xref: /linux/drivers/w1/masters/ds2490.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 	struct w1_bus_master	master;
157 };
158 
159 struct ds_status
160 {
161 	u8			enable;
162 	u8			speed;
163 	u8			pullup_dur;
164 	u8			ppuls_dur;
165 	u8			pulldown_slew;
166 	u8			write1_time;
167 	u8			write0_time;
168 	u8			reserved0;
169 	u8			status;
170 	u8			command0;
171 	u8			command1;
172 	u8			command_buffer_status;
173 	u8			data_out_buffer_status;
174 	u8			data_in_buffer_status;
175 	u8			reserved1;
176 	u8			reserved2;
177 
178 };
179 
180 static struct usb_device_id ds_id_table [] = {
181 	{ USB_DEVICE(0x04fa, 0x2490) },
182 	{ },
183 };
184 MODULE_DEVICE_TABLE(usb, ds_id_table);
185 
186 static int ds_probe(struct usb_interface *, const struct usb_device_id *);
187 static void ds_disconnect(struct usb_interface *);
188 
189 static int ds_send_control(struct ds_device *, u16, u16);
190 static int ds_send_control_cmd(struct ds_device *, u16, u16);
191 
192 static LIST_HEAD(ds_devices);
193 static DEFINE_MUTEX(ds_mutex);
194 
195 static struct usb_driver ds_driver = {
196 	.name =		"DS9490R",
197 	.probe =	ds_probe,
198 	.disconnect =	ds_disconnect,
199 	.id_table =	ds_id_table,
200 };
201 
202 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
203 {
204 	int err;
205 
206 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
207 			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
208 	if (err < 0) {
209 		pr_err("Failed to send command control message %x.%x: err=%d.\n",
210 				value, index, err);
211 		return err;
212 	}
213 
214 	return err;
215 }
216 
217 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
218 {
219 	int err;
220 
221 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
222 			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
223 	if (err < 0) {
224 		pr_err("Failed to send mode control message %x.%x: err=%d.\n",
225 				value, index, err);
226 		return err;
227 	}
228 
229 	return err;
230 }
231 
232 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
233 {
234 	int err;
235 
236 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
237 			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
238 	if (err < 0) {
239 		pr_err("Failed to send control message %x.%x: err=%d.\n",
240 				value, index, err);
241 		return err;
242 	}
243 
244 	return err;
245 }
246 
247 static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
248 				 unsigned char *buf, int size)
249 {
250 	int count, err;
251 
252 	memset(st, 0, sizeof(*st));
253 
254 	count = 0;
255 	err = usb_interrupt_msg(dev->udev, usb_rcvintpipe(dev->udev,
256 		dev->ep[EP_STATUS]), buf, size, &count, 1000);
257 	if (err < 0) {
258 		pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
259 		       dev->ep[EP_STATUS], err);
260 		return err;
261 	}
262 
263 	if (count >= sizeof(*st))
264 		memcpy(st, buf, sizeof(*st));
265 
266 	return count;
267 }
268 
269 static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
270 {
271 	pr_info("%45s: %8x\n", str, buf[off]);
272 }
273 
274 static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
275 {
276 	int i;
277 
278 	pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
279 	for (i=0; i<count; ++i)
280 		pr_info("%02x ", buf[i]);
281 	pr_info("\n");
282 
283 	if (count >= 16) {
284 		ds_print_msg(buf, "enable flag", 0);
285 		ds_print_msg(buf, "1-wire speed", 1);
286 		ds_print_msg(buf, "strong pullup duration", 2);
287 		ds_print_msg(buf, "programming pulse duration", 3);
288 		ds_print_msg(buf, "pulldown slew rate control", 4);
289 		ds_print_msg(buf, "write-1 low time", 5);
290 		ds_print_msg(buf, "data sample offset/write-0 recovery time",
291 			6);
292 		ds_print_msg(buf, "reserved (test register)", 7);
293 		ds_print_msg(buf, "device status flags", 8);
294 		ds_print_msg(buf, "communication command byte 1", 9);
295 		ds_print_msg(buf, "communication command byte 2", 10);
296 		ds_print_msg(buf, "communication command buffer status", 11);
297 		ds_print_msg(buf, "1-wire data output buffer status", 12);
298 		ds_print_msg(buf, "1-wire data input buffer status", 13);
299 		ds_print_msg(buf, "reserved", 14);
300 		ds_print_msg(buf, "reserved", 15);
301 	}
302 	for (i = 16; i < count; ++i) {
303 		if (buf[i] == RR_DETECT) {
304 			ds_print_msg(buf, "new device detect", i);
305 			continue;
306 		}
307 		ds_print_msg(buf, "Result Register Value: ", i);
308 		if (buf[i] & RR_NRS)
309 			pr_info("NRS: Reset no presence or ...\n");
310 		if (buf[i] & RR_SH)
311 			pr_info("SH: short on reset or set path\n");
312 		if (buf[i] & RR_APP)
313 			pr_info("APP: alarming presence on reset\n");
314 		if (buf[i] & RR_VPP)
315 			pr_info("VPP: 12V expected not seen\n");
316 		if (buf[i] & RR_CMP)
317 			pr_info("CMP: compare error\n");
318 		if (buf[i] & RR_CRC)
319 			pr_info("CRC: CRC error detected\n");
320 		if (buf[i] & RR_RDP)
321 			pr_info("RDP: redirected page\n");
322 		if (buf[i] & RR_EOS)
323 			pr_info("EOS: end of search error\n");
324 	}
325 }
326 
327 static void ds_reset_device(struct ds_device *dev)
328 {
329 	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
330 	/* Always allow strong pullup which allow individual writes to use
331 	 * the strong pullup.
