drivers/usb/early/ehci-dbgp.c

   1 /*
   2  * Standalone EHCI usb debug driver
   3  *
   4  * Originally written by:
   5  *  Eric W. Biederman" <ebiederm@xmission.com> and
   6  *  Yinghai Lu <yhlu.kernel@gmail.com>
   7  *
   8  * Changes for early/late printk and HW errata:
   9  *  Jason Wessel <jason.wessel@windriver.com>
  10  *  Copyright (C) 2009 Wind River Systems, Inc.
  11  *
  12  */
  13
  14 #include <linux/console.h>
  15 #include <linux/errno.h>
  16 #include <linux/init.h>
  17 #include <linux/pci_regs.h>
  18 #include <linux/pci_ids.h>
  19 #include <linux/usb/ch9.h>
  20 #include <linux/usb/ehci_def.h>
  21 #include <linux/delay.h>
  22 #include <linux/serial_core.h>
  23 #include <linux/kconfig.h>
  24 #include <linux/kgdb.h>
  25 #include <linux/kthread.h>
  26 #include <asm/io.h>
  27 #include <asm/pci-direct.h>
  28 #include <asm/fixmap.h>
  29
  30 /* The code here is intended to talk directly to the EHCI debug port
  31  * and does not require that you have any kind of USB host controller
  32  * drivers or USB device drivers compiled into the kernel.
  33  *
  34  * If you make a change to anything in here, the following test cases
  35  * need to pass where a USB debug device works in the following
  36  * configurations.
  37  *
  38  * 1. boot args:  earlyprintk=dbgp
  39  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  40  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  41  * 2. boot args: earlyprintk=dbgp,keep
  42  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  43  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  44  * 3. boot args: earlyprintk=dbgp console=ttyUSB0
  45  *     o kernel has CONFIG_USB_EHCI_HCD=y and
  46  *       CONFIG_USB_SERIAL_DEBUG=y
  47  * 4. boot args: earlyprintk=vga,dbgp
  48  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  49  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  50  *
  51  * For the 4th configuration you can turn on or off the DBGP_DEBUG
  52  * such that you can debug the dbgp device's driver code.
  53  */
  54
  55 static int dbgp_phys_port = 1;
  56
  57 static struct ehci_caps __iomem *ehci_caps;
  58 static struct ehci_regs __iomem *ehci_regs;
  59 static struct ehci_dbg_port __iomem *ehci_debug;
  60 static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
  61 static unsigned int dbgp_endpoint_out;
  62 static unsigned int dbgp_endpoint_in;
  63
  64 struct ehci_dev {
  65         u32 bus;
  66         u32 slot;
  67         u32 func;
  68 };
  69
  70 static struct ehci_dev ehci_dev;
  71
  72 #define USB_DEBUG_DEVNUM 127
  73
  74 #ifdef DBGP_DEBUG
  75 #define dbgp_printk printk
  76 static void dbgp_ehci_status(char *str)
  77 {
  78         if (!ehci_debug)
  79                 return;
  80         dbgp_printk("dbgp: %s\n", str);
  81         dbgp_printk("  Debug control: %08x", readl(&ehci_debug->control));
  82         dbgp_printk("  ehci cmd     : %08x", readl(&ehci_regs->command));
  83         dbgp_printk("  ehci conf flg: %08x\n",
  84                     readl(&ehci_regs->configured_flag));
  85         dbgp_printk("  ehci status  : %08x", readl(&ehci_regs->status));
  86         dbgp_printk("  ehci portsc  : %08x\n",
  87                     readl(&ehci_regs->port_status[dbgp_phys_port - 1]));
  88 }
  89 #else
  90 static inline void dbgp_ehci_status(char *str) { }
  91 static inline void dbgp_printk(const char *fmt, ...) { }
  92 #endif
  93
  94 static inline u32 dbgp_len_update(u32 x, u32 len)
  95 {
  96         return (x & ~0x0f) | (len & 0x0f);
  97 }
  98
  99 #ifdef CONFIG_KGDB
 100 static struct kgdb_io kgdbdbgp_io_ops;
 101 #define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops)
 102 #else
 103 #define dbgp_kgdb_mode (0)
 104 #endif
 105
 106 /* Local version of HC_LENGTH macro as ehci struct is not available here */
 107 #define EARLY_HC_LENGTH(p)      (0x00ff & (p)) /* bits 7 : 0 */
 108
 109 /*
 110  * USB Packet IDs (PIDs)
 111  */
 112
