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 /* 1-wire data i/o fifo size, 128 bytes */
102 #define FIFO_SIZE 0x80
103
104 /* Result Register flags */
105 #define RR_DETECT 0xA5 /* New device detected */
106 #define RR_NRS 0x01 /* Reset no presence or ... */
107 #define RR_SH 0x02 /* short on reset or set path */
108 #define RR_APP 0x04 /* alarming presence on reset */
109 #define RR_VPP 0x08 /* 12V expected not seen */
110 #define RR_CMP 0x10 /* compare error */
111 #define RR_CRC 0x20 /* CRC error detected */
112 #define RR_RDP 0x40 /* redirected page */
113 #define RR_EOS 0x80 /* end of search error */
114
115 #define SPEED_NORMAL 0x00
116 #define SPEED_FLEXIBLE 0x01
117 #define SPEED_OVERDRIVE 0x02
118
119 #define NUM_EP 4
120 #define EP_CONTROL 0
121 #define EP_STATUS 1
122 #define EP_DATA_OUT 2
123 #define EP_DATA_IN 3
124
125 struct ds_device {
126 struct list_head ds_entry;
127
128 struct usb_device *udev;
129 struct usb_interface *intf;
130
131 int ep[NUM_EP];
132
133 /* Strong PullUp
134 * 0: pullup not active, else duration in milliseconds
135 */
136 int spu_sleep;
137 /* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
138 * should be active or not for writes.
139 */
140 u16 spu_bit;
141
142 u8 st_buf[ST_SIZE];
143 u8 byte_buf;
144
145 struct w1_bus_master master;
146 };
147
148 struct ds_status {
149 u8 enable;
150 u8 speed;
151 u8 pullup_dur;
152 u8 ppuls_dur;
153 u8 pulldown_slew;
154 u8 write1_time;
155 u8 write0_time;
156 u8 reserved0;
157 u8 status;
158 u8 command0;
159 u8 command1;
160 u8 command_buffer_status;
161 u8 data_out_buffer_status;
162 u8 data_in_buffer_status;
163 u8 reserved1;
164 u8 reserved2;
165 };
166
167 static LIST_HEAD(ds_devices);
168 static DEFINE_MUTEX(ds_mutex);
169
ds_send_control_cmd(struct ds_device * dev,u16 value,u16 index)170 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
171 {
172 int err;
173
174 err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
175 CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
176 if (err < 0) {
177 dev_err(&dev->udev->dev,
178 "Failed to send command control message %x.%x: err=%d.\n",
179 value, index, err);
180 return err;
181 }
182
183 return err;
184 }
185
ds_send_control_mode(struct ds_device * dev,u16 value,u16 index)186 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
187 {
188 int err;
189
190 err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
191 MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
192 if (err < 0) {
193 dev_err(&dev->udev->dev,
194 "Failed to send mode control message %x.%x: err=%d.\n",
195 value, index, err);
196 return err;
197 }
198
199 return err;
200 }
201
ds_send_control(struct ds_device * dev,u16 value,u16 index)202 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
203 {
204 int err;
205
206 err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
207 COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
208 if (err < 0) {
209 dev_err(&dev->udev->dev,
210 "Failed to send control message %x.%x: err=%d.\n",
211 value, index, err);
212 return err;
213 }
214
