drivers/usb/host/fhci-tds.c

   1 /*
   2  * Freescale QUICC Engine USB Host Controller Driver
   3  *
   4  * Copyright (c) Freescale Semicondutor, Inc. 2006.
   5  *               Shlomi Gridish <gridish@freescale.com>
   6  *               Jerry Huang <Chang-Ming.Huang@freescale.com>
   7  * Copyright (c) Logic Product Development, Inc. 2007
   8  *               Peter Barada <peterb@logicpd.com>
   9  * Copyright (c) MontaVista Software, Inc. 2008.
  10  *               Anton Vorontsov <avorontsov@ru.mvista.com>
  11  *
  12  * This program is free software; you can redistribute  it and/or modify it
  13  * under  the terms of  the GNU General  Public License as published by the
  14  * Free Software Foundation;  either version 2 of the  License, or (at your
  15  * option) any later version.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/types.h>
  20 #include <linux/errno.h>
  21 #include <linux/list.h>
  22 #include <linux/io.h>
  23 #include <linux/usb.h>
  24 #include "../core/hcd.h"
  25 #include "fhci.h"
  26
  27 #define DUMMY_BD_BUFFER  0xdeadbeef
  28 #define DUMMY2_BD_BUFFER 0xbaadf00d
  29
  30 /* Transaction Descriptors bits */
  31 #define TD_R            0x8000 /* ready bit */
  32 #define TD_W            0x2000 /* wrap bit */
  33 #define TD_I            0x1000 /* interrupt on completion */
  34 #define TD_L            0x0800 /* last */
  35 #define TD_TC           0x0400 /* transmit CRC */
  36 #define TD_CNF          0x0200 /* CNF - Must be always 1 */
  37 #define TD_LSP          0x0100 /* Low-speed transaction */
  38 #define TD_PID          0x00c0 /* packet id */
  39 #define TD_RXER         0x0020 /* Rx error or not */
  40
  41 #define TD_NAK          0x0010 /* No ack. */
  42 #define TD_STAL         0x0008 /* Stall recieved */
  43 #define TD_TO           0x0004 /* time out */
  44 #define TD_UN           0x0002 /* underrun */
  45 #define TD_NO           0x0010 /* Rx Non Octet Aligned Packet */
  46 #define TD_AB           0x0008 /* Frame Aborted */
  47 #define TD_CR           0x0004 /* CRC Error */
  48 #define TD_OV           0x0002 /* Overrun */
  49 #define TD_BOV          0x0001 /* Buffer Overrun */
  50
  51 #define TD_ERRORS       (TD_NAK | TD_STAL | TD_TO | TD_UN | \
  52                          TD_NO | TD_AB | TD_CR | TD_OV | TD_BOV)
  53
  54 #define TD_PID_DATA0    0x0080 /* Data 0 toggle */
  55 #define TD_PID_DATA1    0x00c0 /* Data 1 toggle */
  56 #define TD_PID_TOGGLE   0x00c0 /* Data 0/1 toggle mask */
  57
  58 #define TD_TOK_SETUP    0x0000
  59 #define TD_TOK_OUT      0x4000
  60 #define TD_TOK_IN       0x8000
  61 #define TD_ISO          0x1000
  62 #define TD_ENDP         0x0780
  63 #define TD_ADDR         0x007f
  64
  65 #define TD_ENDP_SHIFT 7
  66
  67 struct usb_td {
  68         __be16 status;
  69         __be16 length;
  70         __be32 buf_ptr;
  71         __be16 extra;
  72         __be16 reserved;
  73 };
  74
  75 static struct usb_td __iomem *next_bd(struct usb_td __iomem *base,
  76                                       struct usb_td __iomem *td,
  77                                       u16 status)
  78 {
  79         if (status & TD_W)
  80                 return base;
  81         else
  82                 return ++td;
  83 }
  84
  85 void fhci_push_dummy_bd(struct endpoint *ep)
  86 {
  87         if (ep->already_pushed_dummy_bd == false) {
  88                 u16 td_status = in_be16(&ep->empty_td->status);
  89
  90                 out_be32(&ep->empty_td->buf_ptr, DUMMY_BD_BUFFER);
