drivers/usb/gadget/udc/aspeed-vhub/ep0.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
   4  *
   5  * ep0.c - Endpoint 0 handling
   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 int ast_vhub_reply(struct ast_vhub_ep *ep, char *ptr, int len)
  36 {
  37         struct usb_request *req = &ep->ep0.req.req;
  38         int rc;
  39
  40         if (WARN_ON(ep->d_idx != 0))
  41                 return std_req_stall;
  42         if (WARN_ON(!ep->ep0.dir_in))
  43                 return std_req_stall;
  44         if (WARN_ON(len > AST_VHUB_EP0_MAX_PACKET))
  45                 return std_req_stall;
  46         if (WARN_ON(req->status == -EINPROGRESS))
  47                 return std_req_stall;
  48
  49         req->buf = ptr;
  50         req->length = len;
  51         req->complete = NULL;
  52         req->zero = true;
  53
  54         /*
  55          * Call internal queue directly after dropping the lock. This is
  56          * safe to do as the reply is always the last thing done when
  57          * processing a SETUP packet, usually as a tail call
  58          */
  59         spin_unlock(&ep->vhub->lock);
  60         if (ep->ep.ops->queue(&ep->ep, req, GFP_ATOMIC))
  61                 rc = std_req_stall;
  62         else
  63                 rc = std_req_data;
  64         spin_lock(&ep->vhub->lock);
  65         return rc;
  66 }
  67
  68 int __ast_vhub_simple_reply(struct ast_vhub_ep *ep, int len, ...)
  69 {
  70         u8 *buffer = ep->buf;
  71         unsigned int i;
  72         va_list args;
  73
  74         va_start(args, len);
  75
  76         /* Copy data directly into EP buffer */
  77         for (i = 0; i < len; i++)
  78                 buffer[i] = va_arg(args, int);
  79         va_end(args);
  80
  81         /* req->buf NULL means data is already there */
  82         return ast_vhub_reply(ep, NULL, len);
  83 }
  84
  85 void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep)
  86 {
  87         struct usb_ctrlrequest crq;
  88         enum std_req_rc std_req_rc;
  89         int rc = -ENODEV;
  90
  91         if (WARN_ON(ep->d_idx != 0))
  92                 return;
  93
  94         /*
  95          * Grab the setup packet from the chip and byteswap
  96          * interesting fields
  97          */
  98         memcpy_fromio(&crq, ep->ep0.setup, sizeof(crq));
  99
 100         EPDBG(ep, "SETUP packet %02x/%02x/%04x/%04x/%04x [%s] st=%d\n",
 101               crq.bRequestType, crq.bRequest,
 102                le16_to_cpu(crq.wValue),
 103                le16_to_cpu(crq.wIndex),
 104                le16_to_cpu(crq.wLength),
 105                (crq.bRequestType & USB_DIR_IN) ? "in" : "out",
 106                ep->ep0.state);
 107
 108         /* Check our state, cancel pending requests if needed */
 109         if (ep->ep0.state != ep0_state_token) {
 110                 EPDBG(ep, "wrong state\n");
 111                 ast_vhub_nuke(ep, -EIO);
 112
 113                 /*
 114                  * Accept the packet regardless, this seems to happen
 115                  * when stalling a SETUP packet that has an OUT data
 116                  * phase.
