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/module.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 <asm/io.h>
  23 #include <asm/pci-direct.h>
  24 #include <asm/fixmap.h>
  25
  26 /* The code here is intended to talk directly to the EHCI debug port
  27  * and does not require that you have any kind of USB host controller
  28  * drivers or USB device drivers compiled into the kernel.
  29  *
  30  * If you make a change to anything in here, the following test cases
  31  * need to pass where a USB debug device works in the following
  32  * configurations.
  33  *
  34  * 1. boot args:  earlyprintk=dbgp
  35  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  36  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  37  * 2. boot args: earlyprintk=dbgp,keep
  38  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  39  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  40  * 3. boot args: earlyprintk=dbgp console=ttyUSB0
  41  *     o kernel has CONFIG_USB_EHCI_HCD=y and
  42  *       CONFIG_USB_SERIAL_DEBUG=y
  43  * 4. boot args: earlyprintk=vga,dbgp
  44  *     o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
  45  *     o kernel compiled with CONFIG_USB_EHCI_HCD=y
  46  *
  47  * For the 4th configuration you can turn on or off the DBGP_DEBUG
  48  * such that you can debug the dbgp device's driver code.
  49  */
  50
  51 static int dbgp_phys_port = 1;
  52
  53 static struct ehci_caps __iomem *ehci_caps;
  54 static struct ehci_regs __iomem *ehci_regs;
  55 static struct ehci_dbg_port __iomem *ehci_debug;
  56 static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
  57 static unsigned int dbgp_endpoint_out;
  58
  59 struct ehci_dev {
  60         u32 bus;
  61         u32 slot;
  62         u32 func;
  63 };
  64
  65 static struct ehci_dev ehci_dev;
  66
  67 #define USB_DEBUG_DEVNUM 127
  68
  69 #define DBGP_DATA_TOGGLE        0x8800
  70
  71 #ifdef DBGP_DEBUG
  72 #define dbgp_printk printk
  73 static void dbgp_ehci_status(char *str)
  74 {
  75         if (!ehci_debug)
  76                 return;
  77         dbgp_printk("dbgp: %s\n", str);
  78         dbgp_printk("  Debug control: %08x", readl(&ehci_debug->control));
  79         dbgp_printk("  ehci cmd     : %08x", readl(&ehci_regs->command));
  80         dbgp_printk("  ehci conf flg: %08x\n",
  81                     readl(&ehci_regs->configured_flag));
  82         dbgp_printk("  ehci status  : %08x", readl(&ehci_regs->status));
  83         dbgp_printk("  ehci portsc  : %08x\n",
  84                     readl(&ehci_regs->port_status[dbgp_phys_port - 1]));
  85 }
  86 #else
  87 static inline void dbgp_ehci_status(char *str) { }
  88 static inline void dbgp_printk(const char *fmt, ...) { }
  89 #endif
  90
  91 static inline u32 dbgp_pid_update(u32 x, u32 tok)
  92 {
  93         return ((x ^ DBGP_DATA_TOGGLE) & 0xffff00) | (tok & 0xff);
  94 }
  95
  96 static inline u32 dbgp_len_update(u32 x, u32 len)
  97 {
  98         return (x & ~0x0f) | (len & 0x0f);
  99 }
 100
 101 /*
 102  * USB Packet IDs (PIDs)
 103  */
 104
 105 /* token */
 106 #define USB_PID_OUT             0xe1
 107 #define USB_PID_IN              0x69
 108 #define USB_PID_SOF             0xa5
 109 #define USB_PID_SETUP           0x2d
 110 /* handshake */
 111 #define USB_PID_ACK             0xd2
 112 #define USB_PID_NAK             0x5a
 113 #define USB_PID_STALL           0x1e
 114 #define USB_PID_NYET            0x96
 115 /* data */
 116 #define USB_PID_DATA0           0xc3
 117 #define USB_PID_DATA1           0x4b
 118 #define USB_PID_DATA2           0x87
 119 #define USB_PID_MDATA           0x0f
 120 /* Special */
 121 #define USB_PID_PREAMBLE        0x3c
 122 #define USB_PID_ERR             0x3c
 123 #define USB_PID_SPLIT           0x78
 124 #define USB_PID_PING            0xb4
 125 #define USB_PID_UNDEF_0         0xf0
 126
 127 #define USB_PID_DATA_TOGGLE     0x88
 128 #define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
 129
 130 #define PCI_CAP_ID_EHCI_DEBUG   0xa
 131
 132 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
 133 #define HUB_SHORT_RESET_TIME    10
 134 #define HUB_LONG_RESET_TIME     200
 135 #define HUB_RESET_TIMEOUT       500
 136
 137 #define DBGP_MAX_PACKET         8
 138 #define DBGP_TIMEOUT            (250 * 1000)
 139
 140 static int dbgp_wait_until_complete(void)
 141 {
 142         u32 ctrl;
 143         int loop = DBGP_TIMEOUT;
 144
 145         do {
 146                 ctrl = readl(&ehci_debug->control);
 147                 /* Stop when the transaction is finished */
 148                 if (ctrl & DBGP_DONE)
 149                         break;
 150                 udelay(1);
 151         } while (--loop > 0);
 152
 153         if (!loop)
 154                 return -DBGP_TIMEOUT;
 155
 156         /*
 157          * Now that we have observed the completed transaction,
 158          * clear the done bit.