  91                 /* get the next TD in the ring */
  92                 ep->empty_td = next_bd(ep->td_base, ep->empty_td, td_status);
  93                 ep->already_pushed_dummy_bd = true;
  94         }
  95 }
  96
  97 /* destroy an USB endpoint */
  98 void fhci_ep0_free(struct fhci_usb *usb)
  99 {
 100         struct endpoint *ep;
 101         int size;
 102
 103         ep = usb->ep0;
 104         if (ep) {
 105                 if (ep->td_base)
 106                         cpm_muram_free(cpm_muram_offset(ep->td_base));
 107
 108                 if (ep->conf_frame_Q) {
 109                         size = cq_howmany(ep->conf_frame_Q);
 110                         for (; size; size--) {
 111                                 struct packet *pkt = cq_get(ep->conf_frame_Q);
 112
 113                                 kfree(pkt);
 114                         }
 115                         cq_delete(ep->conf_frame_Q);
 116                 }
 117
 118                 if (ep->empty_frame_Q) {
 119                         size = cq_howmany(ep->empty_frame_Q);
 120                         for (; size; size--) {
 121                                 struct packet *pkt = cq_get(ep->empty_frame_Q);
 122
 123                                 kfree(pkt);
 124                         }
 125                         cq_delete(ep->empty_frame_Q);
 126                 }
 127
 128                 if (ep->dummy_packets_Q) {
 129                         size = cq_howmany(ep->dummy_packets_Q);
 130                         for (; size; size--) {
 131                                 u8 *buff = cq_get(ep->dummy_packets_Q);
 132
 133                                 kfree(buff);
 134                         }
 135                         cq_delete(ep->dummy_packets_Q);
 136                 }
 137
 138                 kfree(ep);
 139                 usb->ep0 = NULL;
 140         }
 141 }
 142
 143 /*
 144  * create the endpoint structure
 145  *
 146  * arguments:
 147  * usb          A pointer to the data structure of the USB
 148  * data_mem     The data memory partition(BUS)
 149  * ring_len     TD ring length
 150  */
 151 u32 fhci_create_ep(struct fhci_usb *usb, enum fhci_mem_alloc data_mem,
 152                            u32 ring_len)
 153 {
 154         struct endpoint *ep;
 155         struct usb_td __iomem *td;
 156         unsigned long ep_offset;
 157         char *err_for = "enpoint PRAM";
 158         int ep_mem_size;
 159         u32 i;
 160
 161         /* we need at least 3 TDs in the ring */
 162         if (!(ring_len > 2)) {
 163                 fhci_err(usb->fhci, "illegal TD ring length parameters\n");
 164                 return -EINVAL;
 165         }
 166
 167         ep = kzalloc(sizeof(*ep), GFP_KERNEL);
 168         if (!ep)
 169                 return -ENOMEM;
 170
 171         ep_mem_size = ring_len * sizeof(*td) + sizeof(struct fhci_ep_pram);
 172         ep_offset = cpm_muram_alloc(ep_mem_size, 32);
 173         if (IS_ERR_VALUE(ep_offset))
 174                 goto err;
 175         ep->td_base = cpm_muram_addr(ep_offset);
 176
 177         /* zero all queue pointers */
 178         ep->conf_frame_Q = cq_new(ring_len + 2);
 179         ep->empty_frame_Q = cq_new(ring_len + 2);
 180         ep->dummy_packets_Q = cq_new(ring_len + 2);
 181         if (!ep->conf_frame_Q || !ep->empty_frame_Q || !ep->dummy_packets_Q) {
 182                 err_for = "frame_queues";
 183                 goto err;
 184         }
 185
 186         for (i = 0; i < (ring_len + 1); i++) {
 187                 struct packet *pkt;
