linux/drivers/w1/masters/ds2490.c
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   1/*
   2 *      ds2490.c  USB to one wire bridge
   3 *
   4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
   5 *
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/kernel.h>
  24#include <linux/mod_devicetable.h>
  25#include <linux/usb.h>
  26#include <linux/slab.h>
  27
  28#include <linux/w1.h>
  29
  30/* USB Standard */
  31/* USB Control request vendor type */
  32#define VENDOR                          0x40
  33
  34/* COMMAND TYPE CODES */
  35#define CONTROL_CMD                     0x00
  36#define COMM_CMD                        0x01
  37#define MODE_CMD                        0x02
  38
  39/* CONTROL COMMAND CODES */
  40#define CTL_RESET_DEVICE                0x0000
  41#define CTL_START_EXE                   0x0001
  42#define CTL_RESUME_EXE                  0x0002
  43#define CTL_HALT_EXE_IDLE               0x0003
  44#define CTL_HALT_EXE_DONE               0x0004
  45#define CTL_FLUSH_COMM_CMDS             0x0007
  46#define CTL_FLUSH_RCV_BUFFER            0x0008
  47#define CTL_FLUSH_XMT_BUFFER            0x0009
  48#define CTL_GET_COMM_CMDS               0x000A
  49
  50/* MODE COMMAND CODES */
  51#define MOD_PULSE_EN                    0x0000
  52#define MOD_SPEED_CHANGE_EN             0x0001
  53#define MOD_1WIRE_SPEED                 0x0002
  54#define MOD_STRONG_PU_DURATION          0x0003
  55#define MOD_PULLDOWN_SLEWRATE           0x0004
  56#define MOD_PROG_PULSE_DURATION         0x0005
  57#define MOD_WRITE1_LOWTIME              0x0006
  58#define MOD_DSOW0_TREC                  0x0007
  59
  60/* COMMUNICATION COMMAND CODES */
  61#define COMM_ERROR_ESCAPE               0x0601
  62#define COMM_SET_DURATION               0x0012
  63#define COMM_BIT_IO                     0x0020
  64#define COMM_PULSE                      0x0030
  65#define COMM_1_WIRE_RESET               0x0042
  66#define COMM_BYTE_IO                    0x0052
  67#define COMM_MATCH_ACCESS               0x0064
  68#define COMM_BLOCK_IO                   0x0074
  69#define COMM_READ_STRAIGHT              0x0080
  70#define COMM_DO_RELEASE                 0x6092
  71#define COMM_SET_PATH                   0x00A2
  72#define COMM_WRITE_SRAM_PAGE            0x00B2
  73#define COMM_WRITE_EPROM                0x00C4
  74#define COMM_READ_CRC_PROT_PAGE         0x00D4
  75#define COMM_READ_REDIRECT_PAGE_CRC     0x21E4
  76#define COMM_SEARCH_ACCESS              0x00F4
  77
  78/* Communication command bits */
  79#define COMM_TYPE                       0x0008
  80#define COMM_SE                         0x0008
  81#define COMM_D                          0x0008
  82#define COMM_Z                          0x0008
  83#define COMM_CH                         0x0008
  84#define COMM_SM                         0x0008
  85#define COMM_R                          0x0008
  86#define COMM_IM                         0x0001
  87
  88#define COMM_PS                         0x4000
  89#define COMM_PST                        0x4000
  90#define COMM_CIB                        0x4000
  91#define COMM_RTS                        0x4000
  92#define COMM_DT                         0x2000
  93#define COMM_SPU                        0x1000
  94#define COMM_F                          0x0800
  95#define COMM_NTF                        0x0400
  96#define COMM_ICP                        0x0200
  97#define COMM_RST                        0x0100
  98
  99#define PULSE_PROG                      0x01
 100#define PULSE_SPUE                      0x02
 101
 102#define BRANCH_MAIN                     0xCC
 103#define BRANCH_AUX                      0x33
 104
 105/* Status flags */
 106#define ST_SPUA                         0x01  /* Strong Pull-up is active */
 107#define ST_PRGA                         0x02  /* 12V programming pulse is being generated */
 108#define ST_12VP                         0x04  /* external 12V programming voltage is present */
 109#define ST_PMOD                         0x08  /* DS2490 powered from USB and external sources */
 110#define ST_HALT                         0x10  /* DS2490 is currently halted */
 111#define ST_IDLE                         0x20  /* DS2490 is currently idle */
 112#define ST_EPOF                         0x80
 113/* Status transfer size, 16 bytes status, 16 byte result flags */
 114#define ST_SIZE                         0x20
 115
 116/* Result Register flags */
 117#define RR_DETECT                       0xA5 /* New device detected */
 118#define RR_NRS                          0x01 /* Reset no presence or ... */
