drivers/usb/gadget/udc/aspeed-vhub/epn.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
   4  *
   5  * epn.c - Generic endpoints management
   6  *
   7  * Copyright 2017 IBM Corporation
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/delay.h>
  19 #include <linux/ioport.h>
  20 #include <linux/slab.h>
  21 #include <linux/errno.h>
  22 #include <linux/list.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/prefetch.h>
  26 #include <linux/clk.h>
  27 #include <linux/usb/gadget.h>
  28 #include <linux/of.h>
  29 #include <linux/of_gpio.h>
  30 #include <linux/regmap.h>
  31 #include <linux/dma-mapping.h>
  32
  33 #include "vhub.h"
  34
  35 #define EXTRA_CHECKS
  36
  37 #ifdef EXTRA_CHECKS
  38 #define CHECK(ep, expr, fmt...)                                 \
  39         do {                                                    \
  40                 if (!(expr)) EPDBG(ep, "CHECK:" fmt);           \
  41         } while(0)
  42 #else
  43 #define CHECK(ep, expr, fmt...) do { } while(0)
  44 #endif
  45
  46 static void ast_vhub_epn_kick(struct ast_vhub_ep *ep, struct ast_vhub_req *req)
  47 {
  48         unsigned int act = req->req.actual;
  49         unsigned int len = req->req.length;
  50         unsigned int chunk;
  51
  52         /* There should be no DMA ongoing */
  53         WARN_ON(req->active);
  54
  55         /* Calculate next chunk size */
  56         chunk = len - act;
  57         if (chunk > ep->ep.maxpacket)
  58                 chunk = ep->ep.maxpacket;
  59         else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
  60                 req->last_desc = 1;
  61
  62         EPVDBG(ep, "kick req %p act=%d/%d chunk=%d last=%d\n",
  63                req, act, len, chunk, req->last_desc);
  64
  65         /* If DMA unavailable, using staging EP buffer */
  66         if (!req->req.dma) {
  67
  68                 /* For IN transfers, copy data over first */
  69                 if (ep->epn.is_in) {
  70                         memcpy(ep->buf, req->req.buf + act, chunk);
  71                         vhub_dma_workaround(ep->buf);
  72                 }
  73                 writel(ep->buf_dma, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
  74         } else {
  75                 if (ep->epn.is_in)
  76                         vhub_dma_workaround(req->req.buf);
  77                 writel(req->req.dma + act, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
  78         }
  79
  80         /* Start DMA */
  81         req->active = true;
  82         writel(VHUB_EP_DMA_SET_TX_SIZE(chunk),
  83                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  84         writel(VHUB_EP_DMA_SET_TX_SIZE(chunk) | VHUB_EP_DMA_SINGLE_KICK,
  85                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  86 }
  87
  88 static void ast_vhub_epn_handle_ack(struct ast_vhub_ep *ep)
  89 {
  90         struct ast_vhub_req *req;
  91         unsigned int len;
  92         u32 stat;
  93
  94         /* Read EP status */
  95         stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  96
  97         /* Grab current request if any */
  98         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
  99
 100         EPVDBG(ep, "ACK status=%08x is_in=%d, req=%p (active=%d)\n",
 101                stat, ep->epn.is_in, req, req ? req->active : 0);
 102
 103         /* In absence of a request, bail out, must have been dequeued */
 104         if (!req)
 105                 return;
 106
 107         /*
 108          * Request not active, move on to processing queue, active request
 109          * was probably dequeued
 110          */
 111         if (!req->active)
 112                 goto next_chunk;
 113
 114         /* Check if HW has moved on */
 115         if (VHUB_EP_DMA_RPTR(stat) != 0) {
 116                 EPDBG(ep, "DMA read pointer not 0 !\n");
 117                 return;
 118         }
 119
 120         /* No current DMA ongoing */
 121         req->active = false;
 122
 123         /* Grab length out of HW */
 124         len = VHUB_EP_DMA_TX_SIZE(stat);
 125
 126         /* If not using DMA, copy data out if needed */
 127         if (!req->req.dma && !ep->epn.is_in && len)
 128                 memcpy(req->req.buf + req->req.actual, ep->buf, len);
 129
 130         /* Adjust size */
 131         req->req.actual += len;
 132
 133         /* Check for short packet */
 134         if (len < ep->ep.maxpacket)
 135                 req->last_desc = 1;
 136
 137         /* That's it ? complete the request and pick a new one */
 138         if (req->last_desc >= 0) {
 139                 ast_vhub_done(ep, req, 0);
 140                 req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req,
 141                                                queue);
 142
 143                 /*
 144                  * Due to lock dropping inside "done" the next request could
 145                  * already be active, so check for that and bail if needed.
