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
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/delay.h>
  14 #include <linux/ioport.h>
  15 #include <linux/slab.h>
  16 #include <linux/errno.h>
  17 #include <linux/list.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/prefetch.h>
  21 #include <linux/clk.h>
  22 #include <linux/usb/gadget.h>
  23 #include <linux/of.h>
  24 #include <linux/regmap.h>
  25 #include <linux/dma-mapping.h>
  26
  27 #include "vhub.h"
  28
  29 #define EXTRA_CHECKS
  30
  31 #ifdef EXTRA_CHECKS
  32 #define CHECK(ep, expr, fmt...)                                 \
  33         do {                                                    \
  34                 if (!(expr)) EPDBG(ep, "CHECK:" fmt);           \
  35         } while(0)
  36 #else
  37 #define CHECK(ep, expr, fmt...) do { } while(0)
  38 #endif
  39
  40 static void ast_vhub_epn_kick(struct ast_vhub_ep *ep, struct ast_vhub_req *req)
  41 {
  42         unsigned int act = req->req.actual;
  43         unsigned int len = req->req.length;
  44         unsigned int chunk;
  45
  46         /* There should be no DMA ongoing */
  47         WARN_ON(req->active);
  48
  49         /* Calculate next chunk size */
  50         chunk = len - act;
  51         if (chunk > ep->ep.maxpacket)
  52                 chunk = ep->ep.maxpacket;
  53         else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
  54                 req->last_desc = 1;
  55
  56         EPVDBG(ep, "kick req %p act=%d/%d chunk=%d last=%d\n",
  57                req, act, len, chunk, req->last_desc);
  58
  59         /* If DMA unavailable, using staging EP buffer */
  60         if (!req->req.dma) {
  61
  62                 /* For IN transfers, copy data over first */
  63                 if (ep->epn.is_in) {
  64                         memcpy(ep->buf, req->req.buf + act, chunk);
  65                         vhub_dma_workaround(ep->buf);
  66                 }
  67                 writel(ep->buf_dma, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
  68         } else {
  69                 if (ep->epn.is_in)
  70                         vhub_dma_workaround(req->req.buf);
  71                 writel(req->req.dma + act, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
  72         }
  73
  74         /* Start DMA */
  75         req->active = true;
  76         writel(VHUB_EP_DMA_SET_TX_SIZE(chunk),
  77                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  78         writel(VHUB_EP_DMA_SET_TX_SIZE(chunk) | VHUB_EP_DMA_SINGLE_KICK,
  79                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  80 }
  81
  82 static void ast_vhub_epn_handle_ack(struct ast_vhub_ep *ep)
  83 {
  84         struct ast_vhub_req *req;
  85         unsigned int len;
  86         int status = 0;
  87         u32 stat;
  88
  89         /* Read EP status */
  90         stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
  91
  92         /* Grab current request if any */
  93         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
  94
  95         EPVDBG(ep, "ACK status=%08x is_in=%d, req=%p (active=%d)\n",
  96                stat, ep->epn.is_in, req, req ? req->active : 0);
  97
  98         /* In absence of a request, bail out, must have been dequeued */
  99         if (!req)
 100                 return;
 101
 102         /*
 103          * Request not active, move on to processing queue, active request
 104          * was probably dequeued
 105          */
 106         if (!req->active)
 107                 goto next_chunk;
 108
 109         /* Check if HW has moved on */
 110         if (VHUB_EP_DMA_RPTR(stat) != 0) {
 111                 EPDBG(ep, "DMA read pointer not 0 !\n");
 112                 return;
 113         }
 114
 115         /* No current DMA ongoing */
 116         req->active = false;
 117
 118         /* Grab length out of HW */
 119         len = VHUB_EP_DMA_TX_SIZE(stat);
 120
 121         /* If not using DMA, copy data out if needed */
 122         if (!req->req.dma && !ep->epn.is_in && len) {
 123                 if (req->req.actual + len > req->req.length) {
 124                         req->last_desc = 1;
 125                         status = -EOVERFLOW;
 126                         goto done;
 127                 } else {
 128                         memcpy(req->req.buf + req->req.actual, ep->buf, len);
 129                 }
 130         }
 131         /* Adjust size */
 132         req->req.actual += len;
 133
 134         /* Check for short packet */
 135         if (len < ep->ep.maxpacket)
 136                 req->last_desc = 1;
 137
 138 done:
 139         /* That's it ? complete the request and pick a new one */
 140         if (req->last_desc >= 0) {
 141                 ast_vhub_done(ep, req, status);
 142                 req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req,
 143                                                queue);
 144
 145                 /*
 146                  * Due to lock dropping inside "done" the next request could
 147                  * already be active, so check for that and bail if needed.