 119#define RR_SH                           0x02 /* short on reset or set path */
 120#define RR_APP                          0x04 /* alarming presence on reset */
 121#define RR_VPP                          0x08 /* 12V expected not seen */
 122#define RR_CMP                          0x10 /* compare error */
 123#define RR_CRC                          0x20 /* CRC error detected */
 124#define RR_RDP                          0x40 /* redirected page */
 125#define RR_EOS                          0x80 /* end of search error */
 126
 127#define SPEED_NORMAL                    0x00
 128#define SPEED_FLEXIBLE                  0x01
 129#define SPEED_OVERDRIVE                 0x02
 130
 131#define NUM_EP                          4
 132#define EP_CONTROL                      0
 133#define EP_STATUS                       1
 134#define EP_DATA_OUT                     2
 135#define EP_DATA_IN                      3
 136
 137struct ds_device {
 138        struct list_head        ds_entry;
 139
 140        struct usb_device       *udev;
 141        struct usb_interface    *intf;
 142
 143        int                     ep[NUM_EP];
 144
 145        /* Strong PullUp
 146         * 0: pullup not active, else duration in milliseconds
 147         */
 148        int                     spu_sleep;
 149        /* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
 150         * should be active or not for writes.
 151         */
 152        u16                     spu_bit;
 153
 154        u8                      st_buf[ST_SIZE];
 155        u8                      byte_buf;
 156
 157        struct w1_bus_master    master;
 158};
 159
 160struct ds_status {
 161        u8                      enable;
 162        u8                      speed;
 163        u8                      pullup_dur;
 164        u8                      ppuls_dur;
 165        u8                      pulldown_slew;
 166        u8                      write1_time;
 167        u8                      write0_time;
 168        u8                      reserved0;
 169        u8                      status;
 170        u8                      command0;
 171        u8                      command1;
 172        u8                      command_buffer_status;
 173        u8                      data_out_buffer_status;
 174        u8                      data_in_buffer_status;
 175        u8                      reserved1;
 176        u8                      reserved2;
 177};
 178
 179static LIST_HEAD(ds_devices);
 180static DEFINE_MUTEX(ds_mutex);
 181
 182static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
 183{
 184        int err;
 185
 186        err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 187                        CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
 188        if (err < 0) {
 189                pr_err("Failed to send command control message %x.%x: err=%d.\n",
 190                                value, index, err);
 191                return err;
 192        }
 193
 194        return err;
 195}
 196
 197static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
 198{
 199        int err;
 200
 201        err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 202                        MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
 203        if (err < 0) {
 204                pr_err("Failed to send mode control message %x.%x: err=%d.\n",
 205                                value, index, err);
 206                return err;
 207        }
 208
 209        return err;
 210}
 211
 212static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
 213{
 214        int err;
 215
 216        err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
 217                        COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
 218        if (err < 0) {
 219                pr_err("Failed to send control message %x.%x: err=%d.\n",
 220                                value, index, err);
 221                return err;
 222        }
 223
 224        return err;
 225}
 226
 227static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
 228{
 229        pr_info("%45s: %8x\n", str, buf[off]);
 230}
 231
 232static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
 233{
 234        int i;
 235
 236        pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
 237        for (i = 0; i < count; ++i)
 238                pr_info("%02x ", buf[i]);
 239        pr_info("\n");
 240
 241        if (count >= 16) {
 242                ds_print_msg(buf, "enable flag", 0);
 243                ds_print_msg(buf, "1-wire speed", 1);
 244                ds_print_msg(buf, "strong pullup duration", 2);