 113 /* token */
 114 #define USB_PID_OUT             0xe1
 115 #define USB_PID_IN              0x69
 116 #define USB_PID_SOF             0xa5
 117 #define USB_PID_SETUP           0x2d
 118 /* handshake */
 119 #define USB_PID_ACK             0xd2
 120 #define USB_PID_NAK             0x5a
 121 #define USB_PID_STALL           0x1e
 122 #define USB_PID_NYET            0x96
 123 /* data */
 124 #define USB_PID_DATA0           0xc3
 125 #define USB_PID_DATA1           0x4b
 126 #define USB_PID_DATA2           0x87
 127 #define USB_PID_MDATA           0x0f
 128 /* Special */
 129 #define USB_PID_PREAMBLE        0x3c
 130 #define USB_PID_ERR             0x3c
 131 #define USB_PID_SPLIT           0x78
 132 #define USB_PID_PING            0xb4
 133 #define USB_PID_UNDEF_0         0xf0
 134
 135 #define USB_PID_DATA_TOGGLE     0x88
 136 #define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
 137
 138 #define PCI_CAP_ID_EHCI_DEBUG   0xa
 139
 140 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
 141 #define HUB_SHORT_RESET_TIME    10
 142 #define HUB_LONG_RESET_TIME     200
 143 #define HUB_RESET_TIMEOUT       500
 144
 145 #define DBGP_MAX_PACKET         8
 146 #define DBGP_TIMEOUT            (250 * 1000)
 147 #define DBGP_LOOPS              1000
 148
 149 static inline u32 dbgp_pid_write_update(u32 x, u32 tok)
 150 {
 151         static int data0 = USB_PID_DATA1;
 152         data0 ^= USB_PID_DATA_TOGGLE;
 153         return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff);
 154 }
 155
 156 static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
 157 {
 158         return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
 159 }
 160
 161 static int dbgp_wait_until_complete(void)
 162 {
 163         u32 ctrl;
 164         int loop = DBGP_TIMEOUT;
 165
 166         do {
 167                 ctrl = readl(&ehci_debug->control);
 168                 /* Stop when the transaction is finished */
 169                 if (ctrl & DBGP_DONE)
 170                         break;
 171                 udelay(1);
 172         } while (--loop > 0);
 173
 174         if (!loop)
 175                 return -DBGP_TIMEOUT;
 176
 177         /*
 178          * Now that we have observed the completed transaction,
 179          * clear the done bit.
 180          */
 181         writel(ctrl | DBGP_DONE, &ehci_debug->control);
 182         return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
 183 }
 184
 185 static inline void dbgp_mdelay(int ms)
 186 {
 187         int i;
 188
 189         while (ms--) {
 190                 for (i = 0; i < 1000; i++)
 191                         outb(0x1, 0x80);
 192         }
 193 }
 194
 195 static void dbgp_breath(void)
 196 {
 197         /* Sleep to give the debug port a chance to breathe */
 198 }
 199
 200 static int dbgp_wait_until_done(unsigned ctrl, int loop)
 201 {
 202         u32 pids, lpid;
 203         int ret;
 204
 205 retry:
 206         writel(ctrl | DBGP_GO, &ehci_debug->control);
 207         ret = dbgp_wait_until_complete();
 208         pids = readl(&ehci_debug->pids);
 209         lpid = DBGP_PID_GET(pids);
 210
 211         if (ret < 0) {
 212                 /* A -DBGP_TIMEOUT failure here means the device has
 213                  * failed, perhaps because it was unplugged, in which
 214                  * case we do not want to hang the system so the dbgp
 215                  * will be marked as unsafe to use.  EHCI reset is the
 216                  * only way to recover if you unplug the dbgp device.
 217                  */
 218                 if (ret == -DBGP_TIMEOUT && !dbgp_not_safe)
 219                         dbgp_not_safe = 1;
 220                 if (ret == -DBGP_ERR_BAD && --loop > 0)
 221                         goto retry;
 222                 return ret;
 223         }
 224
 225         /*
 226          * If the port is getting full or it has dropped data
 227          * start pacing ourselves, not necessary but it's friendly.
