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 ds_send_control_cmd(struct ds_device * dev,u16 value,u16 index)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 dev_err(&dev->udev->dev, 176 "Failed to send command control message %x.%x: err=%d.\n", 177 value, index, err); 178 return err; 179 } 180 181 return err; 182 } 183 ds_send_control_mode(struct ds_device * dev,u16 value,u16 index)184 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index) 185 { 186 int err; 187 188 err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]), 189 MODE_CMD, VENDOR, value, index, NULL, 0, 1000); 190 if (err < 0) { 191 dev_err(&dev->udev->dev, 192 "Failed to send mode control message %x.%x: err=%d.\n", 193 value, index, err); 194 return err; 195 } 196 197 return err; 198 } 199 ds_send_control(struct ds_device * dev,u16 value,u16 index)200 static int ds_send_control(struct ds_device *dev, u16 value, u16 index) 201 { 202 int err; 203 204 err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]), 205 COMM_CMD, VENDOR, value, index, NULL, 0, 1000); 206 if (err < 0) { 207 dev_err(&dev->udev->dev, 208 "Failed to send control message %x.%x: err=%d.\n", 209 value, index, err); 210 return err; 211 } 212 213 return err; 214 } 215 ds_dump_status(struct ds_device * ds_dev,unsigned char * buf,int count)216 static void ds_dump_status(struct ds_device *ds_dev, unsigned char *buf, int count) 217 { 218 struct device *dev = &ds_dev->udev->dev; 219 int i; 220 221 dev_info(dev, "ep_status=0x%x, count=%d, status=%*phC", 222 ds_dev->ep[EP_STATUS], count, count, buf); 223 224 if (count >= 16) { 225 dev_dbg(dev, "enable flag: 0x%02x", buf[0]); 226 dev_dbg(dev, "1-wire speed: 0x%02x", buf[1]); 227 dev_dbg(dev, "strong pullup duration: 0x%02x", buf[2]); 228 dev_dbg(dev, "programming pulse duration: 0x%02x", buf[3]); 229 dev_dbg(dev, "pulldown slew rate control: 0x%02x", buf[4]); 230 dev_dbg(dev, "write-1 low time: 0x%02x", buf[5]); 231 dev_dbg(dev, "data sample offset/write-0 recovery time: 0x%02x", buf[6]); 232 dev_dbg(dev, "reserved (test register): 0x%02x", buf[7]); 233 dev_dbg(dev, "device status flags: 0x%02x", buf[8]); 234 dev_dbg(dev, "communication command byte 1: 0x%02x", buf[9]); 235 dev_dbg(dev, "communication command byte 2: 0x%02x", buf[10]); 236 dev_dbg(dev, "communication command buffer status: 0x%02x", buf[11]); 237 dev_dbg(dev, "1-wire data output buffer status: 0x%02x", buf[12]); 238 dev_dbg(dev, "1-wire data input buffer status: 0x%02x", buf[13]); 239 dev_dbg(dev, "reserved: 0x%02x", buf[14]); 240 dev_dbg(dev, "reserved: 0x%02x", buf[15]); 241 } 242 243 for (i = 16; i < count; ++i) { 244 if (buf[i] == RR_DETECT) { 245 dev_dbg(dev, "New device detect.\n"); 246 continue; 247 } 248 dev_dbg(dev, "Result Register Value: 0x%02x", buf[i]); 249 if (buf[i] & RR_NRS) 250 dev_dbg(dev, "NRS: Reset no presence or ...\n"); 251 if (buf[i] & RR_SH) 252 dev_dbg(dev, "SH: short on reset or set path\n"); 253 if (buf[i] & RR_APP) 254 dev_dbg(dev, "APP: alarming presence on reset\n"); 255 if (buf[i] & RR_VPP) 256 dev_dbg(dev, "VPP: 12V expected not seen\n"); 257 if (buf[i] & RR_CMP) 258 dev_dbg(dev, "CMP: compare error\n"); 259 if (buf[i] & RR_CRC) 260 dev_dbg(dev, "CRC: CRC error detected\n"); 261 if (buf[i] & RR_RDP) 262 dev_dbg(dev, "RDP: redirected page\n"); 263 if (buf[i] & RR_EOS) 264 dev_dbg(dev, "EOS: end of search error\n"); 265 } 266 } 267 ds_recv_status(struct ds_device * dev,struct ds_status * st)268 static int ds_recv_status(struct ds_device *dev, struct ds_status *st) 269 { 270 int count, err; 271 272 if (st) 273 memset(st, 0, sizeof(*st)); 274 275 count = 0; 276 err = usb_interrupt_msg(dev->udev, 277 usb_rcvintpipe(dev->udev, 278 dev->ep[EP_STATUS]), 279 dev->st_buf, sizeof(dev->st_buf), 280 &count, 1000); 281 if (err < 0) { 282 dev_err(&dev->udev->dev, 283 "Failed to read 1-wire data from 0x%x: err=%d.