drivers/w1/masters/ds2490.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      ds2490.c  USB to one wire bridge
   4  *
   5  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/usb.h>
  12 #include <linux/slab.h>
  13
  14 #include <linux/w1.h>
  15
  16 /* USB Standard */
  17 /* USB Control request vendor type */
  18 #define VENDOR                          0x40
  19
  20 /* COMMAND TYPE CODES */
  21 #define CONTROL_CMD                     0x00
  22 #define COMM_CMD                        0x01
  23 #define MODE_CMD                        0x02
  24
  25 /* CONTROL COMMAND CODES */
  26 #define CTL_RESET_DEVICE                0x0000
  27 #define CTL_START_EXE                   0x0001
  28 #define CTL_RESUME_EXE                  0x0002
  29 #define CTL_HALT_EXE_IDLE               0x0003
  30 #define CTL_HALT_EXE_DONE               0x0004
  31 #define CTL_FLUSH_COMM_CMDS             0x0007
  32 #define CTL_FLUSH_RCV_BUFFER            0x0008
  33 #define CTL_FLUSH_XMT_BUFFER            0x0009
  34 #define CTL_GET_COMM_CMDS               0x000A
  35
  36 /* MODE COMMAND CODES */
  37 #define MOD_PULSE_EN                    0x0000
  38 #define MOD_SPEED_CHANGE_EN             0x0001
  39 #define MOD_1WIRE_SPEED                 0x0002
  40 #define MOD_STRONG_PU_DURATION          0x0003
  41 #define MOD_PULLDOWN_SLEWRATE           0x0004
  42 #define MOD_PROG_PULSE_DURATION         0x0005
  43 #define MOD_WRITE1_LOWTIME              0x0006
  44 #define MOD_DSOW0_TREC                  0x0007
  45
  46 /* COMMUNICATION COMMAND CODES */
  47 #define COMM_ERROR_ESCAPE               0x0601
  48 #define COMM_SET_DURATION               0x0012
  49 #define COMM_BIT_IO                     0x0020
  50 #define COMM_PULSE                      0x0030
  51 #define COMM_1_WIRE_RESET               0x0042
  52 #define COMM_BYTE_IO                    0x0052
  53 #define COMM_MATCH_ACCESS               0x0064
  54 #define COMM_BLOCK_IO                   0x0074
  55 #define COMM_READ_STRAIGHT              0x0080
  56 #define COMM_DO_RELEASE                 0x6092
  57 #define COMM_SET_PATH                   0x00A2
  58 #define COMM_WRITE_SRAM_PAGE            0x00B2
  59 #define COMM_WRITE_EPROM                0x00C4
  60 #define COMM_READ_CRC_PROT_PAGE         0x00D4
  61 #define COMM_READ_REDIRECT_PAGE_CRC     0x21E4
  62 #define COMM_SEARCH_ACCESS              0x00F4
  63
  64 /* Communication command bits */
  65 #define COMM_TYPE                       0x0008
  66 #define COMM_SE                         0x0008
  67 #define COMM_D                          0x0008
  68 #define COMM_Z                          0x0008
  69 #define COMM_CH                         0x0008
  70 #define COMM_SM                         0x0008
  71 #define COMM_R                          0x0008
  72 #define COMM_IM                         0x0001
  73
  74 #define COMM_PS                         0x4000
  75 #define COMM_PST                        0x4000
  76 #define COMM_CIB                        0x4000
  77 #define COMM_RTS                        0x4000
  78 #define COMM_DT                         0x2000
  79 #define COMM_SPU                        0x1000
  80 #define COMM_F                          0x0800
  81 #define COMM_NTF                        0x0400
  82 #define COMM_ICP                        0x0200
  83 #define COMM_RST                        0x0100
  84
  85 #define PULSE_PROG                      0x01
  86 #define PULSE_SPUE                      0x02
  87
  88 #define BRANCH_MAIN                     0xCC
  89 #define BRANCH_AUX                      0x33
  90
  91 /* Status flags */
  92 #define ST_SPUA                         0x01  /* Strong Pull-up is active */
  93 #define ST_PRGA                         0x02  /* 12V programming pulse is being generated */
  94 #define ST_12VP                         0x04  /* external 12V programming voltage is present */
  95 #define ST_PMOD                         0x08  /* DS2490 powered from USB and external sources */
  96 #define ST_HALT                         0x10  /* DS2490 is currently halted */
  97 #define ST_IDLE                         0x20  /* DS2490 is currently idle */
  98 #define ST_EPOF                         0x80
  99 /* Status transfer size, 16 bytes status, 16 byte result flags */
 100 #define ST_SIZE                         0x20
 101
 102 /* Result Register flags */
 103 #define RR_DETECT                       0xA5 /* New device detected */
 104 #define RR_NRS                          0x01 /* Reset no presence or ... */
 105 #define RR_SH                           0x02 /* short on reset or set path */
 106 #define RR_APP                          0x04 /* alarming presence on reset */