 228          */
 229         if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
 230                 dbgp_breath();
 231
 232         /* If I get a NACK reissue the transmission */
 233         if (lpid == USB_PID_NAK) {
 234                 if (--loop > 0)
 235                         goto retry;
 236         }
 237
 238         return ret;
 239 }
 240
 241 static inline void dbgp_set_data(const void *buf, int size)
 242 {
 243         const unsigned char *bytes = buf;
 244         u32 lo, hi;
 245         int i;
 246
 247         lo = hi = 0;
 248         for (i = 0; i < 4 && i < size; i++)
 249                 lo |= bytes[i] << (8*i);
 250         for (; i < 8 && i < size; i++)
 251                 hi |= bytes[i] << (8*(i - 4));
 252         writel(lo, &ehci_debug->data03);
 253         writel(hi, &ehci_debug->data47);
 254 }
 255
 256 static inline void dbgp_get_data(void *buf, int size)
 257 {
 258         unsigned char *bytes = buf;
 259         u32 lo, hi;
 260         int i;
 261
 262         lo = readl(&ehci_debug->data03);
 263         hi = readl(&ehci_debug->data47);
 264         for (i = 0; i < 4 && i < size; i++)
 265                 bytes[i] = (lo >> (8*i)) & 0xff;
 266         for (; i < 8 && i < size; i++)
 267                 bytes[i] = (hi >> (8*(i - 4))) & 0xff;
 268 }
 269
 270 static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
 271                          const char *bytes, int size)
 272 {
 273         int ret;
 274         u32 addr;
 275         u32 pids, ctrl;
 276
 277         if (size > DBGP_MAX_PACKET)
 278                 return -1;
 279
 280         addr = DBGP_EPADDR(devnum, endpoint);
 281
 282         pids = readl(&ehci_debug->pids);
 283         pids = dbgp_pid_write_update(pids, USB_PID_OUT);
 284
 285         ctrl = readl(&ehci_debug->control);
 286         ctrl = dbgp_len_update(ctrl, size);
 287         ctrl |= DBGP_OUT;
 288         ctrl |= DBGP_GO;
 289
 290         dbgp_set_data(bytes, size);
 291         writel(addr, &ehci_debug->address);
 292         writel(pids, &ehci_debug->pids);
 293         ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
 294
 295         return ret;
 296 }
 297
 298 static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
 299                           int size, int loops)
 300 {
 301         u32 pids, addr, ctrl;
 302         int ret;
 303
 304         if (size > DBGP_MAX_PACKET)
 305                 return -1;
 306
 307         addr = DBGP_EPADDR(devnum, endpoint);
 308
 309         pids = readl(&ehci_debug->pids);
 310         pids = dbgp_pid_read_update(pids, USB_PID_IN);
 311
 312         ctrl = readl(&ehci_debug->control);
 313         ctrl = dbgp_len_update(ctrl, size);
 314         ctrl &= ~DBGP_OUT;
 315         ctrl |= DBGP_GO;
 316
 317         writel(addr, &ehci_debug->address);
 318         writel(pids, &ehci_debug->pids);
 319         ret = dbgp_wait_until_done(ctrl, loops);
 320         if (ret < 0)
 321                 return ret;
 322
 323         if (size > ret)
 324                 size = ret;
 325         dbgp_get_data(data, size);
 326         return ret;
 327 }
 328
 329 static int dbgp_control_msg(unsigned devnum, int requesttype,
 330         int request, int value, int index, void *data, int size)
 331 {
 332         u32 pids, addr, ctrl;
 333         struct usb_ctrlrequest req;
 334         int read;
 335         int ret;
 336
 337         read = (requesttype & USB_DIR_IN) != 0;
 338         if (size > (read ? DBGP_MAX_PACKET : 0))
 339                 return -1;
 340
 341         /* Compute the control message */
 342         req.bRequestType = requesttype;
 343         req.bRequest = request;
 344         req.wValue = cpu_to_le16(value);
 345         req.wIndex = cpu_to_le16(index);
 346         req.wLength = cpu_to_le16(size);
 347
 348         pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
 349         addr = DBGP_EPADDR(devnum, 0);
 350
 351         ctrl = readl(&ehci_debug->control);
 352         ctrl = dbgp_len_update(ctrl, sizeof(req));
 353         ctrl |= DBGP_OUT;
 354         ctrl |= DBGP_GO;
 355
 356         /* Send the setup message */
 357         dbgp_set_data(&req, sizeof(req));
 358         writel(addr, &ehci_debug->address);
 359         writel(pids, &ehci_debug->pids);
 360         ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
 361         if (ret < 0)
 362                 return ret;
 363
 364         /* Read the result */
 365         return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS);
 366 }
 367
 368 /* Find a PCI capability */
 369 static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
 370 {
 371         u8 pos;
 372         int bytes;
 373
 374         if (!(read_pci_config_16(num, slot, func, PCI_STATUS) &
 375                 PCI_STATUS_CAP_LIST))
 376                 return 0;
 377
 378         pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST);
 379         for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
 380                 u8 id;
 381
 382                 pos &= ~3;
 383                 id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID);
 384                 if (id == 0xff)
 385                         break;
 386                 if (id == cap)
 387                         return pos;
 388