 117                  */
 118                 ast_vhub_nuke(ep, 0);
 119                 goto stall;
 120         }
 121
 122         /* Calculate next state for EP0 */
 123         ep->ep0.state = ep0_state_data;
 124         ep->ep0.dir_in = !!(crq.bRequestType & USB_DIR_IN);
 125
 126         /* If this is the vHub, we handle requests differently */
 127         std_req_rc = std_req_driver;
 128         if (ep->dev == NULL) {
 129                 if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
 130                         std_req_rc = ast_vhub_std_hub_request(ep, &crq);
 131                 else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
 132                         std_req_rc = ast_vhub_class_hub_request(ep, &crq);
 133                 else
 134                         std_req_rc = std_req_stall;
 135         } else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
 136                 std_req_rc = ast_vhub_std_dev_request(ep, &crq);
 137
 138         /* Act upon result */
 139         switch(std_req_rc) {
 140         case std_req_complete:
 141                 goto complete;
 142         case std_req_stall:
 143                 goto stall;
 144         case std_req_driver:
 145                 break;
 146         case std_req_data:
 147                 return;
 148         }
 149
 150         /* Pass request up to the gadget driver */
 151         if (WARN_ON(!ep->dev))
 152                 goto stall;
 153         if (ep->dev->driver) {
 154                 EPDBG(ep, "forwarding to gadget...\n");
 155                 spin_unlock(&ep->vhub->lock);
 156                 rc = ep->dev->driver->setup(&ep->dev->gadget, &crq);
 157                 spin_lock(&ep->vhub->lock);
 158                 EPDBG(ep, "driver returned %d\n", rc);
 159         } else {
 160                 EPDBG(ep, "no gadget for request !\n");
 161         }
 162         if (rc >= 0)
 163                 return;
 164
 165  stall:
 166         EPDBG(ep, "stalling\n");
 167         writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
 168         ep->ep0.state = ep0_state_status;
 169         ep->ep0.dir_in = false;
 170         return;
 171
 172  complete:
 173         EPVDBG(ep, "sending [in] status with no data\n");
 174         writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
 175         ep->ep0.state = ep0_state_status;
 176         ep->ep0.dir_in = false;
 177 }
 178
 179
 180 static void ast_vhub_ep0_do_send(struct ast_vhub_ep *ep,
 181                                  struct ast_vhub_req *req)
 182 {
 183         unsigned int chunk;
 184         u32 reg;
 185
 186         /* If this is a 0-length request, it's the gadget trying to
 187          * send a status on our behalf. We take it from here.
 188          */
 189         if (req->req.length == 0)
 190                 req->last_desc = 1;
 191
 192         /* Are we done ? Complete request, otherwise wait for next interrupt */
 193         if (req->last_desc >= 0) {
 194                 EPVDBG(ep, "complete send %d/%d\n",
 195                        req->req.actual, req->req.length);
 196                 ep->ep0.state = ep0_state_status;
 197                 writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
 198                 ast_vhub_done(ep, req, 0);
 199                 return;
 200         }
 201
 202         /*
 203          * Next chunk cropped to max packet size. Also check if this
 204          * is the last packet
 205          */
 206         chunk = req->req.length - req->req.actual;
 207         if (chunk > ep->ep.maxpacket)
 208                 chunk = ep->ep.maxpacket;
 209         else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
 210                 req->last_desc = 1;
 211
 212         EPVDBG(ep, "send chunk=%d last=%d, req->act=%d mp=%d\n",
 213                chunk, req->last_desc, req->req.actual, ep->ep.maxpacket);
 214
 215         /*
 216          * Copy data if any (internal requests already have data
 217          * in the EP buffer)
 218          */
 219         if (chunk && req->req.buf)
 220                 memcpy(ep->buf, req->req.buf + req->req.actual, chunk);
 221
 222         vhub_dma_workaround(ep->buf);
 223
 224         /* Remember chunk size and trigger send */
 225         reg = VHUB_EP0_SET_TX_LEN(chunk);
 226         writel(reg, ep->ep0.ctlstat);
 227         writel(reg | VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
 228         req->req.actual += chunk;
 229 }
 230
 231 static void ast_vhub_ep0_rx_prime(struct ast_vhub_ep *ep)
 232 {
 233         EPVDBG(ep, "rx prime\n");
 234
 235         /* Prime endpoint for receiving data */
 236         writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
 237 }
 238
 239 static void ast_vhub_ep0_do_receive(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
 240                                     unsigned int len)
 241 {
 242         unsigned int remain;
 243         int rc = 0;
 244
 245         /* We are receiving... grab request */
 246         remain = req->req.length - req->req.actual;
 247