215 return err;
216 }
217
ds_dump_status(struct ds_device * ds_dev,unsigned char * buf,int count)218 static void ds_dump_status(struct ds_device *ds_dev, unsigned char *buf, int count)
219 {
220 struct device *dev = &ds_dev->udev->dev;
221 int i;
222
223 dev_info(dev, "ep_status=0x%x, count=%d, status=%*phC",
224 ds_dev->ep[EP_STATUS], count, count, buf);
225
226 if (count >= 16) {
227 dev_dbg(dev, "enable flag: 0x%02x", buf[0]);
228 dev_dbg(dev, "1-wire speed: 0x%02x", buf[1]);
229 dev_dbg(dev, "strong pullup duration: 0x%02x", buf[2]);
230 dev_dbg(dev, "programming pulse duration: 0x%02x", buf[3]);
231 dev_dbg(dev, "pulldown slew rate control: 0x%02x", buf[4]);
232 dev_dbg(dev, "write-1 low time: 0x%02x", buf[5]);
233 dev_dbg(dev, "data sample offset/write-0 recovery time: 0x%02x", buf[6]);
234 dev_dbg(dev, "reserved (test register): 0x%02x", buf[7]);
235 dev_dbg(dev, "device status flags: 0x%02x", buf[8]);
236 dev_dbg(dev, "communication command byte 1: 0x%02x", buf[9]);
237 dev_dbg(dev, "communication command byte 2: 0x%02x", buf[10]);
238 dev_dbg(dev, "communication command buffer status: 0x%02x", buf[11]);
239 dev_dbg(dev, "1-wire data output buffer status: 0x%02x", buf[12]);
240 dev_dbg(dev, "1-wire data input buffer status: 0x%02x", buf[13]);
241 dev_dbg(dev, "reserved: 0x%02x", buf[14]);
242 dev_dbg(dev, "reserved: 0x%02x", buf[15]);
243 }
244
245 for (i = 16; i < count; ++i) {
246 if (buf[i] == RR_DETECT) {
247 dev_dbg(dev, "New device detect.\n");
248 continue;
249 }
250 dev_dbg(dev, "Result Register Value: 0x%02x", buf[i]);
251 if (buf[i] & RR_NRS)
252 dev_dbg(dev, "NRS: Reset no presence or ...\n");
253 if (buf[i] & RR_SH)
254 dev_dbg(dev, "SH: short on reset or set path\n");
255 if (buf[i] & RR_APP)
256 dev_dbg(dev, "APP: alarming presence on reset\n");
257 if (buf[i] & RR_VPP)
258 dev_dbg(dev, "VPP: 12V expected not seen\n");
259 if (buf[i] & RR_CMP)
260 dev_dbg(dev, "CMP: compare error\n");
261 if (buf[i] & RR_CRC)
262 dev_dbg(dev, "CRC: CRC error detected\n");
263 if (buf[i] & RR_RDP)
264 dev_dbg(dev, "RDP: redirected page\n");
265 if (buf[i] & RR_EOS)
266 dev_dbg(dev, "EOS: end of search error\n");
267 }
268 }
269
ds_recv_status(struct ds_device * dev,struct ds_status * st)270 static int ds_recv_status(struct ds_device *dev, struct ds_status *st)
271 {
272 int count, err;
273
274 if (st)
275 memset(st, 0, sizeof(*st));
276
277 count = 0;
278 err = usb_interrupt_msg(dev->udev,
279 usb_rcvintpipe(dev->udev,
280 dev->ep[EP_STATUS]),
281 dev->st_buf, sizeof(dev->st_buf),
282 &count, 1000);
283 if (err < 0) {
284 dev_err(&dev->udev->dev,
285 "Failed to read 1-wire data from 0x%x: err=%d.\n",
286 dev->ep[EP_STATUS], err);
287 return err;
288 }
289
290 if (st && count >= sizeof(*st))
291 memcpy(st, dev->st_buf, sizeof(*st));
292
293 return count;
294 }
295
ds_reset_device(struct ds_device * dev)296 static void ds_reset_device(struct ds_device *dev)
297 {
298 ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
299 /* Always allow strong pullup which allow individual writes to use
300 * the strong pullup.