\n", 284 dev->ep[EP_STATUS], err); 285 return err; 286 } 287 288 if (st && count >= sizeof(*st)) 289 memcpy(st, dev->st_buf, sizeof(*st)); 290 291 return count; 292 } 293 ds_reset_device(struct ds_device * dev)294 static void ds_reset_device(struct ds_device *dev) 295 { 296 ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0); 297 /* Always allow strong pullup which allow individual writes to use 298 * the strong pullup. 299 */ 300 if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE)) 301 dev_err(&dev->udev->dev, 302 "%s: Error allowing strong pullup\n", __func__); 303 /* Chip strong pullup time was cleared. */ 304 if (dev->spu_sleep) { 305 /* lower 4 bits are 0, see ds_set_pullup */ 306 u8 del = dev->spu_sleep>>4; 307 308 if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del)) 309 dev_err(&dev->udev->dev, 310 "%s: Error setting duration\n", __func__); 311 } 312 } 313 ds_recv_data(struct ds_device * dev,unsigned char * buf,int size)314 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size) 315 { 316 int count, err; 317 318 /* Careful on size. If size is less than what is available in 319 * the input buffer, the device fails the bulk transfer and 320 * clears the input buffer. It could read the maximum size of 321 * the data buffer, but then do you return the first, last, or 322 * some set of the middle size bytes? As long as the rest of 323 * the code is correct there will be size bytes waiting. A 324 * call to ds_wait_status will wait until the device is idle 325 * and any data to be received would have been available. 326 */ 327 count = 0; 328 err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]), 329 buf, size, &count, 1000); 330 if (err < 0) { 331 int recv_len; 332 333 dev_info(&dev->udev->dev, "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]); 334 usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN])); 335 336 /* status might tell us why endpoint is stuck? */ 337 recv_len = ds_recv_status(dev, NULL); 338 if (recv_len >= 0) 339 ds_dump_status(dev, dev->st_buf, recv_len); 340 341 return err; 342 } 343 344 #if 0 345 { 346 int i; 347 348 printk("%s: count=%d: ", __func__, count); 349 for (i = 0; i < count; ++i) 350 printk("%02x ", buf[i]); 351 printk("\n"); 352 } 353 #endif 354 return count; 355 } 356 ds_send_data(struct ds_device * dev,unsigned char * buf,int len)357 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len) 358 { 359 int count, err; 360 361 count = 0; 362 err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000); 363 if (err < 0) { 364 dev_err(&dev->udev->dev, "Failed to write 1-wire data to ep0x%x: " 365 "err=%d.\n", dev->ep[EP_DATA_OUT], err); 366 return err; 367 } 368 369 return err; 370 } 371 372 #if 0 373 374 int ds_stop_pulse(struct ds_device *dev, int limit) 375 { 376 struct ds_status st; 377 int count = 0, err = 0; 378 379 do { 380 err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0); 381 if (err) 382 break; 383 err = ds_send_control(dev, CTL_RESUME_EXE, 0); 384 if (err) 385 break; 386 err = ds_recv_status(dev, &st); 387 if (err) 388 break; 389 390 if ((st.status & ST_SPUA) == 0) { 391 err = ds_send_control_mode(dev, MOD_PULSE_EN, 0); 392 if (err) 393 break; 394 } 395 } while (++count < limit); 396 397 return err; 398 } 399 400 int ds_detect(struct ds_device *dev, struct ds_status *st) 401 { 402 int err; 403 404 err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0); 405 if (err) 406 return err; 407 408 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0); 409 if (err) 410 return err; 411 412 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40); 413 if (err) 414 return err; 415 416 err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG); 417 if (err) 418 return err; 419 420 err = ds_dump_status(dev, st); 421 422 return err; 423 } 424 425 #endif /* 0 */ 426 ds_wait_status(struct ds_device * dev,struct ds_status * st)427 static int ds_wait_status(struct ds_device *dev, struct ds_status *st) 428 { 429 int err, count = 0; 430 431 do { 432 st->status = 0; 433 err = ds_recv_status(dev, st); 434 #if 0 435 if (err >= 0) { 436 int i; 437 printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err); 438 for (i = 0; i < err; ++i) 439 printk("%02x ", dev->st_buf[i]); 440 printk("\n"); 441 } 442 #endif 443 } while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100); 444 445 if (err >= 16 && st->status & ST_EPOF) { 446 dev_info(&dev->udev->dev, "Resetting device after ST_EPOF.\n"); 447 ds_reset_device(dev); 448 /* Always dump the device status. */ 449 count = 101; 450 } 451 452 /* Dump the status for errors or if there is extended return data. 453 * The extended status includes new device detection (maybe someone 454 * can do something with it). 455 */ 456 if (err > 16 || count >= 100 || err < 0) 457 ds_dump_status(dev, dev->st_buf, err); 458 459 /* Extended data isn't an error. Well, a short is, but the dump 460 * would have already told the user that and we can't do anything 461 * about it in software anyway. 462 */ 463 if (count >= 100 || err < 0) 464 return -1; 465 else 466 return 0; 467 } 468 ds_reset(struct ds_device * dev)469 static int ds_reset(struct ds_device *dev) 470 { 471 int err; 472 473 /* Other potentionally interesting flags for reset. 474 * 475 * COMM_NTF: Return result register feedback. This could be used to 476 * detect some conditions such as short, alarming presence, or 477 * detect if a new device was detected. 478 * 479 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE: 480 * Select the data transfer rate. 481 */ 482 err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL); 483 if (err) 484 return err; 485 486 return 0; 487 } 488 489 #if 0 490 static int ds_set_speed(struct ds_device *dev, int speed) 491 { 492 int err; 493 494 if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE) 495 return -EINVAL; 496 497 if (speed != SPEED_OVERDRIVE) 498 speed = SPEED_FLEXIBLE; 499 500 speed &= 0xff; 501 502 err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed); 503 if (err) 504 return err; 505 506 return err; 507 } 508 #endif /* 0 */ 509 ds_set_pullup(struct ds_device * dev,int delay)510 static int ds_set_pullup(struct ds_device *dev, int delay) 511 { 512 int err = 0; 513 u8 del = 1 + (u8)(delay >> 4); 514 /* Just storing delay would not get the trunication and roundup. */ 515 int ms = del<<4; 516 517 /* Enable spu_bit if a delay is set. */ 518 dev->spu_bit = delay ? COMM_SPU : 0; 519 /* If delay is zero, it has already been disabled, if the time is 520 * the same as the hardware was last programmed to, there is also 521 * nothing more to do. Compare with the recalculated value ms 522 * rather than del or delay which can have a different value. 