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 if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
308 dev_err(&dev->udev->dev,
309 "%s: Error setting duration\n", __func__);
310 }
311 }
312
ds_recv_data(struct ds_device * dev,unsigned char * buf,int size)313 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
314 {
315 int count, err;
316
317 /* Careful on size. If size is less than what is available in
318 * the input buffer, the device fails the bulk transfer and
319 * clears the input buffer. It could read the maximum size of
320 * the data buffer, but then do you return the first, last, or
321 * some set of the middle size bytes? As long as the rest of
322 * the code is correct there will be size bytes waiting. A
323 * call to ds_wait_status will wait until the device is idle
324 * and any data to be received would have been available.
325 */
326 count = 0;
327 err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
328 buf, size, &count, 1000);
329 if (err < 0) {
330 int recv_len;
331
332 dev_info(&dev->udev->dev, "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
333 usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
334
335 /* status might tell us why endpoint is stuck? */
336 recv_len = ds_recv_status(dev, NULL);
337 if (recv_len >= 0)
338 ds_dump_status(dev, dev->st_buf, recv_len);
339
340 return err;
341 }
342
343 #if 0
344 {
345 int i;
346
347 printk("%s: count=%d: ", __func__, count);
348 for (i = 0; i < count; ++i)
349 printk("%02x ", buf[i]);
350 printk("\n");
351 }
352 #endif
353 return count;
354 }
355
ds_send_data(struct ds_device * dev,unsigned char * buf,int len)356 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
357 {
358 int count, err;
359
360 count = 0;
361 err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
362 if (err < 0) {
363 dev_err(&dev->udev->dev, "Failed to write 1-wire data to ep0x%x: "
364 "err=%d.\n", dev->ep[EP_DATA_OUT], err);
365 return err;
366 }
367
368 return err;
369 }
370
371 #if 0
372
373 int ds_stop_pulse(struct ds_device *dev, int limit)
374 {
375 struct ds_status st;
376 int count = 0, err = 0;
377
378 do {
379 err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
380 if (err)
381 break;
382 err = ds_send_control(dev, CTL_RESUME_EXE, 0);
383 if (err)
384 break;
385 err = ds_recv_status(dev, &st);
386 if (err)
387 break;
388
389 if ((st.status & ST_SPUA) == 0) {
390 err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
391 if (err)
392 break;
393 }
394 } while (++count < limit);
395
396 return err;
397 }
398
399 int ds_detect(struct ds_device *dev, struct ds_status *st)
400 {
401 int err;
402
403 err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
404 if (err)
405 return err;
406
407 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
408 if (err)
409 return err;
410
411 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
412 if (err)
413 return err;
414
415 err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
416 if (err)
417 return err;
418
419 err = ds_dump_status(dev, st);
420
421 return err;
422 }
423
424 #endif /* 0 */
425
ds_wait_status(struct ds_device * dev,struct ds_status * st)426 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
427 {
428 int err, count = 0;
429
430 do {
431 st->status = 0;
432 err = ds_recv_status(dev, st);
433 #if 0
434 if (err >= 0) {
435 int i;
436 printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
437 for (i = 0; i < err; ++i)
438 printk("%02x ", dev->st_buf[i]);
439 printk("\n");
440 }
441 #endif
442 } while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
443
444 if (err >= 16 && st->status & ST_EPOF) {
445 dev_info(&dev->udev->dev, "Resetting device after ST_EPOF.\n");
446 ds_reset_device(dev);
447 /* Always dump the device status. */
448 count = 101;
449 }
450
451 /* Dump the status for errors or if there is extended return data.
452 * The extended status includes new device detection (maybe someone
453 * can do something with it).
454 */
455 if (err > 16 || count >= 100 || err < 0)
456 ds_dump_status(dev, dev->st_buf, err);
457
458 /* Extended data isn't an error. Well, a short is, but the dump
459 * would have already told the user that and we can't do anything
460 * about it in software anyway.
461 */
462 if (count >= 100 || err < 0)
463 return -1;
464 else
465 return 0;
466 }
467
ds_reset(struct ds_device * dev)468 static int ds_reset(struct ds_device *dev)
469 {
470 int err;
471
472 /* Other potentionally interesting flags for reset.
473 *
474 * COMM_NTF: Return result register feedback. This could be used to
475 * detect some conditions such as short, alarming presence, or
476 * detect if a new device was detected.
477 *
478 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
479 * Select the data transfer rate.