301 */
302 if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
303 dev_err(&dev->udev->dev,
304 "%s: Error allowing strong pullup\n", __func__);
305 /* Chip strong pullup time was cleared. */
306 if (dev->spu_sleep) {
307 /* lower 4 bits are 0, see ds_set_pullup */
308 u8 del = dev->spu_sleep>>4;
309
310 if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
311 dev_err(&dev->udev->dev,
312 "%s: Error setting duration\n", __func__);
313 }
314 }
315
ds_recv_data(struct ds_device * dev,unsigned char * buf,int size)316 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
317 {
318 int count, err;
319
320 /* Careful on size. If size is less than what is available in
321 * the input buffer, the device fails the bulk transfer and
322 * clears the input buffer. It could read the maximum size of
323 * the data buffer, but then do you return the first, last, or
324 * some set of the middle size bytes? As long as the rest of
325 * the code is correct there will be size bytes waiting. A
326 * call to ds_wait_status will wait until the device is idle
327 * and any data to be received would have been available.
328 */
329 count = 0;
330 err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
331 buf, size, &count, 1000);
332 if (err < 0) {
333 int recv_len;
334
335 dev_info(&dev->udev->dev, "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
336 usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
337
338 /* status might tell us why endpoint is stuck? */
339 recv_len = ds_recv_status(dev, NULL);
340 if (recv_len >= 0)
341 ds_dump_status(dev, dev->st_buf, recv_len);
342
343 return err;
344 }
345
346 #if 0
347 {
348 int i;
349
350 printk("%s: count=%d: ", __func__, count);
351 for (i = 0; i < count; ++i)
352 printk("%02x ", buf[i]);
353 printk("\n");
354 }
355 #endif
356 return count;
357 }
358
ds_send_data(struct ds_device * dev,unsigned char * buf,int len)359 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
360 {
361 int count, err;
362
363 count = 0;
364 err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
365 if (err < 0) {
366 dev_err(&dev->udev->dev, "Failed to write 1-wire data to ep0x%x: "
367 "err=%d.\n", dev->ep[EP_DATA_OUT], err);
368 return err;
369 }
370
371 return err;
372 }
373
374 #if 0
375
376 int ds_stop_pulse(struct ds_device *dev, int limit)
377 {
378 struct ds_status st;
379 int count = 0, err = 0;
380
381 do {
382 err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
383 if (err)
384 break;
385 err = ds_send_control(dev, CTL_RESUME_EXE, 0);
386 if (err)
387 break;
388 err = ds_recv_status(dev, &st);
389 if (err)
390 break;
391
392 if ((st.status & ST_SPUA) == 0) {
393 err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
394 if (err)
395 break;
396 }
397 } while (++count < limit);
398
399 return err;
400 }
401
402 int ds_detect(struct ds_device *dev, struct ds_status *st)
403 {
404 int err;
405
406 err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
407 if (err)
408 return err;
409
410 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
411 if (err)
412 return err;
413
414 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
415 if (err)
416 return err;
417
418 err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
419 if (err)
420 return err;
421
422 err = ds_dump_status(dev, st);
423
424 return err;
425 }
426
427 #endif /* 0 */
428
ds_wait_status(struct ds_device * dev,struct ds_status * st)429 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
430 {
431 int err, count = 0;
432
433 do {
434 st->status = 0;
435 err = ds_recv_status(dev, st);
436 #if 0
437 if (err >= 0) {
438 int i;
439 printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
440 for (i = 0; i < err; ++i)
441 printk("%02x ", dev->st_buf[i]);
442 printk("\n");
443 }
444 #endif
445 } while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
446
447 if (err >= 16 && st->status & ST_EPOF) {
448 dev_info(&dev->udev->dev, "Resetting device after ST_EPOF.\n");
449 ds_reset_device(dev);
450 /* Always dump the device status. */
451 count = 101;
452 }
453
454 /* Dump the status for errors or if there is extended return data.
455 * The extended status includes new device detection (maybe someone
456 * can do something with it).
457 */
458 if (err > 16 || count >= 100 || err < 0)
459 ds_dump_status(dev, dev->st_buf, err);
460
461 /* Extended data isn't an error. Well, a short is, but the dump
462 * would have already told the user that and we can't do anything
463 * about it in software anyway.