 159          */
 160         writel(ctrl | DBGP_DONE, &ehci_debug->control);
 161         return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
 162 }
 163
 164 static inline void dbgp_mdelay(int ms)
 165 {
 166         int i;
 167
 168         while (ms--) {
 169                 for (i = 0; i < 1000; i++)
 170                         outb(0x1, 0x80);
 171         }
 172 }
 173
 174 static void dbgp_breath(void)
 175 {
 176         /* Sleep to give the debug port a chance to breathe */
 177 }
 178
 179 static int dbgp_wait_until_done(unsigned ctrl)
 180 {
 181         u32 pids, lpid;
 182         int ret;
 183         int loop = 3;
 184
 185 retry:
 186         writel(ctrl | DBGP_GO, &ehci_debug->control);
 187         ret = dbgp_wait_until_complete();
 188         pids = readl(&ehci_debug->pids);
 189         lpid = DBGP_PID_GET(pids);
 190
 191         if (ret < 0) {
 192                 /* A -DBGP_TIMEOUT failure here means the device has
 193                  * failed, perhaps because it was unplugged, in which
 194                  * case we do not want to hang the system so the dbgp
 195                  * will be marked as unsafe to use.  EHCI reset is the
 196                  * only way to recover if you unplug the dbgp device.
 197                  */
 198                 if (ret == -DBGP_TIMEOUT && !dbgp_not_safe)
 199                         dbgp_not_safe = 1;
 200                 return ret;
 201         }
 202
 203         /*
 204          * If the port is getting full or it has dropped data
 205          * start pacing ourselves, not necessary but it's friendly.
 206          */
 207         if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
 208                 dbgp_breath();
 209
 210         /* If I get a NACK reissue the transmission */
 211         if (lpid == USB_PID_NAK) {
 212                 if (--loop > 0)
 213                         goto retry;
 214         }
 215
 216         return ret;
 217 }
 218
 219 static inline void dbgp_set_data(const void *buf, int size)
 220 {
 221         const unsigned char *bytes = buf;
 222         u32 lo, hi;
 223         int i;
 224
 225         lo = hi = 0;
 226         for (i = 0; i < 4 && i < size; i++)
 227                 lo |= bytes[i] << (8*i);
 228         for (; i < 8 && i < size; i++)
 229                 hi |= bytes[i] << (8*(i - 4));
 230         writel(lo, &ehci_debug->data03);
 231         writel(hi, &ehci_debug->data47);
 232 }
 233
 234 static inline void dbgp_get_data(void *buf, int size)
 235 {
 236         unsigned char *bytes = buf;
 237         u32 lo, hi;
 238         int i;
 239
 240         lo = readl(&ehci_debug->data03);
 241         hi = readl(&ehci_debug->data47);
 242         for (i = 0; i < 4 && i < size; i++)
 243                 bytes[i] = (lo >> (8*i)) & 0xff;
 244         for (; i < 8 && i < size; i++)
 245                 bytes[i] = (hi >> (8*(i - 4))) & 0xff;
 246 }
 247
 248 static int dbgp_out(u32 addr, const char *bytes, int size)
 249 {
 250         u32 pids, ctrl;
 251
 252         pids = readl(&ehci_debug->pids);
 253         pids = dbgp_pid_update(pids, USB_PID_OUT);
 254
 255         ctrl = readl(&ehci_debug->control);
 256         ctrl = dbgp_len_update(ctrl, size);
 257         ctrl |= DBGP_OUT;
 258         ctrl |= DBGP_GO;
 259
 260         dbgp_set_data(bytes, size);
 261         writel(addr, &ehci_debug->address);
 262         writel(pids, &ehci_debug->pids);
 263         return dbgp_wait_until_done(ctrl);
 264 }
 265
 266 static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
 267                          const char *bytes, int size)
 268 {
 269         int ret;
 270         int loops = 5;
 271         u32 addr;
 272         if (size > DBGP_MAX_PACKET)
 273                 return -1;
 274
 275         addr = DBGP_EPADDR(devnum, endpoint);
 276 try_again:
 277         if (loops--) {
 278                 ret = dbgp_out(addr, bytes, size);
 279                 if (ret == -DBGP_ERR_BAD) {
 280                         int try_loops = 3;
 281                         do {
 282                                 /* Emit a dummy packet to re-sync communication
 283                                  * with the debug device */
 284                                 if (dbgp_out(addr, "12345678", 8) >= 0) {
 285                                         udelay(2);
 286                                         goto try_again;
 287                                 }
 288                         } while (try_loops--);