 389                 pos = read_pci_config_byte(num, slot, func,
 390                                                  pos+PCI_CAP_LIST_NEXT);
 391         }
 392         return 0;
 393 }
 394
 395 static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func)
 396 {
 397         u32 class;
 398
 399         class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
 400         if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
 401                 return 0;
 402
 403         return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
 404 }
 405
 406 static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc)
 407 {
 408         u32 bus, slot, func;
 409
 410         for (bus = 0; bus < 256; bus++) {
 411                 for (slot = 0; slot < 32; slot++) {
 412                         for (func = 0; func < 8; func++) {
 413                                 unsigned cap;
 414
 415                                 cap = __find_dbgp(bus, slot, func);
 416
 417                                 if (!cap)
 418                                         continue;
 419                                 if (ehci_num-- != 0)
 420                                         continue;
 421                                 *rbus = bus;
 422                                 *rslot = slot;
 423                                 *rfunc = func;
 424                                 return cap;
 425                         }
 426                 }
 427         }
 428         return 0;
 429 }
 430
 431 static int dbgp_ehci_startup(void)
 432 {
 433         u32 ctrl, cmd, status;
 434         int loop;
 435
 436         /* Claim ownership, but do not enable yet */
 437         ctrl = readl(&ehci_debug->control);
 438         ctrl |= DBGP_OWNER;
 439         ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
 440         writel(ctrl, &ehci_debug->control);
 441         udelay(1);
 442
 443         dbgp_ehci_status("EHCI startup");
 444         /* Start the ehci running */
 445         cmd = readl(&ehci_regs->command);
 446         cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
 447         cmd |= CMD_RUN;
 448         writel(cmd, &ehci_regs->command);
 449
 450         /* Ensure everything is routed to the EHCI */
 451         writel(FLAG_CF, &ehci_regs->configured_flag);
 452
 453         /* Wait until the controller is no longer halted */
 454         loop = 1000;
 455         do {
 456                 status = readl(&ehci_regs->status);
 457                 if (!(status & STS_HALT))
 458                         break;
 459                 udelay(1);
 460         } while (--loop > 0);
 461
 462         if (!loop) {
 463                 dbgp_printk("ehci can not be started\n");
 464                 return -ENODEV;
 465         }
 466         dbgp_printk("ehci started\n");
 467         return 0;
 468 }
 469
 470 static int dbgp_ehci_controller_reset(void)
 471 {
 472         int loop = 250 * 1000;
 473         u32 cmd;
 474
 475         /* Reset the EHCI controller */
 476         cmd = readl(&ehci_regs->command);
 477         cmd |= CMD_RESET;
 478         writel(cmd, &ehci_regs->command);
 479         do {
 480                 cmd = readl(&ehci_regs->command);
 481         } while ((cmd & CMD_RESET) && (--loop > 0));
 482
 483         if (!loop) {
 484                 dbgp_printk("can not reset ehci\n");
 485                 return -1;
 486         }
 487         dbgp_ehci_status("ehci reset done");
 488         return 0;
 489 }
 490 static int ehci_wait_for_port(int port);
 491 /* Return 0 on success
 492  * Return -ENODEV for any general failure
 493  * Return -EIO if wait for port fails
 494  */
 495 static int _dbgp_external_startup(void)
 496 {
 497         int devnum;
 498         struct usb_debug_descriptor dbgp_desc;
 499         int ret;
 500         u32 ctrl, portsc, cmd;
 501         int dbg_port = dbgp_phys_port;
 502         int tries = 3;
 503         int reset_port_tries = 1;
 504         int try_hard_once = 1;
 505
 506 try_port_reset_again:
 507         ret = dbgp_ehci_startup();
 508         if (ret)
 509                 return ret;
 510
 511         /* Wait for a device to show up in the debug port */
 512         ret = ehci_wait_for_port(dbg_port);
 513         if (ret < 0) {
 514                 portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 515                 if (!(portsc & PORT_CONNECT) && try_hard_once) {
 516                         /* Last ditch effort to try to force enable
 517                          * the debug device by using the packet test
 518                          * ehci command to try and wake it up. */
 519                         try_hard_once = 0;
 520                         cmd = readl(&ehci_regs->command);
 521                         cmd &= ~CMD_RUN;
 522                         writel(cmd, &ehci_regs->command);
 523                         portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 524                         portsc |= PORT_TEST_PKT;
 525                         writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
 526                         dbgp_ehci_status("Trying to force debug port online");
 527                         mdelay(50);
 528                         dbgp_ehci_controller_reset();
 529                         goto try_port_reset_again;
 530                 } else if (reset_port_tries--) {