 146                  */
 147                 if (!req || req->active)
 148                         return;
 149         }
 150
 151  next_chunk:
 152         ast_vhub_epn_kick(ep, req);
 153 }
 154
 155 static inline unsigned int ast_vhub_count_free_descs(struct ast_vhub_ep *ep)
 156 {
 157         /*
 158          * d_next == d_last means descriptor list empty to HW,
 159          * thus we can only have AST_VHUB_DESCS_COUNT-1 descriptors
 160          * in the list
 161          */
 162         return (ep->epn.d_last + AST_VHUB_DESCS_COUNT - ep->epn.d_next - 1) &
 163                 (AST_VHUB_DESCS_COUNT - 1);
 164 }
 165
 166 static void ast_vhub_epn_kick_desc(struct ast_vhub_ep *ep,
 167                                    struct ast_vhub_req *req)
 168 {
 169         struct ast_vhub_desc *desc = NULL;
 170         unsigned int act = req->act_count;
 171         unsigned int len = req->req.length;
 172         unsigned int chunk;
 173
 174         /* Mark request active if not already */
 175         req->active = true;
 176
 177         /* If the request was already completely written, do nothing */
 178         if (req->last_desc >= 0)
 179                 return;
 180
 181         EPVDBG(ep, "kick act=%d/%d chunk_max=%d free_descs=%d\n",
 182                act, len, ep->epn.chunk_max, ast_vhub_count_free_descs(ep));
 183
 184         /* While we can create descriptors */
 185         while (ast_vhub_count_free_descs(ep) && req->last_desc < 0) {
 186                 unsigned int d_num;
 187
 188                 /* Grab next free descriptor */
 189                 d_num = ep->epn.d_next;
 190                 desc = &ep->epn.descs[d_num];
 191                 ep->epn.d_next = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
 192
 193                 /* Calculate next chunk size */
 194                 chunk = len - act;
 195                 if (chunk <= ep->epn.chunk_max) {
 196                         /*
 197                          * Is this the last packet ? Because of having up to 8
 198                          * packets in a descriptor we can't just compare "chunk"
 199                          * with ep.maxpacket. We have to see if it's a multiple
 200                          * of it to know if we have to send a zero packet.
 201                          * Sadly that involves a modulo which is a bit expensive
 202                          * but probably still better than not doing it.
 203                          */
 204                         if (!chunk || !req->req.zero || (chunk % ep->ep.maxpacket) != 0)
 205                                 req->last_desc = d_num;
 206                 } else {
 207                         chunk = ep->epn.chunk_max;
 208                 }
 209
 210                 EPVDBG(ep, " chunk: act=%d/%d chunk=%d last=%d desc=%d free=%d\n",
 211                        act, len, chunk, req->last_desc, d_num,
 212                        ast_vhub_count_free_descs(ep));
 213
 214                 /* Populate descriptor */
 215                 desc->w0 = cpu_to_le32(req->req.dma + act);
 216
 217                 /* Interrupt if end of request or no more descriptors */
 218
 219                 /*
 220                  * TODO: Be smarter about it, if we don't have enough
 221                  * descriptors request an interrupt before queue empty
 222                  * or so in order to be able to populate more before
 223                  * the HW runs out. This isn't a problem at the moment
 224                  * as we use 256 descriptors and only put at most one
 225                  * request in the ring.