523 */ 524 if (delay == 0 || ms == dev->spu_sleep) 525 return err; 526 527 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del); 528 if (err) 529 return err; 530 531 dev->spu_sleep = ms; 532 533 return err; 534 } 535 ds_touch_bit(struct ds_device * dev,u8 bit,u8 * tbit)536 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit) 537 { 538 int err; 539 struct ds_status st; 540 541 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0), 542 0); 543 if (err) 544 return err; 545 546 ds_wait_status(dev, &st); 547 548 err = ds_recv_data(dev, tbit, sizeof(*tbit)); 549 if (err < 0) 550 return err; 551 552 return 0; 553 } 554 555 #if 0 556 static int ds_write_bit(struct ds_device *dev, u8 bit) 557 { 558 int err; 559 struct ds_status st; 560 561 /* Set COMM_ICP to write without a readback. Note, this will 562 * produce one time slot, a down followed by an up with COMM_D 563 * only determing the timing. 564 */ 565 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP | 566 (bit ? COMM_D : 0), 0); 567 if (err) 568 return err; 569 570 ds_wait_status(dev, &st); 571 572 return 0; 573 } 574 #endif 575 ds_write_byte(struct ds_device * dev,u8 byte)576 static int ds_write_byte(struct ds_device *dev, u8 byte) 577 { 578 int err; 579 struct ds_status st; 580 581 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte); 582 if (err) 583 return err; 584 585 if (dev->spu_bit) 586 msleep(dev->spu_sleep); 587 588 err = ds_wait_status(dev, &st); 589 if (err) 590 return err; 591 592 err = ds_recv_data(dev, &dev->byte_buf, 1); 593 if (err < 0) 594 return err; 595 596 return !(byte == dev->byte_buf); 597 } 598 ds_read_byte(struct ds_device * dev,u8 * byte)599 static int ds_read_byte(struct ds_device *dev, u8 *byte) 600 { 601 int err; 602 struct ds_status st; 603 604 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff); 605 if (err) 606 return err; 607 608 ds_wait_status(dev, &st); 609 610 err = ds_recv_data(dev, byte, sizeof(*byte)); 611 if (err < 0) 612 return err; 613 614 return 0; 615 } 616 ds_read_block(struct ds_device * dev,u8 * buf,int len)617 static int ds_read_block(struct ds_device *dev, u8 *buf, int len) 618 { 619 struct ds_status st; 620 int err; 621 622 if (len > 64*1024) 623 return -E2BIG; 624 625 memset(buf, 0xFF, len); 626 627 err = ds_send_data(dev, buf, len); 628 if (err < 0) 629 return err; 630 631 err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len); 632 if (err) 633 return err; 634 635 ds_wait_status(dev, &st); 636 637 memset(buf, 0x00, len); 638 err = ds_recv_data(dev, buf, len); 639 640 return err; 641 } 642 ds_write_block(struct ds_device * dev,u8 * buf,int len)643 static int ds_write_block(struct ds_device *dev, u8 *buf, int len) 644 { 645 int err; 646 struct ds_status st; 647 648 err = ds_send_data(dev, buf, len); 649 if (err < 0) 650 return err; 651 652 err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len); 653 if (err) 654 return err; 655 656 if (dev->spu_bit) 657 msleep(dev->spu_sleep); 658 659 ds_wait_status(dev, &st); 660 661 err = ds_recv_data(dev, buf, len); 662 if (err < 0) 663 return err; 664 665 return !(err == len); 666 } 667 ds9490r_search(void * data,struct w1_master * master,u8 search_type,w1_slave_found_callback callback)668 static void ds9490r_search(void *data, struct w1_master *master, 669 u8 search_type, w1_slave_found_callback callback) 670 { 671 /* When starting with an existing id, the first id returned will 672 * be that device (if it is still on the bus most likely). 673 * 674 * If the number of devices found is less than or equal to the 675 * search_limit, that number of IDs will be returned. If there are 676 * more, search_limit IDs will be returned followed by a non-zero 677 * discrepency value. 