 107 #define RR_VPP                          0x08 /* 12V expected not seen */
 108 #define RR_CMP                          0x10 /* compare error */
 109 #define RR_CRC                          0x20 /* CRC error detected */
 110 #define RR_RDP                          0x40 /* redirected page */
 111 #define RR_EOS                          0x80 /* end of search error */
 112
 113 #define SPEED_NORMAL                    0x00
 114 #define SPEED_FLEXIBLE                  0x01
 115 #define SPEED_OVERDRIVE                 0x02
 116
 117 #define NUM_EP                          4
 118 #define EP_CONTROL                      0
 119 #define EP_STATUS                       1
 120 #define EP_DATA_OUT                     2
 121 #define EP_DATA_IN                      3
 122
 123 struct ds_device {
 124         struct list_head        ds_entry;
 125
 126         struct usb_device       *udev;
 127         struct usb_interface    *intf;
 128
 129         int                     ep[NUM_EP];
 130
 131         /* Strong PullUp
 132          * 0: pullup not active, else duration in milliseconds
 133          */
 134         int                     spu_sleep;
 135         /* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
 136          * should be active or not for writes.
 137          */
 138         u16                     spu_bit;
 139
 140         u8                      st_buf[ST_SIZE];
 141         u8                      byte_buf;
 142
 143         struct w1_bus_master    master;
 144 };
 145
 146 struct ds_status {
 147         u8                      enable;
 148         u8                      speed;
 149         u8                      pullup_dur;
 150         u8                      ppuls_dur;
 151         u8                      pulldown_slew;
 152         u8                      write1_time;
 153         u8                      write0_time;
 154         u8                      reserved0;
 155         u8                      status;
 156         u8                      command0;
 157         u8                      command1;
 158         u8                      command_buffer_status;
 159         u8                      data_out_buffer_status;
 160         u8                      data_in_buffer_status;
 161         u8                      reserved1;
 162         u8                      reserved2;
 163 };
 164
 165 static LIST_HEAD(ds_devices);
 166 static DEFINE_MUTEX(ds_mutex);
 167
 168 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
 169 {
 170         int err;
 171
 172         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 173                         CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
 174         if (err < 0) {
 175                 pr_err("Failed to send command control message %x.%x: err=%d.\n",
 176                                 value, index, err);
 177                 return err;
 178         }
 179
 180         return err;
 181 }
 182
 183 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
 184 {
 185         int err;
 186
 187         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 188                         MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
 189         if (err < 0) {
 190                 pr_err("Failed to send mode control message %x.%x: err=%d.\n",
 191                                 value, index, err);
 192                 return err;
 193         }
 194
 195         return err;
 196 }
 197
 198 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
 199 {
 200         int err;
 201
 202         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 203                         COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
 204         if (err < 0) {
 205                 pr_err("Failed to send control message %x.%x: err=%d.\n",
 206                                 value, index, err);
 207                 return err;
 208         }
 209
 210         return err;
 211 }
 212
 213 static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
 214 {
 215         pr_info("%45s: %8x\n", str, buf[off]);
 216 }
 217
 218 static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
 219 {
 220         int i;
 221
 222         pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
 223         for (i = 0; i < count; ++i)
 224                 pr_info("%02x ", buf[i]);
 225         pr_info("\n");
 226
 227         if (count >= 16) {
 228                 ds_print_msg(buf, "enable flag", 0);
 229                 ds_print_msg(buf, "1-wire speed", 1);
 230                 ds_print_msg(buf, "strong pullup duration", 2);
 231                 ds_print_msg(buf, "programming pulse duration", 3);