 531                         goto try_port_reset_again;
 532                 }
 533                 dbgp_printk("No device found in debug port\n");
 534                 return -EIO;
 535         }
 536         dbgp_ehci_status("wait for port done");
 537
 538         /* Enable the debug port */
 539         ctrl = readl(&ehci_debug->control);
 540         ctrl |= DBGP_CLAIM;
 541         writel(ctrl, &ehci_debug->control);
 542         ctrl = readl(&ehci_debug->control);
 543         if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
 544                 dbgp_printk("No device in debug port\n");
 545                 writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
 546                 return -ENODEV;
 547         }
 548         dbgp_ehci_status("debug ported enabled");
 549
 550         /* Completely transfer the debug device to the debug controller */
 551         portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 552         portsc &= ~PORT_PE;
 553         writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
 554
 555         dbgp_mdelay(100);
 556
 557 try_again:
 558         /* Find the debug device and make it device number 127 */
 559         for (devnum = 0; devnum <= 127; devnum++) {
 560                 ret = dbgp_control_msg(devnum,
 561                         USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 562                         USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
 563                         &dbgp_desc, sizeof(dbgp_desc));
 564                 if (ret > 0)
 565                         break;
 566         }
 567         if (devnum > 127) {
 568                 dbgp_printk("Could not find attached debug device\n");
 569                 goto err;
 570         }
 571         dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
 572         dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint;
 573
 574         /* Move the device to 127 if it isn't already there */
 575         if (devnum != USB_DEBUG_DEVNUM) {
 576                 ret = dbgp_control_msg(devnum,
 577                         USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 578                         USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
 579                 if (ret < 0) {
 580                         dbgp_printk("Could not move attached device to %d\n",
 581                                 USB_DEBUG_DEVNUM);
 582                         goto err;
 583                 }
 584                 devnum = USB_DEBUG_DEVNUM;
 585                 dbgp_printk("debug device renamed to 127\n");
 586         }
 587
 588         /* Enable the debug interface */
 589         ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
 590                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 591                 USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
 592         if (ret < 0) {
 593                 dbgp_printk(" Could not enable the debug device\n");
 594                 goto err;
 595         }
 596         dbgp_printk("debug interface enabled\n");
 597         /* Perform a small write to get the even/odd data state in sync
 598          */
 599         ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
 600         if (ret < 0) {
 601                 dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
 602                 goto err;
 603         }
 604         dbgp_printk("small write done\n");
 605         dbgp_not_safe = 0;
 606
 607         return 0;
 608 err:
 609         if (tries--)
 610                 goto try_again;
 611         return -ENODEV;
 612 }
 613
 614 static int ehci_reset_port(int port)
 615 {
 616         u32 portsc;
 617         u32 delay_time, delay;
 618         int loop;
 619
 620         dbgp_ehci_status("reset port");
 621         /* Reset the usb debug port */
 622         portsc = readl(&ehci_regs->port_status[port - 1]);
 623         portsc &= ~PORT_PE;
 624         portsc |= PORT_RESET;
 625         writel(portsc, &ehci_regs->port_status[port - 1]);
 626
 627         delay = HUB_ROOT_RESET_TIME;
 628         for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
 629              delay_time += delay) {
 630                 dbgp_mdelay(delay);
 631                 portsc = readl(&ehci_regs->port_status[port - 1]);
 632                 if (!(portsc & PORT_RESET))
 633                         break;
 634         }
 635                 if (portsc & PORT_RESET) {
 636                         /* force reset to complete */
 637                         loop = 100 * 1000;
 638                         writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
 639                                 &ehci_regs->port_status[port - 1]);
 640                         do {
 641                                 udelay(1);
 642                                 portsc = readl(&ehci_regs->port_status[port-1]);
 643                         } while ((portsc & PORT_RESET) && (--loop > 0));
 644                 }
 645
 646                 /* Device went away? */
 647                 if (!(portsc & PORT_CONNECT))
 648                         return -ENOTCONN;
 649
 650                 /* bomb out completely if something weird happened */
 651                 if ((portsc & PORT_CSC))
 652                         return -EINVAL;