 188                 u8 *buff;
 189
 190                 pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
 191                 if (!pkt) {
 192                         err_for = "frame";
 193                         goto err;
 194                 }
 195
 196                 buff = kmalloc(1028 * sizeof(*buff), GFP_KERNEL);
 197                 if (!buff) {
 198                         kfree(pkt);
 199                         err_for = "buffer";
 200                         goto err;
 201                 }
 202                 cq_put(ep->empty_frame_Q, pkt);
 203                 cq_put(ep->dummy_packets_Q, buff);
 204         }
 205
 206         /* we put the endpoint parameter RAM right behind the TD ring */
 207         ep->ep_pram_ptr = (void __iomem *)ep->td_base + sizeof(*td) * ring_len;
 208
 209         ep->conf_td = ep->td_base;
 210         ep->empty_td = ep->td_base;
 211
 212         ep->already_pushed_dummy_bd = false;
 213
 214         /* initialize tds */
 215         td = ep->td_base;
 216         for (i = 0; i < ring_len; i++) {
 217                 out_be32(&td->buf_ptr, 0);
 218                 out_be16(&td->status, 0);
 219                 out_be16(&td->length, 0);
 220                 out_be16(&td->extra, 0);
 221                 td++;
 222         }
 223         td--;
 224         out_be16(&td->status, TD_W); /* for last TD set Wrap bit */
 225         out_be16(&td->length, 0);
 226
 227         /* endpoint structure has been created */
 228         usb->ep0 = ep;
 229
 230         return 0;
 231 err:
 232         fhci_ep0_free(usb);
 233         kfree(ep);
 234         fhci_err(usb->fhci, "no memory for the %s\n", err_for);
 235         return -ENOMEM;
 236 }
 237
 238 /*
 239  * initialize the endpoint register according to the given parameters
 240  *
 241  * artuments:
 242  * usb          A pointer to the data strucutre of the USB
 243  * ep           A pointer to the endpoint structre
 244  * data_mem     The data memory partition(BUS)
 245  */
 246 void fhci_init_ep_registers(struct fhci_usb *usb, struct endpoint *ep,
 247                             enum fhci_mem_alloc data_mem)
 248 {
 249         u8 rt;
 250
 251         /* set the endpoint registers according to the endpoint */
 252         out_be16(&usb->fhci->regs->usb_ep[0],
 253                  USB_TRANS_CTR | USB_EP_MF | USB_EP_RTE);
 254         out_be16(&usb->fhci->pram->ep_ptr[0],
 255                  cpm_muram_offset(ep->ep_pram_ptr));
 256
 257         rt = (BUS_MODE_BO_BE | BUS_MODE_GBL);
 258 #ifdef MULTI_DATA_BUS
 259         if (data_mem == MEM_SECONDARY)
 260                 rt |= BUS_MODE_DTB;
 261 #endif
 262         out_8(&ep->ep_pram_ptr->rx_func_code, rt);
 263         out_8(&ep->ep_pram_ptr->tx_func_code, rt);
 264         out_be16(&ep->ep_pram_ptr->rx_buff_len, 1028);
 265         out_be16(&ep->ep_pram_ptr->rx_base, 0);
 266         out_be16(&ep->ep_pram_ptr->tx_base, cpm_muram_offset(ep->td_base));
 267         out_be16(&ep->ep_pram_ptr->rx_bd_ptr, 0);
 268         out_be16(&ep->ep_pram_ptr->tx_bd_ptr, cpm_muram_offset(ep->td_base));
 269         out_be32(&ep->ep_pram_ptr->tx_state, 0);
 270 }
 271
 272 /*
 273  * Collect the submitted frames and inform the application about them
 274  * It is also prepearing the TDs for new frames. If the Tx interrupts
 275  * are diabled, the application should call that routine to get
 276  * confirmation about the submitted frames. Otherwise, the routine is
 277  * called frome the interrupt service routine during the Tx interrupt.