464 */
465 if (count >= 100 || err < 0)
466 return -1;
467 else
468 return 0;
469 }
470
ds_reset(struct ds_device * dev)471 static int ds_reset(struct ds_device *dev)
472 {
473 int err;
474
475 /* Other potentionally interesting flags for reset.
476 *
477 * COMM_NTF: Return result register feedback. This could be used to
478 * detect some conditions such as short, alarming presence, or
479 * detect if a new device was detected.
480 *
481 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
482 * Select the data transfer rate.
483 */
484 err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
485 if (err)
486 return err;
487
488 return 0;
489 }
490
491 #if 0
492 static int ds_set_speed(struct ds_device *dev, int speed)
493 {
494 int err;
495
496 if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
497 return -EINVAL;
498
499 if (speed != SPEED_OVERDRIVE)
500 speed = SPEED_FLEXIBLE;
501
502 speed &= 0xff;
503
504 err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
505 if (err)
506 return err;
507
508 return err;
509 }
510 #endif /* 0 */
511
ds_set_pullup(struct ds_device * dev,int delay)512 static int ds_set_pullup(struct ds_device *dev, int delay)
513 {
514 int err = 0;
515 u8 del = 1 + (u8)(delay >> 4);
516 /* Just storing delay would not get the trunication and roundup. */
517 int ms = del<<4;
518
519 /* Enable spu_bit if a delay is set. */
520 dev->spu_bit = delay ? COMM_SPU : 0;
521 /* If delay is zero, it has already been disabled, if the time is
522 * the same as the hardware was last programmed to, there is also
523 * nothing more to do. Compare with the recalculated value ms
524 * rather than del or delay which can have a different value.
525 */
526 if (delay == 0 || ms == dev->spu_sleep)
527 return err;
528
529 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
530 if (err)
531 return err;
532
533 dev->spu_sleep = ms;
534
535 return err;
536 }
537
ds_touch_bit(struct ds_device * dev,u8 bit,u8 * tbit)538 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
539 {
540 int err;
541 struct ds_status st;
542
543 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
544 0);
545 if (err)
546 return err;
547
548 ds_wait_status(dev, &st);
549
550 err = ds_recv_data(dev, tbit, sizeof(*tbit));
551 if (err < 0)
552 return err;
553
554 return 0;
555 }
556
557 #if 0
558 static int ds_write_bit(struct ds_device *dev, u8 bit)
559 {
560 int err;
561 struct ds_status st;
562
563 /* Set COMM_ICP to write without a readback. Note, this will
564 * produce one time slot, a down followed by an up with COMM_D
565 * only determing the timing.
