xref: /openbmc/linux/drivers/w1/masters/ds2490.c (revision bb0eb050)
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 struct usb_device_id ds_id_table [] = {
183 	{ USB_DEVICE(0x04fa, 0x2490) },
184 	{ },
185 };
186 MODULE_DEVICE_TABLE(usb, ds_id_table);
187 
188 static int ds_probe(struct usb_interface *, const struct usb_device_id *);
189 static void ds_disconnect(struct usb_interface *);
190 
191 static int ds_send_control(struct ds_device *, u16, u16);
192 static int ds_send_control_cmd(struct ds_device *, u16, u16);
193 
194 static LIST_HEAD(ds_devices);
195 static DEFINE_MUTEX(ds_mutex);
196 
197 static struct usb_driver ds_driver = {
198 	.name =		"DS9490R",
199 	.probe =	ds_probe,
200 	.disconnect =	ds_disconnect,
201 	.id_table =	ds_id_table,
202 };
203 
204 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
205 {
206 	int err;
207 
208 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
209 			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
210 	if (err < 0) {
211 		pr_err("Failed to send command control message %x.%x: err=%d.\n",
212 				value, index, err);
213 		return err;
214 	}
215 
216 	return err;
217 }
218 
219 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
220 {
221 	int err;
222 
223 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
224 			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
225 	if (err < 0) {
226 		pr_err("Failed to send mode control message %x.%x: err=%d.\n",
227 				value, index, err);
228 		return err;
229 	}
230 
231 	return err;
232 }
233 
234 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
235 {
236 	int err;
237 
238 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
239 			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
240 	if (err < 0) {
241 		pr_err("Failed to send control message %x.%x: err=%d.\n",
242 				value, index, err);
243 		return err;
244 	}
245 
246 	return err;
247 }
248 
249 static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
250 {
251 	pr_info("%45s: %8x\n", str, buf[off]);
252 }
253 
254 static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
255 {
256 	int i;
257 
258 	pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
259 	for (i=0; i<count; ++i)
260 		pr_info("%02x ", buf[i]);
261 	pr_info("\n");
262 
263 	if (count >= 16) {
264 		ds_print_msg(buf, "enable flag", 0);
265 		ds_print_msg(buf, "1-wire speed", 1);
266 		ds_print_msg(buf, "strong pullup duration", 2);
267 		ds_print_msg(buf, "programming pulse duration", 3);
268 		ds_print_msg(buf, "pulldown slew rate control", 4);
269 		ds_print_msg(buf, "write-1 low time", 5);
270 		ds_print_msg(buf, "data sample offset/write-0 recovery time",
271 			6);
272 		ds_print_msg(buf, "reserved (test register)", 7);
273 		ds_print_msg(buf, "device status flags", 8);
274 		ds_print_msg(buf, "communication command byte 1", 9);
275 		ds_print_msg(buf, "communication command byte 2", 10);
276 		ds_print_msg(buf, "communication command buffer status", 11);
277 		ds_print_msg(buf, "1-wire data output buffer status", 12);
278 		ds_print_msg(buf, "1-wire data input buffer status", 13);
279 		ds_print_msg(buf, "reserved", 14);
280 		ds_print_msg(buf, "reserved", 15);
281 	}
282 	for (i = 16; i < count; ++i) {
283 		if (buf[i] == RR_DETECT) {
284 			ds_print_msg(buf, "new device detect", i);
285 			continue;
286 		}
287 		ds_print_msg(buf, "Result Register Value: ", i);
288 		if (buf[i] & RR_NRS)
289 			pr_info("NRS: Reset no presence or ...\n");
290 		if (buf[i] & RR_SH)
291 			pr_info("SH: short on reset or set path\n");
292 		if (buf[i] & RR_APP)
293 			pr_info("APP: alarming presence on reset\n");
294 		if (buf[i] & RR_VPP)
295 			pr_info("VPP: 12V expected not seen\n");
296 		if (buf[i] & RR_CMP)
297 			pr_info("CMP: compare error\n");
298 		if (buf[i] & RR_CRC)
299 			pr_info("CRC: CRC error detected\n");
300 		if (buf[i] & RR_RDP)
301 			pr_info("RDP: redirected page\n");
302 		if (buf[i] & RR_EOS)
303 			pr_info("EOS: end of search error\n");
304 	}
305 }
306 
307 static int ds_recv_status(struct ds_device *dev, struct ds_status *st,
308 			  bool dump)
309 {
310 	int count, err;
311 
312 	if (st)
313 		memset(st, 0, sizeof(*st));
314 
315 	count = 0;
316 	err = usb_interrupt_msg(dev->udev,
317 				usb_rcvintpipe(dev->udev,
318 					       dev->ep[EP_STATUS]),
319 				dev->st_buf, sizeof(dev->st_buf),
320 				&count, 1000);
321 	if (err < 0) {