 248         EPVDBG(ep, "receive got=%d remain=%d\n", len, remain);
 249
 250         /* Are we getting more than asked ? */
 251         if (len > remain) {
 252                 EPDBG(ep, "receiving too much (ovf: %d) !\n",
 253                       len - remain);
 254                 len = remain;
 255                 rc = -EOVERFLOW;
 256         }
 257         if (len && req->req.buf)
 258                 memcpy(req->req.buf + req->req.actual, ep->buf, len);
 259         req->req.actual += len;
 260
 261         /* Done ? */
 262         if (len < ep->ep.maxpacket || len == remain) {
 263                 ep->ep0.state = ep0_state_status;
 264                 writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
 265                 ast_vhub_done(ep, req, rc);
 266         } else
 267                 ast_vhub_ep0_rx_prime(ep);
 268 }
 269
 270 void ast_vhub_ep0_handle_ack(struct ast_vhub_ep *ep, bool in_ack)
 271 {
 272         struct ast_vhub_req *req;
 273         struct ast_vhub *vhub = ep->vhub;
 274         struct device *dev = &vhub->pdev->dev;
 275         bool stall = false;
 276         u32 stat;
 277
 278         /* Read EP0 status */
 279         stat = readl(ep->ep0.ctlstat);
 280
 281         /* Grab current request if any */
 282         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
 283
 284         EPVDBG(ep, "ACK status=%08x,state=%d is_in=%d in_ack=%d req=%p\n",
 285                 stat, ep->ep0.state, ep->ep0.dir_in, in_ack, req);
 286
 287         switch(ep->ep0.state) {
 288         case ep0_state_token:
 289                 /* There should be no request queued in that state... */
 290                 if (req) {
 291                         dev_warn(dev, "request present while in TOKEN state\n");
 292                         ast_vhub_nuke(ep, -EINVAL);
 293                 }
 294                 dev_warn(dev, "ack while in TOKEN state\n");
 295                 stall = true;
 296                 break;
 297         case ep0_state_data:
 298                 /* Check the state bits corresponding to our direction */
 299                 if ((ep->ep0.dir_in && (stat & VHUB_EP0_TX_BUFF_RDY)) ||
 300                     (!ep->ep0.dir_in && (stat & VHUB_EP0_RX_BUFF_RDY)) ||
 301                     (ep->ep0.dir_in != in_ack)) {
 302                         dev_warn(dev, "irq state mismatch");
 303                         stall = true;
 304                         break;
 305                 }
 306                 /*
 307                  * We are in data phase and there's no request, something is
 308                  * wrong, stall
 309                  */
 310                 if (!req) {
 311                         dev_warn(dev, "data phase, no request\n");
 312                         stall = true;
 313                         break;
 314                 }
 315
 316                 /* We have a request, handle data transfers */
 317                 if (ep->ep0.dir_in)
 318                         ast_vhub_ep0_do_send(ep, req);
 319                 else
 320                         ast_vhub_ep0_do_receive(ep, req, VHUB_EP0_RX_LEN(stat));
 321                 return;
 322         case ep0_state_status:
 323                 /* Nuke stale requests */
 324                 if (req) {
 325                         dev_warn(dev, "request present while in STATUS state\n");
 326                         ast_vhub_nuke(ep, -EINVAL);
 327                 }
 328
 329                 /*
 330                  * If the status phase completes with the wrong ack, stall
 331                  * the endpoint just in case, to abort whatever the host
 332                  * was doing.
 333                  */
 334                 if (ep->ep0.dir_in == in_ack) {
 335                         dev_warn(dev, "status direction mismatch\n");
 336                         stall = true;
 337                 }
 338         }
 339
 340         /* Reset to token state */
 341         ep->ep0.state = ep0_state_token;
 342         if (stall)
 343                 writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
 344 }
 345
 346 static int ast_vhub_ep0_queue(struct usb_ep* u_ep, struct usb_request *u_req,
 347                               gfp_t gfp_flags)
 348 {
 349         struct ast_vhub_req *req = to_ast_req(u_req);
 350         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 351         struct ast_vhub *vhub = ep->vhub;
 352         struct device *dev = &vhub->pdev->dev;
 353         unsigned long flags;
 354
 355         /* Paranoid cheks */
 356         if (!u_req || (!u_req->complete && !req->internal)) {
 357                 dev_warn(dev, "Bogus EP0 request ! u_req=%p\n", u_req);
 358                 if (u_req) {
 359                         dev_warn(dev, "complete=%p internal=%d\n",
 360                                  u_req->complete, req->internal);
 361                 }
 362                 return -EINVAL;
 363         }
 364
 365         /* Not endpoint 0 ? */
 366         if (WARN_ON(ep->d_idx != 0))
 367                 return -EINVAL;
 368
 369         /* Disabled device */