 226                  */
 227                 desc->w1 = cpu_to_le32(VHUB_DSC1_IN_SET_LEN(chunk));
 228                 if (req->last_desc >= 0 || !ast_vhub_count_free_descs(ep))
 229                         desc->w1 |= cpu_to_le32(VHUB_DSC1_IN_INTERRUPT);
 230
 231                 /* Account packet */
 232                 req->act_count = act = act + chunk;
 233         }
 234
 235         if (likely(desc))
 236                 vhub_dma_workaround(desc);
 237
 238         /* Tell HW about new descriptors */
 239         writel(VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next),
 240                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 241
 242         EPVDBG(ep, "HW kicked, d_next=%d dstat=%08x\n",
 243                ep->epn.d_next, readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS));
 244 }
 245
 246 static void ast_vhub_epn_handle_ack_desc(struct ast_vhub_ep *ep)
 247 {
 248         struct ast_vhub_req *req;
 249         unsigned int len, d_last;
 250         u32 stat, stat1;
 251
 252         /* Read EP status, workaround HW race */
 253         do {
 254                 stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 255                 stat1 = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 256         } while(stat != stat1);
 257
 258         /* Extract RPTR */
 259         d_last = VHUB_EP_DMA_RPTR(stat);
 260
 261         /* Grab current request if any */
 262         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
 263
 264         EPVDBG(ep, "ACK status=%08x is_in=%d ep->d_last=%d..%d\n",
 265                stat, ep->epn.is_in, ep->epn.d_last, d_last);
 266
 267         /* Check all completed descriptors */
 268         while (ep->epn.d_last != d_last) {
 269                 struct ast_vhub_desc *desc;
 270                 unsigned int d_num;
 271                 bool is_last_desc;
 272
 273                 /* Grab next completed descriptor */
 274                 d_num = ep->epn.d_last;
 275                 desc = &ep->epn.descs[d_num];
 276                 ep->epn.d_last = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
 277
 278                 /* Grab len out of descriptor */
 279                 len = VHUB_DSC1_IN_LEN(le32_to_cpu(desc->w1));
 280
 281                 EPVDBG(ep, " desc %d len=%d req=%p (act=%d)\n",
 282                        d_num, len, req, req ? req->active : 0);
 283
 284                 /* If no active request pending, move on */
 285                 if (!req || !req->active)
 286                         continue;
 287
 288                 /* Adjust size */
 289                 req->req.actual += len;
 290
 291                 /* Is that the last chunk ? */
 292                 is_last_desc = req->last_desc == d_num;
 293                 CHECK(ep, is_last_desc == (len < ep->ep.maxpacket ||
 294                                            (req->req.actual >= req->req.length &&
 295                                             !req->req.zero)),
 296                       "Last packet discrepancy: last_desc=%d len=%d r.act=%d "
 297                       "r.len=%d r.zero=%d mp=%d\n",
 298                       is_last_desc, len, req->req.actual, req->req.length,
 299                       req->req.zero, ep->ep.maxpacket);
 300
 301                 if (is_last_desc) {
 302                         /*
 303                          * Because we can only have one request at a time
 304                          * in our descriptor list in this implementation,
 305                          * d_last and ep->d_last should now be equal
 306                          */
 307                         CHECK(ep, d_last == ep->epn.d_last,
 308                               "DMA read ptr mismatch %d vs %d\n",
 309                               d_last, ep->epn.d_last);
 310
 311                         /* Note: done will drop and re-acquire the lock */
 312                         ast_vhub_done(ep, req, 0);
 313                         req = list_first_entry_or_null(&ep->queue,
 314                                                        struct ast_vhub_req,
 315                                                        queue);
 316                         break;
 317                 }
 318         }
 319
 320         /* More work ? */
 321         if (req)
 322                 ast_vhub_epn_kick_desc(ep, req);
 323 }
 324
 325 void ast_vhub_epn_ack_irq(struct ast_vhub_ep *ep)
 326 {
 327         if (ep->epn.desc_mode)
 328                 ast_vhub_epn_handle_ack_desc(ep);
 329         else
 330                 ast_vhub_epn_handle_ack(ep);
 331 }
 332
 333 static int ast_vhub_epn_queue(struct usb_ep* u_ep, struct usb_request *u_req,
 334                               gfp_t gfp_flags)
 335 {