322 		pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
323 		       dev->ep[EP_STATUS], err);
324 		return err;
325 	}
326 
327 	if (dump)
328 		ds_dump_status(dev, dev->st_buf, count);
329 
330 	if (st && count >= sizeof(*st))
331 		memcpy(st, dev->st_buf, sizeof(*st));
332 
333 	return count;
334 }
335 
336 static void ds_reset_device(struct ds_device *dev)
337 {
338 	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
339 	/* Always allow strong pullup which allow individual writes to use
340 	 * the strong pullup.
341 	 */
342 	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
343 		pr_err("ds_reset_device: Error allowing strong pullup\n");
344 	/* Chip strong pullup time was cleared. */
345 	if (dev->spu_sleep) {
346 		/* lower 4 bits are 0, see ds_set_pullup */
347 		u8 del = dev->spu_sleep>>4;
348 		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
349 			pr_err("ds_reset_device: Error setting duration\n");
350 	}
351 }
352 
353 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
354 {
355 	int count, err;
356 
357 	/* Careful on size.  If size is less than what is available in
358 	 * the input buffer, the device fails the bulk transfer and
359 	 * clears the input buffer.  It could read the maximum size of
360 	 * the data buffer, but then do you return the first, last, or
361 	 * some set of the middle size bytes?  As long as the rest of
362 	 * the code is correct there will be size bytes waiting.  A
363 	 * call to ds_wait_status will wait until the device is idle
364 	 * and any data to be received would have been available.
365 	 */
366 	count = 0;
367 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
368 				buf, size, &count, 1000);
369 	if (err < 0) {
370 		pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
371 		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
372 		ds_recv_status(dev, NULL, true);
373 		return err;
374 	}
375 
376 #if 0
377 	{
378 		int i;
379 
380 		printk("%s: count=%d: ", __func__, count);
381 		for (i=0; i<count; ++i)
382 			printk("%02x ", buf[i]);
383 		printk("\n");
384 	}
385 #endif
386 	return count;
387 }
388 
389 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
390 {
391 	int count, err;
392 
393 	count = 0;
394 	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
395 	if (err < 0) {
396 		pr_err("Failed to write 1-wire data to ep0x%x: "
397 			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
398 		return err;
399 	}
400 
401 	return err;
402 }
403 
404 #if 0
405 
406 int ds_stop_pulse(struct ds_device *dev, int limit)
407 {
408 	struct ds_status st;
409 	int count = 0, err = 0;
410 
411 	do {
412 		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
413 		if (err)
414 			break;
415 		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
416 		if (err)
417 			break;
418 		err = ds_recv_status(dev, &st, false);
419 		if (err)
420 			break;
421 
422 		if ((st.status & ST_SPUA) == 0) {
423 			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
424 			if (err)
425 				break;
426 		}
427 	} while(++count < limit);
428 
429 	return err;
430 }
431 
432 int ds_detect(struct ds_device *dev, struct ds_status *st)
433 {
434 	int err;
435 
436 	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
437 	if (err)
438 		return err;
439 
440 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
441 	if (err)
442 		return err;
443 
444 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
445 	if (err)
446 		return err;
447 
448 	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
449 	if (err)
450 		return err;
451 
452 	err = ds_dump_status(dev, st);
453 
454 	return err;
455 }
456 
457 #endif  /*  0  */
458 
459 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
460 {
461 	int err, count = 0;
462 
463 	do {
464 		st->status = 0;
465 		err = ds_recv_status(dev, st, false);
466 #if 0
467 		if (err >= 0) {
468 			int i;
469 			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
470 			for (i=0; i<err; ++i)
471 				printk("%02x ", dev->st_buf[i]);
472 			printk("\n");
473 		}
474 #endif
475 	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
476 
477 	if (err >= 16 && st->status & ST_EPOF) {
478 		pr_info("Resetting device after ST_EPOF.\n");
479 		ds_reset_device(dev);
480 		/* Always dump the device status. */
481 		count = 101;
482 	}
483 
484 	/* Dump the status for errors or if there is extended return data.