 289                 }
 290         }
 291
 292         return ret;
 293 }
 294
 295 static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
 296                                  int size)
 297 {
 298         u32 pids, addr, ctrl;
 299         int ret;
 300
 301         if (size > DBGP_MAX_PACKET)
 302                 return -1;
 303
 304         addr = DBGP_EPADDR(devnum, endpoint);
 305
 306         pids = readl(&ehci_debug->pids);
 307         pids = dbgp_pid_update(pids, USB_PID_IN);
 308
 309         ctrl = readl(&ehci_debug->control);
 310         ctrl = dbgp_len_update(ctrl, size);
 311         ctrl &= ~DBGP_OUT;
 312         ctrl |= DBGP_GO;
 313
 314         writel(addr, &ehci_debug->address);
 315         writel(pids, &ehci_debug->pids);
 316         ret = dbgp_wait_until_done(ctrl);
 317         if (ret < 0)
 318                 return ret;
 319
 320         if (size > ret)
 321                 size = ret;
 322         dbgp_get_data(data, size);
 323         return ret;
 324 }
 325
 326 static int dbgp_control_msg(unsigned devnum, int requesttype,
 327         int request, int value, int index, void *data, int size)
 328 {
 329         u32 pids, addr, ctrl;
 330         struct usb_ctrlrequest req;
 331         int read;
 332         int ret;
 333
 334         read = (requesttype & USB_DIR_IN) != 0;
 335         if (size > (read ? DBGP_MAX_PACKET:0))
 336                 return -1;
 337
 338         /* Compute the control message */
 339         req.bRequestType = requesttype;
 340         req.bRequest = request;
 341         req.wValue = cpu_to_le16(value);
 342         req.wIndex = cpu_to_le16(index);
 343         req.wLength = cpu_to_le16(size);
 344
 345         pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
 346         addr = DBGP_EPADDR(devnum, 0);
 347
 348         ctrl = readl(&ehci_debug->control);
 349         ctrl = dbgp_len_update(ctrl, sizeof(req));
 350         ctrl |= DBGP_OUT;
 351         ctrl |= DBGP_GO;
 352
 353         /* Send the setup message */
 354         dbgp_set_data(&req, sizeof(req));
 355         writel(addr, &ehci_debug->address);
 356         writel(pids, &ehci_debug->pids);
 357         ret = dbgp_wait_until_done(ctrl);
 358         if (ret < 0)
 359                 return ret;
 360
 361         /* Read the result */
 362         return dbgp_bulk_read(devnum, 0, data, size);
 363 }
 364
 365
 366 /* Find a PCI capability */
 367 static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
 368 {
 369         u8 pos;
 370         int bytes;
 371
 372         if (!(read_pci_config_16(num, slot, func, PCI_STATUS) &
 373                 PCI_STATUS_CAP_LIST))
 374                 return 0;
 375
 376         pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST);
 377         for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
 378                 u8 id;
 379
 380                 pos &= ~3;
 381                 id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID);
 382                 if (id == 0xff)
 383                         break;
 384                 if (id == cap)
 385                         return pos;
 386
 387                 pos = read_pci_config_byte(num, slot, func,
 388                                                  pos+PCI_CAP_LIST_NEXT);
 389         }
 390         return 0;
 391 }
 392
 393 static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func)
 394 {
 395         u32 class;
 396
 397         class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
 398         if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
 399                 return 0;
 400
 401         return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
 402 }
 403
 404 static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc)
 405 {
 406         u32 bus, slot, func;
 407
 408         for (bus = 0; bus < 256; bus++) {
 409                 for (slot = 0; slot < 32; slot++) {
 410                         for (func = 0; func < 8; func++) {
 411                                 unsigned cap;
 412
 413                                 cap = __find_dbgp(bus, slot, func);
 414
 415                                 if (!cap)
 416                                         continue;
 417                                 if (ehci_num-- != 0)
 418                                         continue;
 419                                 *rbus = bus;
 420                                 *rslot = slot;
 421                                 *rfunc = func;