 232                 ds_print_msg(buf, "pulldown slew rate control", 4);
 233                 ds_print_msg(buf, "write-1 low time", 5);
 234                 ds_print_msg(buf, "data sample offset/write-0 recovery time",
 235                         6);
 236                 ds_print_msg(buf, "reserved (test register)", 7);
 237                 ds_print_msg(buf, "device status flags", 8);
 238                 ds_print_msg(buf, "communication command byte 1", 9);
 239                 ds_print_msg(buf, "communication command byte 2", 10);
 240                 ds_print_msg(buf, "communication command buffer status", 11);
 241                 ds_print_msg(buf, "1-wire data output buffer status", 12);
 242                 ds_print_msg(buf, "1-wire data input buffer status", 13);
 243                 ds_print_msg(buf, "reserved", 14);
 244                 ds_print_msg(buf, "reserved", 15);
 245         }
 246         for (i = 16; i < count; ++i) {
 247                 if (buf[i] == RR_DETECT) {
 248                         ds_print_msg(buf, "new device detect", i);
 249                         continue;
 250                 }
 251                 ds_print_msg(buf, "Result Register Value: ", i);
 252                 if (buf[i] & RR_NRS)
 253                         pr_info("NRS: Reset no presence or ...\n");
 254                 if (buf[i] & RR_SH)
 255                         pr_info("SH: short on reset or set path\n");
 256                 if (buf[i] & RR_APP)
 257                         pr_info("APP: alarming presence on reset\n");
 258                 if (buf[i] & RR_VPP)
 259                         pr_info("VPP: 12V expected not seen\n");
 260                 if (buf[i] & RR_CMP)
 261                         pr_info("CMP: compare error\n");
 262                 if (buf[i] & RR_CRC)
 263                         pr_info("CRC: CRC error detected\n");
 264                 if (buf[i] & RR_RDP)
 265                         pr_info("RDP: redirected page\n");
 266                 if (buf[i] & RR_EOS)
 267                         pr_info("EOS: end of search error\n");
 268         }
 269 }
 270
 271 static int ds_recv_status(struct ds_device *dev, struct ds_status *st,
 272                           bool dump)
 273 {
 274         int count, err;
 275
 276         if (st)
 277                 memset(st, 0, sizeof(*st));
 278
 279         count = 0;
 280         err = usb_interrupt_msg(dev->udev,
 281                                 usb_rcvintpipe(dev->udev,
 282                                                dev->ep[EP_STATUS]),
 283                                 dev->st_buf, sizeof(dev->st_buf),
 284                                 &count, 1000);
 285         if (err < 0) {
 286                 pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
 287                        dev->ep[EP_STATUS], err);
 288                 return err;
 289         }
 290
 291         if (dump)
 292                 ds_dump_status(dev, dev->st_buf, count);
 293
 294         if (st && count >= sizeof(*st))
 295                 memcpy(st, dev->st_buf, sizeof(*st));
 296
 297         return count;
 298 }
 299
 300 static void ds_reset_device(struct ds_device *dev)
 301 {
 302         ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
 303         /* Always allow strong pullup which allow individual writes to use
 304          * the strong pullup.
 305          */
 306         if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
 307                 pr_err("ds_reset_device: Error allowing strong pullup\n");
 308         /* Chip strong pullup time was cleared. */
 309         if (dev->spu_sleep) {
 310                 /* lower 4 bits are 0, see ds_set_pullup */
 311                 u8 del = dev->spu_sleep>>4;
 312                 if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
 313                         pr_err("ds_reset_device: Error setting duration\n");
 314         }
 315 }
 316
 317 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
 318 {
 319         int count, err;
 320
 321         /* Careful on size.  If size is less than what is available in
 322          * the input buffer, the device fails the bulk transfer and
 323          * clears the input buffer.  It could read the maximum size of
 324          * the data buffer, but then do you return the first, last, or
 325          * some set of the middle size bytes?  As long as the rest of
 326          * the code is correct there will be size bytes waiting.  A
 327          * call to ds_wait_status will wait until the device is idle
 328          * and any data to be received would have been available.