485 	 * The extended status includes new device detection (maybe someone
486 	 * can do something with it).
487 	 */
488 	if (err > 16 || count >= 100 || err < 0)
489 		ds_dump_status(dev, dev->st_buf, err);
490 
491 	/* Extended data isn't an error.  Well, a short is, but the dump
492 	 * would have already told the user that and we can't do anything
493 	 * about it in software anyway.
494 	 */
495 	if (count >= 100 || err < 0)
496 		return -1;
497 	else
498 		return 0;
499 }
500 
501 static int ds_reset(struct ds_device *dev)
502 {
503 	int err;
504 
505 	/* Other potentionally interesting flags for reset.
506 	 *
507 	 * COMM_NTF: Return result register feedback.  This could be used to
508 	 * detect some conditions such as short, alarming presence, or
509 	 * detect if a new device was detected.
510 	 *
511 	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
512 	 * Select the data transfer rate.
513 	 */
514 	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
515 	if (err)
516 		return err;
517 
518 	return 0;
519 }
520 
521 #if 0
522 static int ds_set_speed(struct ds_device *dev, int speed)
523 {
524 	int err;
525 
526 	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
527 		return -EINVAL;
528 
529 	if (speed != SPEED_OVERDRIVE)
530 		speed = SPEED_FLEXIBLE;
531 
532 	speed &= 0xff;
533 
534 	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
535 	if (err)
536 		return err;
537 
538 	return err;
539 }
540 #endif  /*  0  */
541 
542 static int ds_set_pullup(struct ds_device *dev, int delay)
543 {
544 	int err = 0;
545 	u8 del = 1 + (u8)(delay >> 4);
546 	/* Just storing delay would not get the trunication and roundup. */
547 	int ms = del<<4;
548 
549 	/* Enable spu_bit if a delay is set. */
550 	dev->spu_bit = delay ? COMM_SPU : 0;
551 	/* If delay is zero, it has already been disabled, if the time is
552 	 * the same as the hardware was last programmed to, there is also
553 	 * nothing more to do.  Compare with the recalculated value ms
554 	 * rather than del or delay which can have a different value.
555 	 */
556 	if (delay == 0 || ms == dev->spu_sleep)
557 		return err;
558 
559 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
560 	if (err)
561 		return err;
562 
563 	dev->spu_sleep = ms;
564 
565 	return err;
566 }
567 
568 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
569 {
570 	int err;
571 	struct ds_status st;
572 
573 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
574 		0);
575 	if (err)
576 		return err;
577 
578 	ds_wait_status(dev, &st);
579 
580 	err = ds_recv_data(dev, tbit, sizeof(*tbit));
581 	if (err < 0)
582 		return err;
583 
584 	return 0;
585 }
586 
587 #if 0
588 static int ds_write_bit(struct ds_device *dev, u8 bit)
589 {
590 	int err;
591 	struct ds_status st;
592 
593 	/* Set COMM_ICP to write without a readback.  Note, this will
594 	 * produce one time slot, a down followed by an up with COMM_D
595 	 * only determing the timing.
596 	 */
597 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
598 		(bit ? COMM_D : 0), 0);
599 	if (err)
600 		return err;
601 
602 	ds_wait_status(dev, &st);
603 
604 	return 0;
605 }
606 #endif
607 
608 static int ds_write_byte(struct ds_device *dev, u8 byte)
609 {
610 	int err;
611 	struct ds_status st;
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, &dev->byte_buf, 1);
625 	if (err < 0)
626 		return err;
627 
628 	return !(byte == dev->byte_buf);
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 	int search_limit;
716 	int found = 0;
717 	int i;
718 
719 	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
720 	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
721 	 */
722 	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
723 	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
724 	 * packet size.