 245                ds_print_msg(buf, "programming pulse duration", 3);
 246                ds_print_msg(buf, "pulldown slew rate control", 4);
 247                ds_print_msg(buf, "write-1 low time", 5);
 248                ds_print_msg(buf, "data sample offset/write-0 recovery time",
 249                        6);
 250                ds_print_msg(buf, "reserved (test register)", 7);
 251                ds_print_msg(buf, "device status flags", 8);
 252                ds_print_msg(buf, "communication command byte 1", 9);
 253                ds_print_msg(buf, "communication command byte 2", 10);
 254                ds_print_msg(buf, "communication command buffer status", 11);
 255                ds_print_msg(buf, "1-wire data output buffer status", 12);
 256                ds_print_msg(buf, "1-wire data input buffer status", 13);
 257                ds_print_msg(buf, "reserved", 14);
 258                ds_print_msg(buf, "reserved", 15);
 259        }
 260        for (i = 16; i < count; ++i) {
 261                if (buf[i] == RR_DETECT) {
 262                        ds_print_msg(buf, "new device detect", i);
 263                        continue;
 264                }
 265                ds_print_msg(buf, "Result Register Value: ", i);
 266                if (buf[i] & RR_NRS)
 267                        pr_info("NRS: Reset no presence or ...\n");
 268                if (buf[i] & RR_SH)
 269                        pr_info("SH: short on reset or set path\n");
 270                if (buf[i] & RR_APP)
 271                        pr_info("APP: alarming presence on reset\n");
 272                if (buf[i] & RR_VPP)
 273                        pr_info("VPP: 12V expected not seen\n");
 274                if (buf[i] & RR_CMP)
 275                        pr_info("CMP: compare error\n");
 276                if (buf[i] & RR_CRC)
 277                        pr_info("CRC: CRC error detected\n");
 278                if (buf[i] & RR_RDP)
 279                        pr_info("RDP: redirected page\n");
 280                if (buf[i] & RR_EOS)
 281                        pr_info("EOS: end of search error\n");
 282        }
 283}
 284
 285static int ds_recv_status(struct ds_device *dev, struct ds_status *st,
 286                          bool dump)
 287{
 288        int count, err;
 289
 290        if (st)
 291                memset(st, 0, sizeof(*st));
 292
 293        count = 0;
 294        err = usb_interrupt_msg(dev->udev,
 295                                usb_rcvintpipe(dev->udev,
 296                                               dev->ep[EP_STATUS]),
 297                                dev->st_buf, sizeof(dev->st_buf),
 298                                &count, 1000);
 299        if (err < 0) {
 300                pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
 301                       dev->ep[EP_STATUS], err);
 302                return err;
 303        }
 304
 305        if (dump)
 306                ds_dump_status(dev, dev->st_buf, count);
 307
 308        if (st && count >= sizeof(*st))
 309                memcpy(st, dev->st_buf, sizeof(*st));
 310
 311        return count;
 312}
 313
 314static void ds_reset_device(struct ds_device *dev)
 315{
 316        ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
 317        /* Always allow strong pullup which allow individual writes to use
 318         * the strong pullup.
 319         */
 320        if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
 321                pr_err("ds_reset_device: Error allowing strong pullup\n");
 322        /* Chip strong pullup time was cleared. */
 323        if (dev->spu_sleep) {
 324                /* lower 4 bits are 0, see ds_set_pullup */
 325                u8 del = dev->spu_sleep>>4;
 326                if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
 327                        pr_err("ds_reset_device: Error setting duration\n");
 328        }
 329}
 330
 331static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
 332{
 333        int count, err;
 334
 335        /* Careful on size.  If size is less than what is available in
 336         * the input buffer, the device fails the bulk transfer and
 337         * clears the input buffer.  It could read the maximum size of
 338         * the data buffer, but then do you return the first, last, or
 339         * some set of the middle size bytes?  As long as the rest of
 340         * the code is correct there will be size bytes waiting.  A
 341         * call to ds_wait_status will wait until the device is idle
 342         * and any data to be received would have been available.