480 */
481 err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
482 if (err)
483 return err;
484
485 return 0;
486 }
487
488 #if 0
489 static int ds_set_speed(struct ds_device *dev, int speed)
490 {
491 int err;
492
493 if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
494 return -EINVAL;
495
496 if (speed != SPEED_OVERDRIVE)
497 speed = SPEED_FLEXIBLE;
498
499 speed &= 0xff;
500
501 err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
502 if (err)
503 return err;
504
505 return err;
506 }
507 #endif /* 0 */
508
ds_set_pullup(struct ds_device * dev,int delay)509 static int ds_set_pullup(struct ds_device *dev, int delay)
510 {
511 int err = 0;
512 u8 del = 1 + (u8)(delay >> 4);
513 /* Just storing delay would not get the trunication and roundup. */
514 int ms = del<<4;
515
516 /* Enable spu_bit if a delay is set. */
517 dev->spu_bit = delay ? COMM_SPU : 0;
518 /* If delay is zero, it has already been disabled, if the time is
519 * the same as the hardware was last programmed to, there is also
520 * nothing more to do. Compare with the recalculated value ms
521 * rather than del or delay which can have a different value.
522 */
523 if (delay == 0 || ms == dev->spu_sleep)
524 return err;
525
526 err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
527 if (err)
528 return err;
529
530 dev->spu_sleep = ms;
531
532 return err;
533 }
534
ds_touch_bit(struct ds_device * dev,u8 bit,u8 * tbit)535 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
536 {
537 int err;
538 struct ds_status st;
539
540 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
541 0);
542 if (err)
543 return err;
544
545 ds_wait_status(dev, &st);
546
547 err = ds_recv_data(dev, tbit, sizeof(*tbit));
548 if (err < 0)
549 return err;
550
551 return 0;
552 }
553
554 #if 0
555 static int ds_write_bit(struct ds_device *dev, u8 bit)
556 {
557 int err;
558 struct ds_status st;
559
560 /* Set COMM_ICP to write without a readback. Note, this will
561 * produce one time slot, a down followed by an up with COMM_D
562 * only determing the timing.
563 */
564 err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
565 (bit ? COMM_D : 0), 0);
566 if (err)
567 return err;
568
569 ds_wait_status(dev, &st);
570
571 return 0;
572 }
573 #endif
574
ds_write_byte(struct ds_device * dev,u8 byte)575 static int ds_write_byte(struct ds_device *dev, u8 byte)
576 {
577 int err;
578 struct ds_status st;
579
580 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
581 if (err)
582 return err;
583
584 if (dev->spu_bit)
585 msleep(dev->spu_sleep);
586
587 err = ds_wait_status(dev, &st);
588 if (err)
589 return err;
590
591 err = ds_recv_data(dev, &dev->byte_buf, 1);
592 if (err < 0)
593 return err;
594
595 return !(byte == dev->byte_buf);
596 }
597
ds_read_byte(struct ds_device * dev,u8 * byte)598 static int ds_read_byte(struct ds_device *dev, u8 *byte)
599 {
600 int err;
601 struct ds_status st;
602
603 err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
604 if (err)
605 return err;
606
607 ds_wait_status(dev, &st);
608
609 err = ds_recv_data(dev, byte, sizeof(*byte));
610 if (err < 0)
611 return err;
612
613 return 0;
614 }
615
ds_read_block(struct ds_device * dev,u8 * buf,int len)616 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
617 {
618 struct ds_status st;
619 int err;
620
621 if (len > 64*1024)
622 return -E2BIG;
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_write_block(struct ds_device * dev,u8 * buf,int len)642 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
643 {
644 int err;
645 struct ds_status st;
646
647 err = ds_send_data(dev, buf, len);
648 if (err < 0)
649 return err;
650
651 err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
652 if (err)
653 return err;
654
655 if (dev->spu_bit)
656 msleep(dev->spu_sleep);
657
658 ds_wait_status(dev, &st);
659
660 err = ds_recv_data(dev, buf, len);
661 if (err < 0)
662 return err;
663
664 return !(err == len);
665 }
666
ds9490r_search(void * data,struct w1_master * master,u8 search_type,w1_slave_found_callback callback)667 static void ds9490r_search(void *data, struct w1_master *master,
668 u8 search_type, w1_slave_found_callback callback)
669 {
670 /* When starting with an existing id, the first id returned will
671 * be that device (if it is still on the bus most likely).