 329          */
 330         count = 0;
 331         err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
 332                                 buf, size, &count, 1000);
 333         if (err < 0) {
 334                 pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
 335                 usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
 336                 ds_recv_status(dev, NULL, true);
 337                 return err;
 338         }
 339
 340 #if 0
 341         {
 342                 int i;
 343
 344                 printk("%s: count=%d: ", __func__, count);
 345                 for (i = 0; i < count; ++i)
 346                         printk("%02x ", buf[i]);
 347                 printk("\n");
 348         }
 349 #endif
 350         return count;
 351 }
 352
 353 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
 354 {
 355         int count, err;
 356
 357         count = 0;
 358         err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
 359         if (err < 0) {
 360                 pr_err("Failed to write 1-wire data to ep0x%x: "
 361                         "err=%d.\n", dev->ep[EP_DATA_OUT], err);
 362                 return err;
 363         }
 364
 365         return err;
 366 }
 367
 368 #if 0
 369
 370 int ds_stop_pulse(struct ds_device *dev, int limit)
 371 {
 372         struct ds_status st;
 373         int count = 0, err = 0;
 374
 375         do {
 376                 err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
 377                 if (err)
 378                         break;
 379                 err = ds_send_control(dev, CTL_RESUME_EXE, 0);
 380                 if (err)
 381                         break;
 382                 err = ds_recv_status(dev, &st, false);
 383                 if (err)
 384                         break;
 385
 386                 if ((st.status & ST_SPUA) == 0) {
 387                         err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
 388                         if (err)
 389                                 break;
 390                 }
 391         } while (++count < limit);
 392
 393         return err;
 394 }
 395
 396 int ds_detect(struct ds_device *dev, struct ds_status *st)
 397 {
 398         int err;
 399
 400         err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
 401         if (err)
 402                 return err;
 403
 404         err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
 405         if (err)
 406                 return err;
 407
 408         err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
 409         if (err)
 410                 return err;
 411
 412         err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
 413         if (err)
 414                 return err;
 415
 416         err = ds_dump_status(dev, st);
 417
 418         return err;
 419 }
 420
 421 #endif  /*  0  */
 422
 423 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
 424 {
 425         int err, count = 0;
 426
 427         do {
 428                 st->status = 0;
 429                 err = ds_recv_status(dev, st, false);
 430 #if 0
 431                 if (err >= 0) {
 432                         int i;
 433                         printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
 434                         for (i = 0; i < err; ++i)
 435                                 printk("%02x ", dev->st_buf[i]);
 436                         printk("\n");
 437                 }
 438 #endif
 439         } while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
 440
 441         if (err >= 16 && st->status & ST_EPOF) {
 442                 pr_info("Resetting device after ST_EPOF.\n");
 443                 ds_reset_device(dev);
 444                 /* Always dump the device status. */
 445                 count = 101;
 446         }
 447
 448         /* Dump the status for errors or if there is extended return data.
 449          * The extended status includes new device detection (maybe someone
 450          * can do something with it).
 451          */
 452         if (err > 16 || count >= 100 || err < 0)
 453                 ds_dump_status(dev, dev->st_buf, err);
 454
 455         /* Extended data isn't an error.  Well, a short is, but the dump
 456          * would have already told the user that and we can't do anything
 457          * about it in software anyway.
 458          */
 459         if (count >= 100 || err < 0)
 460                 return -1;
 461         else
 462                 return 0;
 463 }
 464
 465 static int ds_reset(struct ds_device *dev)
 466 {
 467         int err;
 468
 469         /* Other potentionally interesting flags for reset.
 470          *
 471          * COMM_NTF: Return result register feedback.  This could be used to
 472          * detect some conditions such as short, alarming presence, or
 473          * detect if a new device was detected.
 474          *
 475          * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
 476          * Select the data transfer rate.
 477          */
 478         err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
 479         if (err)
 480                 return err;
 481
 482         return 0;
 483 }
 484
 485 #if 0
 486 static int ds_set_speed(struct ds_device *dev, int speed)
 487 {
 488         int err;
 489
 490         if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
 491                 return -EINVAL;
 492
 493         if (speed != SPEED_OVERDRIVE)
 494                 speed = SPEED_FLEXIBLE;
 495
 496         speed &= 0xff;
 497
 498         err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
 499         if (err)
 500                 return err;
 501
 502         return err;
 503 }
 504 #endif  /*  0  */
 505
 506 static int ds_set_pullup(struct ds_device *dev, int delay)
 507 {
 508         int err = 0;
 509         u8 del = 1 + (u8)(delay >> 4);
 510         /* Just storing delay would not get the trunication and roundup. */
 511         int ms = del<<4;
 512
 513         /* Enable spu_bit if a delay is set. */
 514         dev->spu_bit = delay ? COMM_SPU : 0;
 515         /* If delay is zero, it has already been disabled, if the time is
 516          * the same as the hardware was last programmed to, there is also
 517          * nothing more to do.  Compare with the recalculated value ms
 518          * rather than del or delay which can have a different value.