 278  * In that case the application is informed by calling the application
 279  * specific 'fhci_transaction_confirm' routine
 280  */
 281 static void fhci_td_transaction_confirm(struct fhci_usb *usb)
 282 {
 283         struct endpoint *ep = usb->ep0;
 284         struct packet *pkt;
 285         struct usb_td __iomem *td;
 286         u16 extra_data;
 287         u16 td_status;
 288         u16 td_length;
 289         u32 buf;
 290
 291         /*
 292          * collect transmitted BDs from the chip. The routine clears all BDs
 293          * with R bit = 0 and the pointer to data buffer is not NULL, that is
 294          * BDs which point to the transmitted data buffer
 295          */
 296         while (1) {
 297                 td = ep->conf_td;
 298                 td_status = in_be16(&td->status);
 299                 td_length = in_be16(&td->length);
 300                 buf = in_be32(&td->buf_ptr);
 301                 extra_data = in_be16(&td->extra);
 302
 303                 /* check if the TD is empty */
 304                 if (!(!(td_status & TD_R) && ((td_status & ~TD_W) || buf)))
 305                         break;
 306                 /* check if it is a dummy buffer */
 307                 else if ((buf == DUMMY_BD_BUFFER) && !(td_status & ~TD_W))
 308                         break;
 309
 310                 /* mark TD as empty */
 311                 clrbits16(&td->status, ~TD_W);
 312                 out_be16(&td->length, 0);
 313                 out_be32(&td->buf_ptr, 0);
 314                 out_be16(&td->extra, 0);
 315                 /* advance the TD pointer */
 316                 ep->conf_td = next_bd(ep->td_base, ep->conf_td, td_status);
 317
 318                 /* check if it is a dummy buffer(type2) */
 319                 if ((buf == DUMMY2_BD_BUFFER) && !(td_status & ~TD_W))
 320                         continue;
 321
 322                 pkt = cq_get(ep->conf_frame_Q);
 323                 if (!pkt)
 324                         fhci_err(usb->fhci, "no frame to confirm\n");
 325
 326                 if (td_status & TD_ERRORS) {
 327                         if (td_status & TD_RXER) {
 328                                 if (td_status & TD_CR)
 329                                         pkt->status = USB_TD_RX_ER_CRC;
 330                                 else if (td_status & TD_AB)
 331                                         pkt->status = USB_TD_RX_ER_BITSTUFF;
 332                                 else if (td_status & TD_OV)
 333                                         pkt->status = USB_TD_RX_ER_OVERUN;
 334                                 else if (td_status & TD_BOV)
 335                                         pkt->status = USB_TD_RX_DATA_OVERUN;
 336                                 else if (td_status & TD_NO)
 337                                         pkt->status = USB_TD_RX_ER_NONOCT;
 338                                 else
 339                                         fhci_err(usb->fhci, "illegal error "
 340                                                  "occured\n");
 341                         } else if (td_status & TD_NAK)
 342                                 pkt->status = USB_TD_TX_ER_NAK;
 343                         else if (td_status & TD_TO)
 344                                 pkt->status = USB_TD_TX_ER_TIMEOUT;
 345                         else if (td_status & TD_UN)
 346                                 pkt->status = USB_TD_TX_ER_UNDERUN;