678 */ 679 struct ds_device *dev = data; 680 int err; 681 u16 value, index; 682 struct ds_status st; 683 int search_limit; 684 int found = 0; 685 int i; 686 687 /* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for 688 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time. 689 */ 690 const unsigned long jtime = msecs_to_jiffies(1000*8/75); 691 /* FIFO 128 bytes, bulk packet size 64, read a multiple of the 692 * packet size. 693 */ 694 const size_t bufsize = 2 * 64; 695 u64 *buf, *found_ids; 696 697 buf = kmalloc(bufsize, GFP_KERNEL); 698 if (!buf) 699 return; 700 701 /* 702 * We are holding the bus mutex during the scan, but adding devices via the 703 * callback needs the bus to be unlocked. So we queue up found ids here. 704 */ 705 found_ids = kmalloc_array(master->max_slave_count, sizeof(u64), GFP_KERNEL); 706 if (!found_ids) { 707 kfree(buf); 708 return; 709 } 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); 731 if (err < 0 || err < sizeof(st)) 732 break; 733 734 if (st.data_in_buffer_status) { 735 /* 736 * Bulk in can receive partial ids, but when it does 737 * they fail crc and will be discarded anyway. 738 * That has only been seen when status in buffer 739 * is 0 and bulk is read anyway, so don't read 740 * bulk without first checking if status says there 741 * is data to read. 742 */ 743 err = ds_recv_data(dev, (u8 *)buf, bufsize); 744 if (err < 0) 745 break; 746 for (i = 0; i < err/8; ++i) { 747 found_ids[found++] = buf[i]; 748 /* 749 * can't know if there will be a discrepancy 750 * value after until the next id 751 */ 752 if (found == search_limit) { 753 master->search_id = buf[i]; 754 break; 755 } 756 } 757 } 758 759 if (test_bit(W1_ABORT_SEARCH, &master->flags)) 760 break; 761 } while (!(st.status & (ST_IDLE | ST_HALT))); 762 763 /* only continue the search if some weren't found */ 764 if (found <= search_limit) { 765 master->search_id = 0; 766 } else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) { 767 /* 768 * Only max_slave_count will be scanned in a search, 769 * but it will start where it left off next search 770 * until all ids are identified and then it will start 771 * over. A continued search will report the previous 772 * last id as the first id (provided it is still on the 773 * bus). 774 */ 775 dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, " 776 "will continue next search.\n", __func__, 777 master->max_slave_count); 778 set_bit(W1_WARN_MAX_COUNT, &master->flags); 779 } 780 781 search_out: 782 mutex_unlock(&master->bus_mutex); 783 kfree(buf); 784 785 for (i = 0; i < found; i++) /* run callback for all queued up IDs */ 786 callback(master, found_ids[i]); 787 kfree(found_ids); 788 } 789 790 #if 0 791 /* 792 * FIXME: if this disabled code is ever used in the future all ds_send_data() 793 * calls must be changed to use a DMAable buffer. 794 */ 795 static int ds_match_access(struct ds_device *dev, u64 init) 796 { 797 int err; 798 struct ds_status st; 799 800 err = ds_send_data(dev, (unsigned char *)&init, sizeof(init)); 801 if (err) 802 return err; 803 804 ds_wait_status(dev, &st); 805 806 err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055); 807 if (err) 808 return err; 809 810 ds_wait_status(dev, &st); 811 812 return 0; 813 } 814 815 static int ds_set_path(struct ds_device *dev, u64 init) 816 { 817 int err; 818 struct ds_status st; 819 u8 buf[9]; 820 821 memcpy(buf, &init, 8); 822 buf[8] = BRANCH_MAIN; 823 824 err = ds_send_data(dev, buf, sizeof(buf)); 825 if (err) 826 return err; 827 828 ds_wait_status(dev, &st); 829 830 err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0); 831 if (err) 832 return err; 833 834 ds_wait_status(dev, &st); 835 836 return 0; 837 } 838 839 #endif /* 0 */ 840 ds9490r_touch_bit(void * data,u8 bit)841 static u8 ds9490r_touch_bit(void *data, u8 bit) 842 { 843 struct ds_device *dev = data; 844 845 if (ds_touch_bit(dev, bit, &dev->byte_buf)) 846 return 0; 847 848 