 519          */
 520         if (delay == 0 || ms == dev->spu_sleep)
 521                 return err;
 522
 523         err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
 524         if (err)
 525                 return err;
 526
 527         dev->spu_sleep = ms;
 528
 529         return err;
 530 }
 531
 532 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
 533 {
 534         int err;
 535         struct ds_status st;
 536
 537         err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
 538                 0);
 539         if (err)
 540                 return err;
 541
 542         ds_wait_status(dev, &st);
 543
 544         err = ds_recv_data(dev, tbit, sizeof(*tbit));
 545         if (err < 0)
 546                 return err;
 547
 548         return 0;
 549 }
 550
 551 #if 0
 552 static int ds_write_bit(struct ds_device *dev, u8 bit)
 553 {
 554         int err;
 555         struct ds_status st;
 556
 557         /* Set COMM_ICP to write without a readback.  Note, this will
 558          * produce one time slot, a down followed by an up with COMM_D
 559          * only determing the timing.
 560          */
 561         err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
 562                 (bit ? COMM_D : 0), 0);
 563         if (err)
 564                 return err;
 565
 566         ds_wait_status(dev, &st);
 567
 568         return 0;
 569 }
 570 #endif
 571
 572 static int ds_write_byte(struct ds_device *dev, u8 byte)
 573 {
 574         int err;
 575         struct ds_status st;
 576
 577         err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
 578         if (err)
 579                 return err;
 580
 581         if (dev->spu_bit)
 582                 msleep(dev->spu_sleep);
 583
 584         err = ds_wait_status(dev, &st);
 585         if (err)
 586                 return err;
 587
 588         err = ds_recv_data(dev, &dev->byte_buf, 1);
 589         if (err < 0)
 590                 return err;
 591
 592         return !(byte == dev->byte_buf);
 593 }
 594
 595 static int ds_read_byte(struct ds_device *dev, u8 *byte)
 596 {
 597         int err;
 598         struct ds_status st;
 599
 600         err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
 601         if (err)
 602                 return err;
 603
 604         ds_wait_status(dev, &st);
 605
 606         err = ds_recv_data(dev, byte, sizeof(*byte));
 607         if (err < 0)
 608                 return err;
 609
 610         return 0;
 611 }
 612
 613 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
 614 {
 615         struct ds_status st;
 616         int err;
 617
 618         if (len > 64*1024)
 619                 return -E2BIG;
 620
 621         memset(buf, 0xFF, len);
 622
 623         err = ds_send_data(dev, buf, len);
 624         if (err < 0)
 625                 return err;
 626
 627         err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
 628         if (err)
 629                 return err;
 630
 631         ds_wait_status(dev, &st);
 632
 633         memset(buf, 0x00, len);
 634         err = ds_recv_data(dev, buf, len);
 635
 636         return err;
 637 }
 638
 639 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
 640 {
 641         int err;
 642         struct ds_status st;
 643
 644         err = ds_send_data(dev, buf, len);
 645         if (err < 0)
 646                 return err;
 647
 648         err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
 649         if (err)
 650                 return err;
 651
 652         if (dev->spu_bit)
 653                 msleep(dev->spu_sleep);
 654
 655         ds_wait_status(dev, &st);
 656
 657         err = ds_recv_data(dev, buf, len);
 658         if (err < 0)
 659                 return err;
 660
 661         return !(err == len);
 662 }
 663
 664 static void ds9490r_search(void *data, struct w1_master *master,
 665         u8 search_type, w1_slave_found_callback callback)
 666 {
 667         /* When starting with an existing id, the first id returned will
 668          * be that device (if it is still on the bus most likely).
 669          *
 670          * If the number of devices found is less than or equal to the
 671          * search_limit, that number of IDs will be returned.  If there are
 672          * more, search_limit IDs will be returned followed by a non-zero
 673          * discrepency value.