 336         struct ast_vhub_req *req = to_ast_req(u_req);
 337         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 338         struct ast_vhub *vhub = ep->vhub;
 339         unsigned long flags;
 340         bool empty;
 341         int rc;
 342
 343         /* Paranoid checks */
 344         if (!u_req || !u_req->complete || !u_req->buf) {
 345                 dev_warn(&vhub->pdev->dev, "Bogus EPn request ! u_req=%p\n", u_req);
 346                 if (u_req) {
 347                         dev_warn(&vhub->pdev->dev, "complete=%p internal=%d\n",
 348                                  u_req->complete, req->internal);
 349                 }
 350                 return -EINVAL;
 351         }
 352
 353         /* Endpoint enabled ? */
 354         if (!ep->epn.enabled || !u_ep->desc || !ep->dev || !ep->d_idx ||
 355             !ep->dev->enabled) {
 356                 EPDBG(ep, "Enqueuing request on wrong or disabled EP\n");
 357                 return -ESHUTDOWN;
 358         }
 359
 360         /* Map request for DMA if possible. For now, the rule for DMA is
 361          * that:
 362          *
 363          *  * For single stage mode (no descriptors):
 364          *
 365          *   - The buffer is aligned to a 8 bytes boundary (HW requirement)
 366          *   - For a OUT endpoint, the request size is a multiple of the EP
 367          *     packet size (otherwise the controller will DMA past the end
 368          *     of the buffer if the host is sending a too long packet).
 369          *
 370          *  * For descriptor mode (tx only for now), always.
 371          *
 372          * We could relax the latter by making the decision to use the bounce
 373          * buffer based on the size of a given *segment* of the request rather
 374          * than the whole request.
 375          */
 376         if (ep->epn.desc_mode ||
 377             ((((unsigned long)u_req->buf & 7) == 0) &&
 378              (ep->epn.is_in || !(u_req->length & (u_ep->maxpacket - 1))))) {
 379                 rc = usb_gadget_map_request(&ep->dev->gadget, u_req,
 380                                             ep->epn.is_in);
 381                 if (rc) {
 382                         dev_warn(&vhub->pdev->dev,
 383                                  "Request mapping failure %d\n", rc);
 384                         return rc;
 385                 }
 386         } else
 387                 u_req->dma = 0;
 388
 389         EPVDBG(ep, "enqueue req @%p\n", req);
 390         EPVDBG(ep, " l=%d dma=0x%x zero=%d noshort=%d noirq=%d is_in=%d\n",
 391                u_req->length, (u32)u_req->dma, u_req->zero,
 392                u_req->short_not_ok, u_req->no_interrupt,
 393                ep->epn.is_in);
 394
 395         /* Initialize request progress fields */
 396         u_req->status = -EINPROGRESS;
 397         u_req->actual = 0;
 398         req->act_count = 0;
 399         req->active = false;
 400         req->last_desc = -1;
 401         spin_lock_irqsave(&vhub->lock, flags);
 402         empty = list_empty(&ep->queue);
 403
 404         /* Add request to list and kick processing if empty */
 405         list_add_tail(&req->queue, &ep->queue);
 406         if (empty) {
 407                 if (ep->epn.desc_mode)
 408                         ast_vhub_epn_kick_desc(ep, req);
 409                 else
 410                         ast_vhub_epn_kick(ep, req);
 411         }
 412         spin_unlock_irqrestore(&vhub->lock, flags);
 413
 414         return 0;
 415 }
 416
 417 static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,
 418                                      bool restart_ep)
 419 {
 420         u32 state, reg, loops;
 421
 422         /* Stop DMA activity */
 423         writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 424
 425         /* Wait for it to complete */
 426         for (loops = 0; loops < 1000; loops++) {
 427                 state = readl(ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 428                 state = VHUB_EP_DMA_PROC_STATUS(state);
 429                 if (state == EP_DMA_PROC_RX_IDLE ||
 430                     state == EP_DMA_PROC_TX_IDLE)
 431                         break;
 432                 udelay(1);
 433         }
 434         if (loops >= 1000)
 435                 dev_warn(&ep->vhub->pdev->dev, "Timeout waiting for DMA\n");
 436
 437         /* If we don't have to restart the endpoint, that's it */
 438         if (!restart_ep)
 439                 return;
 440
 441         /* Restart the endpoint */
 442         if (ep->epn.desc_mode) {
 443                 /*
 444                  * Take out descriptors by resetting the DMA read
 445                  * pointer to be equal to the CPU write pointer.
