xref: /openbmc/linux/drivers/w1/masters/ds2490.c (revision 256ac037)
1 /*
2  *	ds2490.c  USB to one wire bridge
3  *
4  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/mod_devicetable.h>
25 #include <linux/usb.h>
26 #include <linux/slab.h>
27 
28 #include "../w1_int.h"
29 #include "../w1.h"
30 
31 /* USB Standard */
32 /* USB Control request vendor type */
33 #define VENDOR				0x40
34 
35 /* COMMAND TYPE CODES */
36 #define CONTROL_CMD			0x00
37 #define COMM_CMD			0x01
38 #define MODE_CMD			0x02
39 
40 /* CONTROL COMMAND CODES */
41 #define CTL_RESET_DEVICE		0x0000
42 #define CTL_START_EXE			0x0001
43 #define CTL_RESUME_EXE			0x0002
44 #define CTL_HALT_EXE_IDLE		0x0003
45 #define CTL_HALT_EXE_DONE		0x0004
46 #define CTL_FLUSH_COMM_CMDS		0x0007
47 #define CTL_FLUSH_RCV_BUFFER		0x0008
48 #define CTL_FLUSH_XMT_BUFFER		0x0009
49 #define CTL_GET_COMM_CMDS		0x000A
50 
51 /* MODE COMMAND CODES */
52 #define MOD_PULSE_EN			0x0000
53 #define MOD_SPEED_CHANGE_EN		0x0001
54 #define MOD_1WIRE_SPEED			0x0002
55 #define MOD_STRONG_PU_DURATION		0x0003
56 #define MOD_PULLDOWN_SLEWRATE		0x0004
57 #define MOD_PROG_PULSE_DURATION		0x0005
58 #define MOD_WRITE1_LOWTIME		0x0006
59 #define MOD_DSOW0_TREC			0x0007
60 
61 /* COMMUNICATION COMMAND CODES */
62 #define COMM_ERROR_ESCAPE		0x0601
63 #define COMM_SET_DURATION		0x0012
64 #define COMM_BIT_IO			0x0020
65 #define COMM_PULSE			0x0030
66 #define COMM_1_WIRE_RESET		0x0042
67 #define COMM_BYTE_IO			0x0052
68 #define COMM_MATCH_ACCESS		0x0064
69 #define COMM_BLOCK_IO			0x0074
70 #define COMM_READ_STRAIGHT		0x0080
71 #define COMM_DO_RELEASE			0x6092
72 #define COMM_SET_PATH			0x00A2
73 #define COMM_WRITE_SRAM_PAGE		0x00B2
74 #define COMM_WRITE_EPROM		0x00C4
75 #define COMM_READ_CRC_PROT_PAGE		0x00D4
76 #define COMM_READ_REDIRECT_PAGE_CRC	0x21E4
77 #define COMM_SEARCH_ACCESS		0x00F4
78 
79 /* Communication command bits */
80 #define COMM_TYPE			0x0008
81 #define COMM_SE				0x0008
82 #define COMM_D				0x0008
83 #define COMM_Z				0x0008
84 #define COMM_CH				0x0008
85 #define COMM_SM				0x0008
86 #define COMM_R				0x0008
87 #define COMM_IM				0x0001
88 
89 #define COMM_PS				0x4000
90 #define COMM_PST			0x4000
91 #define COMM_CIB			0x4000
92 #define COMM_RTS			0x4000
93 #define COMM_DT				0x2000
94 #define COMM_SPU			0x1000
95 #define COMM_F				0x0800
96 #define COMM_NTF			0x0400
97 #define COMM_ICP			0x0200
98 #define COMM_RST			0x0100
99 
100 #define PULSE_PROG			0x01
101 #define PULSE_SPUE			0x02
102 
103 #define BRANCH_MAIN			0xCC
104 #define BRANCH_AUX			0x33
105 
106 /* Status flags */
107 #define ST_SPUA				0x01  /* Strong Pull-up is active */
108 #define ST_PRGA				0x02  /* 12V programming pulse is being generated */
109 #define ST_12VP				0x04  /* external 12V programming voltage is present */
110 #define ST_PMOD				0x08  /* DS2490 powered from USB and external sources */
111 #define ST_HALT				0x10  /* DS2490 is currently halted */
112 #define ST_IDLE				0x20  /* DS2490 is currently idle */
113 #define ST_EPOF				0x80
114 /* Status transfer size, 16 bytes status, 16 byte result flags */
115 #define ST_SIZE				0x20
116 
117 /* Result Register flags */
118 #define RR_DETECT			0xA5 /* New device detected */
119 #define RR_NRS				0x01 /* Reset no presence or ... */
120 #define RR_SH				0x02 /* short on reset or set path */