 422                                 return cap;
 423                         }
 424                 }
 425         }
 426         return 0;
 427 }
 428
 429 static int dbgp_ehci_startup(void)
 430 {
 431         u32 ctrl, cmd, status;
 432         int loop;
 433
 434         /* Claim ownership, but do not enable yet */
 435         ctrl = readl(&ehci_debug->control);
 436         ctrl |= DBGP_OWNER;
 437         ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
 438         writel(ctrl, &ehci_debug->control);
 439         udelay(1);
 440
 441         dbgp_ehci_status("EHCI startup");
 442         /* Start the ehci running */
 443         cmd = readl(&ehci_regs->command);
 444         cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
 445         cmd |= CMD_RUN;
 446         writel(cmd, &ehci_regs->command);
 447
 448         /* Ensure everything is routed to the EHCI */
 449         writel(FLAG_CF, &ehci_regs->configured_flag);
 450
 451         /* Wait until the controller is no longer halted */
 452         loop = 10;
 453         do {
 454                 status = readl(&ehci_regs->status);
 455                 if (!(status & STS_HALT))
 456                         break;
 457                 udelay(1);
 458         } while (--loop > 0);
 459
 460         if (!loop) {
 461                 dbgp_printk("ehci can not be started\n");
 462                 return -ENODEV;
 463         }
 464         dbgp_printk("ehci started\n");
 465         return 0;
 466 }
 467
 468 static int dbgp_ehci_controller_reset(void)
 469 {
 470         int loop = 250 * 1000;
 471         u32 cmd;
 472
 473         /* Reset the EHCI controller */
 474         cmd = readl(&ehci_regs->command);
 475         cmd |= CMD_RESET;
 476         writel(cmd, &ehci_regs->command);
 477         do {
 478                 cmd = readl(&ehci_regs->command);
 479         } while ((cmd & CMD_RESET) && (--loop > 0));
 480
 481         if (!loop) {
 482                 dbgp_printk("can not reset ehci\n");
 483                 return -1;
 484         }
 485         dbgp_ehci_status("ehci reset done");
 486         return 0;
 487 }
 488 static int ehci_wait_for_port(int port);
 489 /* Return 0 on success
 490  * Return -ENODEV for any general failure
 491  * Return -EIO if wait for port fails
 492  */
 493 int dbgp_external_startup(void)
 494 {
 495         int devnum;
 496         struct usb_debug_descriptor dbgp_desc;
 497         int ret;
 498         u32 ctrl, portsc, cmd;
 499         int dbg_port = dbgp_phys_port;
 500         int tries = 3;
 501         int reset_port_tries = 1;
 502         int try_hard_once = 1;
 503
 504 try_port_reset_again:
 505         ret = dbgp_ehci_startup();
 506         if (ret)
 507                 return ret;
 508
 509         /* Wait for a device to show up in the debug port */
 510         ret = ehci_wait_for_port(dbg_port);
 511         if (ret < 0) {
 512                 portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 513                 if (!(portsc & PORT_CONNECT) && try_hard_once) {
 514                         /* Last ditch effort to try to force enable
 515                          * the debug device by using the packet test
 516                          * ehci command to try and wake it up. */
 517                         try_hard_once = 0;
 518                         cmd = readl(&ehci_regs->command);
 519                         cmd &= ~CMD_RUN;
 520                         writel(cmd, &ehci_regs->command);
 521                         portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 522                         portsc |= PORT_TEST_PKT;
 523                         writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
 524                         dbgp_ehci_status("Trying to force debug port online");
 525                         mdelay(50);
 526                         dbgp_ehci_controller_reset();
 527                         goto try_port_reset_again;
 528                 } else if (reset_port_tries--) {
 529                         goto try_port_reset_again;
 530                 }
 531                 dbgp_printk("No device found in debug port\n");
 532                 return -EIO;
 533         }
 534         dbgp_ehci_status("wait for port done");
 535
 536         /* Enable the debug port */
 537         ctrl = readl(&ehci_debug->control);
 538         ctrl |= DBGP_CLAIM;
 539         writel(ctrl, &ehci_debug->control);
 540         ctrl = readl(&ehci_debug->control);
 541         if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