return dev->byte_buf; 849 } 850 851 #if 0 852 static void ds9490r_write_bit(void *data, u8 bit) 853 { 854 struct ds_device *dev = data; 855 856 ds_write_bit(dev, bit); 857 } 858 859 static u8 ds9490r_read_bit(void *data) 860 { 861 struct ds_device *dev = data; 862 int err; 863 864 err = ds_touch_bit(dev, 1, &dev->byte_buf); 865 if (err) 866 return 0; 867 868 return dev->byte_buf & 1; 869 } 870 #endif 871 ds9490r_write_byte(void * data,u8 byte)872 static void ds9490r_write_byte(void *data, u8 byte) 873 { 874 struct ds_device *dev = data; 875 876 ds_write_byte(dev, byte); 877 } 878 ds9490r_read_byte(void * data)879 static u8 ds9490r_read_byte(void *data) 880 { 881 struct ds_device *dev = data; 882 int err; 883 884 err = ds_read_byte(dev, &dev->byte_buf); 885 if (err) 886 return 0; 887 888 return dev->byte_buf; 889 } 890 ds9490r_write_block(void * data,const u8 * buf,int len)891 static void ds9490r_write_block(void *data, const u8 *buf, int len) 892 { 893 struct ds_device *dev = data; 894 u8 *tbuf; 895 896 if (len <= 0) 897 return; 898 899 tbuf = kmemdup(buf, len, GFP_KERNEL); 900 if (!tbuf) 901 return; 902 903 ds_write_block(dev, tbuf, len); 904 905 kfree(tbuf); 906 } 907 ds9490r_read_block(void * data,u8 * buf,int len)908 static u8 ds9490r_read_block(void *data, u8 *buf, int len) 909 { 910 struct ds_device *dev = data; 911 int err; 912 u8 *tbuf; 913 914 if (len <= 0) 915 return 0; 916 917 tbuf = kmalloc(len, GFP_KERNEL); 918 if (!tbuf) 919 return 0; 920 921 err = ds_read_block(dev, tbuf, len); 922 if (err >= 0) 923 memcpy(buf, tbuf, len); 924 925 kfree(tbuf); 926 927 return err >= 0 ? len : 0; 928 } 929 ds9490r_reset(void * data)930 static u8 ds9490r_reset(void *data) 931 { 932 struct ds_device *dev = data; 933 int err; 934 935 err = ds_reset(dev); 936 if (err) 937 return 1; 938 939 return 0; 940 } 941 ds9490r_set_pullup(void * data,int delay)942 static u8 ds9490r_set_pullup(void *data, int delay) 943 { 944 struct ds_device *dev = data; 945 946 if (ds_set_pullup(dev, delay)) 947 return 1; 948 949 return 0; 950 } 951 ds_w1_init(struct ds_device * dev)952 static int ds_w1_init(struct ds_device *dev) 953 { 954 memset(&dev->master, 0, sizeof(struct w1_bus_master)); 955 956 /* Reset the device as it can be in a bad state. 957 * This is necessary because a block write will wait for data 958 * to be placed in the output buffer and block any later 959 * commands which will keep accumulating and the device will 960 * not be idle. Another case is removing the ds2490 module 961 * while a bus search is in progress, somehow a few commands 962 * get through, but the input transfers fail leaving data in 963 * the input buffer. This will cause the next read to fail 964 * see the note in ds_recv_data. 965 */ 966 ds_reset_device(dev); 967 968 dev->master.data = dev; 969 dev->master.touch_bit = &ds9490r_touch_bit; 970 /* read_bit and write_bit in w1_bus_master are expected to set and 971 * sample the line level. For write_bit that means it is expected to 972 * set it to that value and leave it there. ds2490 only supports an 973 * individual time slot at the lowest level. The requirement from 974 * pulling the bus state down to reading the state is 15us, something 975 * that isn't realistic on the USB bus anyway. 