 148                  */
 149                 if (!req || req->active)
 150                         return;
 151         }
 152
 153  next_chunk:
 154         ast_vhub_epn_kick(ep, req);
 155 }
 156
 157 static inline unsigned int ast_vhub_count_free_descs(struct ast_vhub_ep *ep)
 158 {
 159         /*
 160          * d_next == d_last means descriptor list empty to HW,
 161          * thus we can only have AST_VHUB_DESCS_COUNT-1 descriptors
 162          * in the list
 163          */
 164         return (ep->epn.d_last + AST_VHUB_DESCS_COUNT - ep->epn.d_next - 1) &
 165                 (AST_VHUB_DESCS_COUNT - 1);
 166 }
 167
 168 static void ast_vhub_epn_kick_desc(struct ast_vhub_ep *ep,
 169                                    struct ast_vhub_req *req)
 170 {
 171         struct ast_vhub_desc *desc = NULL;
 172         unsigned int act = req->act_count;
 173         unsigned int len = req->req.length;
 174         unsigned int chunk;
 175
 176         /* Mark request active if not already */
 177         req->active = true;
 178
 179         /* If the request was already completely written, do nothing */
 180         if (req->last_desc >= 0)
 181                 return;
 182
 183         EPVDBG(ep, "kick act=%d/%d chunk_max=%d free_descs=%d\n",
 184                act, len, ep->epn.chunk_max, ast_vhub_count_free_descs(ep));
 185
 186         /* While we can create descriptors */
 187         while (ast_vhub_count_free_descs(ep) && req->last_desc < 0) {
 188                 unsigned int d_num;
 189
 190                 /* Grab next free descriptor */
 191                 d_num = ep->epn.d_next;
 192                 desc = &ep->epn.descs[d_num];
 193                 ep->epn.d_next = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
 194
 195                 /* Calculate next chunk size */
 196                 chunk = len - act;
 197                 if (chunk <= ep->epn.chunk_max) {
 198                         /*
 199                          * Is this the last packet ? Because of having up to 8
 200                          * packets in a descriptor we can't just compare "chunk"
 201                          * with ep.maxpacket. We have to see if it's a multiple
 202                          * of it to know if we have to send a zero packet.
 203                          * Sadly that involves a modulo which is a bit expensive
 204                          * but probably still better than not doing it.
 205                          */
 206                         if (!chunk || !req->req.zero || (chunk % ep->ep.maxpacket) != 0)
 207                                 req->last_desc = d_num;
 208                 } else {
 209                         chunk = ep->epn.chunk_max;
 210                 }
 211
 212                 EPVDBG(ep, " chunk: act=%d/%d chunk=%d last=%d desc=%d free=%d\n",
 213                        act, len, chunk, req->last_desc, d_num,
 214                        ast_vhub_count_free_descs(ep));
 215
 216                 /* Populate descriptor */
 217                 desc->w0 = cpu_to_le32(req->req.dma + act);
 218
 219                 /* Interrupt if end of request or no more descriptors */
 220
 221                 /*
 222                  * TODO: Be smarter about it, if we don't have enough
 223                  * descriptors request an interrupt before queue empty
 224                  * or so in order to be able to populate more before
 225                  * the HW runs out. This isn't a problem at the moment
 226                  * as we use 256 descriptors and only put at most one
 227                  * request in the ring.