 674          */
 675         struct ds_device *dev = data;
 676         int err;
 677         u16 value, index;
 678         struct ds_status st;
 679         int search_limit;
 680         int found = 0;
 681         int i;
 682
 683         /* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
 684          * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
 685          */
 686         const unsigned long jtime = msecs_to_jiffies(1000*8/75);
 687         /* FIFO 128 bytes, bulk packet size 64, read a multiple of the
 688          * packet size.
 689          */
 690         const size_t bufsize = 2 * 64;
 691         u64 *buf;
 692
 693         buf = kmalloc(bufsize, GFP_KERNEL);
 694         if (!buf)
 695                 return;
 696
 697         mutex_lock(&master->bus_mutex);
 698
 699         /* address to start searching at */
 700         if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
 701                 goto search_out;
 702         master->search_id = 0;
 703
 704         value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
 705                 COMM_RTS;
 706         search_limit = master->max_slave_count;
 707         if (search_limit > 255)
 708                 search_limit = 0;
 709         index = search_type | (search_limit << 8);
 710         if (ds_send_control(dev, value, index) < 0)
 711                 goto search_out;
 712
 713         do {
 714                 schedule_timeout(jtime);
 715
 716                 err = ds_recv_status(dev, &st, false);
 717                 if (err < 0 || err < sizeof(st))
 718                         break;
 719
 720                 if (st.data_in_buffer_status) {
 721                         /* Bulk in can receive partial ids, but when it does
 722                          * they fail crc and will be discarded anyway.
 723                          * That has only been seen when status in buffer
 724                          * is 0 and bulk is read anyway, so don't read
 725                          * bulk without first checking if status says there
 726                          * is data to read.
 727                          */
 728                         err = ds_recv_data(dev, (u8 *)buf, bufsize);
 729                         if (err < 0)
 730                                 break;
 731                         for (i = 0; i < err/8; ++i) {
 732                                 ++found;
 733                                 if (found <= search_limit)
 734                                         callback(master, buf[i]);
 735                                 /* can't know if there will be a discrepancy
 736                                  * value after until the next id */
 737                                 if (found == search_limit)
 738                                         master->search_id = buf[i];
 739                         }
 740                 }
 741
 742                 if (test_bit(W1_ABORT_SEARCH, &master->flags))
 743                         break;
 744         } while (!(st.status & (ST_IDLE | ST_HALT)));
 745
 746         /* only continue the search if some weren't found */
 747         if (found <= search_limit) {
 748                 master->search_id = 0;
 749         } else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
 750                 /* Only max_slave_count will be scanned in a search,
 751                  * but it will start where it left off next search
 752                  * until all ids are identified and then it will start
 753                  * over.  A continued search will report the previous
 754                  * last id as the first id (provided it is still on the
 755                  * bus).
 756                  */
 757                 dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
 758                         "will continue next search.\n", __func__,
 759                         master->max_slave_count);
 760                 set_bit(W1_WARN_MAX_COUNT, &master->flags);
 761         }
 762 search_out:
 763         mutex_unlock(&master->bus_mutex);
 764         kfree(buf);
 765 }
 766
 767 #if 0
 768 /*
 769  * FIXME: if this disabled code is ever used in the future all ds_send_data()
 770  * calls must be changed to use a DMAable buffer.