 542                 dbgp_printk("No device in debug port\n");
 543                 writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
 544                 return -ENODEV;
 545         }
 546         dbgp_ehci_status("debug ported enabled");
 547
 548         /* Completely transfer the debug device to the debug controller */
 549         portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
 550         portsc &= ~PORT_PE;
 551         writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
 552
 553         dbgp_mdelay(100);
 554
 555 try_again:
 556         /* Find the debug device and make it device number 127 */
 557         for (devnum = 0; devnum <= 127; devnum++) {
 558                 ret = dbgp_control_msg(devnum,
 559                         USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 560                         USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
 561                         &dbgp_desc, sizeof(dbgp_desc));
 562                 if (ret > 0)
 563                         break;
 564         }
 565         if (devnum > 127) {
 566                 dbgp_printk("Could not find attached debug device\n");
 567                 goto err;
 568         }
 569         if (ret < 0) {
 570                 dbgp_printk("Attached device is not a debug device\n");
 571                 goto err;
 572         }
 573         dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
 574
 575         /* Move the device to 127 if it isn't already there */
 576         if (devnum != USB_DEBUG_DEVNUM) {
 577                 ret = dbgp_control_msg(devnum,
 578                         USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 579                         USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
 580                 if (ret < 0) {
 581                         dbgp_printk("Could not move attached device to %d\n",
 582                                 USB_DEBUG_DEVNUM);
 583                         goto err;
 584                 }
 585                 devnum = USB_DEBUG_DEVNUM;
 586                 dbgp_printk("debug device renamed to 127\n");
 587         }
 588
 589         /* Enable the debug interface */
 590         ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
 591                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 592                 USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
 593         if (ret < 0) {
 594                 dbgp_printk(" Could not enable the debug device\n");
 595                 goto err;
 596         }
 597         dbgp_printk("debug interface enabled\n");
 598         /* Perform a small write to get the even/odd data state in sync
 599          */
 600         ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
 601         if (ret < 0) {
 602                 dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
 603                 goto err;
 604         }
 605         dbgp_printk("small write doned\n");
 606         dbgp_not_safe = 0;
 607
 608         return 0;
 609 err:
 610         if (tries--)
 611                 goto try_again;
 612         return -ENODEV;
 613 }
 614 EXPORT_SYMBOL_GPL(dbgp_external_startup);
 615
 616 static int __init ehci_reset_port(int port)
 617 {
 618         u32 portsc;
 619         u32 delay_time, delay;
 620         int loop;
 621
 622         dbgp_ehci_status("reset port");
 623         /* Reset the usb debug port */
 624         portsc = readl(&ehci_regs->port_status[port - 1]);
 625         portsc &= ~PORT_PE;
 626         portsc |= PORT_RESET;
 627         writel(portsc, &ehci_regs->port_status[port - 1]);
 628
 629         delay = HUB_ROOT_RESET_TIME;
 630         for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
 631              delay_time += delay) {
 632                 dbgp_mdelay(delay);
 633                 portsc = readl(&ehci_regs->port_status[port - 1]);
 634                 if (!(portsc & PORT_RESET))
 635                         break;
 636         }
 637                 if (portsc & PORT_RESET) {
 638                         /* force reset to complete */
 639                         loop = 100 * 1000;
 640                         writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
 641                                 &ehci_regs->port_status[port - 1]);
 642                         do {
 643                                 udelay(1);
 644                                 portsc = readl(&ehci_regs->port_status[port-1]);