725 	 */
726 	const size_t bufsize = 2 * 64;
727 	u64 *buf;
728 
729 	buf = kmalloc(bufsize, GFP_KERNEL);
730 	if (!buf)
731 		return;
732 
733 	mutex_lock(&master->bus_mutex);
734 
735 	/* address to start searching at */
736 	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
737 		goto search_out;
738 	master->search_id = 0;
739 
740 	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
741 		COMM_RTS;
742 	search_limit = master->max_slave_count;
743 	if (search_limit > 255)
744 		search_limit = 0;
745 	index = search_type | (search_limit << 8);
746 	if (ds_send_control(dev, value, index) < 0)
747 		goto search_out;
748 
749 	do {
750 		schedule_timeout(jtime);
751 
752 		err = ds_recv_status(dev, &st, false);
753 		if (err < 0 || err < sizeof(st))
754 			break;
755 
756 		if (st.data_in_buffer_status) {
757 			/* Bulk in can receive partial ids, but when it does
758 			 * they fail crc and will be discarded anyway.
759 			 * That has only been seen when status in buffer
760 			 * is 0 and bulk is read anyway, so don't read
761 			 * bulk without first checking if status says there
762 			 * is data to read.
763 			 */
764 			err = ds_recv_data(dev, (u8 *)buf, bufsize);
765 			if (err < 0)
766 				break;
767 			for (i = 0; i < err/8; ++i) {
768 				++found;
769 				if (found <= search_limit)
770 					callback(master, buf[i]);
771 				/* can't know if there will be a discrepancy
772 				 * value after until the next id */
773 				if (found == search_limit)
774 					master->search_id = buf[i];
775 			}
776 		}
777 
778 		if (test_bit(W1_ABORT_SEARCH, &master->flags))
779 			break;
780 	} while (!(st.status & (ST_IDLE | ST_HALT)));
781 
782 	/* only continue the search if some weren't found */
783 	if (found <= search_limit) {
784 		master->search_id = 0;
785 	} else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
786 		/* Only max_slave_count will be scanned in a search,
787 		 * but it will start where it left off next search
788 		 * until all ids are identified and then it will start
789 		 * over.  A continued search will report the previous
790 		 * last id as the first id (provided it is still on the
791 		 * bus).
792 		 */
793 		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
794 			"will continue next search.\n", __func__,
795 			master->max_slave_count);
796 		set_bit(W1_WARN_MAX_COUNT, &master->flags);
797 	}
798 search_out:
799 	mutex_unlock(&master->bus_mutex);
800 	kfree(buf);
801 }
802 
803 #if 0
804 /*
805  * FIXME: if this disabled code is ever used in the future all ds_send_data()
806  * calls must be changed to use a DMAable buffer.
