0_RXPKTRDY)
 780                         goto setup;
 781
 782                 retval = IRQ_HANDLED;
 783                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 784                 break;
 785
 786         case MUSB_EP0_STAGE_IDLE:
 787                 /*
 788                  * This state is typically (but not always) indiscernible
 789                  * from the status states since the corresponding interrupts
 790                  * tend to happen within too little period of time (with only
 791                  * a zero-length packet in between) and so get coalesced...
 792                  */
 793                 retval = IRQ_HANDLED;
 794                 musb->ep0_state = MUSB_EP0_STAGE_SETUP;
 795                 /* FALLTHROUGH */
 796
 797         case MUSB_EP0_STAGE_SETUP:
 798 setup:
 799                 if (csr & MUSB_CSR0_RXPKTRDY) {
 800                         struct usb_ctrlrequest  setup;
 801                         int                     handled = 0;
 802
 803                         if (len != 8) {
 804                                 ERR("SETUP packet len %d != 8 ?\n", len);
 805                                 break;
 806                         }
 807                         musb_read_setup(musb, &setup);
 808                         retval = IRQ_HANDLED;
 809
 810                         /* sometimes the RESET won't be reported */
 811                         if (unlikely(musb->g.speed == USB_SPEED_UNKNOWN)) {
 812                                 u8      power;
 813
 814                                 printk(KERN_NOTICE "%s: peripheral reset "
 815                                                 "irq lost!\n",
 816                                                 musb_driver_name);
 817                                 power = musb_readb(mbase, MUSB_POWER);
 818                                 musb->g.speed = (power & MUSB_POWER_HSMODE)
 819                                         ? USB_SPEED_HIGH : USB_SPEED_FULL;
 820
 821                         }
 822
 823                         switch (musb->ep0_state) {
 824
 825                         /* sequence #3 (no data stage), includes requests
 826                          * we can't forward (notably SET_ADDRESS and the
 827                          * device/endpoint feature set/clear operations)
 828                          * plus SET_CONFIGURATION and others we must
 829                          */
 830                         case MUSB_EP0_STAGE_ACKWAIT:
 831                                 handled = service_zero_data_request(
 832                                                 musb, &setup);
 833
 834                                 /*
 835                                  * We're expecting no data in any case, so
 836                                  * always set the DATAEND bit -- doing this
 837                                  * here helps avoid SetupEnd interrupt coming
 838                                  * in the idle stage when we're stalling...
 839                                  */
 840                                 musb->ackpend |= MUSB_CSR0_P_DATAEND;
 841
 842                                 /* status stage might be immediate */
 843                                 if (handled > 0)
 844                                         musb->ep0_state =
 845                                                 MUSB_EP0_STAGE_STATUSIN;
 846                                 break;
 847
 848                         /* sequence #1 (IN to host), includes GET_STATUS
 849                          * requests that we can't forward, GET_DESCRIPTOR
 850                          * and others that we must
 851                          */
 852                         case MUSB_EP0_STAGE_TX:
 853                                 handled = service_in_request(musb, &setup);
 854                                 if (handled > 0) {
 855                                         musb->ackpend = MUSB_CSR0_TXPKTRDY
 856                                                 | MUSB_CSR0_P_DATAEND;
 857                                         musb->ep0_state =
 858                                                 MUSB_EP0_STAGE_STATUSOUT;
 859                                 }
 860                                 break;
 861
 862                         /* sequence #2 (OUT from host), always forward */
 863                         default:                /* MUSB_EP0_STAGE_RX */
 864                                 break;
 865                         }
 866
 867                         dev_dbg(musb->controller, "handled %d, csr %04x, ep0stage %s\n",
 868                                 handled, csr,
 869                                 decode_ep0stage(musb->ep0_state));
 870
 871                         /* unless we need to delegate this to the gadget
 872                          * driver, we know how to wrap this up:  csr0 has
 873                          * not yet been written.
 874                          */
 875                         if (handled < 0)
 876                                 goto stall;
 877                         else if (handled > 0)
 878                                 goto finish;
 879
 880                         handled = forward_to_driver(musb, &setup);
 881                         if (handled < 0) {
 882                                 musb_ep_select(mbase, 0);
 883 stall:
 884                                 dev_dbg(musb->controller, "stall (%d)\n", handled);
 885                                 musb->ackpend |= MUSB_CSR0_P_SENDSTALL;
 886                                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 887 finish:
 888                                 musb_writew(regs, MUSB_CSR0,
 889                                                 musb->ackpend);
 890                                 musb->ackpend = 0;
 891                         }
 892                 }
 893                 break;
 894
 895         case MUSB_EP0_STAGE_ACKWAIT:
 896                 /* This should not happen. But happens with tusb6010 with
 897                  * g_file_storage and high speed. Do nothing.