 228                  */
 229                 desc->w1 = cpu_to_le32(VHUB_DSC1_IN_SET_LEN(chunk));
 230                 if (req->last_desc >= 0 || !ast_vhub_count_free_descs(ep))
 231                         desc->w1 |= cpu_to_le32(VHUB_DSC1_IN_INTERRUPT);
 232
 233                 /* Account packet */
 234                 req->act_count = act = act + chunk;
 235         }
 236
 237         if (likely(desc))
 238                 vhub_dma_workaround(desc);
 239
 240         /* Tell HW about new descriptors */
 241         writel(VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next),
 242                ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 243
 244         EPVDBG(ep, "HW kicked, d_next=%d dstat=%08x\n",
 245                ep->epn.d_next, readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS));
 246 }
 247
 248 static void ast_vhub_epn_handle_ack_desc(struct ast_vhub_ep *ep)
 249 {
 250         struct ast_vhub_req *req;
 251         unsigned int len, d_last;
 252         u32 stat, stat1;
 253
 254         /* Read EP status, workaround HW race */
 255         do {
 256                 stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 257                 stat1 = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 258         } while(stat != stat1);
 259
 260         /* Extract RPTR */
 261         d_last = VHUB_EP_DMA_RPTR(stat);
 262
 263         /* Grab current request if any */
 264         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
 265
 266         EPVDBG(ep, "ACK status=%08x is_in=%d ep->d_last=%d..%d\n",
 267                stat, ep->epn.is_in, ep->epn.d_last, d_last);
 268
 269         /* Check all completed descriptors */
 270         while (ep->epn.d_last != d_last) {
 271                 struct ast_vhub_desc *desc;
 272                 unsigned int d_num;
 273                 bool is_last_desc;
 274
 275                 /* Grab next completed descriptor */
 276                 d_num = ep->epn.d_last;
 277                 desc = &ep->epn.descs[d_num];
 278                 ep->epn.d_last = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
 279
 280                 /* Grab len out of descriptor */
 281                 len = VHUB_DSC1_IN_LEN(le32_to_cpu(desc->w1));
 282
 283                 EPVDBG(ep, " desc %d len=%d req=%p (act=%d)\n",
 284                        d_num, len, req, req ? req->active : 0);
 285
 286                 /* If no active request pending, move on */
 287                 if (!req || !req->active)
 288                         continue;
 289
 290                 /* Adjust size */
 291                 req->req.actual += len;
 292
 293                 /* Is that the last chunk ? */
 294                 is_last_desc = req->last_desc == d_num;
 295                 CHECK(ep, is_last_desc == (len < ep->ep.maxpacket ||
 296                                            (req->req.actual >= req->req.length &&
 297                                             !req->req.zero)),
 298                       "Last packet discrepancy: last_desc=%d len=%d r.act=%d "
 299                       "r.len=%d r.zero=%d mp=%d\n",
 300                       is_last_desc, len, req->req.actual, req->req.length,
 301                       req->req.zero, ep->ep.maxpacket);
 302
 303                 if (is_last_desc) {
 304                         /*
 305                          * Because we can only have one request at a time
 306                          * in our descriptor list in this implementation,
 307                          * d_last and ep->d_last should now be equal
 308                          */
 309                         CHECK(ep, d_last == ep->epn.d_last,
 310                               "DMA read ptr mismatch %d vs %d\n",
 311                               d_last, ep->epn.d_last);
 312
 313                         /* Note: done will drop and re-acquire the lock */
 314                         ast_vhub_done(ep, req, 0);
 315                         req = list_first_entry_or_null(&ep->queue,
 316                                                        struct ast_vhub_req,
 317                                                        queue);
 318                         break;
 319                 }
 320         }
 321
 322         /* More work ? */
 323         if (req)
 324                 ast_vhub_epn_kick_desc(ep, req);
 325 }
 326
 327 void ast_vhub_epn_ack_irq(struct ast_vhub_ep *ep)
 328 {
 329         if (ep->epn.desc_mode)
 330                 ast_vhub_epn_handle_ack_desc(ep);
 331         else
 332                 ast_vhub_epn_handle_ack(ep);
 333 }
 334
 335 static int ast_vhub_epn_queue(struct usb_ep* u_ep, struct usb_request *u_req,
 336                               gfp_t gfp_flags)
 337 {
 338         struct ast_vhub_req *req = to_ast_req(u_req);