 370         if (ep->dev && (!ep->dev->enabled || ep->dev->suspended))
 371                 return -ESHUTDOWN;
 372
 373         /* Data, no buffer and not internal ? */
 374         if (u_req->length && !u_req->buf && !req->internal) {
 375                 dev_warn(dev, "Request with no buffer !\n");
 376                 return -EINVAL;
 377         }
 378
 379         EPVDBG(ep, "enqueue req @%p\n", req);
 380         EPVDBG(ep, "  l=%d zero=%d noshort=%d is_in=%d\n",
 381                u_req->length, u_req->zero,
 382                u_req->short_not_ok, ep->ep0.dir_in);
 383
 384         /* Initialize request progress fields */
 385         u_req->status = -EINPROGRESS;
 386         u_req->actual = 0;
 387         req->last_desc = -1;
 388         req->active = false;
 389
 390         spin_lock_irqsave(&vhub->lock, flags);
 391
 392         /* EP0 can only support a single request at a time */
 393         if (!list_empty(&ep->queue) || ep->ep0.state == ep0_state_token) {
 394                 dev_warn(dev, "EP0: Request in wrong state\n");
 395                 spin_unlock_irqrestore(&vhub->lock, flags);
 396                 return -EBUSY;
 397         }
 398
 399         /* Add request to list and kick processing if empty */
 400         list_add_tail(&req->queue, &ep->queue);
 401
 402         if (ep->ep0.dir_in) {
 403                 /* IN request, send data */
 404                 ast_vhub_ep0_do_send(ep, req);
 405         } else if (u_req->length == 0) {
 406                 /* 0-len request, send completion as rx */
 407                 EPVDBG(ep, "0-length rx completion\n");
 408                 ep->ep0.state = ep0_state_status;
 409                 writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
 410                 ast_vhub_done(ep, req, 0);
 411         } else {
 412                 /* OUT request, start receiver */
 413                 ast_vhub_ep0_rx_prime(ep);
 414         }
 415
 416         spin_unlock_irqrestore(&vhub->lock, flags);
 417
 418         return 0;
 419 }
 420
 421 static int ast_vhub_ep0_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
 422 {
 423         struct ast_vhub_ep *ep = to_ast_ep(u_ep);
 424         struct ast_vhub *vhub = ep->vhub;
 425         struct ast_vhub_req *req;
 426         unsigned long flags;
 427         int rc = -EINVAL;
 428
 429         spin_lock_irqsave(&vhub->lock, flags);
 430
 431         /* Only one request can be in the queue */
 432         req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
 433
 434         /* Is it ours ? */
 435         if (req && u_req == &req->req) {
 436                 EPVDBG(ep, "dequeue req @%p\n", req);
 437
 438                 /*
 439                  * We don't have to deal with "active" as all
 440                  * DMAs go to the EP buffers, not the request.
 441                  */
 442                 ast_vhub_done(ep, req, -ECONNRESET);
 443
 444                 /* We do stall the EP to clean things up in HW */
 445                 writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
 446                 ep->ep0.state = ep0_state_status;
 447                 ep->ep0.dir_in = false;
 448                 rc = 0;
 449         }
 450         spin_unlock_irqrestore(&vhub->lock, flags);
 451         return rc;
 452 }
 453
 454
 455 static const struct usb_ep_ops ast_vhub_ep0_ops = {
 456         .queue          = ast_vhub_ep0_queue,
 457         .dequeue        = ast_vhub_ep0_dequeue,
 458         .alloc_request  = ast_vhub_alloc_request,
 459         .free_request   = ast_vhub_free_request,
 460 };
 461
 462 void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
 463                        struct ast_vhub_dev *dev)
 464 {
 465         memset(ep, 0, sizeof(*ep));
 466
 467         INIT_LIST_HEAD(&ep->ep.ep_list);
 468         INIT_LIST_HEAD(&ep->queue);
 469         ep->ep.ops = &ast_vhub_ep0_ops;
 470         ep->ep.name = "ep0";
 471         ep->ep.caps.type_control = true;
 472         usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EP0_MAX_PACKET);
 473         ep->d_idx = 0;
 474         ep->dev = dev;
 475         ep->vhub = vhub;
 476         ep->ep0.state = ep0_state_token;
 477         INIT_LIST_HEAD(&ep->ep0.req.queue);
 478         ep->ep0.req.internal = true;
 479
 480         /* Small difference between vHub and devices */
 481         if (dev) {
 482                 ep->ep0.ctlstat = dev->regs + AST_VHUB_DEV_EP0_CTRL;
 483                 ep->ep0.setup = vhub->regs +
 484                         AST_VHUB_SETUP0 + 8 * (dev->index + 1);
 485                 ep->buf = vhub->ep0_bufs +
 486                         AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
 487                 ep->buf_dma = vhub->ep0_bufs_dma +
 488                         AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
 489         } else {
 490                 ep->ep0.ctlstat = vhub->regs + AST_VHUB_EP0_CTRL;
 491                 ep->ep0.setup = vhub->regs + AST_VHUB_SETUP0;
 492                 ep->buf = vhub->ep0_bufs;
 493                 ep->buf_dma = vhub->ep0_bufs_dma;
 494         }
 495 }