121 #define RR_APP				0x04 /* alarming presence on reset */
122 #define RR_VPP				0x08 /* 12V expected not seen */
123 #define RR_CMP				0x10 /* compare error */
124 #define RR_CRC				0x20 /* CRC error detected */
125 #define RR_RDP				0x40 /* redirected page */
126 #define RR_EOS				0x80 /* end of search error */
127 
128 #define SPEED_NORMAL			0x00
129 #define SPEED_FLEXIBLE			0x01
130 #define SPEED_OVERDRIVE			0x02
131 
132 #define NUM_EP				4
133 #define EP_CONTROL			0
134 #define EP_STATUS			1
135 #define EP_DATA_OUT			2
136 #define EP_DATA_IN			3
137 
138 struct ds_device
139 {
140 	struct list_head	ds_entry;
141 
142 	struct usb_device	*udev;
143 	struct usb_interface	*intf;
144 
145 	int			ep[NUM_EP];
146 
147 	/* Strong PullUp
148 	 * 0: pullup not active, else duration in milliseconds
149 	 */
150 	int			spu_sleep;
151 	/* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
152 	 * should be active or not for writes.
153 	 */
154 	u16			spu_bit;
155 
156 	u8			st_buf[ST_SIZE];
157 	u8			byte_buf;
158 
159 	struct w1_bus_master	master;
160 };
161 
162 struct ds_status
163 {
164 	u8			enable;
165 	u8			speed;
166 	u8			pullup_dur;
167 	u8			ppuls_dur;
168 	u8			pulldown_slew;
169 	u8			write1_time;
170 	u8			write0_time;
171 	u8			reserved0;
172 	u8			status;
173 	u8			command0;
174 	u8			command1;
175 	u8			command_buffer_status;
176 	u8			data_out_buffer_status;
177 	u8			data_in_buffer_status;
178 	u8			reserved1;
179 	u8			reserved2;
180 };
181 
182 static LIST_HEAD(ds_devices);
183 static DEFINE_MUTEX(ds_mutex);
184 
185 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
186 {
187 	int err;
188 
189 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
190 			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
191 	if (err < 0) {
192 		pr_err("Failed to send command control message %x.%x: err=%d.\n",
193 				value, index, err);
194 		return err;
195 	}
196 
197 	return err;
198 }
199 
200 static int ds_send_control_mode(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 			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
206 	if (err < 0) {
207 		pr_err("Failed to send mode control message %x.%x: err=%d.\n",
208 				value, index, err);
209 		return err;
210 	}
211 
212 	return err;
213 }
214 
215 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
216 {
217 	int err;
218 
219 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
220 			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
221 	if (err < 0) {
222 		pr_err("Failed to send control message %x.%x: err=%d.\n",
223 				value, index, err);
224 		return err;
225 	}
226 
227 	return err;
228 }
229 
230 static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
231 {
232 	pr_info("%45s: %8x\n", str, buf[off]);
233 }
234 
235 static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
236 {
237 	int i;
238 
239 	pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
240 	for (i=0; i<count; ++i)
241 		pr_info("%02x ", buf[i]);
242 	pr_info("\n");
243 
244 	if (count >= 16) {
245 		ds_print_msg(buf, "enable flag", 0);
246 		ds_print_msg(buf, "1-wire speed", 1);
247 		ds_print_msg(buf, "strong pullup duration", 2);
248 		ds_print_msg(buf, "programming pulse duration", 3);
249 		ds_print_msg(buf, "pulldown slew rate control", 4);
250 		ds_print_msg(buf, "write-1 low time", 5);
251 		ds_print_msg(buf, "data sample offset/write-0 recovery time",