 339         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 340         struct ast_vhub *vhub = ep->vhub;
 341         unsigned long flags;
 342         bool empty;
 343         int rc;
 344
 345         /* Paranoid checks */
 346         if (!u_req || !u_req->complete || !u_req->buf) {
 347                 dev_warn(&vhub->pdev->dev, "Bogus EPn request ! u_req=%p\n", u_req);
 348                 if (u_req) {
 349                         dev_warn(&vhub->pdev->dev, "complete=%p internal=%d\n",
 350                                  u_req->complete, req->internal);
 351                 }
 352                 return -EINVAL;
 353         }
 354
 355         /* Endpoint enabled ? */
 356         if (!ep->epn.enabled || !u_ep->desc || !ep->dev || !ep->d_idx ||
 357             !ep->dev->enabled) {
 358                 EPDBG(ep, "Enqueuing request on wrong or disabled EP\n");
 359                 return -ESHUTDOWN;
 360         }
 361
 362         /* Map request for DMA if possible. For now, the rule for DMA is
 363          * that:
 364          *
 365          *  * For single stage mode (no descriptors):
 366          *
 367          *   - The buffer is aligned to a 8 bytes boundary (HW requirement)
 368          *   - For a OUT endpoint, the request size is a multiple of the EP
 369          *     packet size (otherwise the controller will DMA past the end
 370          *     of the buffer if the host is sending a too long packet).
 371          *
 372          *  * For descriptor mode (tx only for now), always.
 373          *
 374          * We could relax the latter by making the decision to use the bounce
 375          * buffer based on the size of a given *segment* of the request rather
 376          * than the whole request.
 377          */
 378         if (ep->epn.desc_mode ||
 379             ((((unsigned long)u_req->buf & 7) == 0) &&
 380              (ep->epn.is_in || !(u_req->length & (u_ep->maxpacket - 1))))) {
 381                 rc = usb_gadget_map_request_by_dev(&vhub->pdev->dev, u_req,
 382                                             ep->epn.is_in);
 383                 if (rc) {
 384                         dev_warn(&vhub->pdev->dev,
 385                                  "Request mapping failure %d\n", rc);
 386                         return rc;
 387                 }
 388         } else
 389                 u_req->dma = 0;
 390
 391         EPVDBG(ep, "enqueue req @%p\n", req);
 392         EPVDBG(ep, " l=%d dma=0x%x zero=%d noshort=%d noirq=%d is_in=%d\n",
 393                u_req->length, (u32)u_req->dma, u_req->zero,
 394                u_req->short_not_ok, u_req->no_interrupt,
 395                ep->epn.is_in);
 396
 397         /* Initialize request progress fields */
 398         u_req->status = -EINPROGRESS;
 399         u_req->actual = 0;
 400         req->act_count = 0;
 401         req->active = false;
 402         req->last_desc = -1;
 403         spin_lock_irqsave(&vhub->lock, flags);
 404         empty = list_empty(&ep->queue);
 405
 406         /* Add request to list and kick processing if empty */
 407         list_add_tail(&req->queue, &ep->queue);
 408         if (empty) {
 409                 if (ep->epn.desc_mode)
 410                         ast_vhub_epn_kick_desc(ep, req);
 411                 else
 412                         ast_vhub_epn_kick(ep, req);
 413         }
 414         spin_unlock_irqrestore(&vhub->lock, flags);
 415
 416         return 0;
 417 }
 418
 419 static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,
 420                                      bool restart_ep)
 421 {
 422         u32 state, reg, loops;
 423
 424         /* Stop DMA activity */
 425         if (ep->epn.desc_mode)
 426                 writel(VHUB_EP_DMA_CTRL_RESET, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 427         else
 428                 writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 429
 430         /* Wait for it to complete */
 431         for (loops = 0; loops < 1000; loops++) {
 432                 state = readl(ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 433                 state = VHUB_EP_DMA_PROC_STATUS(state);
 434                 if (state == EP_DMA_PROC_RX_IDLE ||
 435                     state == EP_DMA_PROC_TX_IDLE)
 436                         break;
 437                 udelay(1);
 438         }
 439         if (loops >= 1000)
 440                 dev_warn(&ep->vhub->pdev->dev, "Timeout waiting for DMA\n");
 441
 442         /* If we don't have to restart the endpoint, that's it */
 443         if (!restart_ep)
 444                 return;
 445
 446         /* Restart the endpoint */
 447         if (ep->epn.desc_mode) {
 448                 /*
 449                  * Take out descriptors by resetting the DMA read
 450                  * pointer to be equal to the CPU write pointer.