672 *
673 * If the number of devices found is less than or equal to the
674 * search_limit, that number of IDs will be returned. If there are
675 * more, search_limit IDs will be returned followed by a non-zero
676 * discrepency value.
677 */
678 struct ds_device *dev = data;
679 int err;
680 u16 value, index;
681 struct ds_status st;
682 int search_limit;
683 int found = 0;
684 int i;
685
686 /* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
687 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
688 */
689 const unsigned long jtime = msecs_to_jiffies(1000*8/75);
690 /* FIFO 128 bytes, bulk packet size 64, read a multiple of the
691 * packet size.
692 */
693 const size_t bufsize = 2 * 64;
694 u64 *buf, *found_ids;
695
696 buf = kmalloc(bufsize, GFP_KERNEL);
697 if (!buf)
698 return;
699
700 /*
701 * We are holding the bus mutex during the scan, but adding devices via the
702 * callback needs the bus to be unlocked. So we queue up found ids here.
703 */
704 found_ids = kmalloc_array(master->max_slave_count, sizeof(u64), GFP_KERNEL);
705 if (!found_ids) {
706 kfree(buf);
707 return;
708 }
709
710 mutex_lock(&master->bus_mutex);
711
712 /* address to start searching at */
713 if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
714 goto search_out;
715 master->search_id = 0;
716
717 value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
718 COMM_RTS;
719 search_limit = master->max_slave_count;
720 if (search_limit > 255)
721 search_limit = 0;
722 index = search_type | (search_limit << 8);
723 if (ds_send_control(dev, value, index) < 0)
724 goto search_out;
725
726 do {
727 schedule_timeout(jtime);
728
729 err = ds_recv_status(dev, &st);
730 if (err < 0 || err < sizeof(st))
731 break;
732
733 if (st.data_in_buffer_status) {
734 /* Bulk in can receive partial ids, but when it does
735 * they fail crc and will be discarded anyway.
736 * That has only been seen when status in buffer
737 * is 0 and bulk is read anyway, so don't read
738 * bulk without first checking if status says there
739 * is data to read.
740 */
741 err = ds_recv_data(dev, (u8 *)buf, bufsize);
742 if (err < 0)
743 break;
744 for (i = 0; i < err/8; ++i) {
745 found_ids[found++] = buf[i];
746 /* can't know if there will be a discrepancy
747 * value after until the next id */
748 if (found == search_limit) {
749 master->search_id = buf[i];
750 break;
751 }
752 }
753 }
754
755 if (test_bit(W1_ABORT_SEARCH, &master->flags))
756 break;
757 } while (!(st.status & (ST_IDLE | ST_HALT)));
758
759 /* only continue the search if some weren't found */
760 if (found <= search_limit) {
761 master->search_id = 0;
762 } else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
763 /* Only max_slave_count will be scanned in a search,
764 * but it will start where it left off next search
765 * until all ids are identified and then it will start
766 * over. A continued search will report the previous
767 * last id as the first id (provided it is still on the
768 * bus).
769 */
770 dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
771 "will continue next search.\n", __func__,
772 master->max_slave_count);
773 set_bit(W1_WARN_MAX_COUNT, &master->flags);
774 }
775
776 search_out:
777 mutex_unlock(&master->bus_mutex);
778 kfree(buf);
779
780 for (i = 0; i < found; i++) /* run callback for all queued up IDs */
781 callback(master, found_ids[i]);
782 kfree(found_ids);
783 }
784
785 #if 0
786 /*
787 * FIXME: if this disabled code is ever used in the future all ds_send_data()
788 * calls must be changed to use a DMAable buffer.