 343         */
 344        count = 0;
 345        err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
 346                                buf, size, &count, 1000);
 347        if (err < 0) {
 348                pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
 349                usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
 350                ds_recv_status(dev, NULL, true);
 351                return err;
 352        }
 353
 354#if 0
 355        {
 356                int i;
 357
 358                printk("%s: count=%d: ", __func__, count);
 359                for (i = 0; i < count; ++i)
 360                        printk("%02x ", buf[i]);
 361                printk("\n");
 362        }
 363#endif
 364        return count;
 365}
 366
 367static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
 368{
 369        int count, err;
 370
 371        count = 0;
 372        err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
 373        if (err < 0) {
 374                pr_err("Failed to write 1-wire data to ep0x%x: "
 375                        "err=%d.\n", dev->ep[EP_DATA_OUT], err);
 376                return err;
 377        }
 378
 379        return err;
 380}
 381
 382#if 0
 383
 384int ds_stop_pulse(struct ds_device *dev, int limit)
 385{
 386        struct ds_status st;
 387        int count = 0, err = 0;
 388
 389        do {
 390                err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
 391                if (err)
 392                        break;
 393                err = ds_send_control(dev, CTL_RESUME_EXE, 0);
 394                if (err)
 395                        break;
 396                err = ds_recv_status(dev, &st, false);
 397                if (err)
 398                        break;
 399
 400                if ((st.status & ST_SPUA) == 0) {
 401                        err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
 402                        if (err)
 403                                break;
 404                }
 405        } while (++count < limit);
 406
 407        return err;
 408}
 409
 410int ds_detect(struct ds_device *dev, struct ds_status *st)
 411{
 412        int err;
 413
 414        err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
 415        if (err)
 416                return err;
 417
 418        err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
 419        if (err)
 420                return err;
 421
 422        err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
 423        if (err)
 424                return err;
 425
 426        err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
 427        if (err)
 428                return err;
 429
 430        err = ds_dump_status(dev, st);
 431
 432        return err;
 433}
 434
 435#endif  /*  0  */
 436
 437static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
 438{
 439        int err, count = 0;
 440
 441        do {
 442                st->status = 0;
 443                err = ds_recv_status(dev, st, false);
 444#if 0
 445                if (err >= 0) {
 446                        int i;
 447                        printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
 448                        for (i = 0; i < err; ++i)
 449                                printk("%02x ", dev->st_buf[i]);
 450                        printk("\n");
 451                }
 452#endif
 453        } while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
 454
 455        if (err >= 16 && st->status & ST_EPOF) {
 456                pr_info("Resetting device after ST_EPOF.\n");
 457                ds_reset_device(dev);
 458                /* Always dump the device status. */
 459                count = 101;
 460        }
 461
 462        /* Dump the status for errors or if there is extended return data.
 463         * The extended status includes new device detection (maybe someone
 464         * can do something with it).
 465         */
 466        if (err > 16 || count >= 100 || err < 0)
 467                ds_dump_status(dev, dev->st_buf, err);
 468
 469        /* Extended data isn't an error.  Well, a short is, but the dump
 470         * would have already told the user that and we can't do anything
 471         * about it in software anyway.
 472         */
 473        if (count >= 100 || err < 0)
 474                return -1;
 475        else
 476                return 0;
 477}
 478
 479static int ds_reset(struct ds_device *dev)
 480{
 481        int err;
 482
 483        /* Other potentionally interesting flags for reset.
 484         *
 485         * COMM_NTF: Return result register feedback.  This could be used to
 486         * detect some conditions such as short, alarming presence, or
 487         * detect if a new device was detected.
 488         *
 489         * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
 490         * Select the data transfer rate.
 491         */
 492        err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
 493        if (err)
 494                return err;
 495
 496        return 0;
 497}
 498
 499#if 0
 500static int ds_set_speed(struct ds_device *dev, int speed)
 501{
 502        int err;
 503
 504        if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
 505                return -EINVAL;
 506
 507        if (speed != SPEED_OVERDRIVE)
 508                speed = SPEED_FLEXIBLE;
 509
 510        speed &= 0xff;
 511
 512        err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
 513        if (err)
 514                return err;
 515
 516        return err;
 517}
 518#endif  /*  0  */
 519
 520static int ds_set_pullup(struct ds_device *dev, int delay)
 521{
 522        int err = 0;
 523        u8 del = 1 + (u8)(delay >> 4);
 524        /* Just storing delay would not get the trunication and roundup. */
 525        int ms = del<<4;
 526
 527        /* Enable spu_bit if a delay is set. */
 528        dev->spu_bit = delay ? COMM_SPU : 0;
 529        /* If delay is zero, it has already been disabled, if the time is
 530         * the same as the hardware was last programmed to, there is also
 531         * nothing more to do.  Compare with the recalculated value ms
 532         * rather than del or delay which can have a different value.