807  */
808 static int ds_match_access(struct ds_device *dev, u64 init)
809 {
810 	int err;
811 	struct ds_status st;
812 
813 	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
814 	if (err)
815 		return err;
816 
817 	ds_wait_status(dev, &st);
818 
819 	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
820 	if (err)
821 		return err;
822 
823 	ds_wait_status(dev, &st);
824 
825 	return 0;
826 }
827 
828 static int ds_set_path(struct ds_device *dev, u64 init)
829 {
830 	int err;
831 	struct ds_status st;
832 	u8 buf[9];
833 
834 	memcpy(buf, &init, 8);
835 	buf[8] = BRANCH_MAIN;
836 
837 	err = ds_send_data(dev, buf, sizeof(buf));
838 	if (err)
839 		return err;
840 
841 	ds_wait_status(dev, &st);
842 
843 	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
844 	if (err)
845 		return err;
846 
847 	ds_wait_status(dev, &st);
848 
849 	return 0;
850 }
851 
852 #endif  /*  0  */
853 
854 static u8 ds9490r_touch_bit(void *data, u8 bit)
855 {
856 	struct ds_device *dev = data;
857 
858 	if (ds_touch_bit(dev, bit, &dev->byte_buf))
859 		return 0;
860 
861 	return dev->byte_buf;
862 }
863 
864 #if 0
865 static void ds9490r_write_bit(void *data, u8 bit)
866 {
867 	struct ds_device *dev = data;
868 
869 	ds_write_bit(dev, bit);
870 }
871 
872 static u8 ds9490r_read_bit(void *data)
873 {
874 	struct ds_device *dev = data;
875 	int err;
876 
877 	err = ds_touch_bit(dev, 1, &dev->byte_buf);
878 	if (err)
879 		return 0;
880 
881 	return dev->byte_buf & 1;
882 }
883 #endif
884 
885 static void ds9490r_write_byte(void *data, u8 byte)
886 {
887 	struct ds_device *dev = data;
888 
889 	ds_write_byte(dev, byte);
890 }
891 
892 static u8 ds9490r_read_byte(void *data)
893 {
894 	struct ds_device *dev = data;
895 	int err;
896 
897 	err = ds_read_byte(dev, &dev->byte_buf);
898 	if (err)
899 		return 0;
900 
901 	return dev->byte_buf;
902 }
903 
904 static void ds9490r_write_block(void *data, const u8 *buf, int len)
905 {
906 	struct ds_device *dev = data;
907 	u8 *tbuf;
908 
909 	if (len <= 0)
910 		return;
911 
912 	tbuf = kmemdup(buf, len, GFP_KERNEL);
913 	if (!tbuf)
914 		return;
915 
916 	ds_write_block(dev, tbuf, len);
917 
918 	kfree(tbuf);
919 }
920 
921 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
922 {
923 	struct ds_device *dev = data;
924 	int err;
925 	u8 *tbuf;
926 
927 	if (len <= 0)
928 		return 0;
929 
930 	tbuf = kmalloc(len, GFP_KERNEL);
931 	if (!tbuf)
932 		return 0;
933 
934 	err = ds_read_block(dev, tbuf, len);
935 	if (err >= 0)
936 		memcpy(buf, tbuf, len);
937 
938 	kfree(tbuf);
939 
940 	return err >= 0 ? len : 0;
941 }
942 
943 static u8 ds9490r_reset(void *data)
944 {
945 	struct ds_device *dev = data;
946 	int err;
947 
948 	err = ds_reset(dev);
949 	if (err)
950 		return 1;
951 
952 	return 0;
953 }
954 
955 static u8 ds9490r_set_pullup(void *data, int delay)
956 {
957 	struct ds_device *dev = data;
958 
959 	if (ds_set_pullup(dev, delay))
960 		return 1;
961 
962 	return 0;
963 }
964 
965 static int ds_w1_init(struct ds_device *dev)
966 {
967 	memset(&dev->master, 0, sizeof(struct w1_bus_master));
968 
969 	/* Reset the device as it can be in a bad state.
970 	 * This is necessary because a block write will wait for data
971 	 * to be placed in the output buffer and block any later
972 	 * commands which will keep accumulating and the device will
973 	 * not be idle.  Another case is removing the ds2490 module
974 	 * while a bus search is in progress, somehow a few commands
975 	 * get through, but the input transfers fail leaving data in
976 	 * the input buffer.  This will cause the next read to fail
977 	 * see the note in ds_recv_data.
978 	 */
979 	ds_reset_device(dev);
980 
981 	dev->master.data	= dev;
982 	dev->master.touch_bit	= &ds9490r_touch_bit;
983 	/* read_bit and write_bit in w1_bus_master are expected to set and
984 	 * sample the line level.  For write_bit that means it is expected to
985 	 * set it to that value and leave it there.  ds2490 only supports an
986 	 * individual time slot at the lowest level.  The requirement from
987 	 * pulling the bus state down to reading the state is 15us, something
988 	 * that isn't realistic on the USB bus anyway.