332 	 */
333 	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
334 		pr_err("ds_reset_device: Error allowing strong pullup\n");
335 	/* Chip strong pullup time was cleared. */
336 	if (dev->spu_sleep) {
337 		/* lower 4 bits are 0, see ds_set_pullup */
338 		u8 del = dev->spu_sleep>>4;
339 		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
340 			pr_err("ds_reset_device: Error setting duration\n");
341 	}
342 }
343 
344 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
345 {
346 	int count, err;
347 	struct ds_status st;
348 
349 	/* Careful on size.  If size is less than what is available in
350 	 * the input buffer, the device fails the bulk transfer and
351 	 * clears the input buffer.  It could read the maximum size of
352 	 * the data buffer, but then do you return the first, last, or
353 	 * some set of the middle size bytes?  As long as the rest of
354 	 * the code is correct there will be size bytes waiting.  A
355 	 * call to ds_wait_status will wait until the device is idle
356 	 * and any data to be received would have been available.
357 	 */
358 	count = 0;
359 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
360 				buf, size, &count, 1000);
361 	if (err < 0) {
362 		u8 buf[ST_SIZE];
363 		int count;
364 
365 		pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
366 		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
367 
368 		count = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
369 		ds_dump_status(dev, buf, count);
370 		return err;
371 	}
372 
373 #if 0
374 	{
375 		int i;
376 
377 		printk("%s: count=%d: ", __func__, count);
378 		for (i=0; i<count; ++i)
379 			printk("%02x ", buf[i]);
380 		printk("\n");
381 	}
382 #endif
383 	return count;
384 }
385 
386 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
387 {
388 	int count, err;
389 
390 	count = 0;
391 	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
392 	if (err < 0) {
393 		pr_err("Failed to write 1-wire data to ep0x%x: "
394 			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
395 		return err;
396 	}
397 
398 	return err;
399 }
400 
401 #if 0
402 
403 int ds_stop_pulse(struct ds_device *dev, int limit)
404 {
405 	struct ds_status st;
406 	int count = 0, err = 0;
407 	u8 buf[ST_SIZE];
408 
409 	do {
410 		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
411 		if (err)
412 			break;
413 		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
414 		if (err)
415 			break;
416 		err = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
417 		if (err)
418 			break;
419 
420 		if ((st.status & ST_SPUA) == 0) {
421 			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
422 			if (err)
423 				break;
424 		}
425 	} while(++count < limit);
426 
427 	return err;
428 }
429 
430 int ds_detect(struct ds_device *dev, struct ds_status *st)
431 {
432 	int err;
433 
434 	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
435 	if (err)
436 		return err;
437 
438 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
439 	if (err)
440 		return err;
441 
442 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
443 	if (err)
444 		return err;
445 
446 	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
447 	if (err)
448 		return err;
449 
450 	err = ds_dump_status(dev, st);
451 
452 	return err;
453 }
454 
455 #endif  /*  0  */
456 
457 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
458 {
459 	u8 buf[ST_SIZE];
460 	int err, count = 0;
461 
462 	do {
463 		st->status = 0;
464 		err = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
465 #if 0
466 		if (err >= 0) {
467 			int i;
468 			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
469 			for (i=0; i<err; ++i)
470 				printk("%02x ", buf[i]);
471 			printk("\n");
472 		}
473 #endif
474 	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
475 
476 	if (err >= 16 && st->status & ST_EPOF) {
477 		pr_info("Resetting device after ST_EPOF.\n");
478 		ds_reset_device(dev);
479 		/* Always dump the device status. */
480 		count = 101;
481 	}
482 
483 	/* Dump the status for errors or if there is extended return data.