 451                  *
 452                  * Note: If we ever support creating descriptors for
 453                  * requests that aren't the head of the queue, we
 454                  * may have to do something more complex here,
 455                  * especially if the request being taken out is
 456                  * not the current head descriptors.
 457                  */
 458                 reg = VHUB_EP_DMA_SET_RPTR(ep->epn.d_next) |
 459                         VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next);
 460                 writel(reg, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 461
 462                 /* Then turn it back on */
 463                 writel(ep->epn.dma_conf,
 464                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 465         } else {
 466                 /* Single mode: just turn it back on */
 467                 writel(ep->epn.dma_conf,
 468                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 469         }
 470 }
 471
 472 static int ast_vhub_epn_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
 473 {
 474         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 475         struct ast_vhub *vhub = ep->vhub;
 476         struct ast_vhub_req *req = NULL, *iter;
 477         unsigned long flags;
 478         int rc = -EINVAL;
 479
 480         spin_lock_irqsave(&vhub->lock, flags);
 481
 482         /* Make sure it's actually queued on this endpoint */
 483         list_for_each_entry(iter, &ep->queue, queue) {
 484                 if (&iter->req != u_req)
 485                         continue;
 486                 req = iter;
 487                 break;
 488         }
 489
 490         if (req) {
 491                 EPVDBG(ep, "dequeue req @%p active=%d\n",
 492                        req, req->active);
 493                 if (req->active)
 494                         ast_vhub_stop_active_req(ep, true);
 495                 ast_vhub_done(ep, req, -ECONNRESET);
 496                 rc = 0;
 497         }
 498
 499         spin_unlock_irqrestore(&vhub->lock, flags);
 500         return rc;
 501 }
 502
 503 void ast_vhub_update_epn_stall(struct ast_vhub_ep *ep)
 504 {
 505         u32 reg;
 506
 507         if (WARN_ON(ep->d_idx == 0))
 508                 return;
 509         reg = readl(ep->epn.regs + AST_VHUB_EP_CONFIG);
 510         if (ep->epn.stalled || ep->epn.wedged)
 511                 reg |= VHUB_EP_CFG_STALL_CTRL;
 512         else
 513                 reg &= ~VHUB_EP_CFG_STALL_CTRL;
 514         writel(reg, ep->epn.regs + AST_VHUB_EP_CONFIG);
 515
 516         if (!ep->epn.stalled && !ep->epn.wedged)
 517                 writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
 518                        ep->vhub->regs + AST_VHUB_EP_TOGGLE);
 519 }
 520
 521 static int ast_vhub_set_halt_and_wedge(struct usb_ep* u_ep, bool halt,
 522                                       bool wedge)
 523 {
 524         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 525         struct ast_vhub *vhub = ep->vhub;
 526         unsigned long flags;
 527
 528         EPDBG(ep, "Set halt (%d) & wedge (%d)\n", halt, wedge);
 529
 530         if (!u_ep || !u_ep->desc)
 531                 return -EINVAL;
 532         if (ep->d_idx == 0)
 533                 return 0;
 534         if (ep->epn.is_iso)
 535                 return -EOPNOTSUPP;
 536
 537         spin_lock_irqsave(&vhub->lock, flags);
 538
 539         /* Fail with still-busy IN endpoints */
 540         if (halt && ep->epn.is_in && !list_empty(&ep->queue)) {
 541                 spin_unlock_irqrestore(&vhub->lock, flags);
 542                 return -EAGAIN;
 543         }
 544         ep->epn.stalled = halt;
 545         ep->epn.wedged = wedge;
 546         ast_vhub_update_epn_stall(ep);
 547
 548         spin_unlock_irqrestore(&vhub->lock, flags);
 549
 550         return 0;
 551 }
 552
 553 static int ast_vhub_epn_set_halt(struct usb_ep *u_ep, int value)
 554 {