 645                         } while ((portsc & PORT_RESET) && (--loop > 0));
 646                 }
 647
 648                 /* Device went away? */
 649                 if (!(portsc & PORT_CONNECT))
 650                         return -ENOTCONN;
 651
 652                 /* bomb out completely if something weird happend */
 653                 if ((portsc & PORT_CSC))
 654                         return -EINVAL;
 655
 656                 /* If we've finished resetting, then break out of the loop */
 657                 if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
 658                         return 0;
 659         return -EBUSY;
 660 }
 661
 662 static int ehci_wait_for_port(int port)
 663 {
 664         u32 status;
 665         int ret, reps;
 666
 667         for (reps = 0; reps < 300; reps++) {
 668                 status = readl(&ehci_regs->status);
 669                 if (status & STS_PCD)
 670                         break;
 671                 dbgp_mdelay(1);
 672         }
 673         ret = ehci_reset_port(port);
 674         if (ret == 0)
 675                 return 0;
 676         return -ENOTCONN;
 677 }
 678
 679 typedef void (*set_debug_port_t)(int port);
 680
 681 static void __init default_set_debug_port(int port)
 682 {
 683 }
 684
 685 static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
 686
 687 static void __init nvidia_set_debug_port(int port)
 688 {
 689         u32 dword;
 690         dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 691                                  0x74);
 692         dword &= ~(0x0f<<12);
 693         dword |= ((port & 0x0f)<<12);
 694         write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
 695                                  dword);
 696         dbgp_printk("set debug port to %d\n", port);
 697 }
 698
 699 static void __init detect_set_debug_port(void)
 700 {
 701         u32 vendorid;
 702
 703         vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 704                  0x00);
 705
 706         if ((vendorid & 0xffff) == 0x10de) {
 707                 dbgp_printk("using nvidia set_debug_port\n");
 708                 set_debug_port = nvidia_set_debug_port;
 709         }
 710 }
 711
 712 /* The code in early_ehci_bios_handoff() is derived from the usb pci
 713  * quirk initialization, but altered so as to use the early PCI
 714  * routines. */
 715 #define EHCI_USBLEGSUP_BIOS     (1 << 16)       /* BIOS semaphore */
 716 #define EHCI_USBLEGCTLSTS       4               /* legacy control/status */
 717 static void __init early_ehci_bios_handoff(void)
 718 {
 719         u32 hcc_params = readl(&ehci_caps->hcc_params);
 720         int offset = (hcc_params >> 8) & 0xff;
 721         u32 cap;
 722         int msec;
 723
 724         if (!offset)
 725                 return;
 726
 727         cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
 728                               ehci_dev.func, offset);
 729         dbgp_printk("dbgp: ehci BIOS state %08x\n", cap);
 730
 731         if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) {
 732                 dbgp_printk("dbgp: BIOS handoff\n");
 733                 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
 734                                       ehci_dev.func, offset + 3, 1);
 735         }
 736
 737         /* if boot firmware now owns EHCI, spin till it hands it over. */
 738         msec = 1000;
 739         while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
 740                 mdelay(10);
 741                 msec -= 10;
 742                 cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
 743                                       ehci_dev.func, offset);
 744         }
 745
 746         if (cap & EHCI_USBLEGSUP_BIOS) {
 747                 /* well, possibly buggy BIOS... try to shut it down,
 748                  * and hope nothing goes too wrong */
 749                 dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap);
 750                 write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
 751                                       ehci_dev.func, offset + 2, 0);
 752         }
 753
 754         /* just in case, always disable EHCI SMIs */
 755         write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
 756                               offset + EHCI_USBLEGCTLSTS, 0);
 757 }
 758
 759 static int __init ehci_setup(void)
 760 {
 761         u32 ctrl, portsc, hcs_params;
 762         u32 debug_port, new_debug_port = 0, n_ports;
