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