 898                  */
 899                 retval = IRQ_HANDLED;
 900                 break;
 901
 902         default:
 903                 /* "can't happen" */
 904                 WARN_ON(1);
 905                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);
 906                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 907                 break;
 908         }
 909
 910         return retval;
 911 }
 912
 913
 914 static int
 915 musb_g_ep0_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
 916 {
 917         /* always enabled */
 918         return -EINVAL;
 919 }
 920
 921 static int musb_g_ep0_disable(struct usb_ep *e)
 922 {
 923         /* always enabled */
 924         return -EINVAL;
 925 }
 926
 927 static int
 928 musb_g_ep0_queue(struct usb_ep *e, struct usb_request *r, gfp_t gfp_flags)
 929 {
 930         struct musb_ep          *ep;
 931         struct musb_request     *req;
 932         struct musb             *musb;
 933         int                     status;
 934         unsigned long           lockflags;
 935         void __iomem            *regs;
 936
 937         if (!e || !r)
 938                 return -EINVAL;
 939
 940         ep = to_musb_ep(e);
 941         musb = ep->musb;
 942         regs = musb->control_ep->regs;
 943
 944         req = to_musb_request(r);
 945         req->musb = musb;
 946         req->request.actual = 0;
 947         req->request.status = -EINPROGRESS;
 948         req->tx = ep->is_in;
 949
 950         spin_lock_irqsave(&musb->lock, lockflags);
 951
 952         if (!list_empty(&ep->req_list)) {
 953                 status = -EBUSY;
 954                 goto cleanup;
 955         }
 956
 957         switch (musb->ep0_state) {
 958         case MUSB_EP0_STAGE_RX:         /* control-OUT data */
 959         case MUSB_EP0_STAGE_TX:         /* control-IN data */
 960         case MUSB_EP0_STAGE_ACKWAIT:    /* zero-length data */
 961                 status = 0;
 962                 break;
 963         default:
 964                 dev_dbg(musb->controller, "ep0 request queued in state %d\n",
 965                                 musb->ep0_state);
 966                 status = -EINVAL;
 967                 goto cleanup;
 968         }
 969
 970         /* add request to the list */
 971         list_add_tail(&req->list, &ep->req_list);
 972
 973         dev_dbg(musb->controller, "queue to %s (%s), length=%d\n",
 974                         ep->name, ep->is_in ? "IN/TX" : "OUT/RX",
 975                         req->request.length);
 976
 977         musb_ep_select(musb->mregs, 0);
 978
 979         /* sequence #1, IN ... start writing the data */
 980         if (musb->ep0_state == MUSB_EP0_STAGE_TX)
 981                 ep0_txstate(musb);
 982
 983         /* sequence #3, no-data ... issue IN status */
 984         else if (musb->ep0_state == MUSB_EP0_STAGE_ACKWAIT) {
 985                 if (req->request.length)
 986                         status = -EINVAL;
 987                 else {
 988                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 989                         musb_writew(regs, MUSB_CSR0,
 990                                         musb->ackpend | MUSB_CSR0_P_DATAEND);
 991                         musb->ackpend = 0;
 992                         musb_g_ep0_giveback(ep->musb, r);
 993                 }
 994
 995         /* else for sequence #2 (OUT), caller provides a buffer
 996          * before the next packet arrives.  deferred responses
 997          * (after SETUP is acked) are racey.
 998          */
 999         } else if (musb->ackpend) {
1000                 musb_writew(regs, MUSB_CSR0, musb->ackpend);
1001                 musb->ackpend = 0;
1002         }
1003
1004 cleanup:
1005         spin_unlock_irqrestore(&musb->lock, lockflags);
1006         return status;
1007 }
1008
1009 static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
1010 {
1011         /* we just won't support this */
1012         return -EINVAL;
1013 }
1014
1015 static int musb_g_ep0_halt(struct usb_ep *e, int value)
1016 {
1017         struct musb_ep          *ep;
1018         struct musb             *musb;
1019         void __iomem            *base, *regs;
1020         unsigned long           flags;
1021         int                     status;
1022         u16                     csr;
1023
1024         if (!e || !value)
1025                 return -EINVAL;
1026
1027         ep = to_musb_ep(e);
1028         musb = ep->musb;
1029         base = musb->mregs;
1030         regs = musb->control_ep->regs;
1031         status = 0;
1032
1033         spin_lock_irqsave(&musb->lock, flags);
1034
1035         if (!list_empty(&ep->req_list)) {
1036                 status = -EBUSY;
1037                 goto cleanup;
1038         }
1039
1040         musb_ep_select(base, 0);
1041         csr = musb->ackpend;
1042
1043         switch (musb->ep0_state) {
1044
1045         /* Stalls are usually issued after parsing SETUP packet, either
1046          * directly in irq context from setup() or else later.
1047          */
1048         case MUSB_EP0_STAGE_TX:         /* control-IN data */
1049         case MUSB_EP0_STAGE_ACKWAIT:    /* STALL for zero-length data */
1050         case MUSB_EP0_STAGE_RX:         /* control-OUT data */
1051                 csr = musb_readw(regs, MUSB_CSR0);
1052                 /* FALLTHROUGH */
1053
1054         /* It's also OK to issue stalls during callbacks when a non-empty
1055          * DATA stage buffer has been read (or even written).
1056          */
1057         case MUSB_EP0_STAGE_STATUSIN:   /* control-OUT status */
1058         case MUSB_EP0_STAGE_STATUSOUT:  /* control-IN status */
1059
1060                 csr |= MUSB_CSR0_P_SENDSTALL;
1061                 musb_writew(regs, MUSB_CSR0, csr);
1062                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
1063                 musb->ackpend = 0;
1064                 break;
1065         default:
1066                 dev_dbg(musb->controller, "ep0 can't halt in state %d\n", musb->ep0_state);
1067                 status = -EINVAL;
1068         }
1069
1070 cleanup:
1071         spin_unlock_irqrestore(&musb->lock, flags);
1072         return status;
1073 }
1074
1075 const struct usb_ep_ops musb_g_ep0_ops = {
1076         .enable         = musb_g_ep0_enable,
1077         .disable        = musb_g_ep0_disable,
1078         .alloc_request  = musb_alloc_request,
1079         .free_request   = musb_free_request,
1080         .queue          = musb_g_ep0_queue,
1081         .dequeue        = musb_g_ep0_dequeue,
1082         .set_halt       = musb_g_ep0_halt,
1083 };