566 */
567 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
568 (bit ? COMM_D : 0), 0);
569 if (err)
570 return err;
571
572 ds_wait_status(dev, &st);
573
574 return 0;
575 }
576 #endif
577
ds_write_byte(struct ds_device * dev,u8 byte)578 static int ds_write_byte(struct ds_device *dev, u8 byte)
579 {
580 int err;
581 struct ds_status st;
582
583 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
584 if (err)
585 return err;
586
587 if (dev->spu_bit)
588 msleep(dev->spu_sleep);
589
590 err = ds_wait_status(dev, &st);
591 if (err)
592 return err;
593
594 err = ds_recv_data(dev, &dev->byte_buf, 1);
595 if (err < 0)
596 return err;
597
598 return !(byte == dev->byte_buf);
599 }
600
ds_read_byte(struct ds_device * dev,u8 * byte)601 static int ds_read_byte(struct ds_device *dev, u8 *byte)
602 {
603 int err;
604 struct ds_status st;
605
606 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
607 if (err)
608 return err;
609
610 ds_wait_status(dev, &st);
611
612 err = ds_recv_data(dev, byte, sizeof(*byte));
613 if (err < 0)
614 return err;
615
616 return 0;
617 }
618
read_block_chunk(struct ds_device * dev,u8 * buf,int len)619 static int read_block_chunk(struct ds_device *dev, u8 *buf, int len)
620 {
621 struct ds_status st;
622 int err;
623
624 memset(buf, 0xFF, len);
625
626 err = ds_send_data(dev, buf, len);
627 if (err < 0)
628 return err;
629
630 err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
631 if (err)
632 return err;
633
634 ds_wait_status(dev, &st);
635
636 memset(buf, 0x00, len);
637 err = ds_recv_data(dev, buf, len);
638
639 return err;
640 }
641
ds_read_block(struct ds_device * dev,u8 * buf,int len)642 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
643 {
644 int err, to_read, rem = len;
645
646 if (len > 64 * 1024)
647 return -E2BIG;
648
649 do {
650 to_read = rem <= FIFO_SIZE ? rem : FIFO_SIZE;
651 err = read_block_chunk(dev, &buf[len - rem], to_read);
652 if (err < 0)
653 return err;
654 rem -= to_read;
655 } while (rem);
656
657 return err;
658 }
659
ds_write_block(struct ds_device * dev,u8 * buf,int len)660 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
661 {
662 int err;
663 struct ds_status st;
664
665 err = ds_send_data(dev, buf, len);
666 if (err < 0)
667 return err;
668
669 err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
670 if (err)
671 return err;
672
673 if (dev->spu_bit)
674 msleep(dev->spu_sleep);
675
676 ds_wait_status(dev, &st);
677
678 err = ds_recv_data(dev, buf, len);
679 if (err < 0)
680 return err;
681
682 return !(err == len);
683 }
684
ds9490r_search(void * data,struct w1_master * master,u8 search_type,w1_slave_found_callback callback)685 static void ds9490r_search(void *data, struct w1_master *master,
686 u8 search_type, w1_slave_found_callback callback)
687 {
688 /* When starting with an existing id, the first id returned will
689 * be that device (if it is still on the bus most likely).
690 *
691 * If the number of devices found is less than or equal to the
692 * search_limit, that number of IDs will be returned. If there are
693 * more, search_limit IDs will be returned followed by a non-zero
694 * discrepency value.
695 */
696 struct ds_device *dev = data;
697 int err;
698 u16 value, index;
699 struct ds_status st;
700 int search_limit;
701 int found = 0;
702 int i;
703
704 /* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
705 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
706 */
707 const unsigned long jtime = msecs_to_jiffies(1000*8/75);
708 /* FIFO 128 bytes, bulk packet size 64, read a multiple of the
709 * packet size.
710 */
711 const size_t bufsize = 2 * 64;
712 u64 *buf, *found_ids;
713
714 buf = kmalloc(bufsize, GFP_KERNEL);
715 if (!buf)
716 return;
717
718 /*
719 * We are holding the bus mutex during the scan, but adding devices via the
720 * callback needs the bus to be unlocked. So we queue up found ids here.
721 */
722 found_ids = kmalloc_array(master->max_slave_count, sizeof(u64), GFP_KERNEL);
723 if (!found_ids) {
724 kfree(buf);
725 return;
726 }
727
728 mutex_lock(&master->bus_mutex);
729
730 /* address to start searching at */
731 if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
732 goto search_out;
733 master->search_id = 0;
734
735 value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
736 COMM_RTS;
737 search_limit = master->max_slave_count;
738 if (search_limit > 255)
739 search_limit = 0;
740 index = search_type | (search_limit << 8);
741 if (ds_send_control(dev, value, index) < 0)
742 goto search_out;
743
744 do {
745 schedule_timeout(jtime);
746
747 err = ds_recv_status(dev, &st);
748 if (err < 0 || err < sizeof(st))
749 break;
750
751 if (st.data_in_buffer_status) {
752 /*
753 * Bulk in can receive partial ids, but when it does
754 * they fail crc and will be discarded anyway.