 533         */
 534        if (delay == 0 || ms == dev->spu_sleep)
 535                return err;
 536
 537        err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
 538        if (err)
 539                return err;
 540
 541        dev->spu_sleep = ms;
 542
 543        return err;
 544}
 545
 546static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
 547{
 548        int err;
 549        struct ds_status st;
 550
 551        err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
 552                0);
 553        if (err)
 554                return err;
 555
 556        ds_wait_status(dev, &st);
 557
 558        err = ds_recv_data(dev, tbit, sizeof(*tbit));
 559        if (err < 0)
 560                return err;
 561
 562        return 0;
 563}
 564
 565#if 0
 566static int ds_write_bit(struct ds_device *dev, u8 bit)
 567{
 568        int err;
 569        struct ds_status st;
 570
 571        /* Set COMM_ICP to write without a readback.  Note, this will
 572         * produce one time slot, a down followed by an up with COMM_D
 573         * only determing the timing.
 574         */
 575        err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
 576                (bit ? COMM_D : 0), 0);
 577        if (err)
 578                return err;
 579
 580        ds_wait_status(dev, &st);
 581
 582        return 0;
 583}
 584#endif
 585
 586static int ds_write_byte(struct ds_device *dev, u8 byte)
 587{
 588        int err;
 589        struct ds_status st;
 590
 591        err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
 592        if (err)
 593                return err;
 594
 595        if (dev->spu_bit)
 596                msleep(dev->spu_sleep);
 597
 598        err = ds_wait_status(dev, &st);
 599        if (err)
 600                return err;
 601
 602        err = ds_recv_data(dev, &dev->byte_buf, 1);
 603        if (err < 0)
 604                return err;
 605
 606        return !(byte == dev->byte_buf);
 607}
 608
 609static int ds_read_byte(struct ds_device *dev, u8 *byte)
 610{
 611        int err;
 612        struct ds_status st;
 613
 614        err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
 615        if (err)
 616                return err;
 617
 618        ds_wait_status(dev, &st);
 619
 620        err = ds_recv_data(dev, byte, sizeof(*byte));
 621        if (err < 0)
 622                return err;
 623
 624        return 0;
 625}
 626
 627static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
 628{
 629        struct ds_status st;
 630        int err;
 631
 632        if (len > 64*1024)
 633                return -E2BIG;
 634
 635        memset(buf, 0xFF, len);
 636
 637        err = ds_send_data(dev, buf, len);
 638        if (err < 0)
 639                return err;
 640
 641        err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
 642        if (err)
 643                return err;
 644
 645        ds_wait_status(dev, &st);
 646
 647        memset(buf, 0x00, len);
 648        err = ds_recv_data(dev, buf, len);
 649
 650        return err;
 651}
 652
 653static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
 654{
 655        int err;
 656        struct ds_status st;
 657
 658        err = ds_send_data(dev, buf, len);
 659        if (err < 0)
 660                return err;
 661
 662        err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
 663        if (err)
 664                return err;
 665
 666        if (dev->spu_bit)
 667                msleep(dev->spu_sleep);
 668
 669        ds_wait_status(dev, &st);
 670
 671        err = ds_recv_data(dev, buf, len);
 672        if (err < 0)
 673                return err;
 674
 675        return !(err == len);
 676}
 677
 678static void ds9490r_search(void *data, struct w1_master *master,
 679        u8 search_type, w1_slave_found_callback callback)
 680{
 681        /* When starting with an existing id, the first id returned will
 682         * be that device (if it is still on the bus most likely).
 683         *
 684         * If the number of devices found is less than or equal to the
 685         * search_limit, that number of IDs will be returned.  If there are
 686         * more, search_limit IDs will be returned followed by a non-zero
 687         * discrepency value.
