drivers/usb/musb/musb_gadget_ep0.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MUSB OTG peripheral driver ep0 handling
   4  *
   5  * Copyright 2005 Mentor Graphics Corporation
   6  * Copyright (C) 2005-2006 by Texas Instruments
   7  * Copyright (C) 2006-2007 Nokia Corporation
   8  * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/list.h>
  13 #include <linux/timer.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/device.h>
  16 #include <linux/interrupt.h>
  17
  18 #include "musb_core.h"
  19
  20 /* ep0 is always musb->endpoints[0].ep_in */
  21 #define next_ep0_request(musb)  next_in_request(&(musb)->endpoints[0])
  22
  23 /*
  24  * locking note:  we use only the controller lock, for simpler correctness.
  25  * It's always held with IRQs blocked.
  26  *
  27  * It protects the ep0 request queue as well as ep0_state, not just the
  28  * controller and indexed registers.  And that lock stays held unless it
  29  * needs to be dropped to allow reentering this driver ... like upcalls to
  30  * the gadget driver, or adjusting endpoint halt status.
  31  */
  32
  33 static char *decode_ep0stage(u8 stage)
  34 {
  35         switch (stage) {
  36         case MUSB_EP0_STAGE_IDLE:       return "idle";
  37         case MUSB_EP0_STAGE_SETUP:      return "setup";
  38         case MUSB_EP0_STAGE_TX:         return "in";
  39         case MUSB_EP0_STAGE_RX:         return "out";
  40         case MUSB_EP0_STAGE_ACKWAIT:    return "wait";
  41         case MUSB_EP0_STAGE_STATUSIN:   return "in/status";
  42         case MUSB_EP0_STAGE_STATUSOUT:  return "out/status";
  43         default:                        return "?";
  44         }
  45 }
  46
  47 /* handle a standard GET_STATUS request
  48  * Context:  caller holds controller lock
  49  */
  50 static int service_tx_status_request(
  51         struct musb *musb,
  52         const struct usb_ctrlrequest *ctrlrequest)
  53 {
  54         void __iomem    *mbase = musb->mregs;
  55         int handled = 1;
  56         u8 result[2], epnum = 0;
  57         const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
  58
  59         result[1] = 0;
  60
  61         switch (recip) {
  62         case USB_RECIP_DEVICE:
  63                 result[0] = musb->g.is_selfpowered << USB_DEVICE_SELF_POWERED;
  64                 result[0] |= musb->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
  65                 if (musb->g.is_otg) {
  66                         result[0] |= musb->g.b_hnp_enable
  67                                 << USB_DEVICE_B_HNP_ENABLE;
  68                         result[0] |= musb->g.a_alt_hnp_support
  69                                 << USB_DEVICE_A_ALT_HNP_SUPPORT;
  70                         result[0] |= musb->g.a_hnp_support
  71                                 << USB_DEVICE_A_HNP_SUPPORT;
  72                 }
  73                 break;
  74
  75         case USB_RECIP_INTERFACE:
  76                 result[0] = 0;
  77                 break;
  78
  79         case USB_RECIP_ENDPOINT: {
  80                 int             is_in;
  81                 struct musb_ep  *ep;
  82                 u16             tmp;
  83                 void __iomem    *regs;
  84
  85                 epnum = (u8) ctrlrequest->wIndex;
  86                 if (!epnum) {
  87                         result[0] = 0;
  88                         break;
  89                 }
  90
  91                 is_in = epnum & USB_DIR_IN;
  92                 epnum &= 0x0f;
  93                 if (epnum >= MUSB_C_NUM_EPS) {
  94                         handled = -EINVAL;
  95                         break;
  96                 }
  97
  98                 if (is_in)
  99                         ep = &musb->endpoints[epnum].ep_in;
 100                 else
 101                         ep = &musb->endpoints[epnum].ep_out;
 102                 regs = musb->endpoints[epnum].regs;
 103
 104                 if (!ep->desc) {
 105                         handled = -EINVAL;
 106                         break;
 107                 }
 108
 109                 musb_ep_select(mbase, epnum);
 110                 if (is_in)
 111                         tmp = musb_readw(regs, MUSB_TXCSR)
 112                                                 & MUSB_TXCSR_P_SENDSTALL;
 113                 else
 114                         tmp = musb_readw(regs, MUSB_RXCSR)
 115                                                 & MUSB_RXCSR_P_SENDSTALL;
 116                 musb_ep_select(mbase, 0);
 117
 118                 result[0] = tmp ? 1 : 0;
 119                 } break;
 120
 121         default:
 122                 /* class, vendor, etc ... delegate */
 123                 handled = 0;
 124                 break;
 125         }
 126
 127         /* fill up the fifo; caller updates csr0 */
 128         if (handled > 0) {
 129                 u16     len = le16_to_cpu(ctrlrequest->wLength);
 130
 131                 if (len > 2)
 132                         len = 2;
 133                 musb_write_fifo(&musb->endpoints[0], len, result);
 134         }
 135
 136         return handled;
 137 }
 138
 139 /*
 140  * handle a control-IN request, the end0 buffer contains the current request
 141  * that is supposed to be a standard control request. Assumes the fifo to
 142  * be at least 2 bytes long.