 446                  *
 447                  * Note: If we ever support creating descriptors for
 448                  * requests that aren't the head of the queue, we
 449                  * may have to do something more complex here,
 450                  * especially if the request being taken out is
 451                  * not the current head descriptors.
 452                  */
 453                 reg = VHUB_EP_DMA_SET_RPTR(ep->epn.d_next) |
 454                         VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next);
 455                 writel(reg, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 456
 457                 /* Then turn it back on */
 458                 writel(ep->epn.dma_conf,
 459                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 460         } else {
 461                 /* Single mode: just turn it back on */
 462                 writel(ep->epn.dma_conf,
 463                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 464         }
 465 }
 466
 467 static int ast_vhub_epn_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
 468 {
 469         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 470         struct ast_vhub *vhub = ep->vhub;
 471         struct ast_vhub_req *req;
 472         unsigned long flags;
 473         int rc = -EINVAL;
 474
 475         spin_lock_irqsave(&vhub->lock, flags);
 476
 477         /* Make sure it's actually queued on this endpoint */
 478         list_for_each_entry (req, &ep->queue, queue) {
 479                 if (&req->req == u_req)
 480                         break;
 481         }
 482
 483         if (&req->req == u_req) {
 484                 EPVDBG(ep, "dequeue req @%p active=%d\n",
 485                        req, req->active);
 486                 if (req->active)
 487                         ast_vhub_stop_active_req(ep, true);
 488                 ast_vhub_done(ep, req, -ECONNRESET);
 489                 rc = 0;
 490         }
 491
 492         spin_unlock_irqrestore(&vhub->lock, flags);
 493         return rc;
 494 }
 495
 496 void ast_vhub_update_epn_stall(struct ast_vhub_ep *ep)
 497 {
 498         u32 reg;
 499
 500         if (WARN_ON(ep->d_idx == 0))
 501                 return;
 502         reg = readl(ep->epn.regs + AST_VHUB_EP_CONFIG);
 503         if (ep->epn.stalled || ep->epn.wedged)
 504                 reg |= VHUB_EP_CFG_STALL_CTRL;
 505         else
 506                 reg &= ~VHUB_EP_CFG_STALL_CTRL;
 507         writel(reg, ep->epn.regs + AST_VHUB_EP_CONFIG);
 508
 509         if (!ep->epn.stalled && !ep->epn.wedged)
 510                 writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
 511                        ep->vhub->regs + AST_VHUB_EP_TOGGLE);
 512 }
 513
 514 static int ast_vhub_set_halt_and_wedge(struct usb_ep* u_ep, bool halt,
 515                                       bool wedge)
 516 {
 517         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 518         struct ast_vhub *vhub = ep->vhub;
 519         unsigned long flags;
 520
 521         EPDBG(ep, "Set halt (%d) & wedge (%d)\n", halt, wedge);
 522
 523         if (!u_ep || !u_ep->desc)
 524                 return -EINVAL;
 525         if (ep->d_idx == 0)
 526                 return 0;
 527         if (ep->epn.is_iso)
 528                 return -EOPNOTSUPP;
 529
 530         spin_lock_irqsave(&vhub->lock, flags);
 531
 532         /* Fail with still-busy IN endpoints */
 533         if (halt && ep->epn.is_in && !list_empty(&ep->queue)) {
 534                 spin_unlock_irqrestore(&vhub->lock, flags);
 535                 return -EAGAIN;
 536         }
 537         ep->epn.stalled = halt;
 538         ep->epn.wedged = wedge;
 539         ast_vhub_update_epn_stall(ep);
 540
 541         spin_unlock_irqrestore(&vhub->lock, flags);
 542
 543         return 0;
 544 }
 545
 546 static int ast_vhub_epn_set_halt(struct usb_ep *u_ep, int value)
 547 {
 548         return ast_vhub_set_halt_and_wedge(u_ep, value != 0, false);