 555         return ast_vhub_set_halt_and_wedge(u_ep, value != 0, false);
 556 }
 557
 558 static int ast_vhub_epn_set_wedge(struct usb_ep *u_ep)
 559 {
 560         return ast_vhub_set_halt_and_wedge(u_ep, true, true);
 561 }
 562
 563 static int ast_vhub_epn_disable(struct usb_ep* u_ep)
 564 {
 565         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 566         struct ast_vhub *vhub = ep->vhub;
 567         unsigned long flags;
 568         u32 imask, ep_ier;
 569
 570         EPDBG(ep, "Disabling !\n");
 571
 572         spin_lock_irqsave(&vhub->lock, flags);
 573
 574         ep->epn.enabled = false;
 575
 576         /* Stop active DMA if any */
 577         ast_vhub_stop_active_req(ep, false);
 578
 579         /* Disable endpoint */
 580         writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
 581
 582         /* Disable ACK interrupt */
 583         imask = VHUB_EP_IRQ(ep->epn.g_idx);
 584         ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
 585         ep_ier &= ~imask;
 586         writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
 587         writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 588
 589         /* Nuke all pending requests */
 590         ast_vhub_nuke(ep, -ESHUTDOWN);
 591
 592         /* No more descriptor associated with request */
 593         ep->ep.desc = NULL;
 594
 595         spin_unlock_irqrestore(&vhub->lock, flags);
 596
 597         return 0;
 598 }
 599
 600 static int ast_vhub_epn_enable(struct usb_ep* u_ep,
 601                                const struct usb_endpoint_descriptor *desc)
 602 {
 603         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 604         struct ast_vhub_dev *dev;
 605         struct ast_vhub *vhub;
 606         u16 maxpacket, type;
 607         unsigned long flags;
 608         u32 ep_conf, ep_ier, imask;
 609
 610         /* Check arguments */
 611         if (!u_ep || !desc)
 612                 return -EINVAL;
 613
 614         maxpacket = usb_endpoint_maxp(desc);
 615         if (!ep->d_idx || !ep->dev ||
 616             desc->bDescriptorType != USB_DT_ENDPOINT ||
 617             maxpacket == 0 || maxpacket > ep->ep.maxpacket) {
 618                 EPDBG(ep, "Invalid EP enable,d_idx=%d,dev=%p,type=%d,mp=%d/%d\n",
 619                       ep->d_idx, ep->dev, desc->bDescriptorType,
 620                       maxpacket, ep->ep.maxpacket);
 621                 return -EINVAL;
 622         }
 623         if (ep->d_idx != usb_endpoint_num(desc)) {
 624                 EPDBG(ep, "EP number mismatch !\n");
 625                 return -EINVAL;
 626         }
 627
 628         if (ep->epn.enabled) {
 629                 EPDBG(ep, "Already enabled\n");
 630                 return -EBUSY;
 631         }
 632         dev = ep->dev;
 633         vhub = ep->vhub;
 634
 635         /* Check device state */
 636         if (!dev->driver) {
 637                 EPDBG(ep, "Bogus device state: driver=%p speed=%d\n",
 638                        dev->driver, dev->gadget.speed);
 639                 return -ESHUTDOWN;
 640         }
 641
 642         /* Grab some info from the descriptor */
 643         ep->epn.is_in = usb_endpoint_dir_in(desc);
 644         ep->ep.maxpacket = maxpacket;
 645         type = usb_endpoint_type(desc);
 646         ep->epn.d_next = ep->epn.d_last = 0;
 647         ep->epn.is_iso = false;
 648         ep->epn.stalled = false;
 649         ep->epn.wedged = false;
 650
 651         EPDBG(ep, "Enabling [%s] %s num %d maxpacket=%d\n",
 652               ep->epn.is_in ? "in" : "out", usb_ep_type_string(type),
 653               usb_endpoint_num(desc), maxpacket);
 654
 655         /* Can we use DMA descriptor mode ? */
 656         ep->epn.desc_mode = ep->epn.descs && ep->epn.is_in;
 657         if (ep->epn.desc_mode)
 658                 memset(ep->epn.descs, 0, 8 * AST_VHUB_DESCS_COUNT);
 659
 660         /*
 661          * Large send function can send up to 8 packets from
 662          * one descriptor with a limit of 4095 bytes.