252 			6);
253 		ds_print_msg(buf, "reserved (test register)", 7);
254 		ds_print_msg(buf, "device status flags", 8);
255 		ds_print_msg(buf, "communication command byte 1", 9);
256 		ds_print_msg(buf, "communication command byte 2", 10);
257 		ds_print_msg(buf, "communication command buffer status", 11);
258 		ds_print_msg(buf, "1-wire data output buffer status", 12);
259 		ds_print_msg(buf, "1-wire data input buffer status", 13);
260 		ds_print_msg(buf, "reserved", 14);
261 		ds_print_msg(buf, "reserved", 15);
262 	}
263 	for (i = 16; i < count; ++i) {
264 		if (buf[i] == RR_DETECT) {
265 			ds_print_msg(buf, "new device detect", i);
266 			continue;
267 		}
268 		ds_print_msg(buf, "Result Register Value: ", i);
269 		if (buf[i] & RR_NRS)
270 			pr_info("NRS: Reset no presence or ...\n");
271 		if (buf[i] & RR_SH)
272 			pr_info("SH: short on reset or set path\n");
273 		if (buf[i] & RR_APP)
274 			pr_info("APP: alarming presence on reset\n");
275 		if (buf[i] & RR_VPP)
276 			pr_info("VPP: 12V expected not seen\n");
277 		if (buf[i] & RR_CMP)
278 			pr_info("CMP: compare error\n");
279 		if (buf[i] & RR_CRC)
280 			pr_info("CRC: CRC error detected\n");
281 		if (buf[i] & RR_RDP)
282 			pr_info("RDP: redirected page\n");
283 		if (buf[i] & RR_EOS)
284 			pr_info("EOS: end of search error\n");
285 	}
286 }
287 
288 static int ds_recv_status(struct ds_device *dev, struct ds_status *st,
289 			  bool dump)
290 {
291 	int count, err;
292 
293 	if (st)
294 		memset(st, 0, sizeof(*st));
295 
296 	count = 0;
297 	err = usb_interrupt_msg(dev->udev,
298 				usb_rcvintpipe(dev->udev,
299 					       dev->ep[EP_STATUS]),
300 				dev->st_buf, sizeof(dev->st_buf),
301 				&count, 1000);
302 	if (err < 0) {
303 		pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
304 		       dev->ep[EP_STATUS], err);
305 		return err;
306 	}
307 
308 	if (dump)
309 		ds_dump_status(dev, dev->st_buf, count);
310 
311 	if (st && count >= sizeof(*st))
312 		memcpy(st, dev->st_buf, sizeof(*st));
313 
314 	return count;
315 }
316 
317 static void ds_reset_device(struct ds_device *dev)
318 {
319 	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
320 	/* Always allow strong pullup which allow individual writes to use
321 	 * the strong pullup.
322 	 */
323 	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
324 		pr_err("ds_reset_device: Error allowing strong pullup\n");
325 	/* Chip strong pullup time was cleared. */
326 	if (dev->spu_sleep) {
327 		/* lower 4 bits are 0, see ds_set_pullup */
328 		u8 del = dev->spu_sleep>>4;
329 		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
330 			pr_err("ds_reset_device: Error setting duration\n");
331 	}
332 }
333 
334 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
335 {
336 	int count, err;
337 
338 	/* Careful on size.  If size is less than what is available in
339 	 * the input buffer, the device fails the bulk transfer and
340 	 * clears the input buffer.  It could read the maximum size of
341 	 * the data buffer, but then do you return the first, last, or
342 	 * some set of the middle size bytes?  As long as the rest of
343 	 * the code is correct there will be size bytes waiting.  A
344 	 * call to ds_wait_status will wait until the device is idle
345 	 * and any data to be received would have been available.