 549 }
 550
 551 static int ast_vhub_epn_set_wedge(struct usb_ep *u_ep)
 552 {
 553         return ast_vhub_set_halt_and_wedge(u_ep, true, true);
 554 }
 555
 556 static int ast_vhub_epn_disable(struct usb_ep* u_ep)
 557 {
 558         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 559         struct ast_vhub *vhub = ep->vhub;
 560         unsigned long flags;
 561         u32 imask, ep_ier;
 562
 563         EPDBG(ep, "Disabling !\n");
 564
 565         spin_lock_irqsave(&vhub->lock, flags);
 566
 567         ep->epn.enabled = false;
 568
 569         /* Stop active DMA if any */
 570         ast_vhub_stop_active_req(ep, false);
 571
 572         /* Disable endpoint */
 573         writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
 574
 575         /* Disable ACK interrupt */
 576         imask = VHUB_EP_IRQ(ep->epn.g_idx);
 577         ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
 578         ep_ier &= ~imask;
 579         writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
 580         writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 581
 582         /* Nuke all pending requests */
 583         ast_vhub_nuke(ep, -ESHUTDOWN);
 584
 585         /* No more descriptor associated with request */
 586         ep->ep.desc = NULL;
 587
 588         spin_unlock_irqrestore(&vhub->lock, flags);
 589
 590         return 0;
 591 }
 592
 593 static int ast_vhub_epn_enable(struct usb_ep* u_ep,
 594                                const struct usb_endpoint_descriptor *desc)
 595 {
 596         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 597         struct ast_vhub_dev *dev;
 598         struct ast_vhub *vhub;
 599         u16 maxpacket, type;
 600         unsigned long flags;
 601         u32 ep_conf, ep_ier, imask;
 602
 603         /* Check arguments */
 604         if (!u_ep || !desc)
 605                 return -EINVAL;
 606
 607         maxpacket = usb_endpoint_maxp(desc);
 608         if (!ep->d_idx || !ep->dev ||
 609             desc->bDescriptorType != USB_DT_ENDPOINT ||
 610             maxpacket == 0 || maxpacket > ep->ep.maxpacket) {
 611                 EPDBG(ep, "Invalid EP enable,d_idx=%d,dev=%p,type=%d,mp=%d/%d\n",
 612                       ep->d_idx, ep->dev, desc->bDescriptorType,
 613                       maxpacket, ep->ep.maxpacket);
 614                 return -EINVAL;
 615         }
 616         if (ep->d_idx != usb_endpoint_num(desc)) {
 617                 EPDBG(ep, "EP number mismatch !\n");
 618                 return -EINVAL;
 619         }
 620
 621         if (ep->epn.enabled) {
 622                 EPDBG(ep, "Already enabled\n");
 623                 return -EBUSY;
 624         }
 625         dev = ep->dev;
 626         vhub = ep->vhub;
 627
 628         /* Check device state */
 629         if (!dev->driver) {
 630                 EPDBG(ep, "Bogus device state: driver=%p speed=%d\n",
 631                        dev->driver, dev->gadget.speed);
 632                 return -ESHUTDOWN;
 633         }
 634
 635         /* Grab some info from the descriptor */
 636         ep->epn.is_in = usb_endpoint_dir_in(desc);
 637         ep->ep.maxpacket = maxpacket;
 638         type = usb_endpoint_type(desc);
 639         ep->epn.d_next = ep->epn.d_last = 0;
 640         ep->epn.is_iso = false;
 641         ep->epn.stalled = false;
 642         ep->epn.wedged = false;
 643
 644         EPDBG(ep, "Enabling [%s] %s num %d maxpacket=%d\n",
 645               ep->epn.is_in ? "in" : "out", usb_ep_type_string(type),
 646               usb_endpoint_num(desc), maxpacket);
 647
 648         /* Can we use DMA descriptor mode ? */
 649         ep->epn.desc_mode = ep->epn.descs && ep->epn.is_in;
 650         if (ep->epn.desc_mode)
 651                 memset(ep->epn.descs, 0, 8 * AST_VHUB_DESCS_COUNT);
 652
 653         /*
 654          * Large send function can send up to 8 packets from
 655          * one descriptor with a limit of 4095 bytes.