789 */
790 static int ds_match_access(struct ds_device *dev, u64 init)
791 {
792 int err;
793 struct ds_status st;
794
795 err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
796 if (err)
797 return err;
798
799 ds_wait_status(dev, &st);
800
801 err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
802 if (err)
803 return err;
804
805 ds_wait_status(dev, &st);
806
807 return 0;
808 }
809
810 static int ds_set_path(struct ds_device *dev, u64 init)
811 {
812 int err;
813 struct ds_status st;
814 u8 buf[9];
815
816 memcpy(buf, &init, 8);
817 buf[8] = BRANCH_MAIN;
818
819 err = ds_send_data(dev, buf, sizeof(buf));
820 if (err)
821 return err;
822
823 ds_wait_status(dev, &st);
824
825 err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
826 if (err)
827 return err;
828
829 ds_wait_status(dev, &st);
830
831 return 0;
832 }
833
834 #endif /* 0 */
835
ds9490r_touch_bit(void * data,u8 bit)836 static u8 ds9490r_touch_bit(void *data, u8 bit)
837 {
838 struct ds_device *dev = data;
839
840 if (ds_touch_bit(dev, bit, &dev->byte_buf))
841 return 0;
842
843 return dev->byte_buf;
844 }
845
846 #if 0
847 static void ds9490r_write_bit(void *data, u8 bit)
848 {
849 struct ds_device *dev = data;
850
851 ds_write_bit(dev, bit);
852 }
853
854 static u8 ds9490r_read_bit(void *data)
855 {
856 struct ds_device *dev = data;
857 int err;
858
859 err = ds_touch_bit(dev, 1, &dev->byte_buf);
860 if (err)
861 return 0;
862
863 return dev->byte_buf & 1;
864 }
865 #endif
866
ds9490r_write_byte(void * data,u8 byte)867 static void ds9490r_write_byte(void *data, u8 byte)
868 {
869 struct ds_device *dev = data;
870
871 ds_write_byte(dev, byte);
872 }
873
ds9490r_read_byte(void * data)874 static u8 ds9490r_read_byte(void *data)
875 {
876 struct ds_device *dev = data;
877 int err;
878
879 err = ds_read_byte(dev, &dev->byte_buf);
880 if (err)
881 return 0;
882
883 return dev->byte_buf;
884 }
885
ds9490r_write_block(void * data,const u8 * buf,int len)886 static void ds9490r_write_block(void *data, const u8 *buf, int len)
887 {
888 struct ds_device *dev = data;
889 u8 *tbuf;
890
891 if (len <= 0)
892 return;
893
894 tbuf = kmemdup(buf, len, GFP_KERNEL);
895 if (!tbuf)
896 return;
897
898 ds_write_block(dev, tbuf, len);
899
900 kfree(tbuf);
901 }
902
ds9490r_read_block(void * data,u8 * buf,int len)903 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
904 {
905 struct ds_device *dev = data;
906 int err;
907 u8 *tbuf;
908
909 if (len <= 0)
910 return 0;
911
912 tbuf = kmalloc(len, GFP_KERNEL);
913 if (!tbuf)
914 return 0;
915
916 err = ds_read_block(dev, tbuf, len);
917 if (err >= 0)
918 memcpy(buf, tbuf, len);
919
920 kfree(tbuf);
921
922 return err >= 0 ? len : 0;
923 }
924
ds9490r_reset(void * data)925 static u8 ds9490r_reset(void *data)
926 {
927 struct ds_device *dev = data;
928 int err;
929
930 err = ds_reset(dev);
931 if (err)
932 return 1;
933
934 return 0;
935 }
936
ds9490r_set_pullup(void * data,int delay)937 static u8 ds9490r_set_pullup(void *data, int delay)
938 {
939 struct ds_device *dev = data;
940
941 if (ds_set_pullup(dev, delay))
942 return 1;
943
944 return 0;
945 }
946
ds_w1_init(struct ds_device * dev)947 static int ds_w1_init(struct ds_device *dev)
948 {
949 memset(&dev->master, 0, sizeof(struct w1_bus_master));
950
951 /* Reset the device as it can be in a bad state.
952 * This is necessary because a block write will wait for data
953 * to be placed in the output buffer and block any later
954 * commands which will keep accumulating and the device will
955 * not be idle. Another case is removing the ds2490 module
956 * while a bus search is in progress, somehow a few commands
957 * get through, but the input transfers fail leaving data in
958 * the input buffer. This will cause the next read to fail
959 * see the note in ds_recv_data.
960 */
961 ds_reset_device(dev);
962
963 dev->master.data = dev;
964 dev->master.touch_bit = &ds9490r_touch_bit;
965 /* read_bit and write_bit in w1_bus_master are expected to set and
966 * sample the line level. For write_bit that means it is expected to
967 * set it to that value and leave it there. ds2490 only supports an
968 * individual time slot at the lowest level. The requirement from
969 * pulling the bus state down to reading the state is 15us, something
970 * that isn't realistic on the USB bus anyway.