 143  *
 144  * @return 0 if the request was NOT HANDLED,
 145  * < 0 when error
 146  * > 0 when the request is processed
 147  *
 148  * Context:  caller holds controller lock
 149  */
 150 static int
 151 service_in_request(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
 152 {
 153         int handled = 0;        /* not handled */
 154
 155         if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
 156                         == USB_TYPE_STANDARD) {
 157                 switch (ctrlrequest->bRequest) {
 158                 case USB_REQ_GET_STATUS:
 159                         handled = service_tx_status_request(musb,
 160                                         ctrlrequest);
 161                         break;
 162
 163                 /* case USB_REQ_SYNC_FRAME: */
 164
 165                 default:
 166                         break;
 167                 }
 168         }
 169         return handled;
 170 }
 171
 172 /*
 173  * Context:  caller holds controller lock
 174  */
 175 static void musb_g_ep0_giveback(struct musb *musb, struct usb_request *req)
 176 {
 177         musb_g_giveback(&musb->endpoints[0].ep_in, req, 0);
 178 }
 179
 180 /*
 181  * Tries to start B-device HNP negotiation if enabled via sysfs
 182  */
 183 static inline void musb_try_b_hnp_enable(struct musb *musb)
 184 {
 185         void __iomem    *mbase = musb->mregs;
 186         u8              devctl;
 187
 188         musb_dbg(musb, "HNP: Setting HR");
 189         devctl = musb_readb(mbase, MUSB_DEVCTL);
 190         musb_writeb(mbase, MUSB_DEVCTL, devctl | MUSB_DEVCTL_HR);
 191 }
 192
 193 /*
 194  * Handle all control requests with no DATA stage, including standard
 195  * requests such as:
 196  * USB_REQ_SET_CONFIGURATION, USB_REQ_SET_INTERFACE, unrecognized
 197  *      always delegated to the gadget driver
 198  * USB_REQ_SET_ADDRESS, USB_REQ_CLEAR_FEATURE, USB_REQ_SET_FEATURE
 199  *      always handled here, except for class/vendor/... features
 200  *
 201  * Context:  caller holds controller lock
 202  */
 203 static int
 204 service_zero_data_request(struct musb *musb,
 205                 struct usb_ctrlrequest *ctrlrequest)
 206 __releases(musb->lock)
 207 __acquires(musb->lock)
 208 {
 209         int handled = -EINVAL;
 210         void __iomem *mbase = musb->mregs;
 211         const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
 212
 213         /* the gadget driver handles everything except what we MUST handle */
 214         if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
 215                         == USB_TYPE_STANDARD) {
 216                 switch (ctrlrequest->bRequest) {
 217                 case USB_REQ_SET_ADDRESS:
 218                         /* change it after the status stage */
 219                         musb->set_address = true;
 220                         musb->address = (u8) (ctrlrequest->wValue & 0x7f);
 221                         handled = 1;
 222                         break;
 223
 224                 case USB_REQ_CLEAR_FEATURE:
 225                         switch (recip) {
 226                         case USB_RECIP_DEVICE:
 227                                 if (ctrlrequest->wValue
 228                                                 != USB_DEVICE_REMOTE_WAKEUP)
 229                                         break;
 230                                 musb->may_wakeup = 0;
 231                                 handled = 1;
 232                                 break;
 233                         case USB_RECIP_INTERFACE:
 234                                 break;
 235                         case USB_RECIP_ENDPOINT:{
 236                                 const u8                epnum =
 237                                         ctrlrequest->wIndex & 0x0f;
 238                                 struct musb_ep          *musb_ep;
 239                                 struct musb_hw_ep       *ep;
 240                                 struct musb_request     *request;
 241                                 void __iomem            *regs;
 242                                 int                     is_in;
 243                                 u16                     csr;
 244
 245                                 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
 246                                     ctrlrequest->wValue != USB_ENDPOINT_HALT)
 247                                         break;
 248
 249                                 ep = musb->endpoints + epnum;
 250                                 regs = ep->regs;
 251                                 is_in = ctrlrequest->wIndex & USB_DIR_IN;
 252                                 if (is_in)
 253                                         musb_ep = &ep->ep_in;
 254                                 else
 255                                         musb_ep = &ep->ep_out;
 256                                 if (!musb_ep->desc)
 257                                         break;
 258
 259                                 handled = 1;
 260                                 /* Ignore request if endpoint is wedged */
 261                                 if (musb_ep->wedged)
 262                                         break;
 263
 264                                 musb_ep_select(mbase, epnum);
 265                                 if (is_in) {
 266                                         csr  = musb_readw(regs, MUSB_TXCSR);
 267                                         csr |= MUSB_TXCSR_CLRDATATOG |
 268                                                MUSB_TXCSR_P_WZC_BITS;
 269                                         csr &= ~(MUSB_TXCSR_P_SENDSTALL |
 270                                                  MUSB_TXCSR_P_SENTSTALL |
 271                                                  MUSB_TXCSR_TXPKTRDY);
 272                                         musb_writew(regs, MUSB_TXCSR, csr);
 273                                 } else {
 274                                         csr  = musb_readw(regs, MUSB_RXCSR);
 275                                         csr |= MUSB_RXCSR_CLRDATATOG |
 276                                                MUSB_RXCSR_P_WZC_BITS;
 277                                         csr &= ~(MUSB_RXCSR_P_SENDSTALL |
 278                                                  MUSB_RXCSR_P_SENTSTALL);
 279                                         musb_writew(regs, MUSB_RXCSR, csr);