755 * That has only been seen when status in buffer
756 * is 0 and bulk is read anyway, so don't read
757 * bulk without first checking if status says there
758 * is data to read.
759 */
760 err = ds_recv_data(dev, (u8 *)buf, bufsize);
761 if (err < 0)
762 break;
763 for (i = 0; i < err/8; ++i) {
764 found_ids[found++] = buf[i];
765 /*
766 * can't know if there will be a discrepancy
767 * value after until the next id
768 */
769 if (found == search_limit) {
770 master->search_id = buf[i];
771 break;
772 }
773 }
774 }
775
776 if (test_bit(W1_ABORT_SEARCH, &master->flags))
777 break;
778 } while (!(st.status & (ST_IDLE | ST_HALT)));
779
780 /* only continue the search if some weren't found */
781 if (found <= search_limit) {
782 master->search_id = 0;
783 } else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
784 /*
785 * Only max_slave_count will be scanned in a search,
786 * but it will start where it left off next search
787 * until all ids are identified and then it will start
788 * over. A continued search will report the previous
789 * last id as the first id (provided it is still on the
790 * bus).
791 */
792 dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
793 "will continue next search.\n", __func__,
794 master->max_slave_count);
795 set_bit(W1_WARN_MAX_COUNT, &master->flags);
796 }
797
798 search_out:
799 mutex_unlock(&master->bus_mutex);
800 kfree(buf);
801
802 for (i = 0; i < found; i++) /* run callback for all queued up IDs */
803 callback(master, found_ids[i]);
804 kfree(found_ids);
805 }
806
807 #if 0
808 /*
809 * FIXME: if this disabled code is ever used in the future all ds_send_data()
810 * calls must be changed to use a DMAable buffer.
811 */
812 static int ds_match_access(struct ds_device *dev, u64 init)
813 {
814 int err;
815 struct ds_status st;
816
817 err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
818 if (err)
819 return err;
820
821 ds_wait_status(dev, &st);
822
823 err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
824 if (err)
825 return err;
826
827 ds_wait_status(dev, &st);
828
829 return 0;
830 }
831
832 static int ds_set_path(struct ds_device *dev, u64 init)
833 {
834 int err;
835 struct ds_status st;
836 u8 buf[9];
837
838 memcpy(buf, &init, 8);
839 buf[8] = BRANCH_MAIN;
840
841 err = ds_send_data(dev, buf, sizeof(buf));
842 if (err)
843 return err;
844
845 ds_wait_status(dev, &st);
846
847 err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
848 if (err)
849 return err;
850
851 ds_wait_status(dev, &st);
852
853 return 0;
854 }
855
856 #endif /* 0 */
857
ds9490r_touch_bit(void * data,u8 bit)858 static u8 ds9490r_touch_bit(void *data, u8 bit)
859 {
860 struct ds_device *dev = data;
861
862 if (ds_touch_bit(dev, bit, &dev->byte_buf))
863 return 0;
864
865 return dev->byte_buf;
866 }
867
868 #if 0
869 static void ds9490r_write_bit(void *data, u8 bit)
870 {
871 struct ds_device *dev = data;
872
873 ds_write_bit(dev, bit);
874 }
875
876 static u8 ds9490r_read_bit(void *data)
877 {