 653
 654                 /* If we've finished resetting, then break out of the loop */
 655                 if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
 656                         return 0;
 657         return -EBUSY;
 658 }
 659
 660 static int ehci_wait_for_port(int port)
 661 {
 662         u32 status;
 663         int ret, reps;
 664
 665         for (reps = 0; reps < 300; reps++) {
 666                 status = readl(&ehci_regs->status);
 667                 if (status & STS_PCD)
 668                         break;
 669                 dbgp_mdelay(1);
 670         }
 671         ret = ehci_reset_port(port);
 672         if (ret == 0)
 673                 return 0;
 674         return -ENOTCONN;
 675 }
 676
 677 typedef void (*set_debug_port_t)(int port);
 678
 679 static void __init default_set_debug_port(int port)
 680 {
 681 }
 682
 683 static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
 684
 685 static void __init nvidia_set_debug_port(int port)
 686 {
 687         u32 dword;
 688         dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 689                                  0x74);
 690         dword &= ~(0x0f<<12);
 691         dword |= ((port & 0x0f)<<12);
 692         write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
 693                                  dword);
 694         dbgp_printk("set debug port to %d\n", port);
 695 }
 696
 697 static void __init detect_set_debug_port(void)
 698 {
 699         u32 vendorid;
 700
 701         vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 702                  0x00);
 703
 704         if ((vendorid & 0xffff) == 0x10de) {
 705                 dbgp_printk("using nvidia set_debug_port\n");
 706                 set_debug_port = nvidia_set_debug_port;
 707         }
 708 }
 709
 710 /* The code in early_ehci_bios_handoff() is derived from the usb pci
 711  * quirk initialization, but altered so as to use the early PCI
 712  * routines. */
 713 #define EHCI_USBLEGSUP_BIOS     (1 << 16)       /* BIOS semaphore */
 714 #define EHCI_USBLEGCTLSTS       4               /* legacy control/status */
 715 static void __init early_ehci_bios_handoff(void)
 716 {
 717         u32 hcc_params = readl(&ehci_caps->hcc_params);
 718         int offset = (hcc_params >> 8) & 0xff;
 719         u32 cap;
 720         int msec;
 721
 722         if (!offset)
 723                 return;
 724
 725         cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
 726                               ehci_dev.func, offset);
 727         dbgp_printk("dbgp: ehci BIOS state %08x\n", cap);
 728
 729         if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) {
 730                 dbgp_printk("dbgp: BIOS handoff\n");
 731                 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
 732                                       ehci_dev.func, offset + 3, 1);
 733         }
 734
 735         /* if boot firmware now owns EHCI, spin till it hands it over. */
 736         msec = 1000;
 737         while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
 738                 mdelay(10);
 739                 msec -= 10;
 740                 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
 741                                       ehci_dev.func, offset);
 742         }
 743
 744         if (cap & EHCI_USBLEGSUP_BIOS) {
 745                 /* well, possibly buggy BIOS... try to shut it down,
 746                  * and hope nothing goes too wrong */
 747                 dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap);
 748                 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
 749                                       ehci_dev.func, offset + 2, 0);
 750         }
 751
 752         /* just in case, always disable EHCI SMIs */
 753         write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 754                               offset + EHCI_USBLEGCTLSTS, 0);
 755 }
 756
 757 static int __init ehci_setup(void)
 758 {
 759         u32 ctrl, portsc, hcs_params;
 760         u32 debug_port, new_debug_port = 0, n_ports;
 761         int ret, i;
 762         int port_map_tried;
 763         int playtimes = 3;
 764
 765         early_ehci_bios_handoff();
 766
 767 try_next_time:
 768         port_map_tried = 0;
 769
 770 try_next_port:
 771
 772         hcs_params = readl(&ehci_caps->hcs_params);
 773         debug_port = HCS_DEBUG_PORT(hcs_params);
 774         dbgp_phys_port = debug_port;
 775         n_ports    = HCS_N_PORTS(hcs_params);
 776
 777         dbgp_printk("debug_port: %d\n", debug_port);
 778         dbgp_printk("n_ports:    %d\n", n_ports);
 779         dbgp_ehci_status("");
 780
 781         for (i = 1; i <= n_ports; i++) {
 782                 portsc = readl(&ehci_regs->port_status[i-1]);
 783                 dbgp_printk("portstatus%d: %08x\n", i, portsc);
 784         }
 785
 786         if (port_map_tried && (new_debug_port != debug_port)) {
 787                 if (--playtimes) {
 788                         set_debug_port(new_debug_port);
 789                         goto try_next_time;
 790                 }
 791                 return -1;
 792         }
 793
 794         /* Only reset the controller if it is not already in the
 795          * configured state */
 796         if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) {