 280                                 }
 281
 282                                 /* Maybe start the first request in the queue */
 283                                 request = next_request(musb_ep);
 284                                 if (!musb_ep->busy && request) {
 285                                         musb_dbg(musb, "restarting the request");
 286                                         musb_ep_restart(musb, request);
 287                                 }
 288
 289                                 /* select ep0 again */
 290                                 musb_ep_select(mbase, 0);
 291                                 } break;
 292                         default:
 293                                 /* class, vendor, etc ... delegate */
 294                                 handled = 0;
 295                                 break;
 296                         }
 297                         break;
 298
 299                 case USB_REQ_SET_FEATURE:
 300                         switch (recip) {
 301                         case USB_RECIP_DEVICE:
 302                                 handled = 1;
 303                                 switch (ctrlrequest->wValue) {
 304                                 case USB_DEVICE_REMOTE_WAKEUP:
 305                                         musb->may_wakeup = 1;
 306                                         break;
 307                                 case USB_DEVICE_TEST_MODE:
 308                                         if (musb->g.speed != USB_SPEED_HIGH)
 309                                                 goto stall;
 310                                         if (ctrlrequest->wIndex & 0xff)
 311                                                 goto stall;
 312
 313                                         switch (ctrlrequest->wIndex >> 8) {
 314                                         case 1:
 315                                                 pr_debug("TEST_J\n");
 316                                                 /* TEST_J */
 317                                                 musb->test_mode_nr =
 318                                                         MUSB_TEST_J;
 319                                                 break;
 320                                         case 2:
 321                                                 /* TEST_K */
 322                                                 pr_debug("TEST_K\n");
 323                                                 musb->test_mode_nr =
 324                                                         MUSB_TEST_K;
 325                                                 break;
 326                                         case 3:
 327                                                 /* TEST_SE0_NAK */
 328                                                 pr_debug("TEST_SE0_NAK\n");
 329                                                 musb->test_mode_nr =
 330                                                         MUSB_TEST_SE0_NAK;
 331                                                 break;
 332                                         case 4:
 333                                                 /* TEST_PACKET */
 334                                                 pr_debug("TEST_PACKET\n");
 335                                                 musb->test_mode_nr =
 336                                                         MUSB_TEST_PACKET;
 337                                                 break;
 338
 339                                         case 0xc0:
 340                                                 /* TEST_FORCE_HS */
 341                                                 pr_debug("TEST_FORCE_HS\n");
 342                                                 musb->test_mode_nr =
 343                                                         MUSB_TEST_FORCE_HS;
 344                                                 break;
 345                                         case 0xc1:
 346                                                 /* TEST_FORCE_FS */
 347                                                 pr_debug("TEST_FORCE_FS\n");
 348                                                 musb->test_mode_nr =
 349                                                         MUSB_TEST_FORCE_FS;
 350                                                 break;
 351                                         case 0xc2:
 352                                                 /* TEST_FIFO_ACCESS */
 353                                                 pr_debug("TEST_FIFO_ACCESS\n");
 354                                                 musb->test_mode_nr =
 355                                                         MUSB_TEST_FIFO_ACCESS;
 356                                                 break;
 357                                         case 0xc3:
 358                                                 /* TEST_FORCE_HOST */
 359                                                 pr_debug("TEST_FORCE_HOST\n");
 360                                                 musb->test_mode_nr =
 361                                                         MUSB_TEST_FORCE_HOST;
 362                                                 break;
 363                                         default:
 364                                                 goto stall;
 365                                         }
 366
 367                                         /* enter test mode after irq */
 368                                         if (handled > 0)
 369                                                 musb->test_mode = true;
 370                                         break;
 371                                 case USB_DEVICE_B_HNP_ENABLE:
 372                                         if (!musb->g.is_otg)
 373                                                 goto stall;
 374                                         musb->g.b_hnp_enable = 1;
 375                                         musb_try_b_hnp_enable(musb);
 376                                         break;
 377                                 case USB_DEVICE_A_HNP_SUPPORT:
 378                                         if (!musb->g.is_otg)
 379                                                 goto stall;
 380                                         musb->g.a_hnp_support = 1;
 381                                         break;
 382                                 case USB_DEVICE_A_ALT_HNP_SUPPORT:
 383                                         if (!musb->g.is_otg)
 384                                                 goto stall;
 385                                         musb->g.a_alt_hnp_support = 1;
 386                                         break;
 387                                 case USB_DEVICE_DEBUG_MODE:
 388                                         handled = 0;
 389                                         break;
 390 stall:
 391                                 default:
 392                                         handled = -EINVAL;
 393                                         break;
 394                                 }
 395                                 break;
 396
 397                         case USB_RECIP_INTERFACE:
 398                                 break;
 399
 400                         case USB_RECIP_ENDPOINT:{
 401                                 const u8                epnum =
 402                                         ctrlrequest->wIndex & 0x0f;
 403                                 struct musb_ep          *musb_ep;
 404                                 struct musb_hw_ep       *ep;
 405                                 void __iomem            *regs;
 406                                 int                     is_in;
 407                                 u16                     csr;
 408
 409                                 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
 410                                     ctrlrequest->wValue != USB_ENDPOINT_HALT)
 411                                         break;
 412
 413                                 ep = musb->endpoints + epnum;
 414                                 regs = ep->regs;
 415                                 is_in = ctrlrequest->wIndex & USB_DIR_IN;
 416                                 if (is_in)
 417                                         musb_ep = &ep->ep_in;
 418                                 else
 419                                         musb_ep = &ep->ep_out;
 420                                 if (!musb_ep->desc)
 421                                         break;
 422
 423                                 musb_ep_select(mbase, epnum);
 424                                 if (is_in) {
 425                                         csr = musb_readw(regs, MUSB_TXCSR);
 426                                         if (csr & MUSB_TXCSR_FIFONOTEMPTY)
 427                                                 csr |= MUSB_TXCSR_FLUSHFIFO;
 428                                         csr |= MUSB_TXCSR_P_SENDSTALL
 429                                                 | MUSB_TXCSR_CLRDATATOG
 430                                                 | MUSB_TXCSR_P_WZC_BITS;
 431                                         musb_writew(regs, MUSB_TXCSR, csr);
 432                                 } else {
 433                                         csr = musb_readw(regs, MUSB_RXCSR);
 434                                         csr |= MUSB_RXCSR_P_SENDSTALL
 435                                                 | MUSB_RXCSR_FLUSHFIFO
 436                                                 | MUSB_RXCSR_CLRDATATOG
 437                                                 | MUSB_RXCSR_P_WZC_BITS;
 438                                         musb_writew(regs, MUSB_RXCSR, csr);
 439                                 }
 440
 441                                 /* select ep0 again */
 442                                 musb_ep_select(mbase, 0);
 443                                 handled = 1;
 444                                 } break;
 445
 446                         default:
 447                                 /* class, vendor, etc ... delegate */
 448                                 handled = 0;
 449                                 break;
 450                         }
 451                         break;
 452                 default:
 453                         /* delegate SET_CONFIGURATION, etc */
 454                         handled = 0;
 455                 }
 456         } else
 457                 handled = 0;
 458         return handled;
 459 }
 460
 461 /* we have an ep0out data packet
 462  * Context:  caller holds controller lock
 463  */
 464 static void ep0_rxstate(struct musb *musb)
 465 {
 466         void __iomem            *regs = musb->control_ep->regs;
 467         struct musb_request     *request;
 468         struct usb_request      *req;
 469         u16                     count, csr;
 470
 471         request = next_ep0_request(musb);
 472         req = &request->request;
 473
 474         /* read packet and ack; or stall because of gadget driver bug:
 475          * should have provided the rx buffer before setup() returned.
 476          */
 477         if (req) {
 478                 void            *buf = req->buf + req->actual;
 479                 unsigned        len = req->length - req->actual;
 480
 481                 /* read the buffer */
 482                 count = musb_readb(regs, MUSB_COUNT0);
 483                 if (count > len) {
 484                         req->status = -EOVERFLOW;
 485                         count = len;
 486                 }
 487                 if (count > 0) {
 488                         musb_read_fifo(&musb->endpoints[0], count, buf);
 489                         req->actual += count;
 490                 }
 491                 csr = MUSB_CSR0_P_SVDRXPKTRDY;
 492                 if (count < 64 || req->actual == req->length) {
 493                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 494                         csr |= MUSB_CSR0_P_DATAEND;
 495                 } else
 496                         req = NULL;
 497         } else
 498                 csr = MUSB_CSR0_P_SVDRXPKTRDY | MUSB_CSR0_P_SENDSTALL;
 499
 500
 501         /* Completion handler may choose to stall, e.g. because the
 502          * message just received holds invalid data.
 503          */
 504         if (req) {
 505                 musb->ackpend = csr;
 506                 musb_g_ep0_giveback(musb, req);
 507                 if (!musb->ackpend)
 508                         return;
 509                 musb->ackpend = 0;
 510         }
 511         musb_ep_select(musb->mregs, 0);
 512         musb_writew(regs, MUSB_CSR0, csr);
 513 }
 514
 515 /*
 516  * transmitting to the host (IN), this code might be called from IRQ
 517  * and from kernel thread.