878 struct ds_device *dev = data;
879 int err;
880
881 err = ds_touch_bit(dev, 1, &dev->byte_buf);
882 if (err)
883 return 0;
884
885 return dev->byte_buf & 1;
886 }
887 #endif
888
ds9490r_write_byte(void * data,u8 byte)889 static void ds9490r_write_byte(void *data, u8 byte)
890 {
891 struct ds_device *dev = data;
892
893 ds_write_byte(dev, byte);
894 }
895
ds9490r_read_byte(void * data)896 static u8 ds9490r_read_byte(void *data)
897 {
898 struct ds_device *dev = data;
899 int err;
900
901 err = ds_read_byte(dev, &dev->byte_buf);
902 if (err)
903 return 0;
904
905 return dev->byte_buf;
906 }
907
ds9490r_write_block(void * data,const u8 * buf,int len)908 static void ds9490r_write_block(void *data, const u8 *buf, int len)
909 {
910 struct ds_device *dev = data;
911 u8 *tbuf;
912
913 if (len <= 0)
914 return;
915
916 tbuf = kmemdup(buf, len, GFP_KERNEL);
917 if (!tbuf)
918 return;
919
920 ds_write_block(dev, tbuf, len);
921
922 kfree(tbuf);
923 }
924
ds9490r_read_block(void * data,u8 * buf,int len)925 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
926 {
927 struct ds_device *dev = data;
928 int err;
929 u8 *tbuf;
930
931 if (len <= 0)
932 return 0;
933
934 tbuf = kmalloc(len, GFP_KERNEL);
935 if (!tbuf)
936 return 0;
937
938 err = ds_read_block(dev, tbuf, len);
939 if (err >= 0)
940 memcpy(buf, tbuf, len);
941
942 kfree(tbuf);
943
944 return err >= 0 ? len : 0;
945 }
946
ds9490r_reset(void * data)947 static u8 ds9490r_reset(void *data)
948 {
949 struct ds_device *dev = data;
950 int err;
951
952 err = ds_reset(dev);
953 if (err)
954 return 1;
955
956 return 0;
957 }
958
ds9490r_set_pullup(void * data,int delay)959 static u8 ds9490r_set_pullup(void *data, int delay)
960 {
961 struct ds_device *dev = data;
962
963 if (ds_set_pullup(dev, delay))
964 return 1;
965
966 return 0;
967 }
968
ds_w1_init(struct ds_device * dev)969 static int ds_w1_init(struct ds_device *dev)
970 {
971 memset(&dev->master, 0, sizeof(struct w1_bus_master));
972
973 /* Reset the device as it can be in a bad state.
974 * This is necessary because a block write will wait for data
975 * to be placed in the output buffer and block any later
976 * commands which will keep accumulating and the device will
977 * not be idle. Another case is removing the ds2490 module
978 * while a bus search is in progress, somehow a few commands
979 * get through, but the input transfers fail leaving data in
980 * the input buffer. This will cause the next read to fail
981 * see the note in ds_recv_data.
982 */
983 ds_reset_device(dev);
984
985 dev->master.data = dev;
986 dev->master.touch_bit = &ds9490r_touch_bit;
987 /* read_bit and write_bit in w1_bus_master are expected to set and
988 * sample the line level. For write_bit that means it is expected to
989 * set it to that value and leave it there. ds2490 only supports an
990 * individual time slot at the lowest level. The requirement from
991 * pulling the bus state down to reading the state is 15us, something
992 * that isn't realistic on the USB bus anyway.
