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