 688         */
 689        struct ds_device *dev = data;
 690        int err;
 691        u16 value, index;
 692        struct ds_status st;
 693        int search_limit;
 694        int found = 0;
 695        int i;
 696
 697        /* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
 698         * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
 699         */
 700        const unsigned long jtime = msecs_to_jiffies(1000*8/75);
 701        /* FIFO 128 bytes, bulk packet size 64, read a multiple of the
 702         * packet size.
 703         */
 704        const size_t bufsize = 2 * 64;
 705        u64 *buf;
 706
 707        buf = kmalloc(bufsize, GFP_KERNEL);
 708        if (!buf)
 709                return;
 710
 711        mutex_lock(&master->bus_mutex);
 712
 713        /* address to start searching at */
 714        if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
 715                goto search_out;
 716        master->search_id = 0;
 717
 718        value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
 719                COMM_RTS;
 720        search_limit = master->max_slave_count;
 721        if (search_limit > 255)
 722                search_limit = 0;
 723        index = search_type | (search_limit << 8);
 724        if (ds_send_control(dev, value, index) < 0)
 725                goto search_out;
 726
 727        do {
 728                schedule_timeout(jtime);
 729
 730                err = ds_recv_status(dev, &st, false);
 731                if (err < 0 || err < sizeof(st))
 732                        break;
 733
 734                if (st.data_in_buffer_status) {
 735                        /* Bulk in can receive partial ids, but when it does
 736                         * they fail crc and will be discarded anyway.
 737                         * That has only been seen when status in buffer
 738                         * is 0 and bulk is read anyway, so don't read
 739                         * bulk without first checking if status says there
 740                         * is data to read.
 741                         */
 742                        err = ds_recv_data(dev, (u8 *)buf, bufsize);
 743                        if (err < 0)
 744                                break;
 745                        for (i = 0; i < err/8; ++i) {
 746                                ++found;
 747                                if (found <= search_limit)
 748                                        callback(master, buf[i]);
 749                                /* can't know if there will be a discrepancy
 750                                 * value after until the next id */
 751                                if (found == search_limit)
 752                                        master->search_id = buf[i];
 753                        }
 754                }
 755
 756                if (test_bit(W1_ABORT_SEARCH, &master->flags))
 757                        break;
 758        } while (!(st.status & (ST_IDLE | ST_HALT)));
 759
 760        /* only continue the search if some weren't found */
 761        if (found <= search_limit) {
 762                master->search_id = 0;
 763        } else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
 764                /* Only max_slave_count will be scanned in a search,
 765                 * but it will start where it left off next search
 766                 * until all ids are identified and then it will start
 767                 * over.  A continued search will report the previous
 768                 * last id as the first id (provided it is still on the
 769                 * bus).
 770                 */
 771                dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
 772                        "will continue next search.\n", __func__,
 773                        master->max_slave_count);
 774                set_bit(W1_WARN_MAX_COUNT, &master->flags);
 775        }
 776search_out:
 777        mutex_unlock(&master->bus_mutex);
 778        kfree(buf);
 779}
 780
 781#if 0
 782/*
 783 * FIXME: if this disabled code is ever used in the future all ds_send_data()
 784 * calls must be changed to use a DMAable buffer.