 763         int ret, i;
 764         int port_map_tried;
 765         int playtimes = 3;
 766
 767         early_ehci_bios_handoff();
 768
 769 try_next_time:
 770         port_map_tried = 0;
 771
 772 try_next_port:
 773
 774         hcs_params = readl(&ehci_caps->hcs_params);
 775         debug_port = HCS_DEBUG_PORT(hcs_params);
 776         dbgp_phys_port = debug_port;
 777         n_ports    = HCS_N_PORTS(hcs_params);
 778
 779         dbgp_printk("debug_port: %d\n", debug_port);
 780         dbgp_printk("n_ports:    %d\n", n_ports);
 781         dbgp_ehci_status("");
 782
 783         for (i = 1; i <= n_ports; i++) {
 784                 portsc = readl(&ehci_regs->port_status[i-1]);
 785                 dbgp_printk("portstatus%d: %08x\n", i, portsc);
 786         }
 787
 788         if (port_map_tried && (new_debug_port != debug_port)) {
 789                 if (--playtimes) {
 790                         set_debug_port(new_debug_port);
 791                         goto try_next_time;
 792                 }
 793                 return -1;
 794         }
 795
 796         /* Only reset the controller if it is not already in the
 797          * configured state */
 798         if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) {
 799                 if (dbgp_ehci_controller_reset() != 0)
 800                         return -1;
 801         } else {
 802                 dbgp_ehci_status("ehci skip - already configured");
 803         }
 804
 805         ret = dbgp_external_startup();
 806         if (ret == -EIO)
 807                 goto next_debug_port;
 808
 809         if (ret < 0) {
 810                 /* Things didn't work so remove my claim */
 811                 ctrl = readl(&ehci_debug->control);
 812                 ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
 813                 writel(ctrl, &ehci_debug->control);
 814                 return -1;
 815         }
 816         return 0;
 817
 818 next_debug_port:
 819         port_map_tried |= (1<<(debug_port - 1));
 820         new_debug_port = ((debug_port-1+1)%n_ports) + 1;
 821         if (port_map_tried != ((1<<n_ports) - 1)) {
 822                 set_debug_port(new_debug_port);
 823                 goto try_next_port;
 824         }
 825         if (--playtimes) {
 826                 set_debug_port(new_debug_port);
 827                 goto try_next_time;
 828         }
 829
 830         return -1;
 831 }
 832
 833 int __init early_dbgp_init(char *s)
 834 {
 835         u32 debug_port, bar, offset;
 836         u32 bus, slot, func, cap;
 837         void __iomem *ehci_bar;
 838         u32 dbgp_num;
 839         u32 bar_val;
 840         char *e;
 841         int ret;
 842         u8 byte;
 843
 844         if (!early_pci_allowed())
 845                 return -1;
 846
 847         dbgp_num = 0;
 848         if (*s)
 849                 dbgp_num = simple_strtoul(s, &e, 10);
 850         dbgp_printk("dbgp_num: %d\n", dbgp_num);
 851
 852         cap = find_dbgp(dbgp_num, &bus, &slot, &func);
 853         if (!cap)
 854                 return -1;
 855
 856         dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
 857                          func);
 858
 859         debug_port = read_pci_config(bus, slot, func, cap);
 860         bar = (debug_port >> 29) & 0x7;
 861         bar = (bar * 4) + 0xc;
 862         offset = (debug_port >> 16) & 0xfff;
 863         dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
 864         if (bar != PCI_BASE_ADDRESS_0) {
 865                 dbgp_printk("only debug ports on bar 1 handled.\n");
 866
 867                 return -1;
 868         }
 869
 870         bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
 871         dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
 872         if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
 873                 dbgp_printk("only simple 32bit mmio bars supported\n");
 874
 875                 return -1;
 876         }
 877
 878         /* double check if the mem space is enabled */
 879         byte = read_pci_config_byte(bus, slot, func, 0x04);
 880         if (!(byte & 0x2)) {
 881                 byte  |= 0x02;
 882                 write_pci_config_byte(bus, slot, func, 0x04, byte);
 883                 dbgp_printk("mmio for ehci enabled\n");
 884         }
 885
 886         /*
 887          * FIXME I don't have the bar size so just guess PAGE_SIZE is more
 888          * than enough.  1K is the biggest I have seen.