 663          */
 664         ep->epn.chunk_max = ep->ep.maxpacket;
 665         if (ep->epn.is_in) {
 666                 ep->epn.chunk_max <<= 3;
 667                 while (ep->epn.chunk_max > 4095)
 668                         ep->epn.chunk_max -= ep->ep.maxpacket;
 669         }
 670
 671         switch(type) {
 672         case USB_ENDPOINT_XFER_CONTROL:
 673                 EPDBG(ep, "Only one control endpoint\n");
 674                 return -EINVAL;
 675         case USB_ENDPOINT_XFER_INT:
 676                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_INT);
 677                 break;
 678         case USB_ENDPOINT_XFER_BULK:
 679                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_BULK);
 680                 break;
 681         case USB_ENDPOINT_XFER_ISOC:
 682                 ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_ISO);
 683                 ep->epn.is_iso = true;
 684                 break;
 685         default:
 686                 return -EINVAL;
 687         }
 688
 689         /* Encode the rest of the EP config register */
 690         if (maxpacket < 1024)
 691                 ep_conf |= VHUB_EP_CFG_SET_MAX_PKT(maxpacket);
 692         if (!ep->epn.is_in)
 693                 ep_conf |= VHUB_EP_CFG_DIR_OUT;
 694         ep_conf |= VHUB_EP_CFG_SET_EP_NUM(usb_endpoint_num(desc));
 695         ep_conf |= VHUB_EP_CFG_ENABLE;
 696         ep_conf |= VHUB_EP_CFG_SET_DEV(dev->index + 1);
 697         EPVDBG(ep, "config=%08x\n", ep_conf);
 698
 699         spin_lock_irqsave(&vhub->lock, flags);
 700
 701         /* Disable HW and reset DMA */
 702         writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
 703         writel(VHUB_EP_DMA_CTRL_RESET,
 704                ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 705
 706         /* Configure and enable */
 707         writel(ep_conf, ep->epn.regs + AST_VHUB_EP_CONFIG);
 708
 709         if (ep->epn.desc_mode) {
 710                 /* Clear DMA status, including the DMA read ptr */
 711                 writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 712
 713                 /* Set descriptor base */
 714                 writel(ep->epn.descs_dma,
 715                        ep->epn.regs + AST_VHUB_EP_DESC_BASE);
 716
 717                 /* Set base DMA config value */
 718                 ep->epn.dma_conf = VHUB_EP_DMA_DESC_MODE;
 719                 if (ep->epn.is_in)
 720                         ep->epn.dma_conf |= VHUB_EP_DMA_IN_LONG_MODE;
 721
 722                 /* First reset and disable all operations */
 723                 writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
 724                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 725
 726                 /* Enable descriptor mode */
 727                 writel(ep->epn.dma_conf,
 728                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 729         } else {
 730                 /* Set base DMA config value */
 731                 ep->epn.dma_conf = VHUB_EP_DMA_SINGLE_STAGE;
 732
 733                 /* Reset and switch to single stage mode */
 734                 writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
 735                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 736                 writel(ep->epn.dma_conf,
 737                        ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 738                 writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
 739         }
 740
 741         /* Cleanup data toggle just in case */
 742         writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
 743                vhub->regs + AST_VHUB_EP_TOGGLE);
 744
 745         /* Cleanup and enable ACK interrupt */
 746         imask = VHUB_EP_IRQ(ep->epn.g_idx);
 747         writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 748         ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