993 dev->master.read_bit = &ds9490r_read_bit;
994 dev->master.write_bit = &ds9490r_write_bit;
995 */
996 dev->master.read_byte = &ds9490r_read_byte;
997 dev->master.write_byte = &ds9490r_write_byte;
998 dev->master.read_block = &ds9490r_read_block;
999 dev->master.write_block = &ds9490r_write_block;
1000 dev->master.reset_bus = &ds9490r_reset;
1001 dev->master.set_pullup = &ds9490r_set_pullup;
1002 dev->master.search = &ds9490r_search;
1003
1004 return w1_add_master_device(&dev->master);
1005 }
1006
ds_w1_fini(struct ds_device * dev)1007 static void ds_w1_fini(struct ds_device *dev)
1008 {
1009 w1_remove_master_device(&dev->master);
1010 }
1011
ds_probe(struct usb_interface * intf,const struct usb_device_id * udev_id)1012 static int ds_probe(struct usb_interface *intf,
1013 const struct usb_device_id *udev_id)
1014 {
1015 struct usb_device *udev = interface_to_usbdev(intf);
1016 struct usb_endpoint_descriptor *endpoint;
1017 struct usb_host_interface *iface_desc;
1018 struct ds_device *dev;
1019 int i, err, alt;
1020
1021 dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
1022 if (!dev)
1023 return -ENOMEM;
1024
1025 dev->udev = usb_get_dev(udev);
1026 if (!dev->udev) {
1027 err = -ENOMEM;
1028 goto err_out_free;
1029 }
1030 memset(dev->ep, 0, sizeof(dev->ep));
1031
1032 usb_set_intfdata(intf, dev);
1033
1034 err = usb_reset_configuration(dev->udev);
1035 if (err) {
1036 dev_err(&dev->udev->dev,
1037 "Failed to reset configuration: err=%d.\n", err);
1038 goto err_out_clear;
1039 }
1040
1041 /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1042 alt = 3;
1043 err = usb_set_interface(dev->udev,
1044 intf->cur_altsetting->desc.bInterfaceNumber, alt);
1045 if (err) {
1046 dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1047 "for %d interface: err=%d.\n", alt,
1048 intf->cur_altsetting->desc.bInterfaceNumber, err);
1049 goto err_out_clear;
1050 }
1051
1052 iface_desc = intf->cur_altsetting;
1053 if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1054 dev_err(&dev->udev->dev, "Num endpoints=%d. It is not DS9490R.\n",
1055 iface_desc->desc.bNumEndpoints);
1056 err = -EINVAL;
1057 goto err_out_clear;
1058 }
1059
1060 /*
1061 * This loop doesn'd show control 0 endpoint,
1062 * so we will fill only 1-3 endpoints entry.
1063 */
1064 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1065 endpoint = &iface_desc->endpoint[i].desc;
1066
1067 dev->ep[i+1] = endpoint->bEndpointAddress;
1068 #if 0
1069 printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1070 i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1071 (endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1072 endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1073 #endif
1074 }
1075
1076 err = ds_w1_init(dev);
1077 if (err)
1078 goto err_out_clear;
1079
1080 mutex_lock(&ds_mutex);
1081 list_add_tail(&dev->ds_entry, &ds_devices);
1082 mutex_unlock(&ds_mutex);
1083
1084 return 0;
1085
1086 err_out_clear:
1087 usb_set_intfdata(intf, NULL);
1088 usb_put_dev(dev->udev);
1089 err_out_free:
1090 kfree(dev);
1091 return err;
1092 }
1093
ds_disconnect(struct usb_interface * intf)1094 static void ds_disconnect(struct usb_interface *intf)
1095 {
1096 struct ds_device *dev;
1097
1098 dev = usb_get_intfdata(intf);
1099 if (!dev)
1100 return;
1101
1102 mutex_lock(&ds_mutex);
1103 list_del(&dev->ds_entry);
1104 mutex_unlock(&ds_mutex);
1105
1106 ds_w1_fini(dev);
1107
1108 usb_set_intfdata(intf, NULL);
1109
1110 usb_put_dev(dev->udev);
1111 kfree(dev);
1112 }
1113
1114 static const struct usb_device_id ds_id_table[] = {
1115 { USB_DEVICE(0x04fa, 0x2490) },
1116 { },
1117 };
1118 MODULE_DEVICE_TABLE(usb, ds_id_table);
1119
1120 static struct usb_driver ds_driver = {
1121 .name = "DS9490R",
1122 .probe = ds_probe,
1123 .disconnect = ds_disconnect,
1124 .id_table = ds_id_table,
1125 };
1126 module_usb_driver(ds_driver);
1127
1128 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1129 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1130 MODULE_LICENSE("GPL");
1131