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