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