346 	 */
347 	count = 0;
348 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
349 				buf, size, &count, 1000);
350 	if (err < 0) {
351 		pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
352 		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
353 		ds_recv_status(dev, NULL, true);
354 		return err;
355 	}
356 
357 #if 0
358 	{
359 		int i;
360 
361 		printk("%s: count=%d: ", __func__, count);
362 		for (i=0; i<count; ++i)
363 			printk("%02x ", buf[i]);
364 		printk("\n");
365 	}
366 #endif
367 	return count;
368 }
369 
370 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
371 {
372 	int count, err;
373 
374 	count = 0;
375 	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
376 	if (err < 0) {
377 		pr_err("Failed to write 1-wire data to ep0x%x: "
378 			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
379 		return err;
380 	}
381 
382 	return err;
383 }
384 
385 #if 0
386 
387 int ds_stop_pulse(struct ds_device *dev, int limit)
388 {
389 	struct ds_status st;
390 	int count = 0, err = 0;
391 
392 	do {
393 		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
394 		if (err)
395 			break;
396 		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
397 		if (err)
398 			break;
399 		err = ds_recv_status(dev, &st, false);
400 		if (err)
401 			break;
402 
403 		if ((st.status & ST_SPUA) == 0) {
404 			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
405 			if (err)
406 				break;
407 		}
408 	} while(++count < limit);
409 
410 	return err;
411 }
412 
413 int ds_detect(struct ds_device *dev, struct ds_status *st)
414 {
415 	int err;
416 
417 	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
418 	if (err)
419 		return err;
420 
421 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
422 	if (err)
423 		return err;
424 
425 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
426 	if (err)
427 		return err;
428 
429 	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
430 	if (err)
431 		return err;
432 
433 	err = ds_dump_status(dev, st);
434 
435 	return err;
436 }
437 
438 #endif  /*  0  */
439 
440 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
441 {
442 	int err, count = 0;
443 
444 	do {
445 		st->status = 0;
446 		err = ds_recv_status(dev, st, false);
447 #if 0
448 		if (err >= 0) {
449 			int i;
450 			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
451 			for (i=0; i<err; ++i)
452 				printk("%02x ", dev->st_buf[i]);
453 			printk("\n");
454 		}
455 #endif
456 	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
457 
458 	if (err >= 16 && st->status & ST_EPOF) {
459 		pr_info("Resetting device after ST_EPOF.\n");
460 		ds_reset_device(dev);
461 		/* Always dump the device status. */
462 		count = 101;
463 	}
464 
465 	/* Dump the status for errors or if there is extended return data.
466 	 * The extended status includes new device detection (maybe someone
467 	 * can do something with it).
468 	 */
469 	if (err > 16 || count >= 100 || err < 0)
470 		ds_dump_status(dev, dev->st_buf, err);
471 
472 	/* Extended data isn't an error.  Well, a short is, but the dump
473 	 * would have already told the user that and we can't do anything
474 	 * about it in software anyway.
475 	 */
476 	if (count >= 100 || err < 0)
477 		return -1;
478 	else
479 		return 0;
480 }
481 
482 static int ds_reset(struct ds_device *dev)
483 {
484 	int err;
485 
486 	/* Other potentionally interesting flags for reset.
487 	 *
488 	 * COMM_NTF: Return result register feedback.  This could be used to
489 	 * detect some conditions such as short, alarming presence, or
490 	 * detect if a new device was detected.
491 	 *
492 	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
493 	 * Select the data transfer rate.
494 	 */
495 	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
496 	if (err)
497 		return err;
498 
499 	return 0;
500 }
501 
502 #if 0
503 static int ds_set_speed(struct ds_device *dev, int speed)
504 {
505 	int err;
506 
507 	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
508 		return -EINVAL;
509 
510 	if (speed != SPEED_OVERDRIVE)
511 		speed = SPEED_FLEXIBLE;
512 
513 	speed &= 0xff;
514 
515 	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
516 	if (err)
517 		return err;
518 
519 	return err;
520 }
521 #endif  /*  0  */
522 
523 static int ds_set_pullup(struct ds_device *dev, int delay)
524 {
525 	int err = 0;
526 	u8 del = 1 + (u8)(delay >> 4);
527 	/* Just storing delay would not get the trunication and roundup. */
528 	int ms = del<<4;
529 
530 	/* Enable spu_bit if a delay is set. */
531 	dev->spu_bit = delay ? COMM_SPU : 0;
532 	/* If delay is zero, it has already been disabled, if the time is
533 	 * the same as the hardware was last programmed to, there is also
534 	 * nothing more to do.  Compare with the recalculated value ms
535 	 * rather than del or delay which can have a different value.