 347                         else if (td_status & TD_STAL)
 348                                 pkt->status = USB_TD_TX_ER_STALL;
 349                         else
 350                                 fhci_err(usb->fhci, "illegal error occured\n");
 351                 } else if ((extra_data & TD_TOK_IN) &&
 352                                 pkt->len > td_length - CRC_SIZE) {
 353                         pkt->status = USB_TD_RX_DATA_UNDERUN;
 354                 }
 355
 356                 if (extra_data & TD_TOK_IN)
 357                         pkt->len = td_length - CRC_SIZE;
 358                 else if (pkt->info & PKT_ZLP)
 359                         pkt->len = 0;
 360                 else
 361                         pkt->len = td_length;
 362
 363                 fhci_transaction_confirm(usb, pkt);
 364         }
 365 }
 366
 367 /*
 368  * Submitting a data frame to a specified endpoint of a USB device
 369  * The frame is put in the driver's transmit queue for this endpoint
 370  *
 371  * Arguments:
 372  * usb          A pointer to the USB structure
 373  * pkt          A pointer to the user frame structure
 374  * trans_type   Transaction tyep - IN,OUT or SETUP
 375  * dest_addr    Device address - 0~127
 376  * dest_ep      Endpoint number of the device - 0~16
 377  * trans_mode   Pipe type - ISO,Interrupt,bulk or control
 378  * dest_speed   USB speed - Low speed or FULL speed
 379  * data_toggle  Data sequence toggle - 0 or 1
 380  */
 381 u32 fhci_host_transaction(struct fhci_usb *usb,
 382                           struct packet *pkt,
 383                           enum fhci_ta_type trans_type,
 384                           u8 dest_addr,
 385                           u8 dest_ep,
 386                           enum fhci_tf_mode trans_mode,
 387                           enum fhci_speed dest_speed, u8 data_toggle)
 388 {
 389         struct endpoint *ep = usb->ep0;
 390         struct usb_td __iomem *td;
 391         u16 extra_data;
 392         u16 td_status;
 393
 394         fhci_usb_disable_interrupt(usb);
 395         /* start from the next BD that should be filled */
 396         td = ep->empty_td;
 397         td_status = in_be16(&td->status);
 398
 399         if (td_status & TD_R && in_be16(&td->length)) {
 400                 /* if the TD is not free */
 401                 fhci_usb_enable_interrupt(usb);
 402                 return -1;
 403         }
 404
 405         /* get the next TD in the ring */
 406         ep->empty_td = next_bd(ep->td_base, ep->empty_td, td_status);
 407         fhci_usb_enable_interrupt(usb);
 408         pkt->priv_data = td;
 409         out_be32(&td->buf_ptr, virt_to_phys(pkt->data));
 410         /* sets up transaction parameters - addr,endp,dir,and type */
 411         extra_data = (dest_ep << TD_ENDP_SHIFT) | dest_addr;
 412         switch (trans_type) {
 413         case FHCI_TA_IN:
 414                 extra_data |= TD_TOK_IN;
 415                 break;
 416         case FHCI_TA_OUT:
 417                 extra_data |= TD_TOK_OUT;
 418                 break;
 419         case FHCI_TA_SETUP:
 420                 extra_data |= TD_TOK_SETUP;
 421                 break;
 422         }
 423         if (trans_mode == FHCI_TF_ISO)
 424                 extra_data |= TD_ISO;
 425         out_be16(&td->extra, extra_data);
 426
 427         /* sets up the buffer descriptor */
 428         td_status = ((td_status & TD_W) | TD_R | TD_L | TD_I | TD_CNF);