 785 */
 786static int ds_match_access(struct ds_device *dev, u64 init)
 787{
 788        int err;
 789        struct ds_status st;
 790
 791        err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
 792        if (err)
 793                return err;
 794
 795        ds_wait_status(dev, &st);
 796
 797        err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
 798        if (err)
 799                return err;
 800
 801        ds_wait_status(dev, &st);
 802
 803        return 0;
 804}
 805
 806static int ds_set_path(struct ds_device *dev, u64 init)
 807{
 808        int err;
 809        struct ds_status st;
 810        u8 buf[9];
 811
 812        memcpy(buf, &init, 8);
 813        buf[8] = BRANCH_MAIN;
 814
 815        err = ds_send_data(dev, buf, sizeof(buf));
 816        if (err)
 817                return err;
 818
 819        ds_wait_status(dev, &st);
 820
 821        err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
 822        if (err)
 823                return err;
 824
 825        ds_wait_status(dev, &st);
 826
 827        return 0;
 828}
 829
 830#endif  /*  0  */
 831
 832static u8 ds9490r_touch_bit(void *data, u8 bit)
 833{
 834        struct ds_device *dev = data;
 835
 836        if (ds_touch_bit(dev, bit, &dev->byte_buf))
 837                return 0;
 838
 839        return dev->byte_buf;
 840}
 841
 842#if 0
 843static void ds9490r_write_bit(void *data, u8 bit)
 844{
 845        struct ds_device *dev = data;
 846
 847        ds_write_bit(dev, bit);
 848}
 849
 850static u8 ds9490r_read_bit(void *data)
 851{
 852        struct ds_device *dev = data;
 853        int err;
 854
 855        err = ds_touch_bit(dev, 1, &dev->byte_buf);
 856        if (err)
 857                return 0;
 858
 859        return dev->byte_buf & 1;
 860}
 861#endif
 862
 863static void ds9490r_write_byte(void *data, u8 byte)
 864{
 865        struct ds_device *dev = data;
 866
 867        ds_write_byte(dev, byte);
 868}
 869
 870static u8 ds9490r_read_byte(void *data)
 871{
 872        struct ds_device *dev = data;
 873        int err;
 874
 875        err = ds_read_byte(dev, &dev->byte_buf);
 876        if (err)
 877                return 0;
 878
 879        return dev->byte_buf;
 880}
 881
 882static void ds9490r_write_block(void *data, const u8 *buf, int len)
 883{
 884        struct ds_device *dev = data;
 885        u8 *tbuf;
 886
 887        if (len <= 0)
 888                return;
 889
 890        tbuf = kmemdup(buf, len, GFP_KERNEL);
 891        if (!tbuf)
 892                return;
 893
 894        ds_write_block(dev, tbuf, len);
 895
 896        kfree(tbuf);
 897}
 898
 899static u8 ds9490r_read_block(void *data, u8 *buf, int len)
 900{
 901        struct ds_device *dev = data;
 902        int err;
 903        u8 *tbuf;
 904
 905        if (len <= 0)
 906                return 0;
 907
 908        tbuf = kmalloc(len, GFP_KERNEL);
 909        if (!tbuf)
 910                return 0;
 911
 912        err = ds_read_block(dev, tbuf, len);
 913        if (err >= 0)
 914                memcpy(buf, tbuf, len);
 915
 916        kfree(tbuf);
 917
 918        return err >= 0 ? len : 0;
 919}
 920
 921static u8 ds9490r_reset(void *data)
 922{
 923        struct ds_device *dev = data;
 924        int err;
 925
 926        err = ds_reset(dev);
 927        if (err)
 928                return 1;
 929
 930        return 0;
 931}
 932
 933static u8 ds9490r_set_pullup(void *data, int delay)
 934{
 935        struct ds_device *dev = data;
 936
 937        if (ds_set_pullup(dev, delay))
 938                return 1;
 939
 940        return 0;
 941}
 942
 943static int ds_w1_init(struct ds_device *dev)
 944{
 945        memset(&dev->master, 0, sizeof(struct w1_bus_master));
 946
 947        /* Reset the device as it can be in a bad state.
 948         * This is necessary because a block write will wait for data
 949         * to be placed in the output buffer and block any later
 950         * commands which will keep accumulating and the device will
 951         * not be idle.  Another case is removing the ds2490 module
 952         * while a bus search is in progress, somehow a few commands
 953         * get through, but the input transfers fail leaving data in
 954         * the input buffer.  This will cause the next read to fail
 955         * see the note in ds_recv_data.
 956         */
 957        ds_reset_device(dev);
 958
 959        dev->master.data        = dev;
 960        dev->master.touch_bit   = &ds9490r_touch_bit;
 961        /* read_bit and write_bit in w1_bus_master are expected to set and
 962         * sample the line level.  For write_bit that means it is expected to
 963         * set it to that value and leave it there.  ds2490 only supports an
 964         * individual time slot at the lowest level.  The requirement from
 965         * pulling the bus state down to reading the state is 15us, something
 966         * that isn't realistic on the USB bus anyway.