484 	 * The extended status includes new device detection (maybe someone
485 	 * can do something with it).
486 	 */
487 	if (err > 16 || count >= 100 || err < 0)
488 		ds_dump_status(dev, buf, err);
489 
490 	/* Extended data isn't an error.  Well, a short is, but the dump
491 	 * would have already told the user that and we can't do anything
492 	 * about it in software anyway.
493 	 */
494 	if (count >= 100 || err < 0)
495 		return -1;
496 	else
497 		return 0;
498 }
499 
500 static int ds_reset(struct ds_device *dev)
501 {
502 	int err;
503 
504 	/* Other potentionally interesting flags for reset.
505 	 *
506 	 * COMM_NTF: Return result register feedback.  This could be used to
507 	 * detect some conditions such as short, alarming presence, or
508 	 * detect if a new device was detected.
509 	 *
510 	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
511 	 * Select the data transfer rate.
512 	 */
513 	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
514 	if (err)
515 		return err;
516 
517 	return 0;
518 }
519 
520 #if 0
521 static int ds_set_speed(struct ds_device *dev, int speed)
522 {
523 	int err;
524 
525 	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
526 		return -EINVAL;
527 
528 	if (speed != SPEED_OVERDRIVE)
529 		speed = SPEED_FLEXIBLE;
530 
531 	speed &= 0xff;
532 
533 	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
534 	if (err)
535 		return err;
536 
537 	return err;
538 }
539 #endif  /*  0  */
540 
541 static int ds_set_pullup(struct ds_device *dev, int delay)
542 {
543 	int err = 0;
544 	u8 del = 1 + (u8)(delay >> 4);
545 	/* Just storing delay would not get the trunication and roundup. */
546 	int ms = del<<4;
547 
548 	/* Enable spu_bit if a delay is set. */
549 	dev->spu_bit = delay ? COMM_SPU : 0;
550 	/* If delay is zero, it has already been disabled, if the time is
551 	 * the same as the hardware was last programmed to, there is also
552 	 * nothing more to do.  Compare with the recalculated value ms
553 	 * rather than del or delay which can have a different value.
554 	 */
555 	if (delay == 0 || ms == dev->spu_sleep)
556 		return err;
557 
558 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
559 	if (err)
560 		return err;
561 
562 	dev->spu_sleep = ms;
563 
564 	return err;
565 }
566 
567 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
568 {
569 	int err;
570 	struct ds_status st;
571 
572 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
573 		0);
574 	if (err)
575 		return err;
576 
577 	ds_wait_status(dev, &st);
578 
579 	err = ds_recv_data(dev, tbit, sizeof(*tbit));
580 	if (err < 0)
581 		return err;
582 
583 	return 0;
584 }
585 
586 #if 0
587 static int ds_write_bit(struct ds_device *dev, u8 bit)
588 {
589 	int err;
590 	struct ds_status st;
591 
592 	/* Set COMM_ICP to write without a readback.  Note, this will
593 	 * produce one time slot, a down followed by an up with COMM_D
594 	 * only determing the timing.