536 	 */
537 	if (delay == 0 || ms == dev->spu_sleep)
538 		return err;
539 
540 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
541 	if (err)
542 		return err;
543 
544 	dev->spu_sleep = ms;
545 
546 	return err;
547 }
548 
549 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
550 {
551 	int err;
552 	struct ds_status st;
553 
554 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
555 		0);
556 	if (err)
557 		return err;
558 
559 	ds_wait_status(dev, &st);
560 
561 	err = ds_recv_data(dev, tbit, sizeof(*tbit));
562 	if (err < 0)
563 		return err;
564 
565 	return 0;
566 }
567 
568 #if 0
569 static int ds_write_bit(struct ds_device *dev, u8 bit)
570 {
571 	int err;
572 	struct ds_status st;
573 
574 	/* Set COMM_ICP to write without a readback.  Note, this will
575 	 * produce one time slot, a down followed by an up with COMM_D
576 	 * only determing the timing.
577 	 */
578 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
579 		(bit ? COMM_D : 0), 0);
580 	if (err)
581 		return err;
582 
583 	ds_wait_status(dev, &st);
584 
585 	return 0;
586 }
587 #endif
588 
589 static int ds_write_byte(struct ds_device *dev, u8 byte)
590 {
591 	int err;
592 	struct ds_status st;
593 
594 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
595 	if (err)
596 		return err;
597 
598 	if (dev->spu_bit)
599 		msleep(dev->spu_sleep);
600 
601 	err = ds_wait_status(dev, &st);
602 	if (err)
603 		return err;
604 
605 	err = ds_recv_data(dev, &dev->byte_buf, 1);
606 	if (err < 0)
607 		return err;
608 
609 	return !(byte == dev->byte_buf);
610 }
611 
612 static int ds_read_byte(struct ds_device *dev, u8 *byte)
613 {
614 	int err;
615 	struct ds_status st;
616 
617 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM , 0xff);
618 	if (err)
619 		return err;
620 
621 	ds_wait_status(dev, &st);
622 
623 	err = ds_recv_data(dev, byte, sizeof(*byte));
624 	if (err < 0)
625 		return err;
626 
627 	return 0;
628 }
629 
630 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
631 {
632 	struct ds_status st;
633 	int err;
634 
635 	if (len > 64*1024)
636 		return -E2BIG;
637 
638 	memset(buf, 0xFF, len);
639 
640 	err = ds_send_data(dev, buf, len);
641 	if (err < 0)
642 		return err;
643 
644 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
645 	if (err)
646 		return err;
647 
648 	ds_wait_status(dev, &st);
649 
650 	memset(buf, 0x00, len);
651 	err = ds_recv_data(dev, buf, len);
652 
653 	return err;
654 }
655 
656 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
657 {
658 	int err;
659 	struct ds_status st;
660 
661 	err = ds_send_data(dev, buf, len);
662 	if (err < 0)
663 		return err;
664 
665 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
666 	if (err)
667 		return err;
668 
669 	if (dev->spu_bit)
670 		msleep(dev->spu_sleep);
671 
672 	ds_wait_status(dev, &st);
673 
674 	err = ds_recv_data(dev, buf, len);
675 	if (err < 0)
676 		return err;
677 
678 	return !(err == len);
679 }
680 
681 static void ds9490r_search(void *data, struct w1_master *master,
682 	u8 search_type, w1_slave_found_callback callback)
683 {
684 	/* When starting with an existing id, the first id returned will
685 	 * be that device (if it is still on the bus most likely).
686 	 *
687 	 * If the number of devices found is less than or equal to the
688 	 * search_limit, that number of IDs will be returned.  If there are
689 	 * more, search_limit IDs will be returned followed by a non-zero
690 	 * discrepency value.
691 	 */
692 	struct ds_device *dev = data;
693 	int err;
694 	u16 value, index;
695 	struct ds_status st;
696 	int search_limit;
697 	int found = 0;
698 	int i;
699 
700 	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
701 	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
702 	 */
703 	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
704 	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
705 	 * packet size.