 429         if (!(pkt->info & PKT_NO_CRC))
 430                 td_status |= TD_TC;
 431
 432         switch (trans_type) {
 433         case FHCI_TA_IN:
 434                 if (data_toggle)
 435                         pkt->info |= PKT_PID_DATA1;
 436                 else
 437                         pkt->info |= PKT_PID_DATA0;
 438                 break;
 439         default:
 440                 if (data_toggle) {
 441                         td_status |= TD_PID_DATA1;
 442                         pkt->info |= PKT_PID_DATA1;
 443                 } else {
 444                         td_status |= TD_PID_DATA0;
 445                         pkt->info |= PKT_PID_DATA0;
 446                 }
 447                 break;
 448         }
 449
 450         if ((dest_speed == FHCI_LOW_SPEED) &&
 451             (usb->port_status == FHCI_PORT_FULL))
 452                 td_status |= TD_LSP;
 453
 454         out_be16(&td->status, td_status);
 455
 456         /* set up buffer length */
 457         if (trans_type == FHCI_TA_IN)
 458                 out_be16(&td->length, pkt->len + CRC_SIZE);
 459         else
 460                 out_be16(&td->length, pkt->len);
 461
 462         /* put the frame to the confirmation queue */
 463         cq_put(ep->conf_frame_Q, pkt);
 464
 465         if (cq_howmany(ep->conf_frame_Q) == 1)
 466                 out_8(&usb->fhci->regs->usb_comm, USB_CMD_STR_FIFO);
 467
 468         return 0;
 469 }
 470
 471 /* Reset the Tx BD ring */
 472 void fhci_flush_bds(struct fhci_usb *usb)
 473 {
 474         u16 extra_data;
 475         u16 td_status;
 476         u32 buf;
 477         struct usb_td __iomem *td;
 478         struct endpoint *ep = usb->ep0;
 479
 480         td = ep->td_base;
 481         while (1) {
 482                 td_status = in_be16(&td->status);
 483                 buf = in_be32(&td->buf_ptr);
 484                 extra_data = in_be16(&td->extra);
 485
 486                 /* if the TD is not empty - we'll confirm it as Timeout */
 487                 if (td_status & TD_R)
 488                         out_be16(&td->status, (td_status & ~TD_R) | TD_TO);
 489                 /* if this TD is dummy - let's skip this TD */
 490                 else if (in_be32(&td->buf_ptr) == DUMMY_BD_BUFFER)
 491                         out_be32(&td->buf_ptr, DUMMY2_BD_BUFFER);
 492                 /* if this is the last TD - break */
 493                 if (td_status & TD_W)
 494                         break;
 495
 496                 td++;
 497         }
 498
 499         fhci_td_transaction_confirm(usb);
 500
 501         td = ep->td_base;
 502         do {
 503                 out_be16(&td->status, 0);
 504                 out_be16(&td->length, 0);
 505                 out_be32(&td->buf_ptr, 0);
 506                 out_be16(&td->extra, 0);
 507                 td++;
 508         } while (!(in_be16(&td->status) & TD_W));
 509         out_be16(&td->status, TD_W); /* for last TD set Wrap bit */
 510         out_be16(&td->length, 0);
 511         out_be32(&td->buf_ptr, 0);
 512         out_be16(&td->extra, 0);
 513
 514         out_be16(&ep->ep_pram_ptr->tx_bd_ptr,
 515                  in_be16(&ep->ep_pram_ptr->tx_base));
 516         out_be32(&ep->ep_pram_ptr->tx_state, 0);
 517         out_be16(&ep->ep_pram_ptr->tx_cnt, 0);
 518         ep->empty_td = ep->td_base;
 519         ep->conf_td = ep->td_base;
 520 }
 521
 522 /*
 523  * Flush all transmitted packets from TDs in the actual frame.