989 	dev->master.read_bit	= &ds9490r_read_bit;
990 	dev->master.write_bit	= &ds9490r_write_bit;
991 	*/
992 	dev->master.read_byte	= &ds9490r_read_byte;
993 	dev->master.write_byte	= &ds9490r_write_byte;
994 	dev->master.read_block	= &ds9490r_read_block;
995 	dev->master.write_block	= &ds9490r_write_block;
996 	dev->master.reset_bus	= &ds9490r_reset;
997 	dev->master.set_pullup	= &ds9490r_set_pullup;
998 	dev->master.search	= &ds9490r_search;
999 
1000 	return w1_add_master_device(&dev->master);
1001 }
1002 
1003 static void ds_w1_fini(struct ds_device *dev)
1004 {
1005 	w1_remove_master_device(&dev->master);
1006 }
1007 
1008 static int ds_probe(struct usb_interface *intf,
1009 		    const struct usb_device_id *udev_id)
1010 {
1011 	struct usb_device *udev = interface_to_usbdev(intf);
1012 	struct usb_endpoint_descriptor *endpoint;
1013 	struct usb_host_interface *iface_desc;
1014 	struct ds_device *dev;
1015 	int i, err, alt;
1016 
1017 	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
1018 	if (!dev) {
1019 		pr_info("Failed to allocate new DS9490R structure.\n");
1020 		return -ENOMEM;
1021 	}
1022 	dev->udev = usb_get_dev(udev);
1023 	if (!dev->udev) {
1024 		err = -ENOMEM;
1025 		goto err_out_free;
1026 	}
1027 	memset(dev->ep, 0, sizeof(dev->ep));
1028 
1029 	usb_set_intfdata(intf, dev);
1030 
1031 	err = usb_reset_configuration(dev->udev);
1032 	if (err) {
1033 		dev_err(&dev->udev->dev,
1034 			"Failed to reset configuration: err=%d.\n", err);
1035 		goto err_out_clear;
1036 	}
1037 
1038 	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1039 	alt = 3;
1040 	err = usb_set_interface(dev->udev,
1041 		intf->altsetting[alt].desc.bInterfaceNumber, alt);
1042 	if (err) {
1043 		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1044 			"for %d interface: err=%d.\n", alt,
1045 			intf->altsetting[alt].desc.bInterfaceNumber, err);
1046 		goto err_out_clear;
1047 	}
1048 
1049 	iface_desc = &intf->altsetting[alt];
1050 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1051 		pr_info("Num endpoints=%d. It is not DS9490R.\n",
1052 			iface_desc->desc.bNumEndpoints);
1053 		err = -EINVAL;
1054 		goto err_out_clear;
1055 	}
1056 
1057 	/*
1058 	 * This loop doesn'd show control 0 endpoint,
1059 	 * so we will fill only 1-3 endpoints entry.
1060 	 */
1061 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1062 		endpoint = &iface_desc->endpoint[i].desc;
1063 
1064 		dev->ep[i+1] = endpoint->bEndpointAddress;
1065 #if 0
1066 		printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1067 			i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1068 			(endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1069 			endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1070 #endif
1071 	}
1072 
1073 	err = ds_w1_init(dev);
1074 	if (err)
1075 		goto err_out_clear;
1076 
1077 	mutex_lock(&ds_mutex);
1078 	list_add_tail(&dev->ds_entry, &ds_devices);
1079 	mutex_unlock(&ds_mutex);
1080 
1081 	return 0;
1082 
1083 err_out_clear:
1084 	usb_set_intfdata(intf, NULL);
1085 	usb_put_dev(dev->udev);
1086 err_out_free:
1087 	kfree(dev);
1088 	return err;
1089 }
1090 
1091 static void ds_disconnect(struct usb_interface *intf)
1092 {
1093 	struct ds_device *dev;
1094 
1095 	dev = usb_get_intfdata(intf);
1096 	if (!dev)
1097 		return;
1098 
1099 	mutex_lock(&ds_mutex);
1100 	list_del(&dev->ds_entry);
1101 	mutex_unlock(&ds_mutex);
1102 
1103 	ds_w1_fini(dev);
1104 
1105 	usb_set_intfdata(intf, NULL);
1106 
1107 	usb_put_dev(dev->udev);
1108 	kfree(dev);
1109 }
1110 
1111 module_usb_driver(ds_driver);
1112 
1113 MODULE_LICENSE("GPL");
1114 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1115 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1116