595 	 */
596 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
597 		(bit ? COMM_D : 0), 0);
598 	if (err)
599 		return err;
600 
601 	ds_wait_status(dev, &st);
602 
603 	return 0;
604 }
605 #endif
606 
607 static int ds_write_byte(struct ds_device *dev, u8 byte)
608 {
609 	int err;
610 	struct ds_status st;
611 	u8 rbyte;
612 
613 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
614 	if (err)
615 		return err;
616 
617 	if (dev->spu_bit)
618 		msleep(dev->spu_sleep);
619 
620 	err = ds_wait_status(dev, &st);
621 	if (err)
622 		return err;
623 
624 	err = ds_recv_data(dev, &rbyte, sizeof(rbyte));
625 	if (err < 0)
626 		return err;
627 
628 	return !(byte == rbyte);
629 }
630 
631 static int ds_read_byte(struct ds_device *dev, u8 *byte)
632 {
633 	int err;
634 	struct ds_status st;
635 
636 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM , 0xff);
637 	if (err)
638 		return err;
639 
640 	ds_wait_status(dev, &st);
641 
642 	err = ds_recv_data(dev, byte, sizeof(*byte));
643 	if (err < 0)
644 		return err;
645 
646 	return 0;
647 }
648 
649 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
650 {
651 	struct ds_status st;
652 	int err;
653 
654 	if (len > 64*1024)
655 		return -E2BIG;
656 
657 	memset(buf, 0xFF, len);
658 
659 	err = ds_send_data(dev, buf, len);
660 	if (err < 0)
661 		return err;
662 
663 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
664 	if (err)
665 		return err;
666 
667 	ds_wait_status(dev, &st);
668 
669 	memset(buf, 0x00, len);
670 	err = ds_recv_data(dev, buf, len);
671 
672 	return err;
673 }
674 
675 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
676 {
677 	int err;
678 	struct ds_status st;
679 
680 	err = ds_send_data(dev, buf, len);
681 	if (err < 0)
682 		return err;
683 
684 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
685 	if (err)
686 		return err;
687 
688 	if (dev->spu_bit)
689 		msleep(dev->spu_sleep);
690 
691 	ds_wait_status(dev, &st);
692 
693 	err = ds_recv_data(dev, buf, len);
694 	if (err < 0)
695 		return err;
696 
697 	return !(err == len);
698 }
699 
700 static void ds9490r_search(void *data, struct w1_master *master,
701 	u8 search_type, w1_slave_found_callback callback)
702 {
703 	/* When starting with an existing id, the first id returned will
704 	 * be that device (if it is still on the bus most likely).
705 	 *
706 	 * If the number of devices found is less than or equal to the
707 	 * search_limit, that number of IDs will be returned.  If there are
708 	 * more, search_limit IDs will be returned followed by a non-zero
709 	 * discrepency value.
710 	 */
711 	struct ds_device *dev = data;
712 	int err;
713 	u16 value, index;
714 	struct ds_status st;
715 	u8 st_buf[ST_SIZE];
716 	int search_limit;
717 	int found = 0;
718 	int i;
719 
720 	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
721 	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
722 	 */
723 	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
724 	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
725 	 * packet size.
726 	 */
727 	u64 buf[2*64/8];
728 
729 	mutex_lock(&master->bus_mutex);
730 
731 	/* address to start searching at */
732 	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
733 		goto search_out;
734 	master->search_id = 0;
735 
736 	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
737 		COMM_RTS;
738 	search_limit = master->max_slave_count;
739 	if (search_limit > 255)
740 		search_limit = 0;
741 	index = search_type | (search_limit << 8);
742 	if (ds_send_control(dev, value, index) < 0)
743 		goto search_out;
744 
745 	do {
746 		schedule_timeout(jtime);
747 
748 		if (ds_recv_status_nodump(dev, &st, st_buf, sizeof(st_buf)) <
749 			sizeof(st)) {
750 			break;
751 		}
752 
753 		if (st.data_in_buffer_status) {
754 			/* Bulk in can receive partial ids, but when it does
755 			 * they fail crc and will be discarded anyway.
756 			 * That has only been seen when status in buffer
757 			 * is 0 and bulk is read anyway, so don't read
758 			 * bulk without first checking if status says there
759 			 * is data to read.
760 			 */
761 			err = ds_recv_data(dev, (u8 *)buf, sizeof(buf));
762 			if (err < 0)
763 				break;
764 			for (i = 0; i < err/8; ++i) {
765 				++found;
766 				if (found <= search_limit)
767 					callback(master, buf[i]);
768 				/* can't know if there will be a discrepancy
769 				 * value after until the next id */
770 				if (found == search_limit)
771 					master->search_id = buf[i];
772 			}
773 		}
774 
775 		if (test_bit(W1_ABORT_SEARCH, &master->flags))
776 			break;
777 	} while (!(st.status & (ST_IDLE | ST_HALT)));
778 
779 	/* only continue the search if some weren't found */
780 	if (found <= search_limit) {
781 		master->search_id = 0;
782 	} else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
783 		/* Only max_slave_count will be scanned in a search,
784 		 * but it will start where it left off next search
785 		 * until all ids are identified and then it will start
786 		 * over.  A continued search will report the previous
787 		 * last id as the first id (provided it is still on the
788 		 * bus).