 524  * This routine is called when something wrong with the controller and
 525  * we want to get rid of the actual frame and start again next frame
 526  */
 527 void fhci_flush_actual_frame(struct fhci_usb *usb)
 528 {
 529         u8 mode;
 530         u16 tb_ptr;
 531         u16 extra_data;
 532         u16 td_status;
 533         u32 buf_ptr;
 534         struct usb_td __iomem *td;
 535         struct endpoint *ep = usb->ep0;
 536
 537         /* disable the USB controller */
 538         mode = in_8(&usb->fhci->regs->usb_mod);
 539         out_8(&usb->fhci->regs->usb_mod, mode & ~USB_MODE_EN);
 540
 541         tb_ptr = in_be16(&ep->ep_pram_ptr->tx_bd_ptr);
 542         td = cpm_muram_addr(tb_ptr);
 543         td_status = in_be16(&td->status);
 544         buf_ptr = in_be32(&td->buf_ptr);
 545         extra_data = in_be16(&td->extra);
 546         do {
 547                 if (td_status & TD_R) {
 548                         out_be16(&td->status, (td_status & ~TD_R) | TD_TO);
 549                 } else {
 550                         out_be32(&td->buf_ptr, 0);
 551                         ep->already_pushed_dummy_bd = false;
 552                         break;
 553                 }
 554
 555                 /* advance the TD pointer */
 556                 td = next_bd(ep->td_base, td, td_status);
 557                 td_status = in_be16(&td->status);
 558                 buf_ptr = in_be32(&td->buf_ptr);
 559                 extra_data = in_be16(&td->extra);
 560         } while ((td_status & TD_R) || buf_ptr);
 561
 562         fhci_td_transaction_confirm(usb);
 563
 564         out_be16(&ep->ep_pram_ptr->tx_bd_ptr,
 565                  in_be16(&ep->ep_pram_ptr->tx_base));
 566         out_be32(&ep->ep_pram_ptr->tx_state, 0);
 567         out_be16(&ep->ep_pram_ptr->tx_cnt, 0);
 568         ep->empty_td = ep->td_base;
 569         ep->conf_td = ep->td_base;
 570
 571         usb->actual_frame->frame_status = FRAME_TIMER_END_TRANSMISSION;
 572
 573         /* reset the event register */
 574         out_be16(&usb->fhci->regs->usb_event, 0xffff);
 575         /* enable the USB controller */
 576         out_8(&usb->fhci->regs->usb_mod, mode | USB_MODE_EN);
 577 }
 578
 579 /* handles Tx confirm and Tx error interrupt */
 580 void fhci_tx_conf_interrupt(struct fhci_usb *usb)
 581 {
 582         fhci_td_transaction_confirm(usb);
 583
 584         /*
 585          * Schedule another transaction to this frame only if we have
 586          * already confirmed all transaction in the frame.
 587          */
 588         if (((fhci_get_sof_timer_count(usb) < usb->max_frame_usage) ||
 589              (usb->actual_frame->frame_status & FRAME_END_TRANSMISSION)) &&
 590             (list_empty(&usb->actual_frame->tds_list)))
 591                 fhci_schedule_transactions(usb);
 592 }
 593
 594 void fhci_host_transmit_actual_frame(struct fhci_usb *usb)
 595 {
 596         u16 tb_ptr;
 597         u16 td_status;
 598         struct usb_td __iomem *td;
 599         struct endpoint *ep = usb->ep0;
 600
 601         tb_ptr = in_be16(&ep->ep_pram_ptr->tx_bd_ptr);
 602         td = cpm_muram_addr(tb_ptr);
 603
 604         if (in_be32(&td->buf_ptr) == DUMMY_BD_BUFFER) {
 605                 struct usb_td __iomem *old_td = td;
 606
 607                 ep->already_pushed_dummy_bd = false;
 608                 td_status = in_be16(&td->status);
 609                 /* gets the next TD in the ring */
 610                 td = next_bd(ep->td_base, td, td_status);
 611                 tb_ptr = cpm_muram_offset(td);
 612                 out_be16(&ep->ep_pram_ptr->tx_bd_ptr, tb_ptr);
 613
 614                 /* start transmit only if we have something in the TDs */
 615                 if (in_be16(&td->status) & TD_R)
 616                         out_8(&usb->fhci->regs->usb_comm, USB_CMD_STR_FIFO);
 617
 618                 if (in_be32(&ep->conf_td->buf_ptr) == DUMMY_BD_BUFFER) {
 619                         out_be32(&old_td->buf_ptr, 0);
 620                         ep->conf_td = next_bd(ep->td_base, ep->conf_td,
 621                                               td_status);
 622                 } else {
 623                         out_be32(&old_td->buf_ptr, DUMMY2_BD_BUFFER);
 624                 }
 625         }
 626 }