976 dev->master.read_bit = &ds9490r_read_bit; 977 dev->master.write_bit = &ds9490r_write_bit; 978 */ 979 dev->master.read_byte = &ds9490r_read_byte; 980 dev->master.write_byte = &ds9490r_write_byte; 981 dev->master.read_block = &ds9490r_read_block; 982 dev->master.write_block = &ds9490r_write_block; 983 dev->master.reset_bus = &ds9490r_reset; 984 dev->master.set_pullup = &ds9490r_set_pullup; 985 dev->master.search = &ds9490r_search; 986 987 return w1_add_master_device(&dev->master); 988 } 989 ds_w1_fini(struct ds_device * dev)990 static void ds_w1_fini(struct ds_device *dev) 991 { 992 w1_remove_master_device(&dev->master); 993 } 994 ds_probe(struct usb_interface * intf,const struct usb_device_id * udev_id)995 static int ds_probe(struct usb_interface *intf, 996 const struct usb_device_id *udev_id) 997 { 998 struct usb_device *udev = interface_to_usbdev(intf); 999 struct usb_endpoint_descriptor *endpoint; 1000 struct usb_host_interface *iface_desc; 1001 struct ds_device *dev; 1002 int i, err, alt; 1003 1004 dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL); 1005 if (!dev) 1006 return -ENOMEM; 1007 1008 dev->udev = usb_get_dev(udev); 1009 if (!dev->udev) { 1010 err = -ENOMEM; 1011 goto err_out_free; 1012 } 1013 memset(dev->ep, 0, sizeof(dev->ep)); 1014 1015 usb_set_intfdata(intf, dev); 1016 1017 err = usb_reset_configuration(dev->udev); 1018 if (err) { 1019 dev_err(&dev->udev->dev, 1020 "Failed to reset configuration: err=%d.\n", err); 1021 goto err_out_clear; 1022 } 1023 1024 /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */ 1025 alt = 3; 1026 err = usb_set_interface(dev->udev, 1027 intf->cur_altsetting->desc.bInterfaceNumber, alt); 1028 if (err) { 1029 dev_err(&dev->udev->dev, "Failed to set alternative setting %d " 1030 "for %d interface: err=%d.\n", alt, 1031 intf->cur_altsetting->desc.bInterfaceNumber, err); 1032 goto err_out_clear; 1033 } 1034 1035 iface_desc = intf->cur_altsetting; 1036 if (iface_desc->desc.bNumEndpoints != NUM_EP-1) { 1037 dev_err(&dev->udev->dev, "Num endpoints=%d. It is not DS9490R.\n", 1038 iface_desc->desc.bNumEndpoints); 1039 err = -EINVAL; 1040 goto err_out_clear; 1041 } 1042 1043 /* 1044 * This loop doesn'd show control 0 endpoint, 1045 * so we will fill only 1-3 endpoints entry. 1046 */ 1047 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 1048 endpoint = &iface_desc->endpoint[i].desc; 1049 1050 dev->ep[i+1] = endpoint->bEndpointAddress; 1051 #if 0 1052 printk("%d: addr=%x, size=%d, dir=%s, type=%x\n", 1053 i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize), 1054 (endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT", 1055 endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK); 1056 #endif 1057 } 1058 1059 err = ds_w1_init(dev); 1060 if (err) 1061 goto err_out_clear; 1062 1063 mutex_lock(&ds_mutex); 1064 list_add_tail(&dev->ds_entry, &ds_devices); 1065 mutex_unlock(&ds_mutex); 1066 1067 return 0; 1068 1069 err_out_clear: 1070 usb_set_intfdata(intf, NULL); 1071 usb_put_dev(dev->udev); 1072 err_out_free: 1073 kfree(dev); 1074 return err; 1075 } 1076 ds_disconnect(struct usb_interface * intf)1077 static void ds_disconnect(struct usb_interface *intf) 1078 { 1079 struct ds_device *dev; 1080 1081 dev = usb_get_intfdata(intf); 1082 if (!dev) 1083 return; 1084 1085 mutex_lock(&ds_mutex); 1086 list_del(&dev->ds_entry); 1087 mutex_unlock(&ds_mutex); 1088 1089 ds_w1_fini(dev); 1090 1091 usb_set_intfdata(intf, NULL); 1092 1093 usb_put_dev(dev->udev); 1094 kfree(dev); 1095 } 1096 1097 static const struct usb_device_id ds_id_table[] = { 1098 { USB_DEVICE(0x04fa, 0x2490) }, 1099 { }, 1100 }; 1101 MODULE_DEVICE_TABLE(usb, ds_id_table); 1102 1103 static struct usb_driver ds_driver = { 1104 .name = "DS9490R", 1105 .probe = ds_probe, 1106 .disconnect = ds_disconnect, 1107 .id_table = ds_id_table, 1108 }; 1109 module_usb_driver(ds_driver); 1110 1111 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 1112 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)"); 1113 MODULE_LICENSE("GPL"); 1114