971 dev->master.read_bit = &ds9490r_read_bit;
972 dev->master.write_bit = &ds9490r_write_bit;
973 */
974 dev->master.read_byte = &ds9490r_read_byte;
975 dev->master.write_byte = &ds9490r_write_byte;
976 dev->master.read_block = &ds9490r_read_block;
977 dev->master.write_block = &ds9490r_write_block;
978 dev->master.reset_bus = &ds9490r_reset;
979 dev->master.set_pullup = &ds9490r_set_pullup;
980 dev->master.search = &ds9490r_search;
981
982 return w1_add_master_device(&dev->master);
983 }
984
ds_w1_fini(struct ds_device * dev)985 static void ds_w1_fini(struct ds_device *dev)
986 {
987 w1_remove_master_device(&dev->master);
988 }
989
ds_probe(struct usb_interface * intf,const struct usb_device_id * udev_id)990 static int ds_probe(struct usb_interface *intf,
991 const struct usb_device_id *udev_id)
992 {
993 struct usb_device *udev = interface_to_usbdev(intf);
994 struct usb_endpoint_descriptor *endpoint;
995 struct usb_host_interface *iface_desc;
996 struct ds_device *dev;
997 int i, err, alt;
998
999 dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
1000 if (!dev)
1001 return -ENOMEM;
1002
1003 dev->udev = usb_get_dev(udev);
1004 if (!dev->udev) {
1005 err = -ENOMEM;
1006 goto err_out_free;
1007 }
1008 memset(dev->ep, 0, sizeof(dev->ep));
1009
1010 usb_set_intfdata(intf, dev);
1011
1012 err = usb_reset_configuration(dev->udev);
1013 if (err) {
1014 dev_err(&dev->udev->dev,
1015 "Failed to reset configuration: err=%d.\n", err);
1016 goto err_out_clear;
1017 }
1018
1019 /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1020 alt = 3;
1021 err = usb_set_interface(dev->udev,
1022 intf->cur_altsetting->desc.bInterfaceNumber, alt);
1023 if (err) {
1024 dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1025 "for %d interface: err=%d.\n", alt,
1026 intf->cur_altsetting->desc.bInterfaceNumber, err);
1027 goto err_out_clear;
1028 }
1029
1030 iface_desc = intf->cur_altsetting;
1031 if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1032 dev_err(&dev->udev->dev, "Num endpoints=%d. It is not DS9490R.\n",
1033 iface_desc->desc.bNumEndpoints);
1034 err = -EINVAL;
1035 goto err_out_clear;
1036 }
1037
1038 /*
1039 * This loop doesn'd show control 0 endpoint,
1040 * so we will fill only 1-3 endpoints entry.
1041 */
1042 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1043 endpoint = &iface_desc->endpoint[i].desc;
1044
1045 dev->ep[i+1] = endpoint->bEndpointAddress;
1046 #if 0
1047 printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1048 i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1049 (endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1050 endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1051 #endif
1052 }
1053
1054 err = ds_w1_init(dev);
1055 if (err)
1056 goto err_out_clear;
1057
1058 mutex_lock(&ds_mutex);
1059 list_add_tail(&dev->ds_entry, &ds_devices);
1060 mutex_unlock(&ds_mutex);
1061
1062 return 0;
1063
1064 err_out_clear:
1065 usb_set_intfdata(intf, NULL);
1066 usb_put_dev(dev->udev);
1067 err_out_free:
1068 kfree(dev);
1069 return err;
1070 }
1071
ds_disconnect(struct usb_interface * intf)1072 static void ds_disconnect(struct usb_interface *intf)
1073 {
1074 struct ds_device *dev;
1075
1076 dev = usb_get_intfdata(intf);
1077 if (!dev)
1078 return;
1079
1080 mutex_lock(&ds_mutex);
1081 list_del(&dev->ds_entry);
1082 mutex_unlock(&ds_mutex);
1083
1084 ds_w1_fini(dev);
1085
1086 usb_set_intfdata(intf, NULL);
1087
1088 usb_put_dev(dev->udev);
1089 kfree(dev);
1090 }
1091
1092 static const struct usb_device_id ds_id_table[] = {
1093 { USB_DEVICE(0x04fa, 0x2490) },
1094 { },
1095 };
1096 MODULE_DEVICE_TABLE(usb, ds_id_table);
1097
1098 static struct usb_driver ds_driver = {
1099 .name = "DS9490R",
1100 .probe = ds_probe,
1101 .disconnect = ds_disconnect,
1102 .id_table = ds_id_table,
1103 };
1104 module_usb_driver(ds_driver);
1105
1106 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1107 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1108 MODULE_LICENSE("GPL");
1109