 518  *
 519  * Context:  caller holds controller lock
 520  */
 521 static void ep0_txstate(struct musb *musb)
 522 {
 523         void __iomem            *regs = musb->control_ep->regs;
 524         struct musb_request     *req = next_ep0_request(musb);
 525         struct usb_request      *request;
 526         u16                     csr = MUSB_CSR0_TXPKTRDY;
 527         u8                      *fifo_src;
 528         u8                      fifo_count;
 529
 530         if (!req) {
 531                 /* WARN_ON(1); */
 532                 musb_dbg(musb, "odd; csr0 %04x", musb_readw(regs, MUSB_CSR0));
 533                 return;
 534         }
 535
 536         request = &req->request;
 537
 538         /* load the data */
 539         fifo_src = (u8 *) request->buf + request->actual;
 540         fifo_count = min((unsigned) MUSB_EP0_FIFOSIZE,
 541                 request->length - request->actual);
 542         musb_write_fifo(&musb->endpoints[0], fifo_count, fifo_src);
 543         request->actual += fifo_count;
 544
 545         /* update the flags */
 546         if (fifo_count < MUSB_MAX_END0_PACKET
 547                         || (request->actual == request->length
 548                                 && !request->zero)) {
 549                 musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
 550                 csr |= MUSB_CSR0_P_DATAEND;
 551         } else
 552                 request = NULL;
 553
 554         /* report completions as soon as the fifo's loaded; there's no
 555          * win in waiting till this last packet gets acked.  (other than
 556          * very precise fault reporting, needed by USB TMC; possible with
 557          * this hardware, but not usable from portable gadget drivers.)
 558          */
 559         if (request) {
 560                 musb->ackpend = csr;
 561                 musb_g_ep0_giveback(musb, request);
 562                 if (!musb->ackpend)
 563                         return;
 564                 musb->ackpend = 0;
 565         }
 566
 567         /* send it out, triggering a "txpktrdy cleared" irq */
 568         musb_ep_select(musb->mregs, 0);
 569         musb_writew(regs, MUSB_CSR0, csr);
 570 }
 571
 572 /*
 573  * Read a SETUP packet (struct usb_ctrlrequest) from the hardware.
 574  * Fields are left in USB byte-order.
 575  *
 576  * Context:  caller holds controller lock.
 577  */
 578 static void
 579 musb_read_setup(struct musb *musb, struct usb_ctrlrequest *req)
 580 {
 581         struct musb_request     *r;
 582         void __iomem            *regs = musb->control_ep->regs;
 583
 584         musb_read_fifo(&musb->endpoints[0], sizeof *req, (u8 *)req);
 585
 586         /* NOTE:  earlier 2.6 versions changed setup packets to host
 587          * order, but now USB packets always stay in USB byte order.
 588          */
 589         musb_dbg(musb, "SETUP req%02x.%02x v%04x i%04x l%d",
 590                 req->bRequestType,
 591                 req->bRequest,
 592                 le16_to_cpu(req->wValue),
 593                 le16_to_cpu(req->wIndex),
 594                 le16_to_cpu(req->wLength));
 595
 596         /* clean up any leftover transfers */
 597         r = next_ep0_request(musb);
 598         if (r)
 599                 musb_g_ep0_giveback(musb, &r->request);
 600
 601         /* For zero-data requests we want to delay the STATUS stage to
 602          * avoid SETUPEND errors.  If we read data (OUT), delay accepting
 603          * packets until there's a buffer to store them in.
 604          *
 605          * If we write data, the controller acts happier if we enable
 606          * the TX FIFO right away, and give the controller a moment
 607          * to switch modes...
 608          */
 609         musb->set_address = false;
 610         musb->ackpend = MUSB_CSR0_P_SVDRXPKTRDY;
 611         if (req->wLength == 0) {
 612                 if (req->bRequestType & USB_DIR_IN)
 613                         musb->ackpend |= MUSB_CSR0_TXPKTRDY;
 614                 musb->ep0_state = MUSB_EP0_STAGE_ACKWAIT;
 615         } else if (req->bRequestType & USB_DIR_IN) {
 616                 musb->ep0_state = MUSB_EP0_STAGE_TX;
 617                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDRXPKTRDY);
 618                 while ((musb_readw(regs, MUSB_CSR0)
 619                                 & MUSB_CSR0_RXPKTRDY) != 0)
 620                         cpu_relax();
 621                 musb->ackpend = 0;
 622         } else
 623                 musb->ep0_state = MUSB_EP0_STAGE_RX;
 624 }
 625
 626 static int
 627 forward_to_driver(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
 628 __releases(musb->lock)
 629 __acquires(musb->lock)
 630 {
 631         int retval;
 632         if (!musb->gadget_driver)
 633                 return -EOPNOTSUPP;
 634         spin_unlock(&musb->lock);
 635         retval = musb->gadget_driver->setup(&musb->g, ctrlrequest);
 636         spin_lock(&musb->lock);
 637         return retval;
 638 }
 639
 640 /*
 641  * Handle peripheral ep0 interrupt
 642  *
 643  * Context: irq handler; we won't re-enter the driver that way.