 656          */
 657         ep->epn.chunk_max = ep->ep.maxpacket;
 658         if (ep->epn.is_in) {
 659                 ep->epn.chunk_max <<= 3;
 660                 while (ep->epn.chunk_max > 4095)
 661                         ep->epn.chunk_max -= ep->ep.maxpacket;
 662         }
 663
 664         switch(type) {
 665         case USB_ENDPOINT_XFER_CONTROL:
 666                 EPDBG(ep, "Only one control endpoint\n");
 667                 return -EINVAL;
 668         case USB_ENDPOINT_XFER_INT:
 669                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_INT);
 670                 break;
 671         case USB_ENDPOINT_XFER_BULK:
 672                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_BULK);
 673                 break;
 674         case USB_ENDPOINT_XFER_ISOC:
 675                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_ISO);
 676                 ep->epn.is_iso = true;
 677                 break;
 678         default:
 679                 return -EINVAL;
 680         }
 681
 682         /* Encode the rest of the EP config register */
 683         if (maxpacket < 1024)
 684                 ep_conf |= VHUB_EP_CFG_SET_MAX_PKT(maxpacket);
 685         if (!ep->epn.is_in)
 686                 ep_conf |= VHUB_EP_CFG_DIR_OUT;
 687         ep_conf |= VHUB_EP_CFG_SET_EP_NUM(usb_endpoint_num(desc));
 688         ep_conf |= VHUB_EP_CFG_ENABLE;
 689         ep_conf |= VHUB_EP_CFG_SET_DEV(dev->index + 1);
 690         EPVDBG(ep, "config=%08x\n", ep_conf);
 691
 692         spin_lock_irqsave(&vhub->lock, flags);
 693
 694         /* Disable HW and reset DMA */
 695         writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
 696         writel(VHUB_EP_DMA_CTRL_RESET,
 697                ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 698
 699         /* Configure and enable */
 700         writel(ep_conf, ep->epn.regs + AST_VHUB_EP_CONFIG);
 701
 702         if (ep->epn.desc_mode) {
 703                 /* Clear DMA status, including the DMA read ptr */
 704                 writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 705
 706                 /* Set descriptor base */
 707                 writel(ep->epn.descs_dma,
 708                        ep->epn.regs + AST_VHUB_EP_DESC_BASE);
 709
 710                 /* Set base DMA config value */
 711                 ep->epn.dma_conf = VHUB_EP_DMA_DESC_MODE;
 712                 if (ep->epn.is_in)
 713                         ep->epn.dma_conf |= VHUB_EP_DMA_IN_LONG_MODE;
 714
 715                 /* First reset and disable all operations */
 716                 writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
 717                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 718
 719                 /* Enable descriptor mode */
 720                 writel(ep->epn.dma_conf,
 721                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 722         } else {
 723                 /* Set base DMA config value */
 724                 ep->epn.dma_conf = VHUB_EP_DMA_SINGLE_STAGE;
 725
 726                 /* Reset and switch to single stage mode */
 727                 writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
 728                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 729                 writel(ep->epn.dma_conf,
 730                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 731                 writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 732         }
 733
 734         /* Cleanup data toggle just in case */
 735         writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
 736                vhub->regs + AST_VHUB_EP_TOGGLE);
 737
 738         /* Cleanup and enable ACK interrupt */
 739         imask = VHUB_EP_IRQ(ep->epn.g_idx);
 740         writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 741         ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