706 	 */
707 	const size_t bufsize = 2 * 64;
708 	u64 *buf;
709 
710 	buf = kmalloc(bufsize, GFP_KERNEL);
711 	if (!buf)
712 		return;
713 
714 	mutex_lock(&master->bus_mutex);
715 
716 	/* address to start searching at */
717 	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
718 		goto search_out;
719 	master->search_id = 0;
720 
721 	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
722 		COMM_RTS;
723 	search_limit = master->max_slave_count;
724 	if (search_limit > 255)
725 		search_limit = 0;
726 	index = search_type | (search_limit << 8);
727 	if (ds_send_control(dev, value, index) < 0)
728 		goto search_out;
729 
730 	do {
731 		schedule_timeout(jtime);
732 
733 		err = ds_recv_status(dev, &st, false);
734 		if (err < 0 || err < sizeof(st))
735 			break;
736 
737 		if (st.data_in_buffer_status) {
738 			/* Bulk in can receive partial ids, but when it does
739 			 * they fail crc and will be discarded anyway.
740 			 * That has only been seen when status in buffer
741 			 * is 0 and bulk is read anyway, so don't read
742 			 * bulk without first checking if status says there
743 			 * is data to read.
744 			 */
745 			err = ds_recv_data(dev, (u8 *)buf, bufsize);
746 			if (err < 0)
747 				break;
748 			for (i = 0; i < err/8; ++i) {
749 				++found;
750 				if (found <= search_limit)
751 					callback(master, buf[i]);
752 				/* can't know if there will be a discrepancy
753 				 * value after until the next id */
754 				if (found == search_limit)
755 					master->search_id = buf[i];
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 		/* Only max_slave_count will be scanned in a search,
768 		 * but it will start where it left off next search
769 		 * until all ids are identified and then it will start
770 		 * over.  A continued search will report the previous
771 		 * last id as the first id (provided it is still on the
772 		 * bus).
773 		 */
774 		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
775 			"will continue next search.\n", __func__,
776 			master->max_slave_count);
777 		set_bit(W1_WARN_MAX_COUNT, &master->flags);
778 	}
779 search_out:
780 	mutex_unlock(&master->bus_mutex);
781 	kfree(buf);
782 }
783 
784 #if 0
785 /*
786  * FIXME: if this disabled code is ever used in the future all ds_send_data()
787  * calls must be changed to use a DMAable buffer.
788  */
789 static int ds_match_access(struct ds_device *dev, u64 init)
790 {
791 	int err;
792 	struct ds_status st;
793 
794 	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
795 	if (err)
796 		return err;
797 
798 	ds_wait_status(dev, &st);
799 
800 	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
801 	if (err)
802 		return err;
803 
804 	ds_wait_status(dev, &st);
805 
806 	return 0;
807 }
808 
809 static int ds_set_path(struct ds_device *dev, u64 init)
810 {
811 	int err;
812 	struct ds_status st;
813 	u8 buf[9];
814 
815 	memcpy(buf, &init, 8);
816 	buf[8] = BRANCH_MAIN;
817 
818 	err = ds_send_data(dev, buf, sizeof(buf));
819 	if (err)
820 		return err;
821 
822 	ds_wait_status(dev, &st);
823 
824 	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
825 	if (err)
826 		return err;
827 
828 	ds_wait_status(dev, &st);
829 
830 	return 0;
831 }
832 
833 #endif  /*  0  */
834 
835 static u8 ds9490r_touch_bit(void *data, u8 bit)
836 {
837 	struct ds_device *dev = data;
838 
839 	if (ds_touch_bit(dev, bit, &dev->byte_buf))
840 		return 0;
841 
842 	return dev->byte_buf;
843 }
844 
845 #if 0
846 static void ds9490r_write_bit(void *data, u8 bit)
847 {
848 	struct ds_device *dev = data;
849 
850 	ds_write_bit(dev, bit);
851 }
852 
853 static u8 ds9490r_read_bit(void *data)
854 {
855 	struct ds_device *dev = data;
856 	int err;
857 
858 	err = ds_touch_bit(dev, 1, &dev->byte_buf);
859 	if (err)
860 		return 0;
861 
862 	return dev->byte_buf & 1;
863 }
864 #endif
865 
866 static void ds9490r_write_byte(void *data, u8 byte)
867 {
868 	struct ds_device *dev = data;
869 
870 	ds_write_byte(dev, byte);
871 }
872 
873 static u8 ds9490r_read_byte(void *data)
874 {