 644  */
 645 irqreturn_t musb_g_ep0_irq(struct musb *musb)
 646 {
 647         u16             csr;
 648         u16             len;
 649         void __iomem    *mbase = musb->mregs;
 650         void __iomem    *regs = musb->endpoints[0].regs;
 651         irqreturn_t     retval = IRQ_NONE;
 652
 653         musb_ep_select(mbase, 0);       /* select ep0 */
 654         csr = musb_readw(regs, MUSB_CSR0);
 655         len = musb_readb(regs, MUSB_COUNT0);
 656
 657         musb_dbg(musb, "csr %04x, count %d, ep0stage %s",
 658                         csr, len, decode_ep0stage(musb->ep0_state));
 659
 660         if (csr & MUSB_CSR0_P_DATAEND) {
 661                 /*
 662                  * If DATAEND is set we should not call the callback,
 663                  * hence the status stage is not complete.
 664                  */
 665                 return IRQ_HANDLED;
 666         }
 667
 668         /* I sent a stall.. need to acknowledge it now.. */
 669         if (csr & MUSB_CSR0_P_SENTSTALL) {
 670                 musb_writew(regs, MUSB_CSR0,
 671                                 csr & ~MUSB_CSR0_P_SENTSTALL);
 672                 retval = IRQ_HANDLED;
 673                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 674                 csr = musb_readw(regs, MUSB_CSR0);
 675         }
 676
 677         /* request ended "early" */
 678         if (csr & MUSB_CSR0_P_SETUPEND) {
 679                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);
 680                 retval = IRQ_HANDLED;
 681                 /* Transition into the early status phase */
 682                 switch (musb->ep0_state) {
 683                 case MUSB_EP0_STAGE_TX:
 684                         musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
 685                         break;
 686                 case MUSB_EP0_STAGE_RX:
 687                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 688                         break;
 689                 default:
 690                         ERR("SetupEnd came in a wrong ep0stage %s\n",
 691                             decode_ep0stage(musb->ep0_state));
 692                 }
 693                 csr = musb_readw(regs, MUSB_CSR0);
 694                 /* NOTE:  request may need completion */
 695         }
 696
 697         /* docs from Mentor only describe tx, rx, and idle/setup states.
 698          * we need to handle nuances around status stages, and also the
 699          * case where status and setup stages come back-to-back ...
 700          */
 701         switch (musb->ep0_state) {
 702
 703         case MUSB_EP0_STAGE_TX:
 704                 /* irq on clearing txpktrdy */
 705                 if ((csr & MUSB_CSR0_TXPKTRDY) == 0) {
 706                         ep0_txstate(musb);
 707                         retval = IRQ_HANDLED;
 708                 }
 709                 break;
 710
 711         case MUSB_EP0_STAGE_RX:
 712                 /* irq on set rxpktrdy */
 713                 if (csr & MUSB_CSR0_RXPKTRDY) {
 714                         ep0_rxstate(musb);
 715                         retval = IRQ_HANDLED;
 716                 }
 717                 break;
 718
 719         case MUSB_EP0_STAGE_STATUSIN:
 720                 /* end of sequence #2 (OUT/RX state) or #3 (no data) */
 721
 722                 /* update address (if needed) only @ the end of the
 723                  * status phase per usb spec, which also guarantees
 724                  * we get 10 msec to receive this irq... until this
 725                  * is done we won't see the next packet.
 726                  */
 727                 if (musb->set_address) {
 728                         musb->set_address = false;
 729                         musb_writeb(mbase, MUSB_FADDR, musb->address);
 730                 }
 731
 732                 /* enter test mode if needed (exit by reset) */
 733                 else if (musb->test_mode) {
 734                         musb_dbg(musb, "entering TESTMODE");
 735
 736                         if (MUSB_TEST_PACKET == musb->test_mode_nr)
 737                                 musb_load_testpacket(musb);
 738
 739                         musb_writeb(mbase, MUSB_TESTMODE,
 740                                         musb->test_mode_nr);
 741                 }
 742                 /* FALLTHROUGH */
 743
 744         case MUSB_EP0_STAGE_STATUSOUT:
 745                 /* end of sequence #1: write to host (TX state) */
 746                 {
 747                         struct musb_request     *req;
 748
 749                         req = next_ep0_request(musb);
 750                         if (req)
 751                                 musb_g_ep0_giveback(musb, &req->request);
 752                 }
 753
 754                 /*
 755                  * In case when several interrupts can get coalesced,
 756                  * check to see if we've already received a SETUP packet...
 757                  */
 758                 if (csr & MUSB_CSR0_RXPKTRDY)
 759                         goto setup;
 760
 761                 retval = IRQ_HANDLED;
 762                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 763                 break;
 764
 765         case MUSB_EP0_STAGE_IDLE:
 766                 /*
 767                  * This state is typically (but not always) indiscernible
 768                  * from the status states since the corresponding interrupts
 769                  * tend to happen within too little period of time (with only
 770                  * a zero-length packet in between) and so get coalesced...