 742         ep_ier |= imask;
 743         writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
 744
 745         /* Woot, we are online ! */
 746         ep->epn.enabled = true;
 747
 748         spin_unlock_irqrestore(&vhub->lock, flags);
 749
 750         return 0;
 751 }
 752
 753 static void ast_vhub_epn_dispose(struct usb_ep *u_ep)
 754 {
 755         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 756
 757         if (WARN_ON(!ep->dev || !ep->d_idx))
 758                 return;
 759
 760         EPDBG(ep, "Releasing endpoint\n");
 761
 762         /* Take it out of the EP list */
 763         list_del_init(&ep->ep.ep_list);
 764
 765         /* Mark the address free in the device */
 766         ep->dev->epns[ep->d_idx - 1] = NULL;
 767
 768         /* Free name & DMA buffers */
 769         kfree(ep->ep.name);
 770         ep->ep.name = NULL;
 771         dma_free_coherent(&ep->vhub->pdev->dev,
 772                           AST_VHUB_EPn_MAX_PACKET +
 773                           8 * AST_VHUB_DESCS_COUNT,
 774                           ep->buf, ep->buf_dma);
 775         ep->buf = NULL;
 776         ep->epn.descs = NULL;
 777
 778         /* Mark free */
 779         ep->dev = NULL;
 780 }
 781
 782 static const struct usb_ep_ops ast_vhub_epn_ops = {
 783         .enable         = ast_vhub_epn_enable,
 784         .disable        = ast_vhub_epn_disable,
 785         .dispose        = ast_vhub_epn_dispose,
 786         .queue          = ast_vhub_epn_queue,
 787         .dequeue        = ast_vhub_epn_dequeue,
 788         .set_halt       = ast_vhub_epn_set_halt,
 789         .set_wedge      = ast_vhub_epn_set_wedge,
 790         .alloc_request  = ast_vhub_alloc_request,
 791         .free_request   = ast_vhub_free_request,
 792 };
 793
 794 struct ast_vhub_ep *ast_vhub_alloc_epn(struct ast_vhub_dev *d, u8 addr)
 795 {
 796         struct ast_vhub *vhub = d->vhub;
 797         struct ast_vhub_ep *ep;
 798         unsigned long flags;
 799         int i;
 800
 801         /* Find a free one (no device) */
 802         spin_lock_irqsave(&vhub->lock, flags);
 803         for (i = 0; i < vhub->max_epns; i++)
 804                 if (vhub->epns[i].dev == NULL)
 805                         break;
 806         if (i >= vhub->max_epns) {
 807                 spin_unlock_irqrestore(&vhub->lock, flags);
 808                 return NULL;
 809         }
 810
 811         /* Set it up */
 812         ep = &vhub->epns[i];
 813         ep->dev = d;
 814         spin_unlock_irqrestore(&vhub->lock, flags);
 815
 816         DDBG(d, "Allocating gen EP %d for addr %d\n", i, addr);
 817         INIT_LIST_HEAD(&ep->queue);
 818         ep->d_idx = addr;
 819         ep->vhub = vhub;
 820         ep->ep.ops = &ast_vhub_epn_ops;
 821         ep->ep.name = kasprintf(GFP_KERNEL, "ep%d", addr);
 822         d->epns[addr-1] = ep;
 823         ep->epn.g_idx = i;
 824         ep->epn.regs = vhub->regs + 0x200 + (i * 0x10);
 825
 826         ep->buf = dma_alloc_coherent(&vhub->pdev->dev,
 827                                      AST_VHUB_EPn_MAX_PACKET +
 828                                      8 * AST_VHUB_DESCS_COUNT,
 829                                      &ep->buf_dma, GFP_KERNEL);
 830         if (!ep->buf) {
 831                 kfree(ep->ep.name);
 832                 ep->ep.name = NULL;
 833                 return NULL;
 834         }
 835         ep->epn.descs = ep->buf + AST_VHUB_EPn_MAX_PACKET;
 836         ep->epn.descs_dma = ep->buf_dma + AST_VHUB_EPn_MAX_PACKET;
 837
 838         usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EPn_MAX_PACKET);
 839         list_add_tail(&ep->ep.ep_list, &d->gadget.ep_list);
 840         ep->ep.caps.type_iso = true;
 841         ep->ep.caps.type_bulk = true;
 842         ep->ep.caps.type_int = true;
 843         ep->ep.caps.dir_in = true;
 844         ep->ep.caps.dir_out = true;
 845
 846         return ep;
 847 }