875 	struct ds_device *dev = data;
876 	int err;
877 
878 	err = ds_read_byte(dev, &dev->byte_buf);
879 	if (err)
880 		return 0;
881 
882 	return dev->byte_buf;
883 }
884 
885 static void ds9490r_write_block(void *data, const u8 *buf, int len)
886 {
887 	struct ds_device *dev = data;
888 	u8 *tbuf;
889 
890 	if (len <= 0)
891 		return;
892 
893 	tbuf = kmemdup(buf, len, GFP_KERNEL);
894 	if (!tbuf)
895 		return;
896 
897 	ds_write_block(dev, tbuf, len);
898 
899 	kfree(tbuf);
900 }
901 
902 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
903 {
904 	struct ds_device *dev = data;
905 	int err;
906 	u8 *tbuf;
907 
908 	if (len <= 0)
909 		return 0;
910 
911 	tbuf = kmalloc(len, GFP_KERNEL);
912 	if (!tbuf)
913 		return 0;
914 
915 	err = ds_read_block(dev, tbuf, len);
916 	if (err >= 0)
917 		memcpy(buf, tbuf, len);
918 
919 	kfree(tbuf);
920 
921 	return err >= 0 ? len : 0;
922 }
923 
924 static u8 ds9490r_reset(void *data)
925 {
926 	struct ds_device *dev = data;
927 	int err;
928 
929 	err = ds_reset(dev);
930 	if (err)
931 		return 1;
932 
933 	return 0;
934 }
935 
936 static u8 ds9490r_set_pullup(void *data, int delay)
937 {
938 	struct ds_device *dev = data;
939 
940 	if (ds_set_pullup(dev, delay))
941 		return 1;
942 
943 	return 0;
944 }
945 
946 static int ds_w1_init(struct ds_device *dev)
947 {
948 	memset(&dev->master, 0, sizeof(struct w1_bus_master));
949 
950 	/* Reset the device as it can be in a bad state.
951 	 * This is necessary because a block write will wait for data
952 	 * to be placed in the output buffer and block any later
953 	 * commands which will keep accumulating and the device will
954 	 * not be idle.  Another case is removing the ds2490 module
955 	 * while a bus search is in progress, somehow a few commands
956 	 * get through, but the input transfers fail leaving data in
957 	 * the input buffer.  This will cause the next read to fail
958 	 * see the note in ds_recv_data.
959 	 */
960 	ds_reset_device(dev);
961 
962 	dev->master.data	= dev;
963 	dev->master.touch_bit	= &ds9490r_touch_bit;
964 	/* read_bit and write_bit in w1_bus_master are expected to set and
965 	 * sample the line level.  For write_bit that means it is expected to
966 	 * set it to that value and leave it there.  ds2490 only supports an
967 	 * individual time slot at the lowest level.  The requirement from
968 	 * pulling the bus state down to reading the state is 15us, something
969 	 * that isn't realistic on the USB bus anyway.
970 	dev->master.read_bit	= &ds9490r_read_bit;
971 	dev->master.write_bit	= &ds9490r_write_bit;
972 	*/
973 	dev->master.read_byte	= &ds9490r_read_byte;
974 	dev->master.write_byte	= &ds9490r_write_byte;
975 	dev->master.read_block	= &ds9490r_read_block;
976 	dev->master.write_block	= &ds9490r_write_block;
977 	dev->master.reset_bus	= &ds9490r_reset;
978 	dev->master.set_pullup	= &ds9490r_set_pullup;
979 	dev->master.search	= &ds9490r_search;
980 
981 	return w1_add_master_device(&dev->master);
982 }
983 
984 static void ds_w1_fini(struct ds_device *dev)
985 {
986 	w1_remove_master_device(&dev->master);
987 }
988 
989 static int ds_probe(struct usb_interface *intf,
990 		    const struct usb_device_id *udev_id)
991 {
992 	struct usb_device *udev = interface_to_usbdev(intf);
993 	struct usb_endpoint_descriptor *endpoint;
994 	struct usb_host_interface *iface_desc;
995 	struct ds_device *dev;
996 	int i, err, alt;
997 
998 	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
999 	if (!dev) {
1000 		pr_info("Failed to allocate new DS9490R structure.\n");
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->altsetting[alt].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->altsetting[alt].desc.bInterfaceNumber, err);
1027 		goto err_out_clear;
1028 	}
1029 
1030 	iface_desc = &intf->altsetting[alt];
1031 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1032 		pr_info("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 
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 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