 771                  */
 772                 retval = IRQ_HANDLED;
 773                 musb->ep0_state = MUSB_EP0_STAGE_SETUP;
 774                 /* FALLTHROUGH */
 775
 776         case MUSB_EP0_STAGE_SETUP:
 777 setup:
 778                 if (csr & MUSB_CSR0_RXPKTRDY) {
 779                         struct usb_ctrlrequest  setup;
 780                         int                     handled = 0;
 781
 782                         if (len != 8) {
 783                                 ERR("SETUP packet len %d != 8 ?\n", len);
 784                                 break;
 785                         }
 786                         musb_read_setup(musb, &setup);
 787                         retval = IRQ_HANDLED;
 788
 789                         /* sometimes the RESET won't be reported */
 790                         if (unlikely(musb->g.speed == USB_SPEED_UNKNOWN)) {
 791                                 u8      power;
 792
 793                                 printk(KERN_NOTICE "%s: peripheral reset "
 794                                                 "irq lost!\n",
 795                                                 musb_driver_name);
 796                                 power = musb_readb(mbase, MUSB_POWER);
 797                                 musb->g.speed = (power & MUSB_POWER_HSMODE)
 798                                         ? USB_SPEED_HIGH : USB_SPEED_FULL;
 799
 800                         }
 801
 802                         switch (musb->ep0_state) {
 803
 804                         /* sequence #3 (no data stage), includes requests
 805                          * we can't forward (notably SET_ADDRESS and the
 806                          * device/endpoint feature set/clear operations)
 807                          * plus SET_CONFIGURATION and others we must
 808                          */
 809                         case MUSB_EP0_STAGE_ACKWAIT:
 810                                 handled = service_zero_data_request(
 811                                                 musb, &setup);
 812
 813                                 /*
 814                                  * We're expecting no data in any case, so
 815                                  * always set the DATAEND bit -- doing this
 816                                  * here helps avoid SetupEnd interrupt coming
 817                                  * in the idle stage when we're stalling...
 818                                  */
 819                                 musb->ackpend |= MUSB_CSR0_P_DATAEND;
 820
 821                                 /* status stage might be immediate */
 822                                 if (handled > 0)
 823                                         musb->ep0_state =
 824                                                 MUSB_EP0_STAGE_STATUSIN;
 825                                 break;
 826
 827                         /* sequence #1 (IN to host), includes GET_STATUS
 828                          * requests that we can't forward, GET_DESCRIPTOR
 829                          * and others that we must
 830                          */
 831                         case MUSB_EP0_STAGE_TX:
 832                                 handled = service_in_request(musb, &setup);
 833                                 if (handled > 0) {
 834                                         musb->ackpend = MUSB_CSR0_TXPKTRDY
 835                                                 | MUSB_CSR0_P_DATAEND;
 836                                         musb->ep0_state =
 837                                                 MUSB_EP0_STAGE_STATUSOUT;
 838                                 }
 839                                 break;
 840
 841                         /* sequence #2 (OUT from host), always forward */
 842                         default:                /* MUSB_EP0_STAGE_RX */
 843                                 break;
 844                         }
 845
 846                         musb_dbg(musb, "handled %d, csr %04x, ep0stage %s",
 847                                 handled, csr,
 848                                 decode_ep0stage(musb->ep0_state));
 849
 850                         /* unless we need to delegate this to the gadget
 851                          * driver, we know how to wrap this up:  csr0 has
 852                          * not yet been written.
 853                          */
 854                         if (handled < 0)
 855                                 goto stall;
 856                         else if (handled > 0)
 857                                 goto finish;
 858
 859                         handled = forward_to_driver(musb, &setup);
 860                         if (handled < 0) {
 861                                 musb_ep_select(mbase, 0);
 862 stall:
 863                                 musb_dbg(musb, "stall (%d)", handled);
 864                                 musb->ackpend |= MUSB_CSR0_P_SENDSTALL;
 865                                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 866 finish:
 867                                 musb_writew(regs, MUSB_CSR0,
 868                                                 musb->ackpend);
 869                                 musb->ackpend = 0;
 870                         }
 871                 }
 872                 break;
 873
 874         case MUSB_EP0_STAGE_ACKWAIT:
 875                 /* This should not happen. But happens with tusb6010 with
 876                  * g_file_storage and high speed. Do nothing.