 797                 if (dbgp_ehci_controller_reset() != 0)
 798                         return -1;
 799         } else {
 800                 dbgp_ehci_status("ehci skip - already configured");
 801         }
 802
 803         ret = _dbgp_external_startup();
 804         if (ret == -EIO)
 805                 goto next_debug_port;
 806
 807         if (ret < 0) {
 808                 /* Things didn't work so remove my claim */
 809                 ctrl = readl(&ehci_debug->control);
 810                 ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
 811                 writel(ctrl, &ehci_debug->control);
 812                 return -1;
 813         }
 814         return 0;
 815
 816 next_debug_port:
 817         port_map_tried |= (1<<(debug_port - 1));
 818         new_debug_port = ((debug_port-1+1)%n_ports) + 1;
 819         if (port_map_tried != ((1<<n_ports) - 1)) {
 820                 set_debug_port(new_debug_port);
 821                 goto try_next_port;
 822         }
 823         if (--playtimes) {
 824                 set_debug_port(new_debug_port);
 825                 goto try_next_time;
 826         }
 827
 828         return -1;
 829 }
 830
 831 int __init early_dbgp_init(char *s)
 832 {
 833         u32 debug_port, bar, offset;
 834         u32 bus, slot, func, cap;
 835         void __iomem *ehci_bar;
 836         u32 dbgp_num;
 837         u32 bar_val;
 838         char *e;
 839         int ret;
 840         u8 byte;
 841
 842         if (!early_pci_allowed())
 843                 return -1;
 844
 845         dbgp_num = 0;
 846         if (*s)
 847                 dbgp_num = simple_strtoul(s, &e, 10);
 848         dbgp_printk("dbgp_num: %d\n", dbgp_num);
 849
 850         cap = find_dbgp(dbgp_num, &bus, &slot, &func);
 851         if (!cap)
 852                 return -1;
 853
 854         dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
 855                          func);
 856
 857         debug_port = read_pci_config(bus, slot, func, cap);
 858         bar = (debug_port >> 29) & 0x7;
 859         bar = (bar * 4) + 0xc;
 860         offset = (debug_port >> 16) & 0xfff;
 861         dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
 862         if (bar != PCI_BASE_ADDRESS_0) {
 863                 dbgp_printk("only debug ports on bar 1 handled.\n");
 864
 865                 return -1;
 866         }
 867
 868         bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
 869         dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
 870         if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
 871                 dbgp_printk("only simple 32bit mmio bars supported\n");
 872
 873                 return -1;
 874         }
 875
 876         /* double check if the mem space is enabled */
 877         byte = read_pci_config_byte(bus, slot, func, 0x04);
 878         if (!(byte & 0x2)) {
 879                 byte  |= 0x02;
 880                 write_pci_config_byte(bus, slot, func, 0x04, byte);
 881                 dbgp_printk("mmio for ehci enabled\n");
 882         }
 883
 884         /*
 885          * FIXME I don't have the bar size so just guess PAGE_SIZE is more
 886          * than enough.  1K is the biggest I have seen.
 887          */
 888         set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
 889         ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
 890         ehci_bar += bar_val & ~PAGE_MASK;
 891         dbgp_printk("ehci_bar: %p\n", ehci_bar);
 892
 893         ehci_caps  = ehci_bar;
 894         ehci_regs  = ehci_bar + EARLY_HC_LENGTH(readl(&ehci_caps->hc_capbase));
 895         ehci_debug = ehci_bar + offset;
 896         ehci_dev.bus = bus;
 897         ehci_dev.slot = slot;
 898         ehci_dev.func = func;
 899
 900         detect_set_debug_port();
 901
 902         ret = ehci_setup();
 903         if (ret < 0) {
 904                 dbgp_printk("ehci_setup failed\n");
 905                 ehci_debug = NULL;
 906
 907                 return -1;
 908         }
 909         dbgp_ehci_status("early_init_complete");
 910
 911         return 0;
 912 }
 913
 914 static void early_dbgp_write(struct console *con, const char *str, u32 n)
 915 {
 916         int chunk, ret;
 917         char buf[DBGP_MAX_PACKET];
 918         int use_cr = 0;
 919         u32 cmd, ctrl;
 920         int reset_run = 0;
 921
 922         if (!ehci_debug || dbgp_not_safe)
 923                 return;
 924
 925         cmd = readl(&ehci_regs->command);
 926         if (unlikely(!(cmd & CMD_RUN))) {
 927                 /* If the ehci controller is not in the run state do extended
 928                  * checks to see if the acpi or some other initialization also
 929                  * reset the ehci debug port */
 930                 ctrl = readl(&ehci_debug->control);
 931                 if (!(ctrl & DBGP_ENABLED)) {
 932                         dbgp_not_safe = 1;
 933                         _dbgp_external_startup();
 934                 } else {
 935                         cmd |= CMD_RUN;
 936                         writel(cmd, &ehci_regs->command);
 937                         reset_run = 1;
 938                 }
 939         }
 940         while (n > 0) {
 941                 for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0;