 771  */
 772 static int ds_match_access(struct ds_device *dev, u64 init)
 773 {
 774         int err;
 775         struct ds_status st;
 776
 777         err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
 778         if (err)
 779                 return err;
 780
 781         ds_wait_status(dev, &st);
 782
 783         err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
 784         if (err)
 785                 return err;
 786
 787         ds_wait_status(dev, &st);
 788
 789         return 0;
 790 }
 791
 792 static int ds_set_path(struct ds_device *dev, u64 init)
 793 {
 794         int err;
 795         struct ds_status st;
 796         u8 buf[9];
 797
 798         memcpy(buf, &init, 8);
 799         buf[8] = BRANCH_MAIN;
 800
 801         err = ds_send_data(dev, buf, sizeof(buf));
 802         if (err)
 803                 return err;
 804
 805         ds_wait_status(dev, &st);
 806
 807         err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
 808         if (err)
 809                 return err;
 810
 811         ds_wait_status(dev, &st);
 812
 813         return 0;
 814 }
 815
 816 #endif  /*  0  */
 817
 818 static u8 ds9490r_touch_bit(void *data, u8 bit)
 819 {
 820         struct ds_device *dev = data;
 821
 822         if (ds_touch_bit(dev, bit, &dev->byte_buf))
 823                 return 0;
 824
 825         return dev->byte_buf;
 826 }
 827
 828 #if 0
 829 static void ds9490r_write_bit(void *data, u8 bit)
 830 {
 831         struct ds_device *dev = data;
 832
 833         ds_write_bit(dev, bit);
 834 }
 835
 836 static u8 ds9490r_read_bit(void *data)
 837 {
 838         struct ds_device *dev = data;
 839         int err;
 840
 841         err = ds_touch_bit(dev, 1, &dev->byte_buf);
 842         if (err)
 843                 return 0;
 844
 845         return dev->byte_buf & 1;
 846 }
 847 #endif
 848
 849 static void ds9490r_write_byte(void *data, u8 byte)
 850 {
 851         struct ds_device *dev = data;
 852
 853         ds_write_byte(dev, byte);
 854 }
 855
 856 static u8 ds9490r_read_byte(void *data)
 857 {
 858         struct ds_device *dev = data;
 859         int err;
 860
 861         err = ds_read_byte(dev, &dev->byte_buf);
 862         if (err)
 863                 return 0;
 864
 865         return dev->byte_buf;
 866 }
 867
 868 static void ds9490r_write_block(void *data, const u8 *buf, int len)
 869 {
 870         struct ds_device *dev = data;
 871         u8 *tbuf;
 872
 873         if (len <= 0)
 874                 return;
 875
 876         tbuf = kmemdup(buf, len, GFP_KERNEL);
 877         if (!tbuf)
 878                 return;
 879
 880         ds_write_block(dev, tbuf, len);
 881
 882         kfree(tbuf);
 883 }
 884
 885 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
 886 {
 887         struct ds_device *dev = data;
 888         int err;
 889         u8 *tbuf;
 890
 891         if (len <= 0)
 892                 return 0;
 893
 894         tbuf = kmalloc(len, GFP_KERNEL);
 895         if (!tbuf)
 896                 return 0;
 897
 898         err = ds_read_block(dev, tbuf, len);
 899         if (err >= 0)
 900                 memcpy(buf, tbuf, len);
 901
 902         kfree(tbuf);
 903
 904         return err >= 0 ? len : 0;
 905 }
 906
 907 static u8 ds9490r_reset(void *data)
 908 {
 909         struct ds_device *dev = data;
 910         int err;
 911
 912         err = ds_reset(dev);
 913         if (err)
 914                 return 1;
 915
 916         return 0;
 917 }
 918
 919 static u8 ds9490r_set_pullup(void *data, int delay)
 920 {
 921         struct ds_device *dev = data;
 922
 923         if (ds_set_pullup(dev, delay))
 924                 return 1;
 925
 926         return 0;
 927 }
 928
 929 static int ds_w1_init(struct ds_device *dev)
 930 {
 931         memset(&dev->master, 0, sizeof(struct w1_bus_master));
 932
 933         /* Reset the device as it can be in a bad state.
 934          * This is necessary because a block write will wait for data
 935          * to be placed in the output buffer and block any later
 936          * commands which will keep accumulating and the device will
 937          * not be idle.  Another case is removing the ds2490 module
 938          * while a bus search is in progress, somehow a few commands
 939          * get through, but the input transfers fail leaving data in
 940          * the input buffer.  This will cause the next read to fail
 941          * see the note in ds_recv_data.
 942          */
 943         ds_reset_device(dev);
 944
 945         dev->master.data        = dev;
 946         dev->master.touch_bit   = &ds9490r_touch_bit;
 947         /* read_bit and write_bit in w1_bus_master are expected to set and
 948          * sample the line level.  For write_bit that means it is expected to
 949          * set it to that value and leave it there.  ds2490 only supports an
 950          * individual time slot at the lowest level.  The requirement from
 951          * pulling the bus state down to reading the state is 15us, something
 952          * that isn't realistic on the USB bus anyway.