 877                  */
 878                 retval = IRQ_HANDLED;
 879                 break;
 880
 881         default:
 882                 /* "can't happen" */
 883                 WARN_ON(1);
 884                 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);
 885                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
 886                 break;
 887         }
 888
 889         return retval;
 890 }
 891
 892
 893 static int
 894 musb_g_ep0_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
 895 {
 896         /* always enabled */
 897         return -EINVAL;
 898 }
 899
 900 static int musb_g_ep0_disable(struct usb_ep *e)
 901 {
 902         /* always enabled */
 903         return -EINVAL;
 904 }
 905
 906 static int
 907 musb_g_ep0_queue(struct usb_ep *e, struct usb_request *r, gfp_t gfp_flags)
 908 {
 909         struct musb_ep          *ep;
 910         struct musb_request     *req;
 911         struct musb             *musb;
 912         int                     status;
 913         unsigned long           lockflags;
 914         void __iomem            *regs;
 915
 916         if (!e || !r)
 917                 return -EINVAL;
 918
 919         ep = to_musb_ep(e);
 920         musb = ep->musb;
 921         regs = musb->control_ep->regs;
 922
 923         req = to_musb_request(r);
 924         req->musb = musb;
 925         req->request.actual = 0;
 926         req->request.status = -EINPROGRESS;
 927         req->tx = ep->is_in;
 928
 929         spin_lock_irqsave(&musb->lock, lockflags);
 930
 931         if (!list_empty(&ep->req_list)) {
 932                 status = -EBUSY;
 933                 goto cleanup;
 934         }
 935
 936         switch (musb->ep0_state) {
 937         case MUSB_EP0_STAGE_RX:         /* control-OUT data */
 938         case MUSB_EP0_STAGE_TX:         /* control-IN data */
 939         case MUSB_EP0_STAGE_ACKWAIT:    /* zero-length data */
 940                 status = 0;
 941                 break;
 942         default:
 943                 musb_dbg(musb, "ep0 request queued in state %d",
 944                                 musb->ep0_state);
 945                 status = -EINVAL;
 946                 goto cleanup;
 947         }
 948
 949         /* add request to the list */
 950         list_add_tail(&req->list, &ep->req_list);
 951
 952         musb_dbg(musb, "queue to %s (%s), length=%d",
 953                         ep->name, ep->is_in ? "IN/TX" : "OUT/RX",
 954                         req->request.length);
 955
 956         musb_ep_select(musb->mregs, 0);
 957
 958         /* sequence #1, IN ... start writing the data */
 959         if (musb->ep0_state == MUSB_EP0_STAGE_TX)
 960                 ep0_txstate(musb);
 961
 962         /* sequence #3, no-data ... issue IN status */
 963         else if (musb->ep0_state == MUSB_EP0_STAGE_ACKWAIT) {
 964                 if (req->request.length)
 965                         status = -EINVAL;
 966                 else {
 967                         musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
 968                         musb_writew(regs, MUSB_CSR0,
 969                                         musb->ackpend | MUSB_CSR0_P_DATAEND);
 970                         musb->ackpend = 0;
 971                         musb_g_ep0_giveback(ep->musb, r);
 972                 }
 973
 974         /* else for sequence #2 (OUT), caller provides a buffer
 975          * before the next packet arrives.  deferred responses
 976          * (after SETUP is acked) are racey.
 977          */
 978         } else if (musb->ackpend) {
 979                 musb_writew(regs, MUSB_CSR0, musb->ackpend);
 980                 musb->ackpend = 0;
 981         }
 982
 983 cleanup:
 984         spin_unlock_irqrestore(&musb->lock, lockflags);
 985         return status;
 986 }
 987
 988 static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
 989 {
 990         /* we just won't support this */
 991         return -EINVAL;
 992 }
 993
 994 static int musb_g_ep0_halt(struct usb_ep *e, int value)
 995 {
 996         struct musb_ep          *ep;
 997         struct musb             *musb;
 998         void __iomem            *base, *regs;
 999         unsigned long           flags;
1000         int                     status;
1001         u16                     csr;
1002
1003         if (!e || !value)
1004                 return -EINVAL;
1005
1006         ep = to_musb_ep(e);
1007         musb = ep->musb;
1008         base = musb->mregs;
1009         regs = musb->control_ep->regs;
1010         status = 0;
1011
1012         spin_lock_irqsave(&musb->lock, flags);
1013
1014         if (!list_empty(&ep->req_list)) {
1015                 status = -EBUSY;
1016                 goto cleanup;
1017         }
1018
1019         musb_ep_select(base, 0);
1020         csr = musb->ackpend;
1021
1022         switch (musb->ep0_state) {
1023
1024         /* Stalls are usually issued after parsing SETUP packet, either
1025          * directly in irq context from setup() or else later.
1026          */
1027         case MUSB_EP0_STAGE_TX:         /* control-IN data */
1028         case MUSB_EP0_STAGE_ACKWAIT:    /* STALL for zero-length data */
1029         case MUSB_EP0_STAGE_RX:         /* control-OUT data */
1030                 csr = musb_readw(regs, MUSB_CSR0);
1031                 /* FALLTHROUGH */
1032
1033         /* It's also OK to issue stalls during callbacks when a non-empty
1034          * DATA stage buffer has been read (or even written).
1035          */
1036         case MUSB_EP0_STAGE_STATUSIN:   /* control-OUT status */
1037         case MUSB_EP0_STAGE_STATUSOUT:  /* control-IN status */
1038
1039                 csr |= MUSB_CSR0_P_SENDSTALL;
1040                 musb_writew(regs, MUSB_CSR0, csr);
1041                 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
1042                 musb->ackpend = 0;
1043                 break;
1044         default:
1045                 musb_dbg(musb, "ep0 can't halt in state %d", musb->ep0_state);
1046                 status = -EINVAL;
1047         }
1048
1049 cleanup:
1050         spin_unlock_irqrestore(&musb->lock, flags);
1051         return status;
1052 }
1053
1054 const struct usb_ep_ops musb_g_ep0_ops = {
1055         .enable         = musb_g_ep0_enable,
1056         .disable        = musb_g_ep0_disable,
1057         .alloc_request  = musb_alloc_request,
1058         .free_request   = musb_free_request,
1059         .queue          = musb_g_ep0_queue,
1060         .dequeue        = musb_g_ep0_dequeue,
1061         .set_halt       = musb_g_ep0_halt,
1062 };