 889          */
 890         set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
 891         ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
 892         ehci_bar += bar_val & ~PAGE_MASK;
 893         dbgp_printk("ehci_bar: %p\n", ehci_bar);
 894
 895         ehci_caps  = ehci_bar;
 896         ehci_regs  = ehci_bar + HC_LENGTH(readl(&ehci_caps->hc_capbase));
 897         ehci_debug = ehci_bar + offset;
 898         ehci_dev.bus = bus;
 899         ehci_dev.slot = slot;
 900         ehci_dev.func = func;
 901
 902         detect_set_debug_port();
 903
 904         ret = ehci_setup();
 905         if (ret < 0) {
 906                 dbgp_printk("ehci_setup failed\n");
 907                 ehci_debug = NULL;
 908
 909                 return -1;
 910         }
 911         dbgp_ehci_status("early_init_complete");
 912
 913         return 0;
 914 }
 915
 916 static void early_dbgp_write(struct console *con, const char *str, u32 n)
 917 {
 918         int chunk, ret;
 919         char buf[DBGP_MAX_PACKET];
 920         int use_cr = 0;
 921         u32 cmd, ctrl;
 922         int reset_run = 0;
 923
 924         if (!ehci_debug || dbgp_not_safe)
 925                 return;
 926
 927         cmd = readl(&ehci_regs->command);
 928         if (unlikely(!(cmd & CMD_RUN))) {
 929                 /* If the ehci controller is not in the run state do extended
 930                  * checks to see if the acpi or some other initialization also
 931                  * reset the ehci debug port */
 932                 ctrl = readl(&ehci_debug->control);
 933                 if (!(ctrl & DBGP_ENABLED)) {
 934                         dbgp_not_safe = 1;
 935                         dbgp_external_startup();
 936                 } else {
 937                         cmd |= CMD_RUN;
 938                         writel(cmd, &ehci_regs->command);
 939                         reset_run = 1;
 940                 }
 941         }
 942         while (n > 0) {
 943                 for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0;
 944                      str++, chunk++, n--) {
 945                         if (!use_cr && *str == '\n') {
 946                                 use_cr = 1;
 947                                 buf[chunk] = '\r';
 948                                 str--;
 949                                 n++;
 950                                 continue;
 951                         }
 952                         if (use_cr)
 953                                 use_cr = 0;
 954                         buf[chunk] = *str;
 955                 }
 956                 if (chunk > 0) {
 957                         ret = dbgp_bulk_write(USB_DEBUG_DEVNUM,
 958                                       dbgp_endpoint_out, buf, chunk);
 959                 }
 960         }
 961         if (unlikely(reset_run)) {
 962                 cmd = readl(&ehci_regs->command);
 963                 cmd &= ~CMD_RUN;
 964                 writel(cmd, &ehci_regs->command);
 965         }
 966 }
 967
 968 struct console early_dbgp_console = {
 969         .name =         "earlydbg",
 970         .write =        early_dbgp_write,
 971         .flags =        CON_PRINTBUFFER,
 972         .index =        -1,
 973 };
 974
 975 int dbgp_reset_prep(void)
 976 {
 977         u32 ctrl;
 978
 979         dbgp_not_safe = 1;
 980         if (!ehci_debug)
 981                 return 0;
 982
 983         if (early_dbgp_console.index != -1 &&
 984                 !(early_dbgp_console.flags & CON_BOOT))
 985                 return 1;
 986         /* This means the console is not initialized, or should get
 987          * shutdown so as to allow for reuse of the usb device, which
 988          * means it is time to shutdown the usb debug port. */
 989         ctrl = readl(&ehci_debug->control);
 990         if (ctrl & DBGP_ENABLED) {
 991                 ctrl &= ~(DBGP_CLAIM);
 992                 writel(ctrl, &ehci_debug->control);
 993         }
 994         return 0;
 995 }
 996 EXPORT_SYMBOL_GPL(dbgp_reset_prep);