 749         ep_ier |= imask;
 750         writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
 751
 752         /* Woot, we are online ! */
 753         ep->epn.enabled = true;
 754
 755         spin_unlock_irqrestore(&vhub->lock, flags);
 756
 757         return 0;
 758 }
 759
 760 static void ast_vhub_epn_dispose(struct usb_ep *u_ep)
 761 {
 762         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 763
 764         if (WARN_ON(!ep->dev || !ep->d_idx))
 765                 return;
 766
 767         EPDBG(ep, "Releasing endpoint\n");
 768
 769         /* Take it out of the EP list */
 770         list_del_init(&ep->ep.ep_list);
 771
 772         /* Mark the address free in the device */
 773         ep->dev->epns[ep->d_idx - 1] = NULL;
 774
 775         /* Free name & DMA buffers */
 776         kfree(ep->ep.name);
 777         ep->ep.name = NULL;
 778         dma_free_coherent(&ep->vhub->pdev->dev,
 779                           AST_VHUB_EPn_MAX_PACKET +
 780                           8 * AST_VHUB_DESCS_COUNT,
 781                           ep->buf, ep->buf_dma);
 782         ep->buf = NULL;
 783         ep->epn.descs = NULL;
 784
 785         /* Mark free */
 786         ep->dev = NULL;
 787 }
 788
 789 static const struct usb_ep_ops ast_vhub_epn_ops = {
 790         .enable         = ast_vhub_epn_enable,
 791         .disable        = ast_vhub_epn_disable,
 792         .dispose        = ast_vhub_epn_dispose,
 793         .queue          = ast_vhub_epn_queue,
 794         .dequeue        = ast_vhub_epn_dequeue,
 795         .set_halt       = ast_vhub_epn_set_halt,
 796         .set_wedge      = ast_vhub_epn_set_wedge,
 797         .alloc_request  = ast_vhub_alloc_request,
 798         .free_request   = ast_vhub_free_request,
 799 };
 800
 801 struct ast_vhub_ep *ast_vhub_alloc_epn(struct ast_vhub_dev *d, u8 addr)
 802 {
 803         struct ast_vhub *vhub = d->vhub;
 804         struct ast_vhub_ep *ep;
 805         unsigned long flags;
 806         int i;
 807
 808         /* Find a free one (no device) */
 809         spin_lock_irqsave(&vhub->lock, flags);
 810         for (i = 0; i < vhub->max_epns; i++)
 811                 if (vhub->epns[i].dev == NULL)
 812                         break;
 813         if (i >= vhub->max_epns) {
 814                 spin_unlock_irqrestore(&vhub->lock, flags);
 815                 return NULL;
 816         }
 817
 818         /* Set it up */
 819         ep = &vhub->epns[i];
 820         ep->dev = d;
 821         spin_unlock_irqrestore(&vhub->lock, flags);
 822
 823         DDBG(d, "Allocating gen EP %d for addr %d\n", i, addr);
 824         INIT_LIST_HEAD(&ep->queue);
 825         ep->d_idx = addr;
 826         ep->vhub = vhub;
 827         ep->ep.ops = &ast_vhub_epn_ops;
 828         ep->ep.name = kasprintf(GFP_KERNEL, "ep%d", addr);
 829         d->epns[addr-1] = ep;
 830         ep->epn.g_idx = i;
 831         ep->epn.regs = vhub->regs + 0x200 + (i * 0x10);
 832
 833         ep->buf = dma_alloc_coherent(&vhub->pdev->dev,
 834                                      AST_VHUB_EPn_MAX_PACKET +
 835                                      8 * AST_VHUB_DESCS_COUNT,
 836                                      &ep->buf_dma, GFP_KERNEL);
 837         if (!ep->buf) {
 838                 kfree(ep->ep.name);
 839                 ep->ep.name = NULL;
 840                 return NULL;
 841         }
 842         ep->epn.descs = ep->buf + AST_VHUB_EPn_MAX_PACKET;
 843         ep->epn.descs_dma = ep->buf_dma + AST_VHUB_EPn_MAX_PACKET;
 844
 845         usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EPn_MAX_PACKET);
 846         list_add_tail(&ep->ep.ep_list, &d->gadget.ep_list);
 847         ep->ep.caps.type_iso = true;
 848         ep->ep.caps.type_bulk = true;
 849         ep->ep.caps.type_int = true;
 850         ep->ep.caps.dir_in = true;
 851         ep->ep.caps.dir_out = true;
 852
 853         return ep;
 854 }