 967        dev->master.read_bit    = &ds9490r_read_bit;
 968        dev->master.write_bit   = &ds9490r_write_bit;
 969        */
 970        dev->master.read_byte   = &ds9490r_read_byte;
 971        dev->master.write_byte  = &ds9490r_write_byte;
 972        dev->master.read_block  = &ds9490r_read_block;
 973        dev->master.write_block = &ds9490r_write_block;
 974        dev->master.reset_bus   = &ds9490r_reset;
 975        dev->master.set_pullup  = &ds9490r_set_pullup;
 976        dev->master.search      = &ds9490r_search;
 977
 978        return w1_add_master_device(&dev->master);
 979}
 980
 981static void ds_w1_fini(struct ds_device *dev)
 982{
 983        w1_remove_master_device(&dev->master);
 984}
 985
 986static int ds_probe(struct usb_interface *intf,
 987                    const struct usb_device_id *udev_id)
 988{
 989        struct usb_device *udev = interface_to_usbdev(intf);
 990        struct usb_endpoint_descriptor *endpoint;
 991        struct usb_host_interface *iface_desc;
 992        struct ds_device *dev;
 993        int i, err, alt;
 994
 995        dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
 996        if (!dev) {
 997                pr_info("Failed to allocate new DS9490R structure.\n");
 998                return -ENOMEM;
 999        }
1000        dev->udev = usb_get_dev(udev);
1001        if (!dev->udev) {
1002                err = -ENOMEM;
1003                goto err_out_free;
1004        }
1005        memset(dev->ep, 0, sizeof(dev->ep));
1006
1007        usb_set_intfdata(intf, dev);
1008
1009        err = usb_reset_configuration(dev->udev);
1010        if (err) {
1011                dev_err(&dev->udev->dev,
1012                        "Failed to reset configuration: err=%d.\n", err);
1013                goto err_out_clear;
1014        }
1015
1016        /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1017        alt = 3;
1018        err = usb_set_interface(dev->udev,
1019                intf->altsetting[alt].desc.bInterfaceNumber, alt);
1020        if (err) {
1021                dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1022                        "for %d interface: err=%d.\n", alt,
1023                        intf->altsetting[alt].desc.bInterfaceNumber, err);
1024                goto err_out_clear;
1025        }
1026
1027        iface_desc = &intf->altsetting[alt];
1028        if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1029                pr_info("Num endpoints=%d. It is not DS9490R.\n",
1030                        iface_desc->desc.bNumEndpoints);
1031                err = -EINVAL;
1032                goto err_out_clear;
1033        }
1034
1035        /*
1036         * This loop doesn'd show control 0 endpoint,
1037         * so we will fill only 1-3 endpoints entry.
1038         */
1039        for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1040                endpoint = &iface_desc->endpoint[i].desc;
1041
1042                dev->ep[i+1] = endpoint->bEndpointAddress;
1043#if 0
1044                printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1045                        i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1046                        (endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1047                        endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1048#endif
1049        }
1050
1051        err = ds_w1_init(dev);
1052        if (err)
1053                goto err_out_clear;
1054
1055        mutex_lock(&ds_mutex);
1056        list_add_tail(&dev->ds_entry, &ds_devices);
1057        mutex_unlock(&ds_mutex);
1058
1059        return 0;
1060
1061err_out_clear:
1062        usb_set_intfdata(intf, NULL);
1063        usb_put_dev(dev->udev);
1064err_out_free:
1065        kfree(dev);
1066        return err;
1067}
1068
1069static void ds_disconnect(struct usb_interface *intf)
1070{
1071        struct ds_device *dev;
1072
1073        dev = usb_get_intfdata(intf);
1074        if (!dev)
1075                return;
1076
1077        mutex_lock(&ds_mutex);
1078        list_del(&dev->ds_entry);
1079        mutex_unlock(&ds_mutex);
1080
1081        ds_w1_fini(dev);
1082
1083        usb_set_intfdata(intf, NULL);
1084
1085        usb_put_dev(dev->udev);
1086        kfree(dev);
1087}
1088
1089static const struct usb_device_id ds_id_table[] = {
1090        { USB_DEVICE(0x04fa, 0x2490) },
1091        { },
1092};
1093MODULE_DEVICE_TABLE(usb, ds_id_table);
1094
1095static struct usb_driver ds_driver = {
1096        .name =         "DS9490R",
1097        .probe =        ds_probe,
1098        .disconnect =   ds_disconnect,
1099        .id_table =     ds_id_table,
1100};
1101module_usb_driver(ds_driver);
1102
1103MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1104MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1105MODULE_LICENSE("GPL");
1106