 942                      str++, chunk++, n--) {
 943                         if (!use_cr && *str == '\n') {
 944                                 use_cr = 1;
 945                                 buf[chunk] = '\r';
 946                                 str--;
 947                                 n++;
 948                                 continue;
 949                         }
 950                         if (use_cr)
 951                                 use_cr = 0;
 952                         buf[chunk] = *str;
 953                 }
 954                 if (chunk > 0) {
 955                         ret = dbgp_bulk_write(USB_DEBUG_DEVNUM,
 956                                       dbgp_endpoint_out, buf, chunk);
 957                 }
 958         }
 959         if (unlikely(reset_run)) {
 960                 cmd = readl(&ehci_regs->command);
 961                 cmd &= ~CMD_RUN;
 962                 writel(cmd, &ehci_regs->command);
 963         }
 964 }
 965
 966 struct console early_dbgp_console = {
 967         .name =         "earlydbg",
 968         .write =        early_dbgp_write,
 969         .flags =        CON_PRINTBUFFER,
 970         .index =        -1,
 971 };
 972
 973 #if IS_ENABLED(CONFIG_USB)
 974 int dbgp_reset_prep(struct usb_hcd *hcd)
 975 {
 976         int ret = xen_dbgp_reset_prep(hcd);
 977         u32 ctrl;
 978
 979         if (ret)
 980                 return ret;
 981
 982         dbgp_not_safe = 1;
 983         if (!ehci_debug)
 984                 return 0;
 985
 986         if ((early_dbgp_console.index != -1 &&
 987              !(early_dbgp_console.flags & CON_BOOT)) ||
 988             dbgp_kgdb_mode)
 989                 return 1;
 990         /* This means the console is not initialized, or should get
 991          * shutdown so as to allow for reuse of the usb device, which
 992          * means it is time to shutdown the usb debug port. */
 993         ctrl = readl(&ehci_debug->control);
 994         if (ctrl & DBGP_ENABLED) {
 995                 ctrl &= ~(DBGP_CLAIM);
 996                 writel(ctrl, &ehci_debug->control);
 997         }
 998         return 0;
 999 }
1000 EXPORT_SYMBOL_GPL(dbgp_reset_prep);
1001
1002 int dbgp_external_startup(struct usb_hcd *hcd)
1003 {
1004         return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup();
1005 }
1006 EXPORT_SYMBOL_GPL(dbgp_external_startup);
1007 #endif /* USB */
1008
1009 #ifdef CONFIG_KGDB
1010
1011 static char kgdbdbgp_buf[DBGP_MAX_PACKET];
1012 static int kgdbdbgp_buf_sz;
1013 static int kgdbdbgp_buf_idx;
1014 static int kgdbdbgp_loop_cnt = DBGP_LOOPS;
1015
1016 static int kgdbdbgp_read_char(void)
1017 {
1018         int ret;
1019
1020         if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) {
1021                 char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++];
1022                 return ch;
1023         }
1024
1025         ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in,
1026                              &kgdbdbgp_buf, DBGP_MAX_PACKET,
1027                              kgdbdbgp_loop_cnt);
1028         if (ret <= 0)
1029                 return NO_POLL_CHAR;
1030         kgdbdbgp_buf_sz = ret;
1031         kgdbdbgp_buf_idx = 1;
1032         return kgdbdbgp_buf[0];
1033 }
1034
1035 static void kgdbdbgp_write_char(u8 chr)
1036 {
1037         early_dbgp_write(NULL, &chr, 1);
1038 }
1039
1040 static struct kgdb_io kgdbdbgp_io_ops = {
1041         .name = "kgdbdbgp",
1042         .read_char = kgdbdbgp_read_char,
1043         .write_char = kgdbdbgp_write_char,
1044 };
1045
1046 static int kgdbdbgp_wait_time;
1047
1048 static int __init kgdbdbgp_parse_config(char *str)
1049 {
1050         char *ptr;
1051
1052         if (!ehci_debug) {
1053                 if (early_dbgp_init(str))
1054                         return -1;
1055         }
1056         ptr = strchr(str, ',');
1057         if (ptr) {
1058                 ptr++;
1059                 kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10);
1060         }
1061         kgdb_register_io_module(&kgdbdbgp_io_ops);
1062         kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1;
1063
1064         return 0;
1065 }
1066 early_param("kgdbdbgp", kgdbdbgp_parse_config);
1067
1068 static int kgdbdbgp_reader_thread(void *ptr)
1069 {
1070         int ret;
1071
1072         while (readl(&ehci_debug->control) & DBGP_ENABLED) {
1073                 kgdbdbgp_loop_cnt = 1;
1074                 ret = kgdbdbgp_read_char();
1075                 kgdbdbgp_loop_cnt = DBGP_LOOPS;
1076                 if (ret != NO_POLL_CHAR) {
1077                         if (ret == 0x3 || ret == '$') {
1078                                 if (ret == '$')
1079                                         kgdbdbgp_buf_idx--;
1080                                 kgdb_breakpoint();
1081                         }
1082                         continue;
1083                 }
1084                 schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ);
1085         }
1086         return 0;
1087 }
1088
1089 static int __init kgdbdbgp_start_thread(void)
1090 {
1091         if (dbgp_kgdb_mode && kgdbdbgp_wait_time)
1092                 kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp");
1093
1094         return 0;
1095 }
1096 device_initcall(kgdbdbgp_start_thread);
1097 #endif /* CONFIG_KGDB */