 953         dev->master.read_bit    = &ds9490r_read_bit;
 954         dev->master.write_bit   = &ds9490r_write_bit;
 955         */
 956         dev->master.read_byte   = &ds9490r_read_byte;
 957         dev->master.write_byte  = &ds9490r_write_byte;
 958         dev->master.read_block  = &ds9490r_read_block;
 959         dev->master.write_block = &ds9490r_write_block;
 960         dev->master.reset_bus   = &ds9490r_reset;
 961         dev->master.set_pullup  = &ds9490r_set_pullup;
 962         dev->master.search      = &ds9490r_search;
 963
 964         return w1_add_master_device(&dev->master);
 965 }
 966
 967 static void ds_w1_fini(struct ds_device *dev)
 968 {
 969         w1_remove_master_device(&dev->master);
 970 }
 971
 972 static int ds_probe(struct usb_interface *intf,
 973                     const struct usb_device_id *udev_id)
 974 {
 975         struct usb_device *udev = interface_to_usbdev(intf);
 976         struct usb_endpoint_descriptor *endpoint;
 977         struct usb_host_interface *iface_desc;
 978         struct ds_device *dev;
 979         int i, err, alt;
 980
 981         dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
 982         if (!dev) {
 983                 pr_info("Failed to allocate new DS9490R structure.\n");
 984                 return -ENOMEM;
 985         }
 986         dev->udev = usb_get_dev(udev);
 987         if (!dev->udev) {
 988                 err = -ENOMEM;
 989                 goto err_out_free;
 990         }
 991         memset(dev->ep, 0, sizeof(dev->ep));
 992
 993         usb_set_intfdata(intf, dev);
 994
 995         err = usb_reset_configuration(dev->udev);
 996         if (err) {
 997                 dev_err(&dev->udev->dev,
 998                         "Failed to reset configuration: err=%d.\n", err);
 999                 goto err_out_clear;
1000         }
1001
1002         /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1003         alt = 3;
1004         err = usb_set_interface(dev->udev,
1005                 intf->cur_altsetting->desc.bInterfaceNumber, alt);
1006         if (err) {
1007                 dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1008                         "for %d interface: err=%d.\n", alt,
1009                         intf->cur_altsetting->desc.bInterfaceNumber, err);
1010                 goto err_out_clear;
1011         }
1012
1013         iface_desc = intf->cur_altsetting;
1014         if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1015                 pr_info("Num endpoints=%d. It is not DS9490R.\n",
1016                         iface_desc->desc.bNumEndpoints);
1017                 err = -EINVAL;
1018                 goto err_out_clear;
1019         }
1020
1021         /*
1022          * This loop doesn'd show control 0 endpoint,
1023          * so we will fill only 1-3 endpoints entry.
1024          */
1025         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1026                 endpoint = &iface_desc->endpoint[i].desc;
1027
1028                 dev->ep[i+1] = endpoint->bEndpointAddress;
1029 #if 0
1030                 printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1031                         i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1032                         (endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1033                         endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1034 #endif
1035         }
1036
1037         err = ds_w1_init(dev);
1038         if (err)
1039                 goto err_out_clear;
1040
1041         mutex_lock(&ds_mutex);
1042         list_add_tail(&dev->ds_entry, &ds_devices);
1043         mutex_unlock(&ds_mutex);
1044
1045         return 0;
1046
1047 err_out_clear:
1048         usb_set_intfdata(intf, NULL);
1049         usb_put_dev(dev->udev);
1050 err_out_free:
1051         kfree(dev);
1052         return err;
1053 }
1054
1055 static void ds_disconnect(struct usb_interface *intf)
1056 {
1057         struct ds_device *dev;
1058
1059         dev = usb_get_intfdata(intf);
1060         if (!dev)
1061                 return;
1062
1063         mutex_lock(&ds_mutex);
1064         list_del(&dev->ds_entry);
1065         mutex_unlock(&ds_mutex);
1066
1067         ds_w1_fini(dev);
1068
1069         usb_set_intfdata(intf, NULL);
1070
1071         usb_put_dev(dev->udev);
1072         kfree(dev);
1073 }
1074
1075 static const struct usb_device_id ds_id_table[] = {
1076         { USB_DEVICE(0x04fa, 0x2490) },
1077         { },
1078 };
1079 MODULE_DEVICE_TABLE(usb, ds_id_table);
1080
1081 static struct usb_driver ds_driver = {
1082         .name =         "DS9490R",
1083         .probe =        ds_probe,
1084         .disconnect =   ds_disconnect,
1085         .id_table =     ds_id_table,
1086 };
1087 module_usb_driver(ds_driver);
1088
1089 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1090 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1091 MODULE_LICENSE("GPL");