789 		 */
790 		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
791 			"will continue next search.\n", __func__,
792 			master->max_slave_count);
793 		set_bit(W1_WARN_MAX_COUNT, &master->flags);
794 	}
795 search_out:
796 	mutex_unlock(&master->bus_mutex);
797 }
798 
799 #if 0
800 static int ds_match_access(struct ds_device *dev, u64 init)
801 {
802 	int err;
803 	struct ds_status st;
804 
805 	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
806 	if (err)
807 		return err;
808 
809 	ds_wait_status(dev, &st);
810 
811 	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
812 	if (err)
813 		return err;
814 
815 	ds_wait_status(dev, &st);
816 
817 	return 0;
818 }
819 
820 static int ds_set_path(struct ds_device *dev, u64 init)
821 {
822 	int err;
823 	struct ds_status st;
824 	u8 buf[9];
825 
826 	memcpy(buf, &init, 8);
827 	buf[8] = BRANCH_MAIN;
828 
829 	err = ds_send_data(dev, buf, sizeof(buf));
830 	if (err)
831 		return err;
832 
833 	ds_wait_status(dev, &st);
834 
835 	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
836 	if (err)
837 		return err;
838 
839 	ds_wait_status(dev, &st);
840 
841 	return 0;
842 }
843 
844 #endif  /*  0  */
845 
846 static u8 ds9490r_touch_bit(void *data, u8 bit)
847 {
848 	u8 ret;
849 	struct ds_device *dev = data;
850 
851 	if (ds_touch_bit(dev, bit, &ret))
852 		return 0;
853 
854 	return ret;
855 }
856 
857 #if 0
858 static void ds9490r_write_bit(void *data, u8 bit)
859 {
860 	struct ds_device *dev = data;
861 
862 	ds_write_bit(dev, bit);
863 }
864 
865 static u8 ds9490r_read_bit(void *data)
866 {
867 	struct ds_device *dev = data;
868 	int err;
869 	u8 bit = 0;
870 
871 	err = ds_touch_bit(dev, 1, &bit);
872 	if (err)
873 		return 0;
874 
875 	return bit & 1;
876 }
877 #endif
878 
879 static void ds9490r_write_byte(void *data, u8 byte)
880 {
881 	struct ds_device *dev = data;
882 
883 	ds_write_byte(dev, byte);
884 }
885 
886 static u8 ds9490r_read_byte(void *data)
887 {
888 	struct ds_device *dev = data;
889 	int err;
890 	u8 byte = 0;
891 
892 	err = ds_read_byte(dev, &byte);
893 	if (err)
894 		return 0;
895 
896 	return byte;
897 }
898 
899 static void ds9490r_write_block(void *data, const u8 *buf, int len)
900 {
901 	struct ds_device *dev = data;
902 
903 	ds_write_block(dev, (u8 *)buf, len);
904 }
905 
906 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
907 {
908 	struct ds_device *dev = data;
909 	int err;
910 
911 	err = ds_read_block(dev, buf, len);
912 	if (err < 0)
913 		return 0;
914 
915 	return len;
916 }
917 
918 static u8 ds9490r_reset(void *data)
919 {
920 	struct ds_device *dev = data;
921 	int err;
922 
923 	err = ds_reset(dev);
924 	if (err)
925 		return 1;
926 
927 	return 0;
928 }
929 
930 static u8 ds9490r_set_pullup(void *data, int delay)
931 {
932 	struct ds_device *dev = data;
933 
934 	if (ds_set_pullup(dev, delay))
935 		return 1;
936 
937 	return 0;
938 }
939 
940 static int ds_w1_init(struct ds_device *dev)
941 {
942 	memset(&dev->master, 0, sizeof(struct w1_bus_master));
943 
944 	/* Reset the device as it can be in a bad state.
945 	 * This is necessary because a block write will wait for data
946 	 * to be placed in the output buffer and block any later
947 	 * commands which will keep accumulating and the device will
948 	 * not be idle.  Another case is removing the ds2490 module
949 	 * while a bus search is in progress, somehow a few commands
950 	 * get through, but the input transfers fail leaving data in
951 	 * the input buffer.  This will cause the next read to fail
952 	 * see the note in ds_recv_data.
953 	 */
954 	ds_reset_device(dev);
955 
956 	dev->master.data	= dev;
957 	dev->master.touch_bit	= &ds9490r_touch_bit;
958 	/* read_bit and write_bit in w1_bus_master are expected to set and
959 	 * sample the line level.  For write_bit that means it is expected to
960 	 * set it to that value and leave it there.  ds2490 only supports an
961 	 * individual time slot at the lowest level.  The requirement from
962 	 * pulling the bus state down to reading the state is 15us, something
963 	 * that isn't realistic on the USB bus anyway.
964 	dev->master.read_bit	= &ds9490r_read_bit;
965 	dev->master.write_bit	= &ds9490r_write_bit;
966 	*/
967 	dev->master.read_byte	= &ds9490r_read_byte;
968 	dev->master.write_byte	= &ds9490r_write_byte;
969 	dev->master.read_block	= &ds9490r_read_block;
970 	dev->master.write_block	= &ds9490r_write_block;
971 	dev->master.reset_bus	= &ds9490r_reset;
972 	dev->master.set_pullup	= &ds9490r_set_pullup;
973 	dev->master.search	= &ds9490r_search;
974 
975 	return w1_add_master_device(&dev->master);
976 }
977 
978 static void ds_w1_fini(struct ds_device *dev)
979 {
980 	w1_remove_master_device(&dev->master);
981 }
982 
983 static int ds_probe(struct usb_interface *intf,
984 		    const struct usb_device_id *udev_id)
985 {
986 	struct usb_device *udev = interface_to_usbdev(intf);
987 	struct usb_endpoint_descriptor *endpoint;
988 	struct usb_host_interface *iface_desc;
989 	struct ds_device *dev;
990 	int i, err, alt;
991 
992 	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
993 	if (!dev) {
994 		pr_info("Failed to allocate new DS9490R structure.\n");
995 		return -ENOMEM;
996 	}
997 	dev->udev = usb_get_dev(udev);
998 	if (!dev->udev) {
999 		err = -ENOMEM;
1000 		goto err_out_free;
1001 	}
1002 	memset(dev->ep, 0, sizeof(dev->ep));
1003 
1004 	usb_set_intfdata(intf, dev);
1005 
1006 	err = usb_reset_configuration(dev->udev);
1007 	if (err) {
1008 		dev_err(&dev->udev->dev,
1009 			"Failed to reset configuration: err=%d.\n", err);
1010 		goto err_out_clear;
1011 	}
1012 
1013 	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1014 	alt = 3;
1015 	err = usb_set_interface(dev->udev,
1016 		intf->altsetting[alt].desc.bInterfaceNumber, alt);
1017 	if (err) {
1018 		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1019 			"for %d interface: err=%d.\n", alt,
1020 			intf->altsetting[alt].desc.bInterfaceNumber, err);
1021 		goto err_out_clear;
1022 	}
1023 
1024 	iface_desc = &intf->altsetting[alt];
1025 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1026 		pr_info("Num endpoints=%d. It is not DS9490R.\n",
1027 			iface_desc->desc.bNumEndpoints);
1028 		err = -EINVAL;
1029 		goto err_out_clear;
1030 	}
1031 
1032 	/*
1033 	 * This loop doesn'd show control 0 endpoint,
1034 	 * so we will fill only 1-3 endpoints entry.
1035 	 */
1036 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1037 		endpoint = &iface_desc->endpoint[i].desc;
1038 
1039 		dev->ep[i+1] = endpoint->bEndpointAddress;
1040 #if 0
1041 		printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1042 			i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1043 			(endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1044 			endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1045 #endif
1046 	}
1047 
1048 	err = ds_w1_init(dev);
1049 	if (err)
1050 		goto err_out_clear;
1051 
1052 	mutex_lock(&ds_mutex);
1053 	list_add_tail(&dev->ds_entry, &ds_devices);
1054 	mutex_unlock(&ds_mutex);
1055 
1056 	return 0;
1057 
1058 err_out_clear:
1059 	usb_set_intfdata(intf, NULL);
1060 	usb_put_dev(dev->udev);
1061 err_out_free:
1062 	kfree(dev);
1063 	return err;
1064 }
1065 
1066 static void ds_disconnect(struct usb_interface *intf)
1067 {
1068 	struct ds_device *dev;
1069 
1070 	dev = usb_get_intfdata(intf);
1071 	if (!dev)
1072 		return;
1073 
1074 	mutex_lock(&ds_mutex);
1075 	list_del(&dev->ds_entry);
1076 	mutex_unlock(&ds_mutex);
1077 
1078 	ds_w1_fini(dev);
1079 
1080 	usb_set_intfdata(intf, NULL);
1081 
1082 	usb_put_dev(dev->udev);
1083 	kfree(dev);
1084 }
1085 
1086 module_usb_driver(ds_driver);
1087 
1088 MODULE_LICENSE("GPL");
1089 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1090 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1091